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Sample records for earthworms survive freezing

  1. Dual roles of glucose in the freeze-tolerant earthworm Dendrobaena octaedra: cryoprotection and fuel for metabolism

    DEFF Research Database (Denmark)

    Calderon, Sofia; Holmstrup, Martin

    2009-01-01

    Ectothermic animals inhabiting the subarctic and temperate regions have evolved strategies to deal with periods of continuous frost during winter. The earthworm Dendrobaena octaedra is freeze tolerant and accumulates large concentrations of glucose upon freezing. The present study investigates the roles of glucose accumulation for long-term freeze tolerance in worms kept frozen at -2 degrees C for 47 days. During this period, worms were sampled periodically for determination of survival and for measurements of glucose, glycogen, lactate, alanine and succinate. In addition we performed calorimetric measurements to assess metabolic rate of frozen and unfrozen worms. Long-term freezing was associated with a gradual depletion of glucose and worms that succumbed during this period were always characterised by low glucose and glycogen levels. The anaerobic waste products lactate and alanine increased slightly whereas succinate levels remained constant. However, it is argued that other waste products (particularly propionate) could be the primary end product of a continued anaerobic metabolism. Calorimetric measures of the metabolic rate of frozen worms were in accord with values calculated from the reduction in glucose assuming that most (similar to 90%) glucose was metabolised anaerobically. Both estimates of metabolic rate demonstrated a 10-fold metabolic depression associated with freezing. Thus, in addition to the suspected role of glucose as cryoprotectant, the present study demonstrates that glucose accumulation is vital to ensure substrate for long-term anaerobic metabolism in frozen worms. On the basis of the estimated metabolite levels, we calculate that the combined effect of metabolic depression and large glucose stores enables a projected 3 months survival of freezing at -2 degrees C of the 'average' D. octaedra. Such conditions are very likely to occur in the northern distribution ranges of this stress-tolerant earthworm.

  2. Survival of freeze-dried Lactobacillus plantarum and Lactobacillus

    OpenAIRE

    Carvalho, A. Sofia; Silva, Joana; Ho, Peter; Teixeira, Paula; Malcata, F. Xavier; Gibbs, Paul

    2002-01-01

    No significant differences were observed in the viability of Lactobacillus plantarum and Lactobacillus rhamnosus cells during freeze-drying in the presence or absence of inositol, sorbitol, fructose, trehalose, monosodium glutamate and propyl gallate. However, survival was higher during storage when drying took place in the presence of these compounds. Sorbitol produced more significant effects than the other compounds toward maintaining viability of freeze-dried L. plantarum and ...

  3. Surviving freezing in plant tissues by oomycetous snow molds.

    Science.gov (United States)

    Murakami, Ryo; Yajima, Yuka; Kida, Ken-Ichi; Tokura, Katsuyuki; Tojo, Motoaki; Hoshino, Tamotsu

    2015-04-01

    Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free mycelia and hyphal swellings, structures for survival, of Pythium iwayamai and Pythium paddicum lost viability within freeze-thaw 3 cycles; however, mycelia in host plants survived the treatment. It was reported that fungi in permafrost are characterized both by the presence of natural cryoprotectants in these ecotopes and by the ability to utilize their inherent mechanisms of protection. It is conceivable that plant substrates or derivatives thereof are natural cryoprotectants, enabling them to provide advantageous conditions to microorganisms under freezing conditions. Our results are the first to experimentally support this hypothesis. PMID:25661659

  4. Reduced density and nest survival of ground-nesting songbirds relative to earthworm invasions in northern hardwood forests.

    Science.gov (United States)

    Loss, Scott R; Blair, Robert B

    2011-10-01

    European earthworms (Lumbricus spp.) are spreading into previously earthworm-free forests in the United States and Canada and causing substantial changes, including homogenization of soil structure, removal of the litter layer, and reduction in arthropod abundance and species richness of understory plants. Whether these changes affect songbirds that nest and forage on the forest floor is unknown. In stands with and without earthworms in the Chequamegon-Nicolet National Forest, Wisconsin (U.S.A.), we surveyed for, monitored nests of, and measured attributes of habitat of Ovenbirds (Seiurus aurocapillus) and Hermit Thrushes (Catharus guttatus), both ground-dwelling songbirds, and we sampled earthworms at survey points and nests. Bird surveys indicated significantly lower densities of Ovenbirds and Hermit Thrushes in relation to Lumbricus invasions at survey point and stand extents (3.1 and 15-20 ha, respectively). Modeling of Ovenbird nest survival (i.e., the probability that nestlings successfully fledge) indicated that lower survival probabilities were associated with increased sedge cover and decreased litter depth, factors that are related to Lumbricus invasions, possibly due to reduced nest concealment or arthropod abundance. Our findings provide compelling evidence that earthworm invasions may be associated with local declines of forest songbird populations. PMID:21797927

  5. The effects of mercuric chloride on survival, growth, reproduction, burrowing speed and glutathione concentrations in the earthworm species Eisenia fetida Savigny

    OpenAIRE

    Gudbrandsen, Marius

    2005-01-01

    Abstract The common compost earthworm Eisenia fetida was used for toxicity testing of mercury, in a well-characterized agricultural soil obtained from a local field (Ås, Norway). Groups of five or ten clitellate earthworms were exposed to various concentrations of mercury in soil, added in the form of mercuric chloride (HgCl2) in distilled water. The effects on survival, burrowing behaviour, reproduction, growth, and glutathione levels were recorded. Very low mercury concentration (0.22 m...

  6. Effects of a constructed Technosol on mortality, survival and reproduction of earthworms

    Science.gov (United States)

    Pey, Benjamin; Cortet, Jerome; Capowiez, Yvan; Mignot, Lenaic; Nahmani, Johanne; Watteau, Francoise; Schwartz, Christophe

    2010-05-01

    Soils, whose properties and pedogenesis are dominated by artificial materials or transported materials, are classified as Technosols. Some of these Technosols are used in soil engineering, which is the voluntary action to combine technical materials in a given objective to restore an ecosystem. Primary by products that are used to build these Technosols need to be assessed on an ecotoxicological point of view. The following study aims to assess the effects of a constructed Technosol made from different primary by-products on the mortality, survival and reproductions of two earthworm species. The model of Technosol used here is a combination of green-waste compost (GWC) and papermill sludge (PS) mixed with thermally treated industrial soil (TIS). OECD soil is used as a control soil. Three different experiments have been managed: i) the first, to assess the potential toxicity effect on Eisenia foetida biomass (28 days) and reproduction (56 days), ii) the second to assess the short-term effect (7 days) on Lumbricus terrestris biomass, iii) and the third to assess the medium-term effect (30 days) on L. terrestris biomass. Reproduction of E. foetida is enhanced with high proportions of GWC. For biomass, GWC seems to improve body mass contrary to other materials which lead to losses of body mass. Thus, for E. foetida, GWC seems to be a high-quality and long-term source of food. Body mass of L. terrestris decreased with GWC and OECD. At short-term only, TIS/PS leads to a gain of body mass. Only equilibrium of 25% GWC - 75% TIS/PS allows a gain of body mass at medium term. TIS/PS appears to be a low-quality and short-term food resource but an excellent water tank. It can be concluded that the constructed Technosol is not toxic for fauna but some differences appear between different tested material combinations, depending on nature, proportion and trophic properties of materials.

  7. Effects of petroleum and metal contaminated soil on plants and earthworms: Survival and bioaccumulation

    International Nuclear Information System (INIS)

    Earthworms, Eisenia foetida, and bermudagrass, Cynodon dactylon, were used in the laboratory to test the toxicity of contaminated sediment taken from a small fresh water lake in North Carolina. This work was part of an investigation to determine the potential effects of upland disposal of this sediment. The contaminated sediment contained As, Cr, Cu, Pb, Hg, Ni, Zn and petroleum hydrocarbons at concentrations much greater than nearby soils. Test cylinders were planted with bermudagrass; earthworms were added 30 days later. Both species were harvested at 60 days, weighed and submitted for chemical analyses. Cynodon was affected by the contaminated sediment but grew well in the mixtures of sediment and upland soil. Similar results were obtained with the Eisenia. These species did not accumulate hydrocarbons from the sediment with the possible exception of pyrene. The metals Cd, Pb, and Zn were elevated in plants exposed to the contaminated sediment. Earthworms exposed to this sediment accumulated Pb to concentrations greater than animals exposed to the manure control. This work demonstrated that a contaminated freshwater sediment was not toxic to plants or earthworms and that most petroleum hydrocarbons were not accumulated. The only metal that may be of some concern was Pb

  8. Survival and Recovery of Phaeocystis Antarctica (Prymnesiophyceae) from Prolonged Darkness and Freezing

    Science.gov (United States)

    The colony-forming haptophyte Phaeocystis antarctica is an important primary producer in the Ross Sea, and must survive long periods of darkness and freezing in this extreme environment. We conducted experiments on the responses of P. antarctica-dominated phytoplankton assemblage...

  9. Freezing or supercooling: how does an aquatic subterranean crustacean survive exposures at subzero temperatures?

    Science.gov (United States)

    Issartel, Julien; Voituron, Yann; Odagescu, Valentina; Baudot, Anne; Guillot, Geneviève; Ruaud, Jean-Pierre; Renault, David; Vernon, Philippe; Hervant, Frédéric

    2006-09-01

    Crystallization temperature (T(c)), resistance to inoculative freezing (IF), ice contents, bound water, protein and glycogen body contents were measured in the aquatic subterranean crustacean Niphargus rhenorhodanensis and in the morphologically close surface-dwelling aquatic crustacean Gammarus fossarum, both acclimated at 12 degrees C, 3 degrees C and -2 degrees C. Cold acclimation induced an increase in the T(c) values in both species but no survival was observed after thawing. However, after inoculation at high sub-zero temperatures, cold-acclimated N. rhenorhodanensis survived whereas all others, including the 3 degrees C and -2 degrees C acclimated G. fossarum died. In its aquatic environment, N. rhenorhodanensis is likely to encounter inoculative freezing before reaching the T(c) and IF tolerance appears as a highly adaptive trait in this species. Bound water and glycogen were found to increase in the 3 degrees C and -2 degrees C acclimated N. rhenorhodanensis, whereas no variation was observed in G. fossarum. Considering the hydrophilic properties of glycogen, such a rise may be correlated with the increased bound water measured in cold-acclimated N. rhenorhodanensis, and may be linked to the survival of this species when it was inoculated. The ecological significance of the survival of the aquatic subterranean crustacean to inoculative freezing is paradoxical, as temperature is currently highly buffered in its habitat. However, we assume that past geographical distribution and resulting life history traits of N. rhenorhodanensis are key parameters in the current cold-hardiness of the species. PMID:16916982

  10. Survival of Ice Nucleation-Active and Genetically Engineered Non-Ice-Nucleating Pseudomonas syringae Strains after Freezing

    OpenAIRE

    Buttner, Mark P.; Amy, Penny S.

    1989-01-01

    The survival after freezing of ice nucleation-active (INA) and genetically engineered non-INA strains of Pseudomonas syringae was compared. Each strain was applied to oat seedlings and allowed to colonize for 3 days, and the plants were subjected to various freezing temperatures. Plant leaves were harvested before and after freezing on two consecutive days, and bacterial populations were determined. Populations of the INA wild-type strain increased 15-fold in the 18 h after the oat plants inc...

  11. Effects of pentachlorophenol on survival of earthworms (Lumbricus terrestris) and phagocytosis by their immunoactive coelomocytes

    Energy Technology Data Exchange (ETDEWEB)

    Giggleman, M.A.; Fitzpatrick, L.C.; Goven, A.J. [Univ. of North Texas, Denton, TX (United States); Venables, B.J. [TRAC Labs., Denton, TX (United States)

    1998-12-01

    Earthworms, Lumbricus terrestris, exposed for 96 h to filter paper saturated with five nominal concentrations of pentachlorophenol, exhibited a 50% lethal concentration (LC50) of 25.0 {micro}g PCP/cm{sup 2} and corresponding whole worm body burden-based 50% lethal dose (LD50) of 877.7 {micro}g PCP/g dry mass. Linear regression modeling showed that worms increased body concentrations (BC = {micro}g PCP/g dry tissue mass) with increasing exposure concentrations (EC) according to BC = 113.5 + 29.5EC. Phagocytosis of yeast cells by immunoactive coelomocytes was suppressed only at body concentrations (863.3 {micro}g PCP/g dry mass) that approximated the calculated LD50 and overlapped those demonstrating lethality, indicating a sharp transition between sublethal and lethal toxicity. An exposure concentration of 15 {micro}g PCP/cm{sup 2} produced significant suppression of phagocytosis of yeast cells by immunoactive coelomocytes. However, the average measured body burden from this group approximated the estimated LD50, indicating a sharp toxic response slope. Exposure to 10 {micro}g PCP/cm{sup 2} with a corresponding body concentration of 501.3 {micro}g PCP/g dry mass did not affect phagocytosis. The importance of body burden data is emphasized.

  12. Improving survival and storage stability of bacteria recalcitrant to freeze-drying: a coordinated study by European culture collections.

    Science.gov (United States)

    Peiren, Jindrich; Buyse, Joke; De Vos, Paul; Lang, Elke; Clermont, Dominique; Hamon, Sylviane; Bégaud, Evelyne; Bizet, Chantal; Pascual, Javier; Ruvira, María A; Macián, M Carmen; Arahal, David R

    2015-04-01

    The objective of this study is to improve the viability after freeze-drying and during storage of delicate or recalcitrant strains safeguarded at biological resource centers. To achieve this objective, a joint experimental strategy was established among the different involved partner collections of the EMbaRC project ( www.embarc.eu ). Five bacterial strains considered as recalcitrant to freeze-drying were subjected to a standardized freeze-drying protocol and to seven agreed protocol variants. Viability of these strains was determined before and after freeze-drying (within 1 week, after 6 and 12 months, and after accelerated storage) for each of the protocols. Furthermore, strains were exchanged between partners to perform experiments with different freeze-dryer-dependent parameters. Of all tested variables, choice of the lyoprotectant had the biggest impact on viability after freeze-drying and during storage. For nearly all tested strains, skim milk as lyoprotectant resulted in lowest viability after freeze-drying and storage. On the other hand, best freeze-drying and storage conditions were strain and device dependent. For Aeromonas salmonicida CECT 894(T), best survival was obtained when horse serum supplemented with trehalose was used as lyoprotectant, while Aliivibrio fischeri LMG 4414(T) should be freeze-dried in skim milk supplemented with marine broth in a 1:1 ratio. Freeze-drying Campylobacter fetus CIP 53.96(T) using skim milk supplemented with trehalose as lyoprotectant resulted in best recovery. Xanthomonas fragariae DSM 3587(T) expressed high viability after freeze-drying and storage for all tested lyoprotectants and could not be considered as recalcitrant. In contrary, Flavobacterium columnare LMG 10406(T) did not survive the freeze-drying process under all tested conditions. PMID:25773973

  13. Soil salinity increases survival of freezing in the enchytraeid Enchytraeus albidus.

    Czech Academy of Sciences Publication Activity Database

    Patrício Silva, A. L.; Holmstrup, M.; Koš?ál, Vladimír; Amorim, M. J. B.

    2013-01-01

    Ro?. 216, ?. 14 (2013), s. 2732-2740. ISSN 0022-0949 Institutional support: RVO:60077344 Keywords : ice content * freeze tolerance * osmolality Subject RIV: ED - Physiology Impact factor: 3.002, year: 2013

  14. Survival, Pb-uptake and behaviour of three species of earthworm in Pb treated soils determined using an OECD-style toxicity test and a soil avoidance test

    International Nuclear Information System (INIS)

    Mature (clitellate) Eisenia andrei Bouche (ultra epigeic), Lumbricus rubellus Hoffmeister (epigeic), and Aporrectodea caliginosa (Savigny) (endogeic) earthworms were placed in soils treated with Pb(NO3)2 to have concentrations in the range 1000 to 10 000 mg Pb kg-1. After 28 days LC50-95%confidencelimit+95%confidencelimit values were E. andrei5824-361+898 mg Pb kg-1, L. rubellus2867-193+145 mg Pb kg-1 and A. caliginosa2747-304+239 mg Pb kg-1 and EC50s for weight change were E. andrei2841-68+150 mg Pb kg-1, L. rubellus1303-201+240 mg Pb kg-1 and A. caliginosa1208-206+212 mg Pb kg-1. At any given soil Pb concentration, Pb tissue concentrations after 28 days were the same for all three earthworm species. In a soil avoidance test there was no difference between the behaviour of the different species. The lower sensitivity to Pb exhibited by E. andrei is most likely due to physiological adaptations associated with the modes of life of the earthworms, and could have serious implications for the use of this earthworm as the species of choice in standard toxicological testing.

  15. Effect of freezing-thawing process and quercetin on human sperm survival and DNA integrity.

    Science.gov (United States)

    Zribi, Nassira; Chakroun, Nozha Feki; Ben Abdallah, Fatma; Elleuch, Henda; Sellami, Afifa; Gargouri, Jalel; Rebai, Tarek; Fakhfakh, Faiza; Keskes, Leila Ammar

    2012-12-01

    We aimed in the first part of our work to study the effect of cryopreservation on the human sperm DNA integrity and the activation of caspase 3, the main apoptosis indicator. In the second part, we were interested in testing the effect of quercetin, as an antioxidant, in preventing sperm damage during the freeze-thawing process. Seventeen semen samples were obtained from 17 men recruited for infertility investigations. Liquefied sperm was cryopreserved using spermfreeze®. Nine of the used samples were divided into two aliquots; the first one was cryopreserved with spermfreeze only (control) and the second one was cryopreserved with spermfreeze supplemented with quercetin to a final concentration of 50 ?M. Sperm motility and viability were assessed according to WHO criteria. We used TUNEL assay and the Oxy DNA assay to assess sperm DNA integrity. Activated caspase 3 levels were measured in spermatozoa using fluorescein-labeled inhibitor of caspase (FLICA). Cryopreservation led to a significant increase in sperm DNA fragmentation, DNA oxidation and caspase 3 activation (p<0.01). Supplementation of the cryopreservation medium with quercetrin induced a significant improvement in post thaw sperm parameters, compared to those of control, regarding sperm motility (p=0.007), viability (p=0.008) and DNA integrity (p=0.02); however, it had no effect on caspase 3 activation (p=0.3). We conclude that oxidative stress plays a major role in inducing sperm cryodamage but implication of apoptosis in this impairment requires further investigations. Quercetin could have protective effect during cryopreservation but further research is needed to confirm this effect. PMID:23010483

  16. Survival of honey bee (Hymenoptera: Apidae) spermatozoa stored at above-freezing temperatures.

    Science.gov (United States)

    Collins, A M

    2000-06-01

    The development of practical techniques for the storage of honey bee, Apis mellifera L., semen would significantly improve our ability to breed for desirable genotypes and maintain genetic diversity in populations. Artificial insemination of queens has been possible for some time, but the semen used is usually freshly collected, or held for semen was stored in sealed capillary tubes at room temperature (25 degrees C) or in a refrigerator set to 12 degrees C, for periods up to 1 yr. Survival of spermatozoa was assayed by a dual fluorescent staining technique using SYBR-14 and propidium iodide stains, which readily distinguishes live and dead cells. No significant loss of viable spermatozoa occurred within the first 6 wk. Between weeks 6 and 9, the percent live spermatozoa fell from 80 to 58%, and remained at that level until after 39 wk. By week 52, samples at room temperature, but not at 12 degrees C, fell to 18.9% live spermatozoa. Nonfrozen storage of honey bee semen has potential for short-term preservation of germplasm, however several factors need to be studied further to optimize survival rates. PMID:10902300

  17. Impact of different cryoprotectants on the survival of freeze-dried Lactobacillus rhamnosus and Lactobacillus casei/paracasei during long-term storage.

    Science.gov (United States)

    Jofré, A; Aymerich, T; Garriga, M

    2015-01-01

    The production of long shelf-life highly concentrated dried probiotic/starter cultures is of paramount importance for the food industry. The aim of the present study was to evaluate the protective effect of glucose, lactose, trehalose, and skim milk applied alone or combined upon the survival of potentially probiotic Lactobacillus rhamnosus CTC1679, Lactobacillus casei/paracasei CTC1677 and L. casei/paracasei CTC1678 during freeze-drying and after 39 weeks of storage at 4 and 22 °C. Immediately after freeze-drying, the percentage of survivors was very high (?94%) and only slight differences were observed among strains and cryoprotectants. In contrast, during storage, survival in the dried state depended on the cryoprotectant, temperature and strain. For all the protectants assayed, the stability of the cultures was remarkably higher when stored under refrigeration (4 °C). Under these conditions, skim milk alone or supplemented with trehalose or lactose showed the best performance (reductions ?0.9 log units after 39 weeks of storage). The lowest survival was observed during non-refrigerated storage and with glucose and glucose plus milk; no viable cells left at the end of the storage period. Thus, freeze-drying in the presence of appropriate cryoprotectants allows the production of long shelf-life highly concentrated dried cultures ready for incorporation in high numbers into food products as starter/potential probiotic cultures. PMID:25380798

  18. Effects of various sugars added to growth and drying media upon thermotolerance and survival throughout storage of freeze-dried Lactobacillus delbrueckii ssp. bulgaricus.

    Science.gov (United States)

    Carvalho, Ana S; Silva, Joana; Ho, Peter; Teixeira, Paula; Malcata, F Xavier; Gibbs, Paul

    2004-01-01

    The aim of this research effort was to investigate the role of various sugar substrates in the growth medium upon thermotolerance and upon survival during storage after freeze-drying of Lactobacillus bulgaricus. Addition of the sugars tested to the growth medium, and of these and sorbitol to the drying medium (skim milk) was investigated so as to determine whether a relationship exists between growth and drying media, in terms of protection of freeze-dried cells throughout storage. The lowest decrease in viability of L. bulgaricus cells after freeze-drying was obtained when that organism was grown in the presence of mannose. However, L. bulgaricus clearly survived better during storage when cells had been grown in the presence of fructose, lactose or mannose rather than glucose (the standard sugar in the growth medium). A similar effect could not be observed in terms of thermotolerance; in this case, the growth medium supplemented with lactose was found to yield cells bearing the highest heat resistance. Supplementation of the drying medium with glucose, fructose, lactose, mannose or sorbitol led in most cases to enhancement of protection during storage, to a degree that was growth medium-dependent. PMID:14763849

  19. Effects of temperature on infectivity and of commercial freezing on survival of the North American strain of viral hemorrhagic septicemia virus (VHSV).

    Science.gov (United States)

    Arkush, Kristen D; Mendonca, Holly L; McBride, Anne M; Yun, Susan; McDowell, Terry S; Hedrick, Ronald P

    2006-04-01

    Temperature affected the growth of the North American strain of viral hemorrhagic septicemia virus (VHSV) in experimentally infected cell cultures and in Pacific sardine Sardinops sagax. In addition, commercial freezing significantly reduced the infectivity of VHSV in tissues of experimentally infected sardine. Isolates of VHSV representing the geographic range of North American VHSV replicated in the EPC (Epithelioma papulosum cyprini) cell line at 10, 15 and 20 degrees C, but the more northern isolates from British Columbia, Canada, demonstrated significantly reduced growth at 20 degrees C compared to VHSV from more southern locations (p VHSV from California resulted in 66.7% mortality at a seawater temperature of 13 degrees C compared to 6.7% at 20 degrees C. Commercial blast-freezing of sardine experimentally infected with VHSV reduced median concentrations of virus in the kidney and spleen from 5.25 x 10(6) to 5.5 x 10(3) pfu (plaque-forming units) g(-1). Decreased growth of the California isolate of VHSV at higher temperatures following experimental infection of the sardine and reduced virus survival following commercial freezing of infected sardine are factors that would lessen the risk of transmission of VHSV through frozen baitfishes. PMID:16724558

  20. The Resistance to Freeze-Drying and to Storage Was Determined as the Cellular Ability to Recover Its Survival Rate and Acidification Activity

    Directory of Open Access Journals (Sweden)

    Georges Lognay

    2010-01-01

    Full Text Available The protective effects of the fatty acid composition and membrane action of the acidification activity of two strains of Lactobacillus kept at 20?C were studied. The addition of sorbitol, monosodium glutamate and glycerol during storage is causing the decline of acidification and increased concentrations of unsaturated fatty acids observed in both strains. The addition of sorbitol and monosodium glutamate does not alter the fatty acid composition, whatever the strain, but increases the resistance to freeze-drying of L. plantarum CWBI-B1419 and improves survival during storage. The addition of these preservatives and decreased activity of acidification improves the ratio unsaturated. These results indicate that the survival during storage and freeze-drying resistance are closely related to the composition of membrane fatty acids. This behaviour can be interpreted as an adaptation of L. plantarum B1419-CWBI supplemented by cryoprotectant additives such as sorbitol or monosodium glutamate sorbitol and monosodium glutamate as an additive. L. plantarum CWBI-B1419 presents a greater adaptation to culture conditions than L. paracasei ssp. paracasei LMG9192T.

  1. Microencapsulation of Lactobacillus plantarum (mtcc 5422) by spray-freeze-drying method and evaluation of survival in simulated gastrointestinal conditions.

    Science.gov (United States)

    Dolly, Priyanka; Anishaparvin, A; Joseph, G S; Anandharamakrishnan, C

    2011-01-01

    Spray-drying (SD) and freeze-drying (FD) are widely used methods for microencapsulation of heat-sensitive materials like probiotics for long-term preservation and transport. Spray-freeze-drying (SFD) is relatively a new technique that involves spraying a solution into a cold medium and removal of solvent (water) by conventional vacuum FD method. In this study, the SFD microencapsulated Lactobacillus plantarum powder (1:1 and 1:1.5 core-to-wall ratios of whey protein) is compared with the microencapsulated powders produced by FD and SD methods. The SFD and FD processed microencapsulated powder show 20% higher cell viability than the SD samples. In simulated gastrointestinal conditions, the SFD and FD cells show up to 4?h better tolerance than SD samples and unencapsulated cells in acidic and pepsin condition. The morphology of SFD samples shows particles almost in spherical shape with numerous fine pores, which in turn results in good rehydration behaviour of the powdered product. PMID:21827359

  2. Polysialylation of brain gangliosides as a possible molecular mechanism for survival of antarctic ice fish below the freezing point

    Science.gov (United States)

    Becker, K.; Rahmann, H.

    In order to determine possible adaptation strategies of vertebrates to extreme low-temperature environments, we compared the concentration and composition of gangliosides from the brains of eight species of Antarctic Notothenioid ``ice'' fishes with those of warm-adapted species and those of fishes from habitats of moderate temperature. The concentration of whole-brain gangliosides in the ice fishes was comparable with that in moderate-temperature species (between 3.36 and 4.31 mg NeuAc/g protein). The composition of brain gangliosides differed, however. In particular, the relative concentrations of polysialogangliosides (= polarity) and alkali-labile gangliosides was higher in all Antarctic species investigated than in warm-adapted fish species. This difference is considered a suitable mechanism for keeping neuronal membranes functional even below the freezing point. This interpretation is supported by additional physicochemical results with artificial monolayer membranes, which give evidence for a high thermosensitivity of ganglioside complexes in connection with calcium.

  3. Impact of Chlorine, Temperature and Freezing Shock on the Survival Behavior of Escherichia coli O157:H7 on Ready-to-Eat Meats

    Directory of Open Access Journals (Sweden)

    Vijay K. Juneja

    2012-04-01

    Full Text Available Foodborne pathogens continue to pose a potential food safety hazard in ready-to-eat (RTE meat. Chlorine is commonly used to sanitize processing equipment where Escherichia coli O157:H7 (Ec may survive and contaminate food products. The objective of this study was to characterize the survival behavior of Ec with different stresses on RTE meats. A multi-strain cocktail of Ec was pre-treated with freezing shock for 15 - 20 h and/or chlorine (0, 25, and 50 ppm for one hour, and then inoculated onto RTE meat surfaces to obtain about 3.0 log CFU/g. Samples were stored at three abuse temperatures (12?, 18?, and 24? and Ec was enumerated during the storage. The freezing shock impact was studied using the Ec cocktail stored in a freezer overnight followed by chlorine exposure for one hour. The lag phase and growth rate of Ec were estimated using DMFit (Combase, Baranyi’s model. Results indicated that Ec growth was suppressed by chlorine treatment. Freezing shock was found to have little impact in terms of lag time and growth rate. The lag phase of Ec after exposure to 0 ppm of chlorine (50.3 h was shorter than that of Ec treated with 25 ppm (54.6 h and 50 ppm (164.1 h at 12?. However, the lag phase decreased with an increase in temperature, e.g. at 25 ppm, lag times were 54.6, 51.1 and 48.9 h for 12?, 18? and 24?, respectively. Lag times increased with an increase in chlorine concentration. At 24?, lag times were 15.8, 48.9, and 52.4 h for 0, 25, and 50 ppm, respectively. The growth rate increased with an increase in temperature for 0 and 25 ppm chlorine levels, but decreased at 50 ppm level. Growth rate and lag phase as a function of temperature and chlorine concentration can be described by polynomial models and modified Ratkowsky-type and Zwietering-type models. Results of this study will contribute to risk assessment of RTE meats.

  4. Exposure to extremely low frequency (50 Hz electromagnetic field changes the survival rate and morphometric characteristics of neurosecretory neurons of the earthworm Eisenia foetida (Oligochaeta under illumination stress

    Directory of Open Access Journals (Sweden)

    Banova?ki Zorana

    2013-01-01

    Full Text Available An in vivo model was set up to establish the behavioral stress response (rate of survival and morphometric characteristics of A1 protocerebral neurosecretory neurons (cell size of Eisenia foetida (Oligochaeta as a result of the synergetic effect of extremely low frequency electromagnetic fields (ELF-EMF - 50 Hz, 50 ?T, 17 V/m and 50 Hz, 150 ?T, 17 V/m, respectively and constant illumination (420-450 lux. If combined, these two stressors significantly (p<0.05 increased the survival rate of E. foetida in the 150 ?T-exposed animals, because of delayed caudal autotomy reflex, an indicator of stress response. In addition, morphometric analysis indicated that there were changes in the protocerebral neurosecretory cells after exposure to the ELF-EMF. The present data support the view that short-term ELF-EMF exposure in “windows” of intensity is likely to stimulate the immune and neuroendocrine response of E. foetida.

  5. Removal of mercury from soil with earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Dorfman, D. [Monmouth Coll., West Long Branch, NJ (United States)

    1994-12-31

    Earthworms can live in soils containing high quantities of mercury, lead, and zinc. The worms (Lumbricus terrestris) concentrate these heavy metals in their tissues. The use of these worms to reduce the quantities of mercury and other heavy metals in soils may be practical. In July, 1993, a preliminary study was made using earthworms and soils with differing amounts of mercury, The quantities were 0.0 grams, 0.5 grams, and 1.0 grams of mercury as mercuric chloride. Earthworms were placed into these soils for two or more weeks, then harvested. The worms were rinsed with deionized water, then dissolved in nitric acid. Each sample was prepared for analysis with the addition of HNO{sub 3}, H{sub 2}SO{sub 4}, potassium permanganate, and hydrozylamine hydrochloride. A Jerome Instrument gold foil analyzer was used to determine levels of mercury after volatilizing the sample with stannous chloride. Worms exposed to contaminated soils remove 50 to 1,400 times as much mercury as do worms in control soils. In a hypothetical case, a site contaminated with one pound of mercury, 1,000 to 45,000 worms would be required to reduce mercury levels to background levels in the soil (about 250 ppb). After harvesting worms in contaminated soil they could be dried (90% of their weight is water), and the mercury regained by chemical processes. Soil conducive to earthworm survival is required. This includes a well aerated loamy soil, proper pH (7.0), and periodic watering and feeding. There are several methods of harvesting worms, including flooding and electricity. Large numbers of worms can be obtained from commercial growers.

  6. Correlations between Lumbricus terrestris survival and gut microbiota

    OpenAIRE

    Knut Rudi; Tkvern, Knut Olav Str X. E.

    2012-01-01

    Background: The interplay between diet, gut bacteria and health still remain enigmatic. Here, we addressed this issue through the investigation of the effect of crystalline cellulose on the earthworm Lumbricus terrestris gut microbiota composition and survival. Methods : Earthworm gut contents were analyzed after 14 days of feeding using a mixed 16S rRNA gene sequencing approach, in addition to direct measurements of cellulase activity. The survival of earthworms was followed each week for 17...

  7. Earthworm species, a searchable database

    OpenAIRE

    Csuzdi, Cs

    2012-01-01

    The first earthworm species named was Lumbricus terrestris Linnaeus, 1758. Since then, there were some 6000earthworm (Oligochaeta: Megadrili) species names described, from which ca. 3000–3500 are valid. In order to help the orientation in such a huge amount of data a web-based database was created. Each record contains the basic data of the species names described; i.e. family, genus, specific epithet, author, year, reference to the original description and optionally the valid combination ...

  8. Freezing lake

    Science.gov (United States)

    Powell, Adam C., IV

    2005-02-23

    Finite difference solution to mixed conduction-convection limited freezing of a 10 cm thick pool of water, with benchmark against analytical timescales. Requisite software: Gnumeric or Excel to open spreadsheets in source directory.

  9. Earthworm species, a searchable database

    Directory of Open Access Journals (Sweden)

    Csuzdi, Cs.

    2012-07-01

    Full Text Available The first earthworm species named was Lumbricus terrestris Linnaeus, 1758. Since then, there were some 6000earthworm (Oligochaeta: Megadrili species names described, from which ca. 3000–3500 are valid. In order to help the orientation in such a huge amount of data a web-based database was created. Each record contains the basic data of the species names described; i.e. family, genus, specific epithet, author, year, reference to the original description and optionally the valid combination of the species name and deposition of type specimens. The database is searchable by every field mentioned and the resulted list can be arranged alphabetically.

  10. Comparison of earthworm responses to petroleum hydrocarbon exposure in aged field contaminated soil using traditional ecotoxicity endpoints and 1H NMR-based metabolomics

    International Nuclear Information System (INIS)

    1H NMR metabolomics and conventional ecotoxicity endpoints were used to examine the response of earthworms exposed to petroleum hydrocarbons (PHCs) in soil samples collected from a site that was contaminated with crude oil from a pipeline failure in the mid-1990s. The conventional ecotoxicity tests showed that the soils were not acutely toxic to earthworms (average survival ?90%), but some soil samples impaired reproduction endpoints by >50% compared to the field control soil. Additionally, metabolomics revealed significant relationships between earthworm metabolic profiles (collected after 2 or 14 days of exposure) and soil properties including soil PHC concentration. Further comparisons by partial least squares regression revealed a significant relationship between the earthworm metabolomic data (collected after only 2 or 14 days) and the reproduction endpoints (measured after 63 days). Therefore, metabolomic responses measured after short exposure periods may be predictive of chronic, ecologically relevant toxicity endpoints for earthworms exposed to soil contaminants. -- Highlights: •Earthworm response to petroleum hydrocarbon exposure in soil is examined. •Metabolomics shows significant changes to metabolic profile after 2 days. •Significant relationships observed between metabolomic and reproduction endpoints. •Metabolomics may have value as a rapid screening tool for chronic toxicity. -- Earthworm metabolomic responses measured after 2 and 14 days are compared to traditional earthworm ecotoxicity endpoints (survival and reproduction) in petroleum hydrocarbon contaminated soil

  11. The effect of radioecological condition to earthworms and the problems of ecosystems related with them

    International Nuclear Information System (INIS)

    The soil and fertility was evident and breathe regarding to living materials which are composed of billions of microorganisms and pedobionts also earthworms; throughout of it plants get all chemical elements. Living materials inhabit in lamella of soil, essentially within the scope of 5 to 15 cm of depth. Soil is a main source of carbon in nature. There is for about 10 times more carbone dioxide here (the breath product of soil biota) than in atmosphere. From carbonic acid of air, plants by its terrestrial part extract carbone and by the help of photosynthesis transform it to carbohydrates and tissues. Nowadays investigations about earthworms which live in strongly polluted soils has appeared that earthworms have found a way of a survival even in such extreme conditions. Earthworms have adapted to the polluted soils. However, bait attractive in appearance to dig in such places it is not necessary: in such a way the worm accumulates heavy metals in the organism. Though earthworms aren't so attractive, and for many are simply unpleasant, for an ecosystem they are invaluable. Thus even dying they don't leave after itself any traces, and digest itself by means of cages containing in them - lysis. This process is called autolysis. Thereby for investigation of strongly polluted areas of Ramana iodine plant as an ecosystem and there is significant point to determine the effect of radiation on earthworms as one of the most important chain of soil bionetwork. So, in this way ihain of soil bionetwork. So, in this way it was investigated an effect of radioactive pollution to earthworms aboriginal for Absheron peninsula. By the experimentation of earthworms in contaminated soil (with 226Ra, 228Ra, U) in respectively 1 percent, 2,5 percent, 5 percent and 10 percent soil examples during a month, it was established that the earthworms so sensible to the high level of radioactive pollution. Regarding to the data received it has a point that usage of earthworms as bio indicators, in future should help people to apply this original objects in case of remediation of strongly polluted areas of Absheron peninsula.

  12. New earthworm records from Bulgaria (Oligochaeta, Lumbricidae)

    OpenAIRE

    Szederjesi, T.

    2013-01-01

    Elaboration of a small earthworm material collected in different parts of Bulgaria resulted in recording altogether 15 species. Surprisingly, the peregrine Dendrobaena veneta veneta proved to be new to the fauna of Bulgaria and with this, the present list of Bulgarian earthworms consists of 42 confirmed species and subspecies.

  13. EARTHWORMS AND THEIR IMPACT ON SLUG CONTROL

    Science.gov (United States)

    Increases in the anecic earthworm species, Lumbricus terrestris L., have occurred in western Oregon grass fields due to increases in surface residue since the phase-out of open field burning. The use of earthworm toxic chemicals has been reduced through concerns for other important vertebrate and in...

  14. Metal accumulation in earthworms inhabiting floodplain soils

    International Nuclear Information System (INIS)

    The main factors contributing to variation in metal concentrations in earthworms inhabiting floodplain soils were investigated in three floodplains differing in inundation frequency and vegetation type. Metal concentrations in epigeic earthworms showed larger seasonal variations than endogeic earthworms. Variation in internal levels between sampling intervals were largest in earthworms from floodplain sites frequently inundated. High and low frequency flooding did not result in consistent changes in internal metal concentrations. Vegetation types of the floodplains did not affect metal levels in Lumbricus rubellus, except for internal Cd levels, which were positively related to the presence of organic litter. Internal levels of most essential metals were higher in spring. In general, no clear patterns in metal uptake were found and repetition of the sampling campaign will probably yield different results. - Metal levels in earthworms show large variation among sites, among seasons and among epigeic and endogeic species

  15. Earthworm introduction on calcareous minesoils

    International Nuclear Information System (INIS)

    Burrowing activity of the nightcrawler, Lumbricus terrestis (L.t.), incorporates organic matter into mineral soil while creating long-lasting macropores. Thus L.t. has potential as a biological means of improving physical and chemical properties of surface mined areas. Efforts to establish L.t. population on forested acidic or calcareous minesoils have been successful, but thus far have not been able to establish L.t. in grassland ecosystems on calcareous minesoils. In May, 1989, the authors put 11 clitellate L.t. under sphagnum moss on calcareous gray cast overburden on standard graded topsoil, or on ripped and disked topsoil. All soils had cover of agronomic grasses and legumes. They found no L.t. at the 24 points of inoculation during sampling in fall of 1990 with formalin extractant, although smaller species, Lumbricus rubellus and Dendrobaena spp., were found. At another location, in May, 1990, they put 25 clitellate L.t. at 16 points in grasslands growing on gray cast overburden. Using formalin extraction, they found no L.t. in May 1992 at these locations. Working in this same area in November, 1992, they released 10 clitellate L.t. at 16 points under 10 cm of moist Alnus glutinosa leaf litter. Careful examination of the surface inoculation points in spring and fall of 1993 did not show obvious signs of earthworm activity. Their next step will be to use Earthworm Inoculation Units (earthworm-minesoil microcosms containing L.t. adults, immatures, and cocoons) as g L.t. adults, immatures, and cocoons) as the source of the new populations

  16. Earthworm in the 21st century

    Science.gov (United States)

    Friberg, Paul; Lisowski, Stefan; Dricker, Ilya; Hellman, Sidney

    2010-05-01

    Earthworm (Johnson et al., 1995) is a fully open-source earthquake data acquisition and processing package that is in widespread use through out the world. Earthworm includes basic seismic data acquistion for the majority of the dataloggers currently available and provides network transport mechanisms and common formats as output for data transferral. In addition, it comes with network seismology tools to compute network detections, perform automated arrival picking, and automated hypocentral and magnitude estimations. More importantly it is an open and free framework in the C-programming language that can be used to create new modules that process waveform and earthquake data in near real time. The number of Earthworm installations is growing annually as are the number of contributions to the system. Furthermore its growth into other areas of waveform data acquistion (namely Geomagnetic observatories and Infrasound arrays) show its adaptability to other waveform technologies and processing strategies. In this presentation we discuss the coming challenges to growing Earthworm and new developments in its use; namely the open source add-ons that have become interfaces to Earthworm's core. These add-ons include GlowWorm, MagWorm, Hydra, SWARM, Winston, EarlyBird, Iworm, and most importantly, AQMS (formerly known as CHEETAH). The AQMS, ANSS Quake Monitoring System, is the Earthworm system created in California which has now been installed in the majority of Regional Seismic Networks (RSNs) in the United States. AQMS allows additional real-time and post-processing of Earthworm generated data to be stored and manipulated in a database using numerous database oriented tools. The use of a relational database for persistence provides users with the ability to implement configuration control and research capabilities not available in earlier Earthworm add-ons. By centralizing on AQMS, the RSNs will be able to leverage new developments by easily sharing Earthworm and AQMS modules and avoid the duplication and one-off/custom developments of the past.

  17. Arsenic biotransformation in earthworms from contaminated soils

    OpenAIRE

    Button, Mark; Jenkin, Gawen R. T.; Harrington, Chris F.; Watts, Michael J.

    2009-01-01

    Two species of arsenic (As) resistant earthworm, Lumbricus rubellus and Dendrodrillus rubidus, their host soils and soil excretions (casts) were collected from 23 locations at a former As mine in Devon, UK. Total As concentrations, measured by ICP-MS, ranged from 255 to 13,080 mg kg-1 in soils, 11 to 877 mg kg-1 in earthworms and 284 to 4221 mg kg-1 in earthworm casts from a sub-sample of 10 of the 23 investigated sites. The samples were also measured for As speciation using HPLC-ICP-MS to in...

  18. Contact freezing: a review

    Directory of Open Access Journals (Sweden)

    L. A. Ladino

    2013-03-01

    Full Text Available This manuscript compiles both theoretical and experimental information on contact freezing with the aim to better understand this potentially important but still not well quantified heterogeneous freezing mode. There is no complete theory that describes contact freezing and how the energy barrier has to be overcome to nucleate an ice crystal by contact freezing. Experiments on contact freezing indicate that it can initiate ice formation at the highest temperatures. A difference in the freezing temperatures between contact and immersion freezing has been found using different instrumentation and different ice nuclei. There is a lack of data on collision rates in most of the reported data, which inhibits a quantitative calculation of the freezing efficiencies. Thus, new or modified instrumentation to study this heterogeneous freezing mode in the laboratory and in the field are needed. Important questions concerning contact freezing and its potential role for ice cloud formation and climate are also summarized.

  19. Autofluorescence in eleocytes of some earthworm species.

    OpenAIRE

    Barbara P?ytycz; John Morgan, A.; Sta?z?rzenbaum, Stephen R.; Reilly, Michael O.; Feeney, Graham P.; Justyna Cholewa

    2006-01-01

    Immunocompetent cells of earthworms, coelomocytes, comprise adherent amoebocytes and granular eleocytes (chloragocytes). Both cell populations can be expelled via dorsal pores of adult earthworms by exposure to an electric current (4.5 V) for 1 min. Analysis by phase contrast/fluorescence microscopy and flow cytometry demonstrated that eleocyte population of several species exhibits a strong autofluorescence. A high percentage (11-35%) of autofluorescent eleocytes was recorded in Allolobophor...

  20. Environmental Factors That Influence a Mutualism Between the Earthworm Lumbricus terrestris L. and the Annual Weed Ambrosia trifida L.

    Science.gov (United States)

    The earthworm Lumbricus terrestris L. can improve Ambrosia trifida L. seed survival and seedling recruitment in agroecosystems with high risks of post-dispersal seed predation. In a previous 1-yr survey of no-till agricultural fields in the eastern U.S. Corn Belt, both L. terrestris and A. trifida w...

  1. Biochemical diversity of betaines in earthworms

    International Nuclear Information System (INIS)

    Highlights: ? We develop a method for rapid untargetted analysis of betaines. ? We profile betaines in a comparative study of ten earthworm species. ? Earthworms contain a surprisingly high number of different betaine metabolites. ? Earthworms contain betaines normally seen only in plants or marine animals. -- Abstract: The ability to accumulate osmoprotectant compounds, such as betaines, is an important evolutionary feature in many organisms. This is particularly the case for organisms that live in variable environments, which may have fluctuations in moisture and salinity levels. There is, surprisingly, very little known about betaines in soil invertebrates in general, and there is almost no information about earthworms – a group that are important ‘ecosystem engineers’ and key indicators of soil health. Here, we describe a fast and reliable 1H–13C heteronuclear single quantum coherence (HSQC) 2D NMR approach for the metabolic profiling of a series of betaines and related metabolites in tissue extracts, and list 1H and 13C chemical shifts for the trimethylammonium signal for 23 such compounds. The analysis of ten different species from three different families (Lumbricidae, Megascolecidae and Glossoscolecidae) showed an unexpected diversity of betaines present in earthworms. In total ten betaines were identified, including hydroxyproline-betaine, proline-betaine, taurine-betaine, GABA-betaine and histidine-betaine, and a further eleven as-yet unassigned putative betaine metabolites detected. The findings clearly indicate a hitherto-unappreciated important role for betaine metabolism in earthworms

  2. Biochemical diversity of betaines in earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Liebeke, Manuel [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom); Bundy, Jacob G., E-mail: j.bundy@imperial.ac.uk [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom)

    2013-01-25

    Highlights: ? We develop a method for rapid untargetted analysis of betaines. ? We profile betaines in a comparative study of ten earthworm species. ? Earthworms contain a surprisingly high number of different betaine metabolites. ? Earthworms contain betaines normally seen only in plants or marine animals. -- Abstract: The ability to accumulate osmoprotectant compounds, such as betaines, is an important evolutionary feature in many organisms. This is particularly the case for organisms that live in variable environments, which may have fluctuations in moisture and salinity levels. There is, surprisingly, very little known about betaines in soil invertebrates in general, and there is almost no information about earthworms – a group that are important ‘ecosystem engineers’ and key indicators of soil health. Here, we describe a fast and reliable {sup 1}H–{sup 13}C heteronuclear single quantum coherence (HSQC) 2D NMR approach for the metabolic profiling of a series of betaines and related metabolites in tissue extracts, and list {sup 1}H and {sup 13}C chemical shifts for the trimethylammonium signal for 23 such compounds. The analysis of ten different species from three different families (Lumbricidae, Megascolecidae and Glossoscolecidae) showed an unexpected diversity of betaines present in earthworms. In total ten betaines were identified, including hydroxyproline-betaine, proline-betaine, taurine-betaine, GABA-betaine and histidine-betaine, and a further eleven as-yet unassigned putative betaine metabolites detected. The findings clearly indicate a hitherto-unappreciated important role for betaine metabolism in earthworms.

  3. Biological assessment of contaminated land using earthworm biomarkers in support of chemical analysis

    International Nuclear Information System (INIS)

    Biological indicators can be used to assess polluted sites but their success depends on the availability of suitable assays. The aim of this study was to investigate the performance of two earthworm biomarkers, lysosomal membrane stability measured using the neutral red retention assay (NRR-T) and the total immune activity (TIA) assay, that have previously been established as responsive to chemical exposure. Responses of the two assays were measured following in situ exposure to complexly contaminated field soils at three industrial sites as well as urban and rural controls. The industrial sites were contaminated with a range of metal (cadmium, copper, lead, zinc, nickel and cobalt) and organic (including polycyclic aromatic hydrocarbons) contaminants, but at concentrations below the 'New Dutch List' Intervention concentrations. Exposed earthworms accumulated both metals and organic compounds at the contaminated sites, indicating that there was significant exposure. No effect on earthworm survival was found at any of the sites. Biomarker measurements, however, indicated significant effects, with lower NRR-T and TIA found in the contaminated soils when compared to the two controls. The results demonstrate that a comparison of soil pollutant concentrations with guideline values would not have unequivocally identified chemical exposure and toxic effect for soil organisms living in these soils. However, the earthworm biomarkers successfully identified significant exposureccessfully identified significant exposure and biological effects caused by the mixture of chemicals present

  4. Partitioning of habitable pore space in earthworm burrows

    OpenAIRE

    Gorres, Josef H.; Amador, Jose A.

    2010-01-01

    Earthworms affect macro-pore structure of soils. However, some studies suggest that earthworm burrow walls and casts themselves differ greatly in structure from surrounding soils, potentially creating habitat for microbivorours nematodes which accelerate the decomposition and C and N mineralization. In this study aggregates were sampled from the burrow walls of the anecic earthworm Lumbricus terrestris and bulk soil (not altered by earthworms) from mesocosm incubated in the lab for 0, 1, 3, 5...

  5. Freezing and Food Safety

    Science.gov (United States)

    ... Standard Forms FSIS United States Department of Agriculture Food Safety and Inspection Service About FSIS District Offices Careers ... Viewer (JSR 286) Actions ${title} Loading... Freezing and Food Safety What Can You Freeze? Is Frozen Food Safe? ...

  6. Correlations between Lumbricus terrestris survival and gut microbiota

    Directory of Open Access Journals (Sweden)

    Knut Rudi

    2012-04-01

    Full Text Available Background: The interplay between diet, gut bacteria and health still remain enigmatic. Here, we addressed this issue through the investigation of the effect of crystalline cellulose on the earthworm Lumbricus terrestris gut microbiota composition and survival. Methods : Earthworm gut contents were analyzed after 14 days of feeding using a mixed 16S rRNA gene sequencing approach, in addition to direct measurements of cellulase activity. The survival of earthworms was followed each week for 17 weeks. Results : We found a tendency that the crystalline cellulose fed earthworms survived better than the high energy fed earthworms (p=0.08. Independent of feeding we found that the bacterial group related to Ferrimonadaceae was correlated to an increased lifespan (p=0.01. We also found a positive correlation between Ruminococcaceae related bacteria and cellulase activity in the earthworm gut (p=0.05. Surprisingly, however, the cellulase activity was not correlated to the feeding regime. Conclusion : Taken together, the interactions between diet, gut microbiota and lifespan seem complex.

  7. Effect of repeated freeze-thaw cycles on geographically different populations of the freeze-tolerant worm Enchytraeus albidus (Oligochaeta).

    Science.gov (United States)

    Fisker, Karina Vincents; Holmstrup, Martin; Malte, Hans; Overgaard, Johannes

    2014-11-01

    Freeze-tolerant organisms survive internal ice formation; however, the adaptations to repeated freeze-thaw cycles are often not well investigated. Here we report how three geographically different populations of Enchytraeus albidus (Germany, Iceland and Svalbard) respond to three temperature treatments - constant thawed (0°C), constant freezing (-5°C) and fluctuating temperature (0 to -5°C) - over a period of 42 days. Survival varied between treatments and populations such that enchytraeids from arctic locations had a higher survival following prolonged freeze periods compared with temperate populations. However, enchytraeids from temperate locations had the same survival rate as arctic populations when exposed to repeated freeze-thaw events. Across all populations, metabolic rate decreased markedly in frozen animals (-5°C) compared with thawed controls (0°C). This decrease is likely due to the lower temperature of frozen animals, but also to the transition to the frozen state per se. Animals exposed to repeated freeze-thaw events had an intermediate metabolic rate and freeze-thaw events were not associated with pronounced excess energetic costs. Overwintering under either condition was not associated with a decrease in lipid content; however, during exposure to constant freezing and repeated freeze-thaw events there was a noticeable decrease in carbohydrate stores over time. Thus, animals exposed to constant freezing showed a decrease in glycogen stores, while both glucose and glycogen content decreased over time when the organisms were exposed to repeated freezing. The results therefore suggest that carbohydrate resources are important as a fuel for E. albidus during freezing whereas lipid resources are of marginal importance. PMID:25214492

  8. Freezing resistance improvement of Lactobacillus reuteri by using cell immobilization.

    Science.gov (United States)

    Tsen, Jen-Horng; Huang, Hui-Ying; Lin, Yeu-Pyng; King, V An-Erl

    2007-09-01

    Lactobacillus reuteri shows certain beneficial effects to human health and is recognized as a probiotic. However, its application in frozen foods is still not popular because of its low survival during freezing and frozen storage. Cell immobilization technique could effectively exert protection effects to microbial cells in order to enhance their endurance to unfavorable environmental conditions as well as to improve their viability and cell concentration. Ca-alginate and kappa-carrageenan were used to immobilize L. reuteri in this research, and the immobilized cells were exposed to different freezing temperatures, i.e. -20 degrees C, -40 degrees C, -60 degrees C, -80 degrees C, and stored at -40 degrees C and -80 degrees C for 12 weeks. The objectives were to study the protection effects of cell immobilization against the adverse conditions of freezing and frozen storage, and the effects of freezing temperatures to the immobilized cells. Cell immobilization was used to raise the survival of L. reuteri during freezing and frozen storage in order to develop frozen foods with the probiotic effects of L. reuteri. Results indicated that immobilized L. reuteri possessed better survival in both freezing and frozen storage. The survival of immobilized L. reuteri was higher than that of free cells, and the effects of lower freezing temperature were better than higher freezing temperature. The immobilization effects of Ca-alginate were found to be superior to kappa-carrageenan. Cell immobilized L. reuteri exhibits potential to be used in frozen foods. PMID:17617480

  9. Earthworms and their Nephridial Symbionts: Co-diversification and Maintenance of the Symbiosis

    DEFF Research Database (Denmark)

    Lund, Marie Braad; Holmstrup, Martin

    Earthworms harbor in their nephridia (excretory organs) symbiotic bacteria which densely colonize a specific part of the nephridia, called the ampulla [1]. The symbiosis is species-specific and the symbionts form their own monophyletic genus Verminephrobacter (?-proteobacteria) [2] and are vertically transmitted [3]. For these reasons we hypothesized that the earthworm-Verminephrobacter association evolved by co-diversification. This hypothesis was investigated by a comparison of earthworm and symbiont phylogenies. The earthworm phylogeny was based on Cytochrome c oxidase subunit I (COI) and Histone H3 and the symbiont phylogeny was based on 16S rRNA gene sequences and RNA polymerase ? subunit (rpoB). The phylogenies were found to be largely congruent, however, leaving possibility for horizontal symbiont transfer events. In addition symbiont losses have occurred. The overall congruency suggests that the symbiosis has been stably maintained over evolutionary time dating back to the last common lumbricid earthworm ancestor. How this evolutionarily stable association is maintained is unknown; symbiont-free worms can be reared in lab culture and therefore the symbionts are not essential to the survival of the worms, but at the same time the symbionts are consistently found in almost all Lumbricid worm species. The symbionts have been hypothesized to be proteolytically active during excretion, thereby enhancing the earthworm’s absorption of nitrogenous compounds otherwise lost in the urine; such protein recycling should therefore increase worm fitness under nitrogen-limited conditions [4]. To test this hypothesis we conducted a comparative fitness study of worms with and without symbionts; the worms were grown in soil and fed with either a nitrogen-rich or a nitrogen-poor diet. The experiment showed no significant differences in growth rate and fecundity between symbiotic and aposymbiotic worms. Thus the symbionts do not appear to have an effect on worm fitness, under growth conditions tested. The underlying functional and maintaining mechanisms of this symbiosis remain a conundrum. [1] Knop,J. 1926. Z Morph Ökol Tiere, 6(3):588-624. [2] Schramm,A. et al. 2003. Environ Microbiol 5(9):804-809. [3] Davidson,S.K. & Stahl,D.A. 2006. Appl Environ Microbiol 72(1):769-775. [4] Pandazis,G. 1931. Zentralbl Bakteriol 120:440-453.

  10. Autofluorescence in eleocytes of some earthworm species.

    Directory of Open Access Journals (Sweden)

    Barbara P?ytycz

    2006-04-01

    Full Text Available Immunocompetent cells of earthworms, coelomocytes, comprise adherent amoebocytes and granular eleocytes (chloragocytes. Both cell populations can be expelled via dorsal pores of adult earthworms by exposure to an electric current (4.5 V for 1 min. Analysis by phase contrast/fluorescence microscopy and flow cytometry demonstrated that eleocyte population of several species exhibits a strong autofluorescence. A high percentage (11-35% of autofluorescent eleocytes was recorded in Allolobophora chlorotica, Dendrodrilus rubidus, Eisenia fetida, and Octolasion sp. (O. cyaneum, O. tyrtaeum tyrtaeum and O. tyrtaeum lacteum. In contrast, autofluorescent coelomocytes were exceptionally scarce (less than 1% in representative Aporrectodea sp. (A. caliginosa and A. longa and Lumbricus sp. (L. castaneus, L. festivus, L. rubellus, L. terrestris. Thus, this paper for the first time describes profound intrinsic fluorescence of eleocytes in some--but not all--earthworm species. The function (if any and inter-species differences of the autofluorescent coelomocytes still remain elusive.

  11. Productivity Potentials and Nutritional Values of Semi-arid Zone Earthworm (Hyperiodrilus euryaulos; Clausen, 1967 Cultured in Organic Wastes as Fish Meal Supplement

    Directory of Open Access Journals (Sweden)

    A.O. Sogbesan

    2007-01-01

    Full Text Available In the present study 60 Adult Earthworms (H. euryaulos of weight and length range 1.7-3.0 g (mean-2.34±0.91 g and 13.0-28.0 cm (mean-21.5±5.8 cm, respectively were cultured for 12 weeks. The productivity potential and nutrient composition of earthworm (H. euryaulos cultured in two rearing substrata (Cellulose Substrate (Control - Coded Hs1 and Dry Neem and leaves and soil Substrate - Coded Hs2 were assessed using six wooden boxes stocked in triplicates at the rate of 92.7 g earthworms per box. The higher total final weight, weekly weight gain, relative growth rate, specific growth rate and survival of 400.6 g kg-1 of substrate, 25.7 g/week/substrate, 332.5, 0.76/day and 99.0% while the lower of 367.5 g kg-1 of substrate, 22.9 g/week, 296.4, 0.71/day and 98.0% were recorded in earthworm cultured in cellulose substrate and the soil substrate respectively. The proximate analyses, mineral compositions and amino acids indices were comparable to those of conventional fish meal. Based on the results of this study, the utilization of cellulose substrate is recommended for the culture of earthworm and the inclusion of the earthworm meal is guarantee as a reliable and nutritional dependable fish meal supplement.

  12. Acute and chronic toxicity testing of TPH-contaminated soils with the earthworm, Eisenia foetida

    International Nuclear Information System (INIS)

    Responses of Eisenia foetida to petroleum-contaminated soils are being assessed using a 21-day test described previously. The authors prepared dilutions of two soils, referred to as A and B, using their reference-soil counterparts, collected from near the contaminated sites. The total petroleum hydrocarbon (TPH) content of each soil was measured by latroscan before the dilutions were prepared. References for the A and B soils contained 167 and 1,869 ppm of TPH, respectively. Thus, neither reference soil was pristine. Dilutions of the A soil tested with E. foetida contained from 179 to 305 ppm TPH; dilutions of the B soil contained from 1,875 to 1,950 ppm TPH. E foetida survival was 100% in both dilution series. Mean growth of Eisenia in dilutions of the A soil ranged from 48 to 74 mg dry-weight growth per pair of worms; these values were lower than those in any dilution of the B soil series. Lipid levels of worms in higher concentrations of the A and B soils were similar to one another and to published values, suggesting little inhibition of feeding in either dilution series. Earthworm reproduction was zero in the A series, but moderately high in the B series. Thus, the A soil apparently contained materials other than TPH that inhibited earthworm growth and reproduction. This study shows that (1) TPH at concentrations as high as 1,800 ppm may not always be inhibitor to earthworm growth or reproduction and (2) that earthworm survival, as a test endpoint, is much less srvival, as a test endpoint, is much less sensitive than either growth or reproduction

  13. Laboratory Protocol for Measuring the Bioaccumulation of Mercury by Earthworms

    Science.gov (United States)

    Steffy, D.; Nichols, A.; McLaughlin, A.

    2007-12-01

    Protocol was developed for a series of laboratory tests to determine if Canadian earthworms ( Lumbricus terrestris) can hyperaccumulate mercury from the soil in which they live. Two batches of 300 hundred worms each were measured for mercury uptake by establishing 3 populations (one control and two of known contamination). Populations were sampled every two weeks. Worm lengths were measured as an indicator of worm age and health. Worm tissue was processed by a modified EPA Method 7470 consisting of freeze drying, vacuum extraction, oxidation and acid extraction of the mercury. Each sample needed 2.000 g dry weight of worm tissue required 5 to 6 worms to be homogenized. Mercury concentration in the extraction fluid was measured by a CETAC M-6100 cold vapor mercury analyzer with an ASX-400 Autosampler having a method detection limit of 0.05 ppb. QA/QC activities such as calibration of instrumentation, spike samples, blank samples, reagent control samples, triplicate samples, and standard samples ensure acurate and precise measurements of mercury levels in tissue samples.

  14. Extracellular freezing-induced mechanical stress and surface area regulation on the plasma membrane in cold-acclimated plant cells

    OpenAIRE

    Yamazaki, Tomokazu; Kawamura, Yukio; Uemura, Matsuo

    2009-01-01

    Freezing tolerance is an important feature for plant survival during winter. In plants, extracellular freezing occurs at subzero temperatures, resulting in dehydration and mechanical stresses upon the plasma membrane. However, many plants can acquire enhanced freezing tolerance by exposure to non-freezing temperatures, which is referred to as cold acclimation. The plasma membrane is the primary site of freezing injury. During cold acclimation, the lipid composition in the plasma membrane chan...

  15. Cryopreservation of rabbit semen: comparing the effects of different cryoprotectants, cryoprotectant-free vitrification, and the use of albumin plus osmoprotectants on sperm survival and fertility after standard vapor freezing and vitrification.

    Science.gov (United States)

    Rosato, Maria Pina; Iaffaldano, Nicolaia

    2013-02-01

    This study was designed to improve current freezing protocols for rabbit sperm by examining: (1) the toxicity of different permeable cryoprotectants (CPAs) used for standard vapor freezing (conventional freezing); (2) the feasibility of ultrarapid nonequilibrium freezing (vitrification) of sperm in the absence of permeating CPAs; and (3), the addition of bovine serum albumin (BSA), alone or with sucrose or trehalose as osmoprotectants. First, we evaluated the effects on sperm motility of the incubation time (5 to 60 minutes) with different final concentrations (5% to 20%) of glycerol, N-N-dimethylacetamide, dimethylsulfoxide (DMSO), ethylene glycol, propylene glycol, and methanol. N-N-dimethylacetamide (5%) and DMSO (5% and 10%) showed the least toxic effects; the use of 10% DMSO producing the best postthaw sperm motility and membrane integrity results (P freezing. For vitrification, semen was diluted in the absence of permeable CPAs and frozen by dropping semen directly in liquid nitrogen. However, this led to the low or null cryosurvival of sperm postvitrification (0.16 ± 0.4%, 1.8 ± 1.6%, and 94.5 ± 1.4% of motile, membrane-, and DNA-intact sperm cells, respectively). To assess the effects of albumin and osmoprotectants on sperm cryosurvival, sperm was conventionally frozen with 10% DMSO or vitrified in the absence of permeable CPAs without or with 0.5% BSA alone or combined with sucrose or trehalose (range, 0-0.25 M). In the conventional freezing procedure, the addition of BSA alone failed to improve sperm cryosurvival, however, in the presence of BSA plus either sucrose or trehalose, the postthaw motility (using 0.1 M sucrose or trehalose) and DNA integrity (using all additive concentrations) of sperm were significantly better (P membrane-intact cells were observed when semen was vitrified with BSA alone or with BSA and sucrose (0.1 and 0.25 M) or BSA and trehalose (0.25 M) and a best recovery of DNA-intact sperm was recorded for BSA plus sucrose compared with semen vitrified without osmoprotectants (P permeable CPAs used for conventional freezing of rabbit sperm indicated that DMSO 10% was the least damaging; (2) CPA-free vitrification of rabbit semen led to a low or null sperm cryosurvival; and (3) enriching the freezing medium with BSA plus adequate amounts of sucrose or trehalose can improve the cryosurvival of rabbit sperm after conventional freezing or vitrification. In our working conditions, BSA/sucrose was more effective than BSA/trehalose at preserving the in vivo fertilization capacity of rabbit sperm cryopreserved using the standard procedure. PMID:23218394

  16. Activity of earthworm in Latosol under simulated acid rain stress.

    Science.gov (United States)

    Zhang, Jia-En; Yu, Jiayu; Ouyang, Ying

    2015-01-01

    Acid rain is still an issue of environmental concerns. This study investigated the impacts of simulated acid rain (SAR) upon earthworm activity from the Latosol (acidic red soil). Laboratory experiment was performed by leaching the soil columns grown with earthworms (Eisenia fetida) at the SAR pH levels ranged from 2.0 to 6.5 over a 34-day period. Results showed that earthworms tended to escape from the soil and eventually died for the SAR at pH = 2.0 as a result of acid toxicity. The catalase activity in the earthworms decreased with the SAR pH levels, whereas the superoxide dismutases activity in the earthworms showed a fluctuate pattern: decreasing from pH 6.5 to 5.0 and increasing from pH 5.0 to 4.0. Results implied that the growth of earthworms was retarded at the SAR pH ? 3.0. PMID:25351717

  17. Toxicity of a neonicotinoid insecticide, guadipyr, in earthworm (Eisenia fetida).

    Science.gov (United States)

    Wang, Kai; Mu, Xiyan; Qi, Suzhen; Chai, Tingting; Pang, Sen; Yang, Yang; Wang, Chengju; Jiang, Jiazhen

    2015-04-01

    Neonicotinoid insecticides are new class of pesticides and it is very meaningful to evaluate the toxicity of guadipyr to earthworm (Eisenia fetida). In the present study, effects of guadipyr on reproduction, growth, catalase(CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE) and DNA damage in earthworm were assessed using an artificial soil medium. Guadipyr showed low toxicity to earthworms and did not elicit an effect on earthworm reproduction or growth in artificial soils at concentrations <100mg/kg. However, after exposure to guadipyr, the activity of SOD and CAT in earthworm increased and then decreased to control level. AChE activity decreased at day 3 at 50 and 100mg/kg and then increased to control level. Our data indicate that guadipyr did not induce DNA damage in earthworms at concentration of <100mg/kg. PMID:25594687

  18. Recombinant Protein Production of Earthworm Lumbrokinase for Potential Antithrombotic Application

    OpenAIRE

    Kevin Yueju Wang; Lauren Tull; Edwin Cooper; Nan Wang; Dehu Liu

    2013-01-01

    Earthworms have been used as a traditional medicine in China, Japan, and other Far East countries for thousands of years. Oral administration of dry earthworm powder is considered as a potent and effective supplement for supporting healthy blood circulation. Lumbrokinases are a group of enzymes that were isolated and purified from different species of earthworms. These enzymes are recognized as fibrinolytic agents that can be used to treat various conditions associated with thrombosis. Many l...

  19. Effects of Earthworms on the Dispersal of Steinernema spp.

    OpenAIRE

    Shapiro, D. I.; Tylka, G. L.; Berry, E. C.; Lewis, L. C.

    1995-01-01

    Previous studies indicated that dispersal of S. carpocapsae may be enhanced in soil with earthworms. The objective of this research was to determine and compare the effects of earthworms on dispersal of other Steinernema spp. Vertical dispersal of Steinernema carpocapsae, S. feltiae, and S. glaseri was tested in soil columns in the presence and absence of earthworms (Lumbricus terrestris). Dispersal was evaluated by a bioassay and by direct extraction of nematodes from soil. Upward dispersal ...

  20. The association between the earthworm Lumbricus terrestris and giant ragweed (Ambrosia trifida) in agricultural fields across the eastern U.S. Corn Belt

    Science.gov (United States)

    Previous research indicated that secondary seed dispersal by the earthworm Lumbricus terrestris can improve giant ragweed seed survival and influence seedling spatial structure at the quadrat (m2) scale. Here, we examine the association between L. terrestris and giant ragweed at plant neighborhood, ...

  1. Carbon-Mineral Interactions along an Earthworm Invasion Gradient

    Science.gov (United States)

    Lyttle, A.; Yoo, K.; Aufdenkampe, A. K.; Hale, C.; Sebestyen, S. D.

    2010-12-01

    We broadly agree that the interactions of organic matter and minerals contribute to soils’ capacity to store carbon. Such interactions may be controlled by the processes that determine the availability of organic matter and minerals and their physical contacts. One of these processes is bioturbation, and earthworms are the best known organisms that physically mix soils. We are studying carbon mineral interactions along an approximately 200 meter long earthworm invasion transect in a hardwood forest in northern Minnesota. This transect extends from the soils where earthworms are absent to the soils that have been invaded by earthworms for ~30-40 years. Pre-invasion soils have approximately 5 cm thick litter layer, thin (~5 cm) A horizon, silt rich E horizon, and clay-rich Bt horizons. The A and E horizons formed from aeolian deposits, while the clay-rich Bt horizons developed from glacial till. With the advent of earthworm invasion, the litter layer disappears, and the A horizon thickens at the expense of the E horizons. Carbon and nitrogen concentrations in the A and E horizons significantly increased with the advent of earthworm invasion. Simultaneously, minerals’ capacities to complex the organic matter appear to be greater in the soils with active earthworm populations. Based on the data from the two end member soils along the transect, minerals’ specific surface area in the A and E horizons are larger in the earthworm invaded soil than in the pre-invasion soil. Additionally, earthworm invasion rapidly (within species of given ecosystems.

  2. Biomarker response in the earthworm Lumbricus terrestris exposed to chemical pollutants.

    Science.gov (United States)

    Calisi, A; Lionetto, M G; Schettino, T

    2011-09-15

    Earthworms are important organisms for the soil ecosystem. They are sensitive to toxic chemicals and represent useful bioindicator organisms for soil biomonitoring. Recently the use of biomarkers in earthworms has been increasingly investigated for soil monitoring and assessment purpose. The aim of the preset paper was to analyze the pollutant-induced response of a suite of cellular and biochemical biomarkers in the earthworm Lumbricus terrestris exposed to copper sulphate or methiocarb in OECD soil at the maximal concentrations recommended in agriculture. These responses were compared to lifecycle parameters such as survival, growth and reproduction. Granulocyte morphometric alteration, lysosomal membrane stability, metallothionein concentration, and acetylcholinesterase activity were considered. In either copper sulphate or methiocarb exposure conditions the mean percentage variation of the pollutant-induced molecular and cellular biomarkers was consistent with the whole organism end-point responses. In particular pollutant-induced granulocyte enlargement, detected in either copper sulphate or methiocarb exposed organisms, showed to be a potential general biomarker that may be directly linked to organism health. Compared to the other biological responses to pollutants, it showed high sensitivity to pollutant exposure suggesting its possible applications as a sensitive, simple, and quick general biomarker for monitoring and assessment applications. PMID:21783228

  3. Impact of a changed inundation regime caused by climate change and floodplain rehabilitation on population viability of earthworms in a lower River Rhine floodplain.

    Science.gov (United States)

    Thonon, Ivo; Klok, Chris

    2007-01-01

    River floodplains are dynamic and fertile ecosystems where soil invertebrates such as earthworms can reach high population densities. Earthworms are an important food source for a wide range of organisms including species under conservation such as badgers. Flooding, however, reduces earthworm numbers. Populations recover from cocoons that survive floods. If the period between two floods is too short such that cocoons cannot develop into reproductive adults, populations cannot sustain themselves. Both climate change and floodplain rehabilitation change the flooding frequency affecting earthworm populations. The present paper estimates the influence of climate change and floodplain rehabilitation on the viability of earthworm populations in a Dutch floodplain; the Afferdensche and Deestsche Waarden along the River Waal. This floodplain will be part of major river rehabilitation plans of the Dutch government. In those plans, the floodplain will experience the construction of a secondary channel and the removal of part of its minor embankment. To estimate the impact of these plans and climate change, we used a dataset of daily discharges for 1900-2003 for the River Rhine at the Dutch-German border. We perturbed this dataset to obtain two new datasets under climate change scenarios for 2050 and 2100. From the original and two projected datasets we derived the frequency distributions for the annual periods without inundations for the studied floodplain. We subsequently compared the duration of these inundation-free (dry) periods with the maturation age distribution for L. rubellus as derived from a Dynamic Energy Budget model. This comparison yielded in which parts of our study area and under which climate conditions the populations would still be viable, be able to adapt or become extinct. The results show that climate change has almost no adverse effect on earthworm viability. This is because climate change reduces the flooding frequency during the earthworms growing season. Floodplain rehabilitation, on the other hand, reduces the part of the floodplain area where populations can sustain themselves. Before rehabilitation, only 12% of the floodplain area cannot sustain a viable earthworm population. After rehabilitation, this increases to 59%, 28% of which is due to more frequent flooding. Enhanced exposure to soil contaminants may further suppress earthworm viability. This could frustrate further nature development and the viability of earthworm-dependent species such as the badger (Meles meles) or little owl (Athene noctua vidalli species), which is an objective of the river rehabilitation plans in the Netherlands. PMID:17140641

  4. Ecological transfer of radionuclides and metals to free-living earthworm species in natural habitats rich in NORM

    Energy Technology Data Exchange (ETDEWEB)

    Mrdakovic Popic, Jelena, E-mail: jelena.mrdakovic.popic@umb.no; Salbu, Brit; Skipperud, Lindis

    2012-01-01

    Transfer of radionuclides ({sup 232}Th and {sup 238}U) and associated metals (As, Cd, Pb and Cr) from soil to free-living earthworm species was investigated in a thorium ({sup 232}Th) rich area in Norway. Sampling took place within former mining sites representing the technologically enhanced naturally occurring radioactive materials (TENORM), at undisturbed site with unique bedrock geology representing the naturally occurring radioactive materials (NORM) and at site outside the {sup 232}Th rich area taken as reference Background site. Soil analysis revealed the elevated levels of investigated elements at NORM and TENORM sites. Based on sequential extraction, uranium ({sup 238}U) and cadmium (Cd) were quite mobile, while the other elements were strongly associated with mineral components of soil. Four investigated earthworm species (Aporrectodea caliginosa, Aporrectodea rosea, Dendrodrilus rubidus and Lumbricus rubellus) showed large individual variability in the accumulation of radionuclides and metals. Differences in uptake by epigeic and endogeic species, as well as differences within same species from the NORM, TENORM and Background sites were also seen. Based on total concentrations in soil, the transfer factors (TF) were in ranges 0.03-0.08 and 0.09-0.25, for {sup 232}Th and {sup 238}U, respectively. TFs for lead (Pb), chromium (Cr) and arsenic (As) were low (less than 0.5), while TFs for Cd were higher (about 10). Using the ERICA tool, the estimated radiation exposure dose rate of the earthworms ranged from 2.2 to 3.9 {mu}Gy/h. The radiological risk for investigated earthworms was low (0.28). The obtained results demonstrated that free-living earthworm species can survive in soil containing elevated {sup 232}Th and {sup 238}U, as well As, Cd, Pb and Cr levels, although certain amount of radionuclides was accumulated within their bodies. The present investigation contributes to general better understanding of complex soil-to-biota transfer processes of radionuclides and metals and to assessment of risk for non-human species in the ecosystem with multiple contaminants. - Highlights: Black-Right-Pointing-Pointer Transfer of radionuclides ({sup 232}Th, {sup 238}U) and metals (As, Cr, Cd and Pb) from soil to earthworms was investigated. Black-Right-Pointing-Pointer Individual organisms' variability and species specific accumulation were demonstrated. Black-Right-Pointing-Pointer Results suggested that earthworms could survive in habitats with multiple contaminants. Black-Right-Pointing-Pointer Estimated radiological risk was not significant despite high soil concentrations of radionuclides.

  5. Ecological transfer of radionuclides and metals to free-living earthworm species in natural habitats rich in NORM

    International Nuclear Information System (INIS)

    Transfer of radionuclides (232Th and 238U) and associated metals (As, Cd, Pb and Cr) from soil to free-living earthworm species was investigated in a thorium (232Th) rich area in Norway. Sampling took place within former mining sites representing the technologically enhanced naturally occurring radioactive materials (TENORM), at undisturbed site with unique bedrock geology representing the naturally occurring radioactive materials (NORM) and at site outside the 232Th rich area taken as reference Background site. Soil analysis revealed the elevated levels of investigated elements at NORM and TENORM sites. Based on sequential extraction, uranium (238U) and cadmium (Cd) were quite mobile, while the other elements were strongly associated with mineral components of soil. Four investigated earthworm species (Aporrectodea caliginosa, Aporrectodea rosea, Dendrodrilus rubidus and Lumbricus rubellus) showed large individual variability in the accumulation of radionuclides and metals. Differences in uptake by epigeic and endogeic species, as well as differences within same species from the NORM, TENORM and Background sites were also seen. Based on total concentrations in soil, the transfer factors (TF) were in ranges 0.03–0.08 and 0.09–0.25, for 232Th and 238U, respectively. TFs for lead (Pb), chromium (Cr) and arsenic (As) were low (less than 0.5), while TFs for Cd were higher (about 10). Using thor Cd were higher (about 10). Using the ERICA tool, the estimated radiation exposure dose rate of the earthworms ranged from 2.2 to 3.9 ?Gy/h. The radiological risk for investigated earthworms was low (0.28). The obtained results demonstrated that free-living earthworm species can survive in soil containing elevated 232Th and 238U, as well As, Cd, Pb and Cr levels, although certain amount of radionuclides was accumulated within their bodies. The present investigation contributes to general better understanding of complex soil-to-biota transfer processes of radionuclides and metals and to assessment of risk for non-human species in the ecosystem with multiple contaminants. - Highlights: ? Transfer of radionuclides (232Th, 238U) and metals (As, Cr, Cd and Pb) from soil to earthworms was investigated. ? Individual organisms’ variability and species specific accumulation were demonstrated. ? Results suggested that earthworms could survive in habitats with multiple contaminants. ? Estimated radiological risk was not significant despite high soil concentrations of radionuclides.

  6. Gene Expression Analysis of CL-20-induced Reversible Neurotoxicity Reveals GABAA Receptors as Potential Target in the Earthworm Eisenia fetida

    OpenAIRE

    Gong, Ping; Guan, Xin; Pirooznia, Mehdi; Liang, Chun; Perkins, Edward J.

    2012-01-01

    The earthworm Eisenia fetida is one of the most used species in standardized soil ecotoxicity tests. Endpoints such as survival, growth and reproduction are eco-toxicologically relevant but provide little mechanistic insight into toxicity pathways, especially at the molecular level. Here we applied a toxicogenomic approach to investigate the mode of action underlying the reversible neurotoxicity of hexanitrohexaazaisowurtzitane (CL-20), a cyclic nitroamine explosives compound. We developed an...

  7. The survival of mouse oocytes shows little or no correlation with the vitrification or freezing of the external medium, but the ability of the medium to vitrify is affected by its solute concentration and by the cooling rate.?

    OpenAIRE

    Paredes, Estefania; Mazur, Peter

    2013-01-01

    As survival of mouse oocytes subjected to vitrification depends far more on the warming rate than on the cooling rate, we wished to determine whether the lack of correlation between survival and cooling rate was mirrored by a lack of correlation between cooling rate and vitrification of the medium (EAFS), and between survival and the vitrification of the medium. The morphological and functional survival of the oocytes showed little or no relation to whether or not the EAFS medium vitrified or...

  8. Checklist of earthworms (Oligochaeta: Lumbricidae) from Germany.

    Science.gov (United States)

    Lehmitz, Ricarda; Römbke, Jörg; Jänsch, Stephan; Krück, Stefanie; Beylich, Anneke; Graefe, Ulfert

    2014-01-01

    A checklist of the German earthworm fauna (Oligochaeta: Lumbricidae) is presented, including published data, data from reports, diploma- and PhD- theses as well as unpublished data from museum collections, research institutions and private persons. Overall, 16,000 datasets were analyzed to produce the first German checklist of Lumbricidae. The checklist comprises 46 earthworm species from 15 genera and provides ecological information, zoogeographical distribution type and information on the species distribution in Germany. Only one species, Lumbricus badensis Michaelsen, 1907, is endemic to Germany, whereas 41% are peregrine. As there are 14 species occurring exclusively in the southern or eastern part of Germany, the species numbers in German regions increase from north to south. PMID:25283656

  9. Effects of historic metal(loid) pollution on earthworm communities.

    Science.gov (United States)

    Lévêque, Thibaut; Capowiez, Yvan; Schreck, Eva; Mombo, Stéphane; Mazzia, Christophe; Foucault, Yann; Dumat, Camille

    2015-04-01

    The effects of metal(loid)s (Pb, Cd, Cu, Zn, As and Sb) from atmospheric fallout on earthworm communities were investigated in a fallow meadow located close to a 60-year-old lead recycling factory. We examined abundance and species diversity as well as the ratio of adult-to-juvenile earthworms, along five 140 m parallel transects. The influence of soil pollution on the earthworm community at the plot scale was put in context by measuring some physico-chemical soil characteristics (OM content, N content, pH), as well as total and bioavailable metal(loid) concentrations. Earthworms were absent in the highly polluted area (concentration from 30,000 to 5000 mg Pb·kg(-1) of dried soil), just near the factory (0-30 m area). A clear and almost linear relationship was observed between the proportion of juvenile versus mature earthworms and the pollution gradient, with a greater proportion of adults in the most polluted zones (only adult earthworms were observed from 30 to 50 m). Apporectodea longa was the main species present just near the smelter (80% of the earthworms were A. longa from 30 to 50 m). The earthworm density was found to increase progressively from five individuals·m(-2) at 30 m to 135 individuals·m(-2) at 140 m from the factory. On average, metal(loid) accumulation in earthworm tissues decreased linearly with distance from the factory. The concentration of exchangeable metal(loid)s in earthworm surface casts was higher than that of the overall soil. Finally, our field study clearly demonstrated that metal(loid) pollution has a direct impact on earthworm communities (abundance, diversity and proportion of juveniles) especially when Pb concentrations in soil were higher than 2050 mg·kg(-1). PMID:25616191

  10. Teaching basic neurophysiology using intact earthworms.

    Science.gov (United States)

    Kladt, Nikolay; Hanslik, Ulrike; Heinzel, Hans-Georg

    2010-01-01

    Introductory neurobiology courses face the problem that practical exercises often require expensive equipment, dissections, and a favorable student-instructor ratio. Furthermore, the duration of an experiment might exceed available time or the level of required expertise is too high to successfully complete the experiment. As a result, neurobiological experiments are commonly replaced by models and simulations, or provide only very basic experiments, such as the frog sciatic nerve preparation, which are often time consuming and tedious. Action potential recordings in giant fibers of intact earthworms (Lumbricus terrestris) circumvent many of these problems and result in a nearly 100% success rate. Originally, these experiments were introduced as classroom exercises by Charles Drewes in 1978 using awake, moving earthworms. In 1990, Hans-Georg Heinzel described further experiments using anesthetized earthworms. In this article, we focus on the application of these experiments as teaching tools for basic neurobiology courses. We describe and extend selected experiments, focusing on specific neurobiological principles with experimental protocols optimized for classroom application. Furthermore, we discuss our experience using these experiments in animal physiology and various neurobiology courses at the University of Bonn. PMID:23494516

  11. Gene Expression Analysis of CL-20-induced Reversible Neurotoxicity Reveals GABAA Receptors as Potential Target in the Earthworm Eisenia fetida

    Science.gov (United States)

    Gong, Ping; Guan, Xin; Pirooznia, Mehdi; Liang, Chun; Perkins, Edward J.

    2012-01-01

    The earthworm Eisenia fetida is one of the most used species in standardized soil ecotoxicity tests. Endpoints such as survival, growth and reproduction are eco-toxicologically relevant but provide little mechanistic insight into toxicity pathways, especially at the molecular level. Here we applied a toxicogenomic approach to investigate the mode of action underlying the reversible neurotoxicity of hexanitrohexaazaisowurtzitane (CL-20), a cyclic nitroamine explosives compound. We developed an E. fetida-specific shotgun microarray targeting 15119 unique E. fetida transcripts. Using this array we profiled gene expression in E. fetida in response to exposure to CL-20. Eighteen earthworms were exposed for 6 days to 0.2 ?g/cm2 of CL-20 on filter paper, half of which were allowed to recover in a clean environment for 7 days. Nine vehicle control earthworms were sacrificed at day 6 and 13, separately. Electrophysiological measurements indicated that the conduction velocity of earthworm medial giant nerve fiber decreased significantly after 6-day exposure to CL-20, but was restored after 7 days of recovery. Total RNA was isolated from the four treatment groups including 6-day control, 6-day exposed, 13-day control and 13-day exposed (i.e. 6-day exposure followed by 7-day recovery), and was hybridized to the 15K shot-gun oligo array. Statistical and bioinformatic analyses suggest that CL-20 initiated neurotoxicity by non-competitively blocking the ligand-gated GABAA receptor ion channel, leading to altered expression of genes involved in GABAergic, cholinergic, and Agrin-MuSK pathways. In the recovery phase, expression of affected genes returned to normality, possibly as a result of autophagy and CL-20 dissociation/metabolism. This study provides significant insights into potential mechanisms of CL-20-induced neurotoxicity and the recovery of earthworms from transient neurotoxicity stress. PMID:22191394

  12. Comparative efficacy of three epigeic earthworms under different deciduous forest litters decomposition.

    Science.gov (United States)

    Manna, M C; Jha, S; Ghosh, P K; Acharya, C L

    2003-07-01

    An experiment was conducted during 1998-1999, in a deciduous forest located in the semi-arid tropics of central India, to evaluate the suitability of different forest litters as food material for the tropical epigeic earthworms i.e. Eisenia fetida (Savigny), Perionyx excavatus (Perrier) and Dicogaster bolaui (michaelsen). The aim was to examine the influence of these earthworms on the decomposition processes of three types of forest litters i.e. Tectona grandis (teak), Madhuca indica (mahua) and Butea monosperma (palas), on the maintenance of quality in a vermicomposting system, and to assess the effect of applications of in situ prepared vermicomposts on the growth of forest trees. The results indicated that T. grandis litter was the most suitable food material for the earthworms possibly because it contained high reserves of mineral nutrients. Comparisons of the survival and reproduction rates of the three epigeic earthworm species indicated that a higher reproduction rate was maintained for E. fetida compared to P. excavatus and D. bolaui in the decomposition of these forest litters. The rates of growth and population increases of E. fetida approximately doubled after 12 weeks of litter decomposition. The litter decomposition process was associated strongly with the quality of the materials and their chemical composition. Irrespective of earthworm inoculations, the levels of available nutrient such as NH(4)-N, NO(3)-N, available P and K increased significantly (pM. indica litter compost>B. monosperma litter compost. The mature decomposed litter had lower C/N ratios (11.3-24.8:1), water-soluble carbon (0.30-0.58%), water-soluble carbohydrates (0.35-0.71%) and larger cation exchange capacity/total organic carbon ratios than the values in the parent forest litter. The lignin content increased with maturation with a concomitant decrease in cellulose resulting in higher lignin/cellulose ratios. Application of all three vermicomposts to forest trees significantly improved their heights and diameters over those of control trees, although the increases were lower than those resulting from the chemical fertilizer applications. However, soil biological activities i.e. soil respiration, soil microbial biomass carbon and dehydrogenase activity were greater by application of vermicomposts over that after application of inorganic fertilizer in a new plantation of T. grandis. PMID:12618041

  13. Protective effect of sorbitol and monosodium glutamate during storage of freeze-dried lactic acid bacteria

    OpenAIRE

    Carvalho, Ana; Silva, Joana; Ho, Peter; Teixeira, Paula; Xavier Malcata, F.; Gibbs, Paul

    2003-01-01

    The effects of sorbitol and monosodium glutamate upon survival during storage of freeze-dried Lactobacillus bulgaricus, Lactobacillus plantarum, Lactobacillus rhamnosus, Enterococcus durans and Enterococcus faecalis were examined. There were no significant differences in survival during freeze-drying after addition of sorbitol or monosodium glutamate. However, these compounds were found to increase the stability of most strains during long-term storage. Various survival patterns were observed...

  14. Percolation with Constant Freezing

    Science.gov (United States)

    Mottram, Edward

    2014-06-01

    We introduce and study a model of percolation with constant freezing ( PCF) where edges open at constant rate , and clusters freeze at rate independently of their size. Our main result is that the infinite volume process can be constructed on any amenable vertex transitive graph. This is in sharp contrast to models of percolation with freezing previously introduced, where the limit is known not to exist. Our interest is in the study of the percolative properties of the final configuration as a function of . We also obtain more precise results in the case of trees. Surprisingly the algebraic exponent for the cluster size depends on the degree, suggesting that there is no lower critical dimension for the model. Moreover, even for , it is shown that finite clusters have algebraic tail decay, which is a signature of self organised criticality. Partial results are obtained on , and many open questions are discussed.

  15. Polymerization with freezing

    International Nuclear Information System (INIS)

    Irreversible aggregation processes involving reactive and frozen clusters are investigated using the rate equation approach. In aggregation events, two clusters join irreversibly to form a larger cluster; additionally, reactive clusters may spontaneously freeze. Frozen clusters do not participate in merger events. Generally, freezing controls the nature of the aggregation process, as demonstrated by the final distribution of frozen clusters. The cluster mass distribution has a power-law tail, Fk?k-?, when the freezing process is sufficiently slow. Different exponents, ? = 1 and 3, are found for the constant and the product aggregation rates, respectively. For the latter case, the standard polymerization model, either no gels, or a single gel, or even multiple gels, may be produced

  16. Glutathione protects Lactobacillus sanfranciscensis against freeze-thawing, freeze-drying, and cold treatment.

    Science.gov (United States)

    Zhang, Juan; Du, Guo-Cheng; Zhang, Yanping; Liao, Xian-Yan; Wang, Miao; Li, Yin; Chen, Jian

    2010-05-01

    Lactobacillus sanfranciscensis DSM20451 cells containing glutathione (GSH) displayed significantly higher resistance against cold stress induced by freeze-drying, freeze-thawing, and 4 degrees C cold treatment than those without GSH. Cells containing GSH were capable of maintaining their membrane structure intact when exposed to freeze-thawing. In addition, cells containing GSH showed a higher proportion of unsaturated fatty acids in cell membranes upon long-term cold treatment. Subsequent studies revealed that the protective role of GSH against cryodamage of the cell membrane is partly due to preventing peroxidation of membrane fatty acids and protecting Na(+),K(+)-ATPase. Intracellular accumulation of GSH enhanced the survival and the biotechnological performance of L. sanfranciscensis, suggesting that the robustness of starters for sourdough fermentation can be improved by selecting GSH-accumulating strains. Moreover, the results of this study may represent a further example of mechanisms for stress responses in lactic acid bacteria. PMID:20208023

  17. Metabolic changes during estivation in the common earthworm Aporrectodea caliginosa

    DEFF Research Database (Denmark)

    Bayley, Mark; Overgaard, Johannes

    2011-01-01

    The common earthworm Aporrectodea caliginosa survives drought by forming estivation chambers in the topsoil under even very slight reductions in soil water activity. We induced estivation in a soil of a consistency that allowed the removal of intact soil estivation chambers containing a single worm. These estivation chambers were exposed to 97% relative humidity for 30 d to simulate the effect of a severe summer drought. Gas exchange, body fluid osmolality, water balance, urea, and alanine were quantified, and whole-body homogenates were screened for changes in small organic molecules via (1)H-nuclear magnetic resonance (NMR). Formation of estivation chambers was associated with a dramatic increase in body fluid osmolality, from 175 to 562 mOsm kg(-1), accompanied by a 20% increase in water content. Dehydration for 1 mo caused a further increase to 684 mOsm kg(-1), while the worms lost 50% of their water content. Gas exchange was depressed by 50% after worms entered estivation and by 80% after a further 30 d of dehydration. Urea concentrations increased from 0.3 to 1 micromol g(-1) dry mass during this time. Although (1)H-NMR did not provide the identity of the osmolytes responsible for the initial increase in osmolality after estivation, it showed that alanine increased to more than 80 mmol L(-1) in the long-term-estivation group. We propose that alanine functions as a nitrogen depot during dehydration and is not an anaerobe product in this case.

  18. Status, Trends, and Advances in Earthworm Research and Vermitechnology

    International Nuclear Information System (INIS)

    In this special issue reflect the developments in the fields of earthworm research and vermitechnology. Charles Darwins observation on earthworms is a milestone in understanding the soil biology and enormous contribution to some aspects of the genesis of humus and of its role in soils. Earthworms are the best known soil inhabiting animals commonly called friends of farmers due to the beneficial role they play in soil. The research on earthworms has gained importance in India as well as in other countries. In the year 1981, an international symposium entitled Earthworm Ecology: Darwin to Vermiculture was held at Cumbria, UK, to commemorate the centenary celebration of Darwins book The Formation of Vegetable Mould through the Action of Worms, with Observations on Their Habits that was published in 1881 by Murray, London, UK. In the year 2000, Vermillenium-an international workshop and symposium- was held at Kalamazoo, USA, to realize the progress achieved in this field after a decade (since 1991). Recently, Ninth International Symposium on Earthworm Ecology (ISEE-9) that was held at Xalapa, Mexico, during the 5th to 10th of September 2010 clearly proved the importance of earthworms and vermitechnology by the participation of scientists from different countries. About 300 papers were received from the researchers across the world

  19. Earthworms increase plant production: a meta-analysis.

    Science.gov (United States)

    van Groenigen, Jan Willem; Lubbers, Ingrid M; Vos, Hannah M J; Brown, George G; De Deyn, Gerlinde B; van Groenigen, Kees Jan

    2014-01-01

    To meet the challenge of feeding a growing world population with minimal environmental impact, we need comprehensive and quantitative knowledge of ecological factors affecting crop production. Earthworms are among the most important soil dwelling invertebrates. Their activity affects both biotic and abiotic soil properties, in turn affecting plant growth. Yet, studies on the effect of earthworm presence on crop yields have not been quantitatively synthesized. Here we show, using meta-analysis, that on average earthworm presence in agroecosystems leads to a 25% increase in crop yield and a 23% increase in aboveground biomass. The magnitude of these effects depends on presence of crop residue, earthworm density and type and rate of fertilization. The positive effects of earthworms become larger when more residue is returned to the soil, but disappear when soil nitrogen availability is high. This suggests that earthworms stimulate plant growth predominantly through releasing nitrogen locked away in residue and soil organic matter. Our results therefore imply that earthworms are of crucial importance to decrease the yield gap of farmers who can't -or won't- use nitrogen fertilizer. PMID:25219785

  20. Slow desiccation improves dehydration tolerance and accumulation of compatible osmolytes in earthworm cocoons (Dendrobaena octaedra Savigny)

    DEFF Research Database (Denmark)

    Petersen, Christina R; Holmstrup, Martin

    2008-01-01

    The earthworm, Dendrobaena octaedra, is a common species in temperate and subarctic regions of the northern hemisphere. The egg capsules ('cocoons') of D. octaedra are deposited in the upper soil layers where they may be exposed to desiccation. Many previous studies on desiccation tolerance in soil invertebrates have examined acute exposure to harsh desiccating conditions, however, these animals are often more likely to be exposed to a gradually increasing drought stress. In the present study we slowly desiccated D. octaedra cocoons to simulate ecologically realistic drought conditions and the results clearly demonstrate that gradually dehydrated cocoons show an increased tolerance of extreme drought compared with acutely dehydrated cocoons. NMR spectroscopic analysis of compatible osmolytes revealed the presence of sorbitol, glucose, betaine, alanine and mannitol in dehydrated embryos. The superior drought survival of gradually desiccated embryos could partly be attributed to a higher accumulation of osmolytes (especially sorbitol). Thus, gradually and acutely desiccated embryos accumulated approximately 2 mol l(-1) and 1 mol l(-1) total osmolytes, respectively. However, in addition to osmolyte accumulation, the gradually desiccated cocoons also tolerated a higher degree of water loss, demonstrating that gradually dehydrated D. octaedra cocoons are able to survive loss of approximately 95% of the original water content. Although D. octaedra embryos can probably not be categorized as a truly anhydrobiotic organism we propose that they belong in a transition zone between the desiccation sensitive and the truly anhydrobiotic organisms. Clearly, these earthworm embryos share many physiological traits with anhydrobiotic organisms.

  1. Enzymatic Regulation of Glycogenolysis in a Subarctic Population of the Wood Frog: Implications for Extreme Freeze Tolerance

    OpenAIRE

    Do Amaral, M. Clara F.; Lee, Richard E.; Costanzo, Jon P.

    2013-01-01

    The wood frog, Rana sylvatica, from Interior Alaska survives freezing at –16°C, a temperature 10–13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (...

  2. Changes in hardwood forest understory plant communities in response to European earthworm invasions.

    Science.gov (United States)

    Hale, Cindy M; Frelich, Lee E; Reich, Peter B

    2006-07-01

    European earthworms are colonizing earthworm-free northern hardwood forests across North America. Leading edges of earthworm invasion provide an opportunity to investigate the response of understory plant communities to earthworm invasion and whether the species composition of the earthworm community influences that response. Four sugar maple-dominated forest sites with active earthworm invasions were identified in the Chippewa National Forest in north central Minnesota, USA. In each site, we established a 30 x 150 m sample grid that spanned a visible leading edge of earthworm invasion and sampled earthworm populations and understory vegetation over four years. Across leading edges of earthworm invasion, increasing total earthworm biomass was associated with decreasing diversity and abundance of herbaceous plants in two of four study sites, and the abundance and density of tree seedlings decreased in three of four study sites. Sample points with the most diverse earthworm species assemblage, independent of biomass, had the lowest plant diversity. Changes in understory plant community composition were most affected by increasing biomass of the earthworm species Lumbricus rubellus. Where L. rubellus was absent there was a diverse community of native herbaceous plants, but where L. rubellus biomass reached its maximum, the herbaceous-plant community was dominated by Carex pensylvanica and Arisaema triphyllum and, in some cases, was completely absent. Evidence from these forest sites suggests that earthworm invasion can lead to dramatic changes in the understory community and that the nature of these changes is influenced by the species composition of the invading earthworm community. PMID:16922315

  3. Freeze-drying of yeast cultures.

    Science.gov (United States)

    Bond, Chris

    2007-01-01

    A method is described that allows yeast species to be stored using a variation on the standard freeze-drying method, which employs evaporative cooling in a two-stage process. Yeast cultures are placed in glass ampoules after having been mixed with a lyoprotectant. Primary drying is carried out using a centrifuge head connected to a standard freeze-dryer. Once the centrifuge head is running, air is removed and evaporated liquid is captured in the freeze-dryer. Centrifugation continues for 15 min and primary drying for a further 3 h. The ampoules are constricted using a glass blowing torch. They are then placed on the freeze-dryer manifold for secondary drying under vacuum overnight, using phosphorus pentoxide as a desiccant. The ampoules are sealed and removed from the manifold by melting the constricted section. Although the process causes an initial large drop in viability, further losses after storage are minimal. Yeast strains have remained viable for more than 30 yr when stored using this method and sufficient cells are recovered to produce new working stocks. Although survival rates are strain specific, nearly all National Collection of Yeast Cultures strains covering most yeast genera, have been successfully stored with little or no detectable change in strain characteristics. PMID:18080464

  4. Freezing of Triangulations

    OpenAIRE

    Kownacki, Jean-philippe

    2004-01-01

    Zero temperature dynamics of two dimensional triangulations of a torus with curvature energy is described. Numerical simulations strongly suggest that the model get frozen in metastable states, made of topological defects on flat surfaces, that group into clusters of same topological charge. It is conjectured that freezing is related to high temperature structure of baby universes.

  5. Identification and Classification of Earthworm Species in Guyana

    Directory of Open Access Journals (Sweden)

    Preeta Saywack

    2011-01-01

    Full Text Available Earthworms are very important organisms, they are both environmentally and economically beneficial and hence their correct identification and classification is very vital. Taxonomy aims to classify organisms based on their similarities and differences. The present study was carried out during the year 2006-2007 at University of Guyana, Georgetown focusing on identification and classification of local earthworm species of Guyana and comparison with a known non-native species (California red. The earthworms were collected (using hand sorting method, cultured and then carefully examined (worms were washed with water, preserved in 10% formalin solution. The two species studied were identified based on their external morphology and internal anatomy as well as their ecological features. The California red earthworm was grouped under the family Lumbricidae and identified as Eisenia foetida, while the local species was grouped under the family Eudrilidae and identified as Eudrilus eugenia.

  6. Menadione enhances oxyradical formation in earthworm extracts: vulnerability of earthworms to quinone toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Osman, A.M.; Besten, P.J. den; Noort, P.C.M. van

    2003-10-08

    NAD(P)H-cytochrome c reductase activities have been determined in the earthworms, L. rubellus and A. chlorotica, extracts. Menadione (0.35 mM, maximum concentration tested) was found to stimulate the rates of NADPH- and NADH-dependent cytochrome c reduction by three- and twofold, respectively. Superoxide dismutase (SOD) inhibited completely this menadione-mediated stimulation, suggesting that {center_dot}O{sub 2}{sup -} is involved in the redox cycling of menadione. However, SOD had no effect on the basal activity (activity in the absence of quinone) in the case of NADH-dependent cytochrome c reduction, whereas it partially inhibited the basal activity of NADPH-cytochrome c reduction. This indicates direct electron transfer in the former case and the formation of superoxide anion in the latter. DT-diaphorase, measured as the dicumarol-inhibitable part of menadione reductase activity, was not detectable in the earthworms' extracts. In contrast, it was found that DT-diaphorase represents about 70% of the menadione reductase activities in the freshwater mussel, Dreissena polymorpha. The results of this work suggest that earthworms, compared with mussels, could be more vulnerable to oxidative stress from quinones due to lack, or very low level of DT-diaphorase, an enzyme considered to play a significant role in the detoxification of quinones. On the contrary, mussels have efficient DT-diaphorase, which catalyzes two-electron reduction of menadione directly to hydroquinone, thus circumventing the formation of semiquinone.

  7. Menadione enhances oxyradical formation in earthworm extracts: vulnerability of earthworms to quinone toxicity

    International Nuclear Information System (INIS)

    NAD(P)H-cytochrome c reductase activities have been determined in the earthworms, L. rubellus and A. chlorotica, extracts. Menadione (0.35 mM, maximum concentration tested) was found to stimulate the rates of NADPH- and NADH-dependent cytochrome c reduction by three- and twofold, respectively. Superoxide dismutase (SOD) inhibited completely this menadione-mediated stimulation, suggesting that ·O2- is involved in the redox cycling of menadione. However, SOD had no effect on the basal activity (activity in the absence of quinone) in the case of NADH-dependent cytochrome c reduction, whereas it partially inhibited the basal activity of NADPH-cytochrome c reduction. This indicates direct electron transfer in the former case and the formation of superoxide anion in the latter. DT-diaphorase, measured as the dicumarol-inhibitable part of menadione reductase activity, was not detectable in the earthworms' extracts. In contrast, it was found that DT-diaphorase represents about 70% of the menadione reductase activities in the freshwater mussel, Dreissena polymorpha. The results of this work suggest that earthworms, compared with mussels, could be more vulnerable to oxidative stress from quinones due to lack, or very low level of DT-diaphorase, an enzyme considered to play a significant role in the detoxification of quinones. On the contrary, mussels have efficient DT-diaphorase, which catalyzes two-electron reduction of menadione directly to hydroquinoneion of menadione directly to hydroquinone, thus circumventing the formation of semiquinone

  8. Identification of bacteria community associated with earthworm gut

    OpenAIRE

    Lemtiri, Aboulkacem; Alabi, Taofic; Bodson, Bernard; Brostaux, Yves; Destain, Marie-france; Aubinet, Marc; Colinet, Gilles; Vandenbol, Micheline; Portetelle, Daniel; Haubruge, Eric; Francis, Fre?de?ric

    2012-01-01

    The role of earthworms in soil fertility and transformation of organic waste was regulary cited to be of first importance. Associated to these macro-invertebrates, a large diversity of micro-orgnisms are found indirectly in their closed environment or directly in their gut. Functional aspects of these interactions and symbiosis in relation with soil characteristics and fertility rates are poorly developed. Here, the micro-organisms diversity and potential related functions of earthworm gut we...

  9. Earthworms lost from pesticides application in potato crops

    Science.gov (United States)

    Garcia-Santos, Glenda; Forrer, Karin; Binder, Claudia R.

    2010-05-01

    Bioturbation from earthworm's activity contributes to soil creep and soil carbon dynamics, and provide enough aeration conditions for agricultural practices all over the world. In developing countries where there is a long term misuse of pesticides for agricultural purposes, lost of these benefits from earthworms activity might already yielded negative effects in the current crop production. Little research has been performed on earthworms avoidance to pesticides in developing countries located in the tropics. Furthermore, the complete avoidance reaction (from attraction to 100% avoidance) from earthworms to most of the pesticides used in potato cultivation in developing countries like Colombia is incomplete as yet. Hence the aim of this study is to assess the lost of earthworm on the soils caused by different concentrations of pesticides and associated agricultural impacts caused by a lost in the soil bioturbation. As a first stage, we have studied earthworm's avoidance to pesticide concentration in a potato agricultural area located in Colombia. Local cultivated Eisenia fetida were exposed to four of the most frequent applied active ingredients in potato crops i.e. carbofuran, mancozeb, methamidophos and chlorpyriphos. Adult earthworm toxicity experiments were carried out in two soils, untreated grasslands under standard (ISO guidelines) and undisturbed conditions, and exposed to six different concentrations of the active ingredients. The results of the avoidance reaction on the standard soils were significant for carbofuran, mancoceb and chlorpyrifos. For each of the three active ingredients, we found i) overuse of pesticide, ii) applied dose of carbofuran, mancoceb and chlorpyrifos by the farmers potentially caused 20%, 11% and 9% of earthworms avoidance on the cultivated soils, respectively.

  10. Identification and Classification of Earthworm Species in Guyana

    OpenAIRE

    Preeta Saywack; Abdullah Adil Ansari

    2011-01-01

    Earthworms are very important organisms, they are both environmentally and economically beneficial and hence their correct identification and classification is very vital. Taxonomy aims to classify organisms based on their similarities and differences. The present study was carried out during the year 2006-2007 at University of Guyana, Georgetown focusing on identification and classification of local earthworm species of Guyana and comparison with a known non-native species (California red). ...

  11. Root Foraging Influences Plant Growth Responses to Earthworm Foraging

    OpenAIRE

    Cameron, Erin K.; Cahill, James F.; Bayne, Erin M.

    2014-01-01

    Interactions among the foraging behaviours of co-occurring animal species can impact population and community dynamics; the consequences of interactions between plant and animal foraging behaviours have received less attention. In North American forests, invasions by European earthworms have led to substantial changes in plant community composition. Changes in leaf litter have been identified as a critical indirect mechanism driving earthworm impacts on plants. However, there has been limited...

  12. Interactions between Nematodes and Earthworms: Enhanced Dispersal of Steinernema carpocapsae

    OpenAIRE

    Shapiro, D. I.; Berry, E. C.; Lewis, L. C.

    1993-01-01

    Dispersal of the nematode Steinernema carpocapsae (All strain), applied on the top or the bottom of soil columns, was tested in the presence or absence of two earthworm species, Lumbricus terrestris or Aporrectodea trapezoides. Nematode dispersal was estimated after a 2-week period with a bioassay against the greater wax moth, Galleria mellonella. Vertical dispersal of nematodes was increased in the presence of earthworms. When nematodes were placed on the surface of soil columns, significant...

  13. Clostridiaceae and Enterobacteriaceae as active fermenters in earthworm gut content

    OpenAIRE

    Wu?st, Pia K.; Horn, Marcus A.; Drake, Harold L.

    2010-01-01

    The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H2) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut cont...

  14. Earthworm-produced calcite granules: a new terrestrial palaeothermometer?

    OpenAIRE

    Versteegh, Emma A. A.; Black, Stuart; Canti, Matthew G.; Hodson, Mark E.

    2013-01-01

    In this paper we show for the first time that calcite granules, produced by the earthworm Lumbricus terrestris, and commonly recorded at sites of archaeological interest, accurately reflect temperature and soil water ?18O values. Earthworms were cultivated in an orthogonal combination of two different (granule-free) soils moistened by three types of mineral water and kept at three temperatures (10, 16 and 20 ºC) for an acclimatisation period of three weeks followed by transfer to identical ...

  15. Greenhouse-gas emissions from soils increased by earthworms

    OpenAIRE

    Lubbers, I. M.; Groenigen, K. J.; Fonte, S. J.; Six, J.; Brussaard, L.; Groenigen, J. W.

    2013-01-01

    Earthworms play an essential part in determining the greenhouse-gas balance of soils worldwide, and their influence is expected to grow over the next decades. They are thought to stimulate carbon sequestration in soil aggregates, but also to increase emissions of the main greenhouse gases carbon dioxide and nitrous oxide. Hence, it remains highly controversial whether earthworms predominantly affect soils to act as a net source or sink of greenhouse gases. Here, we provide a quantitative revi...

  16. Disposal of dredged sediments in tropical soils: ecotoxicological effects on earthworms.

    Science.gov (United States)

    Cesar, Ricardo; Natal-da-Luz, Tiago; Sousa, José Paulo; Colonese, Juan; Bidone, Edison; Castilhos, Zuleica; Egler, Silvia; Polivanov, Helena

    2014-03-01

    The upper limit concentrations of metals established by international legislations for dredged sediment disposal and soil quality do not take into consideration the properties of tropical soils (generally submitted to more intense weathering processes) on metal availability and ecotoxicity. Aiming to perform an evaluation on the suitability of these threshold values in tropical regions, the ecotoxicity of metal-contaminated dredged sediment from the Guanabara Bay (Rio de Janeiro, Brazil) was investigated. Acute and avoidance tests with Eisenia andrei were performed with mixtures of dredged sediment with a ferralsol (0.00, 6.66, 13.12, 19.98, and 33.30 %) and a chernosol (0.00, 6.58, 13.16, 19.74, and 32.90 %). Mercury, lead, nickel, chromium, copper, and zinc concentrations were measured in test mixtures and in tissues of surviving earthworms from the acute tests. While ferralsol test mixtures provoked significant earthworm avoidance response at concentrations ?13.31 %, the chernosol mixtures showed significant avoidance behavior only at the 19.74 % concentration. The acute tests showed higher toxicity in ferralsol mixtures (LC50?=?9.9 %) compared to chernosol mixtures (LC50?=?16.5 %), and biomass increased at the lowest sediment doses in treatments of both test soils. Most probably, the expansive clay minerals present in chernosol contributed to reduce metal availability in chernosol mixtures, and consequently, the ecotoxicity of these treatments. The bioconcentration factors (BCF) for zinc and copper were lower with increasing concentrations of the dredged sediment, indicating the existence of internal regulating processes. Although the BCF for mercury also decreased with the increasing test concentrations, the known no biological function of this metal in the earthworms metabolism lead to suppose that Hg measured was not present in bioaccumulable forms. BCFs estimated for the other metals were generally higher in the highest dredged sediment doses. PMID:24122142

  17. The survival of mouse oocytes shows little or no correlation with the vitrification or freezing of the external medium, but the ability of the medium to vitrify is affected by its solute concentration and by the cooling rate.?

    Science.gov (United States)

    Paredes, Estefania; Mazur, Peter

    2013-01-01

    As survival of mouse oocytes subjected to vitrification depends far more on the warming rate than on the cooling rate, we wished to determine whether the lack of correlation between survival and cooling rate was mirrored by a lack of correlation between cooling rate and vitrification of the medium (EAFS), and between survival and the vitrification of the medium. The morphological and functional survival of the oocytes showed little or no relation to whether or not the EAFS medium vitrified or froze. We studied if the droplet size and the elapsed time (between placing the droplet on the Cryotop and the start of cooling) affects the result through modification of the cooling rate and solute concentration. Dehydration was rapid; consequently, the time between the placing the droplets into a Cryotop and cooling must be held to a minimum. The size of the EAFS droplet that is being cooled does not seem to affect vitrification. Finally, the degree to which samples of EAFS vitrify is firmly dependent on both its solute concentration and the cooling rate. PMID:24056038

  18. The survival of mouse oocytes shows little or no correlation with the vitrification or freezing of the external medium, but the ability of the medium to vitrify is affected by its solute concentration and by the cooling rate.

    Science.gov (United States)

    Paredes, Estefania; Mazur, Peter

    2013-12-01

    As survival of mouse oocytes subjected to vitrification depends far more on the warming rate than on the cooling rate, we wished to determine whether the lack of correlation between survival and cooling rate was mirrored by a lack of correlation between cooling rate and vitrification of the medium (EAFS), and between survival and the vitrification of the medium. The morphological and functional survival of the oocytes showed little or no relation to whether or not the EAFS medium vitrified or froze. We studied if the droplet size and the elapsed time (between placing the droplet on the Cryotop and the start of cooling) affects the result through modification of the cooling rate and solute concentration. Dehydration was rapid; consequently, the time between the placing the droplets into a Cryotop and cooling must be held to a minimum. The size of the EAFS droplet that is being cooled does not seem to affect vitrification. Finally, the degree to which samples of EAFS vitrify is firmly dependent on both its solute concentration and the cooling rate. PMID:24056038

  19. Use of plant and earthworm bioassays to evaluate remediation of soil from a site contaminated with polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Meier, J.R.; Chang, L.W.; Meckes, M.C.; Smith, M.K. [Environmental Protection Agency, Cincinnati, OH (United States); Jacobs, S. [DynCorp, Cincinnati, OH (United States); Torsella, J. [Oak Ridge Inst. of Science and Education, Cincinnati, OH (United States)

    1997-05-01

    Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The earthworm toxicity bioassays were the 14-d survival test and 21-d reproduction test, using Lumbricus terrestris and Eisenia fetida andrei. The plant bioassays included phytotoxicity tests for seed germination and root elongation in lettuce and oats, and a genotoxicity test (anaphase aberrations) in Allium cepa (common onion). Although the PCB content of the soil was reduced by 99% (below the remediation goal), toxicity to earthworm reproduction remained essentially unchanged following remediation. Furthermore, phytotoxicity and genotoxicity were higher for the remediated soil compared to the untreated soil. The toxicity remaining after treatment appeared to be due to residual solvent introduced during the remediation process, and/or to heavy metals or other inorganic contaminants not removed by the treatment. Mixture studies involving isopropanol and known toxicants indicated possible synergistic effects of the extraction solvent and soil contaminants. The toxicity in plants was essentially eliminated by a postremediation, water-rinsing step. These results demonstrate a need for including toxicity measurements in the evaluation of technologies used in hazardous waste site remediations, and illustrate the potential value of such measurements for making modifications to remediation processes.

  20. Off to the (Earthworm) Races: A Quick and Flexible Lab Experiment for Introductory Zoology Courses.

    Science.gov (United States)

    Switzer, Paul V.; Fritz, Ann H.

    2001-01-01

    Presents a hands-on, investigative lab activity for use in an introductory zoology course. Tests the behavioral hypothesis that substrate texture affects earthworm locomotor ability. Provides background information on earthworm locomotion followed by details of the lab exercise. (NB)

  1. Warming shifts ‘worming': effects of experimental warming on invasive earthworms in northern North America

    OpenAIRE

    Eisenhauer, Nico; Stefanski, Artur; Fisichelli, Nicholas A.; Rice, Karen; Rich, Roy; Reich, Peter B.

    2014-01-01

    Climate change causes species range shifts and potentially alters biological invasions. The invasion of European earthworm species across northern North America has severe impacts on native ecosystems. Given the long and cold winters in that region that to date supposedly have slowed earthworm invasion, future warming is hypothesized to accelerate earthworm invasions into yet non-invaded regions. Alternatively, warming-induced reductions in soil water content (SWC) can also decrease earthworm...

  2. Earthworms and collembola relationships: effects of predatory centipedes and humus forms

    OpenAIRE

    Salmon, Sandrine; Geoffroy, Jean-jacques; Ponge, Jean-franc?ois

    2005-01-01

    Relationships between anecic earthworms (Lumbricus terrestris and Aporrectodea giardi) and the collembolan species Heteromurus nitidus (Templeton, 1835), which is known to be attracted to earthworms, were investigated in an 8-week laboratory experiment. Our aims were (1) to assess whether earthworms influence the population dynamics of H. nitidus, and (2) to study pathways of influence and how earthworm effects are modified by humus forms and predators. Using microcosms with three defaunated ...

  3. Importance of freeze-thaw events in low temperature ecotoxicology of cold tolerant enchytraeids

    DEFF Research Database (Denmark)

    Patrício Silva, Ana L; Enggrob, Kirsten

    2014-01-01

    Due to global warming it is predicted that freeze-thaw cycles will increase in Arctic and cold temperate regions. The effects of this variation becomes of particular ecological importance to freeze-tolerant species when it is combined with chemical pollutants. We compared the effect of control temperature (2 °C), daily freeze-thaw cycles (2 to -4 °C) and constant freezing (-2 °C) temperatures on the cold-tolerance of oligochaete worms (Enchytraeus albidus) and tested how survival was influenced by pre-exposure to 4-nonylphenol (4-NP), a common nonionic detergent found in sewage sludge amended soils. Results showed that combined effect of 4-NP and daily freeze-thaw cycles can cause higher mortality to worms as compared with sustained freezing or control temperature. Exposure to 4-NP caused a substantial depletion of glycogen reserves which is catabolized during freezing to produce cryoprotective concentrations of free glucose. Further, exposure to freeze-thaw cycles resulted in higher concentrations of 4-NP inworm tissues as compared to constant freezing or control temperature (2 °C). Thus, worms exposed to combined effect of freeze-thaw cycles and 4-NP suffer higher consequences, with the toxic effect of the chemical potentiating the deleterious effects of freezing and thawing.

  4. A freezing-sensitive mutant of Arabidopsis, frs1, is a new aba3 allele.

    Science.gov (United States)

    Llorente, F; Oliveros, J C; Martínez-Zapater, J M; Salinas, J

    2000-10-01

    To investigate the molecular mechanisms controlling the process of cold acclimation and to identify genes involved in plant freezing tolerance, mutations that impaired the cold acclimation capability of Arabidopsis thaliana (L.) Heynh were screened for. A new mutation, frs1 (freezing sensitive 1), that reduced both the constitutive freezing tolerance as well as the freezing tolerance of Arabidopsis after cold acclimation was characterized. This mutation also produced a wilty phenotype and excessive water loss. Plants with the frs1 mutation recovered their wild-type phenotype, their capability to tolerate freezing temperatures and their capability to retain water after an exogenous abscisic acid (ABA) treatment. Measurements of ABA revealed that frs1 mutants were ABA deficient, and complementation tests indicated that frs1 mutation was a new allele of the ABA3 locus showing that a mutation in this locus leads to an impairment of freezing tolerance. These results constitute the first report showing that a mutation in ABA3 leads to an impairment of freezing tolerance, and not only strengthen the conclusion that ABA is required for full development of freezing tolerance in cold-acclimated plants, but also demonstrate that ABA mediates the constitutive freezing tolerance of Arabidopsis. Gene expression in frs1 mutants was altered in response to dehydration, suggesting that freezing tolerance in Arabidopsis depends on ABA-regulated proteins that allow plants to survive the challenges imposed by subzero temperatures, mainly freeze-induced cellular dehydration. PMID:11089677

  5. Metallothionein response in earthworms Lampito mauritii (Kinberg) exposed to fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Maity, S.; Hattacharya, S.; Chaudhury, S. [Visva Bharati, Santini Ketan (India)

    2009-10-15

    Among pollutants, the coal fly ash occupies a significant position in industrial wastes. The fly ash matrix is a complex mixture of various organic (polyhalogenated compounds) and inorganic (Si, Al, Fe, As, Cd, Bi, Hg, etc.) chemicals. The application of fly ash for agricultural purposes and as landfills may lead to the contamination of the land with some of the toxic chemical compounds present in fly ash. Thus prior to the application of fly ash for developmental activities, it requires bio-monitoring and risk characterization. In order to achieve this objective adult Lampito mauritii were exposed to different proportions of fly ash in soil for 30 d and the concentrations of metallothionein in earthworm were assessed. The results revealed that up to 50% of fly ash amendment does not apparently harm the earthworm in respect of their survival and growth. A significant increase in tissue metallothionein level was recorded in L mauritii exposed to fly ash amended soil without tissue metal accumulation indicating that metallothionein is involved in scavenging of free radicals and reactive oxygen species metabolites. It is concluded that this biochemical response observed in L mauritii exposed to fly ash amended soil could be used in ecotoxicological field monitoring.

  6. Establishing principal soil quality parameters influencing earthworms in urban soils using bioassays

    International Nuclear Information System (INIS)

    Potential contamination at ex-industrial sites means that, prior to change of use, it will be necessary to quantify the extent of risks to potential receptors. To assess ecological hazards, it is often suggested to use biological assessment to augment chemical analyses. Here we investigate the potential of a commonly recommended bioassay, the earthworm reproduction test, to assess the status of urban contaminated soils. Sample points at all study sites had contaminant concentrations above the Dutch soil criteria Target Values. In some cases, the relevant Intervention Values were exceeded. Earthworm survival at most points was high, but reproduction differed significantly in soil from separate patches on the same site. When the interrelationships between soil parameters and reproduction were studied, it was not possible to create a good model of site soil toxicity based on single or even multiple chemical measurements of the soils. We thus conclude that chemical analysis alone is not sufficient to characterize soil quality and confirms the value of biological assays for risk assessment of potentially contaminated soils. - Bioassays must be applied for the risk assessment complexly-polluted sites to complement chemical analysis of soils

  7. A metabolomics based test of independent action and concentration addition using the earthworm Lumbricus rubellus.

    Science.gov (United States)

    Baylay, A J; Spurgeon, D J; Svendsen, C; Griffin, J L; Swain, Suresh C; Sturzenbaum, Stephen R; Jones, O A H

    2012-07-01

    A major challenge in ecotoxicology is to understand the effects of multiple toxicants on organisms. Here we assess the effects on survival, weight change, cocoon production and metabolism caused by exposure to two similarly acting (imidacloprid/thiacloprid) and two dissimilarly acting (chlorpyrifos/Nickel) chemicals on the earthworm Lumbricus rubellus. We assessed the standard models of concentration addition (CA) and independent action (IA), in conjunction with a metabolomics based approach to elucidate mechanisms of effect. For imidacloprid and thiacloprid the reproductive effects indicated probable additivity. Although this suggests joint effects through a similar mechanism, metabolite changes for each pesticide actually indicated distinct effects. Further, earthworms exposed to a 0.5 toxic unit equitoxic mixture demonstrated metabolic effects intermediate between those for each pesticide, indicating a non-interactive, independent joint effect. For higher effect level mixtures (1 and 1.5 toxic units), metabolite changes associated with thiacloprid exposure began to dominate. The metabolomic effects of the two dissimilarly acting chemicals were distinct, confirming separate modes of action and both proved more toxic than anticipated from previous studies. In the mixtures, phenotypic effects were in accordance with IA estimates, while metabolite changes were dominated by Ni effects, even though chlorpyrifos contributed most to reproductive toxicity. This could be attributed to the greater systematic effect of Ni when compared to the more specifically acting chlorpyrifos. PMID:22476697

  8. Heat shock protects germinating conidiospores of Neurospora crassa against freezing injury.

    OpenAIRE

    Guy, C. L.; Plesofsky-vig, N.; Brambl, R.

    1986-01-01

    Germinating conidiospores of Neurospora crassa that were exposed to 45 degrees C, a temperature that induces a heat shock response, were protected from injury caused by freezing in liquid nitrogen and subsequent thawing at 0 degrees C. Whereas up to 90% of the control spores were killed by this freezing and slow thawing, a prior heat shock increased cell survival four- to fivefold. Survival was determined by three assays: the extent of spore germination in liquid medium, the number of colonie...

  9. Effects of gypsum on trace metals in soils and earthworms.

    Science.gov (United States)

    Chen, Liming; Kost, Dave; Tian, Yongqiang; Guo, Xiaolu; Watts, Dexter; Norton, Darrell; Wolkowski, Richard P; Dick, Warren A

    2014-01-01

    Mined gypsum has been beneficially used for many years as an agricultural amendment. A large amount of flue gas desulfurization (FGD) gypsum is produced by removal of SO from flue gas streams when fuels with high S content are burned. The FGD gypsum, similar to mined gypsum, can enhance crop production. However, information is lacking concerning the potential environmental impacts of trace metals, especially Hg, in the FGD gypsum. Flue gas desulfurization and mined gypsums were evaluated to determine their ability to affect concentrations of Hg and other trace elements in soils and earthworms. The study was conducted at four field sites across the United States (Ohio, Indiana, Alabama, and Wisconsin). The application rates of gypsums ranged from 2.2 Mg ha in Indiana to 20 Mg ha in Ohio and Alabama. These rates are 2 to 10 times higher than typically recommended. The lengths of time from gypsum application to soil and earthworm sampling were 5 and 18 mo in Ohio, 6 mo in Indiana, 11 mo in Alabama, and 4 mo in Wisconsin. Earthworm numbers and biomass were decreased by FGD and mined gypsums in Ohio. Among all the elements examined, Hg was slightly increased in soils and earthworms in the FGD gypsum treatments compared with the control and the mined gypsum treatments. The differences were not statistically significant except for the Hg concentration in the soil at the Wisconsin site. Selenium in earthworms in the FGD gypsum treatments was statistically higher than in the controls but not higher than in the mined gypsum treatments at the Indiana and Wisconsin sites. Bioaccumulation factors for nondepurated earthworms were statistically similar or lower for the FGD gypsum treatments compared with the controls for all elements. Use of FGD gypsum at normal recommended agricultural rates seems not to have a significant impact on concentrations of trace metals in earthworms and soils. PMID:25602559

  10. Earthworm species influence on carbon-mineral association in a sugar maple forest in northern Minnesota

    Science.gov (United States)

    Lyttle, A.; Yoo, K.; Aufdenkampe, A. K.; Hale, C. M.; Sebestyen, S. D.

    2011-12-01

    Non-native European earthworms are invading previously earthworm-free hardwood forests in the northern Great Lakes Region. Whereas earthworms' impacts on soil morphology and geochemical properties have been well documented in agricultural settings, the role of earthworms in biogeochemical cycles of undisturbed forests remains poorly understood. The forest soils that were recently invaded by exotic earthworms, therefore, provide a unique opportunity to understand how and how much earthworms contribute to biogeochemistry of non-agricultural environments. Increased degree and extent of soil mixing is one of the better known consequences of the earthworm invasion. Our hypothesis is that invasive earthworms positively affect carbon (C) stabilization by enhancing contacts between organic matter and minerals. We are studying C-mineral complexation along a well-established earthworm chronosequence in a sugar maple forest in northern Minnesota. We have observed changes in total earthworm biomass, A horizon C storage, and total specific surface area (SSA) of minerals as the invasion progresses. Because each earthworm species has different feeding and dwelling habits, biogeochemical imprints of the invasion reflect not only earthworms' biomass but also their species composition. All earthworm species show an increase in their biomass with greater time length since the invasion, though epigeic earthworms tend to be the pioneer species. As the total earthworm biomass increases, we find greater incorporation of organic C into the A horizon; the O horizon thickness decreases from 8 to 0 cm as the A horizon thickens from ~5 cm to ~12 cm. While leaf litter biomass is negatively correlated with total earthworm biomass, dramatic decreases in litter biomass are coupled with considerable increases in the biomass of epi-endogeic species. Despite the general decrease in C storage in the A horizon with greater degree of invasion, the storages fluctuate along the transect because earthworms affect not only C concentration but also soil bulk density and A horizon thickness. Mineral's SSA in the A and E is significantly larger and greater portions of the mineral SSA are coated with C in soils with greater earthworm biomass. These results show that both mineral's capacity to complex C and the actual complexation are enhanced by earthworm invasion presumably because earthworms' ability to vertically mix soils. This growing data set will ultimately elucidate how soils' capacity to stabilize C is influenced by exotic earthworm species.

  11. Competitive freezing in gold nanoparticles

    Science.gov (United States)

    Asuquo, Cletus C.; Bowles, Richard K.

    2013-05-01

    We use molecular dynamics simulations to study the freezing of gold nanoparticles in a size range of N = 309-923 gold atoms and find the clusters freeze to a variety of structures, including icosahedra, decahedra and face-centered cubic type structures. Measurements of the rate of freezing for the different structures reveal that the icosahedral clusters form an order ofmagnitude faster than the remaining structures over the entire range of cluster sizes studied. An analysis of the structural evolution of the icosahedral and decahedral clusters during freezing events suggests that, despite the vast difference in freezing rates, the two structures both initially form the same five-fold symmetric cap, constructed from tetrahedral sub-units of face-centered cubic packed atoms. The slow rate of decahedron freezing may be caused introduction of strain into the structure as it grows along the five-fold symmetric axis of the cluster and the need to form high energy facets.

  12. Studies on Freezing RAM Semen in Absence of Glycerol.

    Science.gov (United States)

    Abdelnaby, Abdelhady Abdelhakeam

    1988-12-01

    Glycerol is widely used as a major cryoprotective agent for freezing spermatozoa of almost all species. However, it reduces fertility of sheep inseminated cervically compared with intrauterine insemination. Studies were conducted to develop a method and procedure for freezing ram semen in the absence of glycerol. Post -thaw survival of ram spermatozoa frozen in the absence of glycerol was affected by time and temperature after collection and before dilution and time after dilution and before freezing. Increase in time at 5^ circC before or after dilution and before freezing increased both post-thaw motility and number of cells passing through Sephadex filter. A cold dilution method was developed. Slow cooling of fresh ram semen and diluting at 5^circ C 2-3 hr. after collection, then freezing 1 hr. after dilution improved both post-thaw motility and number of cells passing through Sephadex filter compared with immediate dilution at 30-37^circC after collection and freezing 3-4 hr. later (P ram semen in the absence of glycerol. An increase in post-thaw motility was obtained when semen was extended in TES titrated with Tris to pH 7.0 (TEST) and osmotic pressure of 375-400 mOsm/kg, containing 25-30% (v/v) egg yolk and 10% (v/v) maltose. A special device (boat) for freezing was constructed to insure the same height of the sample above LN _2 and thus the same freezing rate from freeze to freeze. Freezing of semen in 0.25cc straws at 5-10 cm above LN_2 (73.8 to 49.5 ^circC/min) yielded higher post-thaw motility than the rates resulted from freezing at 15 cm above LN_2 or 1 cm above LN _2. Faster Thawing in 37^ circC water for 30 sec. (7.8^ circC/sec.) increased post-thaw motility compared with slower thawing in 5 or 20^circ C water (P ram semen frozen without glycerol and 17.1% in a second trial. One injection (IM) of 15 mg PGF_{2alpha}/ewe for estrus synchronization during breeding season resulted in higher heat response and lambing rate than two injections given 10 days apart.

  13. Do earthworms mobilize fixed zinc from ingested soil?

    Science.gov (United States)

    Scott-Fordsmand, Janeck J; Stevens, Daryl; McLaughlin, Mike

    2004-06-01

    A wide range of organisms inhabit the soil and has to deal with soil-bound metals. The bioavailable fraction of metals may be estimated explicitly using the isotopic dilution technique. In the present paper, we evaluated the isotopic exchange technique for assessing the bioavailability of soil Zn (using 65Zn) to earthworms. To validate the technique, the worms were first exposed to various 65Zn levels, and errors due to soil entrained in the gut were evaluated. This exposure indicated no effect of gamma-radiation on growth (wet weight gain) of the organisms and that depuration of the earthworms minimized errors in labile pools determined by isotopic dilution. Our study further showed that the earthworms accessed 55-65% of the total Zn in the soil. The labile pool for the earthworms Eisenia andrei was similar to that for the plant Lactuca sativa, indicating that earthworms and plants to a large extent access the same fraction of soil Zn. Hence, the isotopic dilution technique has the potential to assess biologically available pool of Zn in soils. As lettuce is not known to significantly mobilize nonlabile metals in soil, this study indicates that Zn uptake by E. andrei is predominantly via the exchangeable pools (possibly the soil pore water) rather than dissolution of Zn held within soil particles or within soil organic matter or other food sources. PMID:15224732

  14. Genotoxic effects of glyphosate or paraquat on earthworm coelomocytes.

    Science.gov (United States)

    Muangphra, Ptumporn; Kwankua, Wimon; Gooneratne, Ravi

    2014-06-01

    The potential genotoxicity (nuclear anomalies, damage to single-strand DNA) and pinocytic adherence activity of two (glyphosate-based and paraquat-based) commercial herbicides to earthworm coelomocytes (immune cells in the coelomic cavity) were assessed. Coelomocytes were extracted from earthworms (Pheretima peguana) exposed to concentrations glyphosate-based or paraquat-based herbicides on filter paper for 48 h. Three assays were performed: Micronucleus (light microscopy count of micronuclei, binuclei, and trinuclei), Comet (epifluorescent microscope and LUCIA image analyzer measure of tail DNA %, tail length, and tail moment), and Neutral Red (to detect phagocytic or pinocytic activity). The LC50 value for paraquat was 65-fold lower than for glyphosate indicating that paraquat was far more acutely toxic to P. peguana. There were significant (P glyphosate at 25 × 10(-1) (10(-3) LC50) and paraquat at 39 × 10(-5) (10(-4) LC50) ?g cm(-2) filter paper. In earthworms exposed to glyphosate, no differences in tail DNA%, tail length, and tail moment of coelomocytes were detected. In contrast, for paraquat at 10(-1) LC50 concentration, there were significant (P glyphosate or paraquat at 10(-3) LC50 concentration. This study showed that, at concentrations well below field application rates, paraquat induces both clastogenic and aneugenic effects on earthworm coelomocytes whereas glyphosate causes only aneugenic effects and therefore does not pose a risk of gene mutation in this earthworm. PMID:22644885

  15. Performance Characteristics of an Isothermal Freeze Valve

    Energy Technology Data Exchange (ETDEWEB)

    Hailey, A.E.

    2001-08-22

    This document discusses performance characteristics of an isothermal freeze valve. A freeze valve has been specified for draining the DWPF melter at the end of its lifetime. Two freeze valve designs have been evaluated on the Small Cylindrical Melter-2 (SCM-2). In order to size the DWPF freeze valve, the basic principles governing freeze valve behavior need to be identified and understood.

  16. Effect of different feed types on growth, spawning, hatching and larval survival in angel fish (Pterophyllum scalare Lictenstein, 1823)

    OpenAIRE

    Amin Farahi; Milad Kasiri; Amir Talebi; Mohammad Sudagar

    2010-01-01

    In this study effects of commercial extruder diet (T1), earthworm (T2), 50 % commercialextruder diet + 50 % earthworm (T3) on growth, spawning, hatching and larval survival of angel fish(average weight 4.06 g) (Pterophyllum scalare Lictenstein, 1823) were investigated. The experimentalgroups were fed for 60 days. According to the results of this study, the best spawning and hatching werefound in group T3 but there was no significant difference with other groups (p>0.05). Also larval survivalr...

  17. Gene expression analysis of CL-20-induced reversible neurotoxicity reveals GABA(A) receptors as potential targets in the earthworm Eisenia fetida.

    Science.gov (United States)

    Gong, Ping; Guan, Xin; Pirooznia, Mehdi; Liang, Chun; Perkins, Edward J

    2012-01-17

    The earthworm Eisenia fetida is one of the most used species in standardized soil ecotoxicity tests. End points such as survival, growth, and reproduction are eco-toxicologically relevant but provide little mechanistic insight into toxicity pathways, especially at the molecular level. Here we apply a toxicogenomic approach to investigate the mode of action underlying the reversible neurotoxicity of hexanitrohexaazaisowurtzitane (CL-20), a cyclic nitroamine explosives compound. We developed an E. fetida-specific shotgun microarray targeting 15119 unique E. fetida transcripts. Using this array we profiled gene expression in E. fetida in response to exposure to CL-20. Eighteen earthworms were exposed for 6 days to 0.2 ?g/cm(2) of CL-20 on filter paper, half of which were allowed to recover in a clean environment for 7 days. Nine vehicle control earthworms were sacrificed at days 6 and 13, separately. Electrophysiological measurements indicated that the conduction velocity of earthworm medial giant nerve fiber decreased significantly after 6-day exposure to CL-20, but was restored after 7 days of recovery. Total RNA was isolated from the four treatment groups including 6-day control, 6-day exposed, 13-day control, and 13-day exposed (i.e., 6-day exposure followed by 7-day recovery), and was hybridized to the 15K shotgun oligo array. Statistical and bioinformatic analyses suggest that CL-20 initiated neurotoxicity by noncompetitively blocking the ligand-gated GABA(A) receptor ion channel, leading to altered expression of genes involved in GABAergic, cholinergic, and Agrin-MuSK pathways. In the recovery phase, expression of affected genes returned to normality, possibly as a result of autophagy and CL-20 dissociation/metabolism. This study provides significant insights into potential mechanisms of CL-20-induced neurotoxicity and the recovery of earthworms from transient neurotoxicity stress. PMID:22191394

  18. Anhydrobiosis and Freezing-Tolerance : Adaptations That Facilitate the Establishment of Panagrolaimus Nematodes in Polar Habitats

    DEFF Research Database (Denmark)

    McGill, Lorraine; Shannon, Adam

    2015-01-01

    Anhydrobiotic animals can survive the loss of both free and bound water from their cells. While in this state they are also resistant to freezing. This physiology adapts anhydrobiotes to harsh environments and it aids their dispersal. Panagrolaimus davidi, a bacterial feeding anhydrobiotic nematode isolated from Ross Island Antarctica, can survive intracellular ice formation when fully hydrated. A capacity to survive freezing while fully hydrated has also been observed in some other Antarctic nematodes. We experimentally determined the anhydrobiotic and freezing-tolerance phenotypes of 24 Panagrolaimus strains from tropical, temperate, continental and polar habitats and we analysed their phylogenetic relationships. We found that several other Panagrolaimus isolates can also survive freezing when fully hydrated and that tissue extracts from these freezing-tolerant nematodes can inhibit the growth of ice crystals. We show that P. davidi belongs to a clade of anhydrobiotic and freezing-tolerant panagrolaimids containing strains from temperate and continental regions and that P. superbus, an early colonizer at Surtsey island, Iceland after its volcanic formation, is closely related to a species from Pennsylvania, USA. Ancestral state reconstructions show that anhydrobiosis evolved deep in the phylogeny of Panagrolaimus. The early-diverging Panagrolaimus lineages are strongly anhydrobiotic but weakly freezing-tolerant, suggesting that freezing tolerance is most likely a derived trait. The common ancestors of the davidi and the superbus clades were anhydrobiotic and also possessed robust freezing tolerance, along with a capacity to inhibit the growth and recrystallization of ice crystals. Unlike other endemic Antarctic nematodes, the life history traits of P. davidi do not show evidence of an evolved response to polar conditions. Thus we suggest that the colonization of Antarctica by P. davidi and of Surtsey by P. superbus may be examples of recent “ecological fitting” of freezing-tolerant anhydrobiotic propagules to the respective abiotic conditions in Ross Island and Surtsey

  19. Anhydrobiosis and Freezing-Tolerance: Adaptations That Facilitate the Establishment of Panagrolaimus Nematodes in Polar Habitats

    Science.gov (United States)

    McGill, Lorraine M.; Shannon, Adam J.; Pisani, Davide; Félix, Marie-Anne; Ramløv, Hans; Dix, Ilona; Wharton, David A.; Burnell, Ann M.

    2015-01-01

    Anhydrobiotic animals can survive the loss of both free and bound water from their cells. While in this state they are also resistant to freezing. This physiology adapts anhydrobiotes to harsh environments and it aids their dispersal. Panagrolaimus davidi, a bacterial feeding anhydrobiotic nematode isolated from Ross Island Antarctica, can survive intracellular ice formation when fully hydrated. A capacity to survive freezing while fully hydrated has also been observed in some other Antarctic nematodes. We experimentally determined the anhydrobiotic and freezing-tolerance phenotypes of 24 Panagrolaimus strains from tropical, temperate, continental and polar habitats and we analysed their phylogenetic relationships. We found that several other Panagrolaimus isolates can also survive freezing when fully hydrated and that tissue extracts from these freezing-tolerant nematodes can inhibit the growth of ice crystals. We show that P. davidi belongs to a clade of anhydrobiotic and freezing-tolerant panagrolaimids containing strains from temperate and continental regions and that P. superbus, an early colonizer at Surtsey island, Iceland after its volcanic formation, is closely related to a species from Pennsylvania, USA. Ancestral state reconstructions show that anhydrobiosis evolved deep in the phylogeny of Panagrolaimus. The early-diverging Panagrolaimus lineages are strongly anhydrobiotic but weakly freezing-tolerant, suggesting that freezing tolerance is most likely a derived trait. The common ancestors of the davidi and the superbus clades were anhydrobiotic and also possessed robust freezing tolerance, along with a capacity to inhibit the growth and recrystallization of ice crystals. Unlike other endemic Antarctic nematodes, the life history traits of P. davidi do not show evidence of an evolved response to polar conditions. Thus we suggest that the colonization of Antarctica by P. davidi and of Surtsey by P. superbus may be examples of recent “ecological fitting” of freezing-tolerant anhydrobiotic propagules to the respective abiotic conditions in Ross Island and Surtsey. PMID:25747673

  20. Recombinant protein production of earthworm lumbrokinase for potential antithrombotic application.

    Science.gov (United States)

    Wang, Kevin Yueju; Tull, Lauren; Cooper, Edwin; Wang, Nan; Liu, Dehu

    2013-01-01

    Earthworms have been used as a traditional medicine in China, Japan, and other Far East countries for thousands of years. Oral administration of dry earthworm powder is considered as a potent and effective supplement for supporting healthy blood circulation. Lumbrokinases are a group of enzymes that were isolated and purified from different species of earthworms. These enzymes are recognized as fibrinolytic agents that can be used to treat various conditions associated with thrombosis. Many lumbrokinase (LK) genes have been cloned and characterized. Advances in genetic technology have provided the ability to produce recombinant LK and have made it feasible to purify a single lumbrokinase enzyme for potential antithrombotic application. In this review, we focus on expression systems that can be used for lumbrokinase production. In particular, the advantages of using a transgenic plant system to produce edible lumbrokinase are described. PMID:24416067

  1. Second contribution to the knowledge of earthworms (Lumbricidae in Montenegro

    Directory of Open Access Journals (Sweden)

    Stojanovi? Mirjana M.

    2003-01-01

    Full Text Available This paper contains the results of qualitative analysis of Lumbricidae (Oligochaeta in Montenegro, during the period 1997-2003. The research has included natural and cultivated biotopes. The presence of 15 species was established and the habitats, localities and their zoogeographical position are given. In Montenegro we found four species for the first time Dendrobaena jastrebensis, D. vejdovskyi, Octodrilus bretcheri and Lumbricus terrestris. The complete list of earthworm species in Montenegro includes 45 taxa. With respects to the zoogeographic situation of the earthworms in Montenegro, the largest number belongs to endemic (10 and European (10 species. But 8 taxa are south-European, 9 Holarctic, 7 cosmopolitan, and 1 Palearctic. The degree of endemism of the earthworm fauna of Montenegro is quite high, exceeding 22.2%.

  2. Bioavailability of nonextractable (bound) pesticide residues to earthworms.

    Science.gov (United States)

    Gevao, B; Mordaunt, C; Semple, K T; Piearce, T G; Jones, K C

    2001-02-01

    There is an ongoing debate regarding whether nonextractable (bound) pesticide residues in soils are occluded or may remain bioavailable in the long term in the environment. This study investigated the release of 14C-labeled residues, which were previously nonextractable after exhaustive extraction with organic solvents in soils, and their uptake by earthworms (Aporrectodea longa). After a 100-day incubation of soils treated with 14C-labeled atrazine, isoproturon, and dicamba and exhaustive Soxhlet extractions with methanol and dichloromethane, nonextracted 14C-labeled residues remaining in the soils were 18, 70, and 67%, respectively. Adding clean soil in the ratio of 7:1 increased the volumes of these extracted soils. After earthworms had lived in these previously extracted soils for 28 days, 0.02-0.2% of previously bound 14C activity was absorbed into the earthworm tissue. Uptake by earthworms was found to be 2-10 times higher in soils containing freshly introduced 14C-labeled pesticides as compared to soils containing nonextractable 14C-labeled residues. The differential bioavailability observed between freshly introduced 14C-labeled pesticides and those previously nonextractable may be related to the ease of transfer of the 14C activity into the solution phase. By the end of the 28-day incubation period, 3, 23, and 24% of previously nonextractable 14C-labeled isoproturon, dicamba, and atrazine residues, respectively, were extracted by solvents or mineralized to 14CO2. The amounts of 14C activity released were not significantly different in the presence or in the absence of earthworms in soils containing previously nonextractable residues. However, the formation of bound residues was 2, 2, and 4 times lower for freshly introduced 14C-labeled isoproturon, dicamba, and atrazine, respectively, suggesting that the presence of earthworms retarded bound residue formation. PMID:11351720

  3. Enantioseletive bioaccumulation of tebuconazole in earthworm Eisenia fetida.

    Science.gov (United States)

    Yu, Dingyi; Li, Jianzhong; Zhang, Yanfeng; Wang, Huili; Guo, Baoyuan; Zheng, Lin

    2012-01-01

    Methods of extraction and determination of tebuconazole enantiomers in earthworm (Eisenia fetida) were developed by capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). Both CE and HPLC have excellent resolution and recovery. The linearity ranges were 2.9-102.4 mg/kg and 3.0-99.6 mg/kg for (+)-R-tebuconazole and (-)-S-tebuconazole respectively in CE, and from 0.56 to 1000 mg/kg for both enantiomers in HPLC. Enantioselective bioaccumulation in earthworms from soil was investigated under laboratory condition at concentrations of 10 and 50 mg/kg dw in soil. The uptake kinetics of (+)-R-tebuconazole fitted the first-order kinetics well with r2 0.97 and 0.94 under 10 and 50 mg/kg dw exposure condition, respectively, while (-)-S-tebuconazole with r2 0.75 and 0.22 did not show the same. Bioaccumulation of tebuconazole in earthworm tissues was enantioselective with a preferential accumulation of (+)-R-tebuconazole. The (+)-R-tebuconazole might also have biomagnifying effect potential in earthworm food chain with biota-sediment accumulation factor (BSAF) of 1.64 kg OC/kg lip in 10 mg/kg dw exposure group and 2.61 kg OC/kg lip in 50 mg/kg dw exposure group from soil to earthworm after 36 days. Although (-)-S-tebuconazole shares the same physicochemical properties with (+)-R-tebuconazole, it did not biomagnify. BSAFs of (-)-S-tebuconazole were 0.50 kg OC/kg lip (10 mg/kg dw tebuconazole exposure) and 0.28 kg OC/kg lip (50 mg/kg dw tebuconazole exposure) after 36 days, which was possibly owing to biotransformation or metabolism in earthworm tissues. PMID:23534218

  4. Ecological transfer of radionuclides and metals to free-living earthworm species in natural habitats rich in NORM.

    Science.gov (United States)

    Mrdakovic Popic, Jelena; Salbu, Brit; Skipperud, Lindis

    2012-01-01

    Transfer of radionuclides ((232)Th and (238)U) and associated metals (As, Cd, Pb and Cr) from soil to free-living earthworm species was investigated in a thorium ((232)Th) rich area in Norway. Sampling took place within former mining sites representing the technologically enhanced naturally occurring radioactive materials (TENORM), at undisturbed site with unique bedrock geology representing the naturally occurring radioactive materials (NORM) and at site outside the (232)Th rich area taken as reference Background site. Soil analysis revealed the elevated levels of investigated elements at NORM and TENORM sites. Based on sequential extraction, uranium ((238)U) and cadmium (Cd) were quite mobile, while the other elements were strongly associated with mineral components of soil. Four investigated earthworm species (Aporrectodea caliginosa, Aporrectodea rosea, Dendrodrilus rubidus and Lumbricus rubellus) showed large individual variability in the accumulation of radionuclides and metals. Differences in uptake by epigeic and endogeic species, as well as differences within same species from the NORM, TENORM and Background sites were also seen. Based on total concentrations in soil, the transfer factors (TF) were in ranges 0.03-0.08 and 0.09-0.25, for (232)Th and (238)U, respectively. TFs for lead (Pb), chromium (Cr) and arsenic (As) were low (less than 0.5), while TFs for Cd were higher (about 10). Using the ERICA tool, the estimated radiation exposure dose rate of the earthworms ranged from 2.2 to 3.9 ?Gy/h. The radiological risk for investigated earthworms was low (0.28). The obtained results demonstrated that free-living earthworm species can survive in soil containing elevated (232)Th and (238)U, as well As, Cd, Pb and Cr levels, although certain amount of radionuclides was accumulated within their bodies. The present investigation contributes to general better understanding of complex soil-to-biota transfer processes of radionuclides and metals and to assessment of risk for non-human species in the ecosystem with multiple contaminants. PMID:22115612

  5. Regional extent of an ecosystem engineer: earthworm invasion in northern hardwood forests.

    Science.gov (United States)

    Holdsworth, Andrew R; Frelich, Lee E; Reich, Peter B

    2007-09-01

    The invasion of exotic earthworms into northern temperate and boreal forests previously devoid of earthworms is an important driver of ecosystem change. Earthworm invasion can cause significant changes in soil structure and communities, nutrient cycles, and the diversity and abundance of herbaceous plants. However, the regional extent and patterns of this invasion are poorly known. We conducted a regional survey in the Chippewa and Chequamegon National Forests, in Minnesota and Wisconsin, U.S.A., respectively, to measure the extent and patterns of earthworm invasion and their relationship to potential earthworm introduction sites. We sampled earthworms, soils, and vegetation in 20 mature, sugar maple-dominated forest stands in each national forest and analyzed the relationship between the presence of five earthworm taxonomic groups, habitat variables, and distance to the nearest potential introduction site. Earthworm invasion was extensive but incomplete in the two national forests. Four of the six earthworm taxonomic groups occurred in 55-95% of transects; however 20% of all transects were invaded by only one taxonomic group that has relatively minor ecological effects. Earthworm taxonomic groups exhibited a similar sequence of invasion found in other studies: Dendrobaena > Aporrectodea = Lumbricus juveniles > L. rubellus > L. terrestris. Distance to the nearest road was the best predictor of earthworm invasion in Wisconsin while distance to the nearest cabin was the best predictor in Minnesota. These data allow us to make preliminary assessments of landscape patterns of earthworm invasion. As an example, we estimate that 82% of upland mesic hardwood stands in the Wisconsin region are likely invaded by most taxonomic groups while only 3% are unlikely to be invaded at present. Distance to roads and cabins provides a coarse-scale predictor of earthworm invasion to focus stand-level assessments that will help forest managers better understand current and potential forest conditions and identify uninvaded areas that could serve as important refugia for plant species threatened by earthworm invasion. PMID:17913131

  6. Accumulation of chlorinated benzenes in earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, W.N. [Patuxent Wildlife Research Center, Laurel, MD (United States)

    1996-12-31

    Chlorinated benzenes are widespread in the environment. Hexachlorobenzene, pentachlorobenzene and all isomers of dichlorobenzenes, trichlorobenzenes, and tetrachlorobenzenes, have been detected in fish, water, and sediments from the Great Lakes. They probably entered the water as leachates from chemical waste dumps and as effluents from manufacturing. Hexachlorobenzene and pentachlorobenzene are commonly present in Herring gull (Larus argentatus) eggs from the Great Lakes, and some of the isomers of trichlorobenzene and tetrachlorobenzene are occasionally detected at low concentrations. Hexachlorobenzene, which was formerly used as a fungicide, has been the most thoroughly studied chlorinated benzene, and has been detected in many species. Its use as a fungicide in the United States was canceled in 1984. Since about 1975 hexachlorobenzene has been formed mainly in the production of chlorinated solvents. It is highly persistent in the environment and some species are poisoned by hexachlorobenzene at very low chronic dietary exposures. As little as 1 ppm in the diet of mink (Mustela vison) reduced the birth weights of young, and 5 ppm in the diet of Japanese quail (Coturnix coturnix japonica) caused slight liver damage. This paper describes a long-term (26 wk) experiment relating the concentrations of chlorinated benzenes in earthworms to length of exposure and three 8 wk experiments relating concentration to the concentration in soil the soil organic matter content, and the degree of chlorination. 20 refs., 3 figs., 1 tab.

  7. Understanding Slag Freeze Linings

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2014-09-01

    Slag freeze linings, the formation of protective deposit layers on the inner walls of furnaces and reactors, are increasingly used in industrial pyrometallurgical processes to ensure that furnace integrity is maintained in these aggressive, high-temperature environments. Most previous studies of freeze-linings have analyzed the formation of slag deposits based solely on heat transfer considerations. These thermal models have assumed that the interface between the stationary frozen layer and the agitated molten bath at steady-state deposit thickness consists of the primary phase, which stays in contact with the bulk liquid at the liquidus temperature. Recent experimental studies, however, have clearly demonstrated that the temperature of the deposit/liquid bath interface can be lower than the liquidus temperature of the bulk liquid. A conceptual framework has been proposed to explain the observations and the factors influencing the microstructure and the temperature of the interface at steady-state conditions. The observations are consistent with a dynamic steady state that is a balance between (I) the rate of nucleation and growth of solids on detached crystals in a subliquidus layer as this fluid material moves toward the stagnant deposit interface and (II) the dissolution of these detached crystals as they are transported away from the interface by turbulent eddies. It is argued that the assumption that the interface temperature is the liquidus of the bulk material represents only a limiting condition, and that the interface temperature can be between T liquidus and T solidus depending on the process conditions and bath chemistry. These findings have implications for the modeling approach and boundary conditions required to accurately describe these systems. They also indicate the opportunity to integrate considerations of heat and mass flows with the selection of melt chemistries in the design of future high temperature industrial reactors.

  8. Surviving the cold: molecular analyses of insect cryoprotective dehydration in the Arctic springtail Megaphorura arctica (Tullberg

    Directory of Open Access Journals (Sweden)

    Popovi? Željko D

    2009-07-01

    Full Text Available Abstract Background Insects provide tractable models for enhancing our understanding of the physiological and cellular processes that enable survival at extreme low temperatures. They possess three main strategies to survive the cold: freeze tolerance, freeze avoidance or cryoprotective dehydration, of which the latter method is exploited by our model species, the Arctic springtail Megaphorura arctica, formerly Onychiurus arcticus (Tullberg 1876. The physiological mechanisms underlying cryoprotective dehydration have been well characterised in M. arctica and to date this process has been described in only a few other species: the Antarctic nematode Panagrolaimus davidi, an enchytraied worm, the larvae of the Antarctic midge Belgica antarctica and the cocoons of the earthworm Dendrobaena octaedra. There are no in-depth molecular studies on the underlying cold survival mechanisms in any species. Results A cDNA microarray was generated using 6,912 M. arctica clones printed in duplicate. Analysis of clones up-regulated during dehydration procedures (using both cold- and salt-induced dehydration has identified a number of significant cellular processes, namely the production and mobilisation of trehalose, protection of cellular systems via small heat shock proteins and tissue/cellular remodelling during the dehydration process. Energy production, initiation of protein translation and cell division, plus potential tissue repair processes dominate genes identified during recovery. Heat map analysis identified a duplication of the trehalose-6-phosphate synthase (TPS gene in M. arctica and also 53 clones co-regulated with TPS, including a number of membrane associated and cell signalling proteins. Q-PCR on selected candidate genes has also contributed to our understanding with glutathione-S-transferase identified as the major antioxdidant enzyme protecting the cells during these stressful procedures, and a number of protein kinase signalling molecules involved in recovery. Conclusion Microarray analysis has proved to be a powerful technique for understanding the processes and genes involved in cryoprotective dehydration, beyond the few candidate genes identified in the current literature. Dehydration is associated with the mobilisation of trehalose, cell protection and tissue remodelling. Energy production, leading to protein production, and cell division characterise the recovery process. Novel membrane proteins, along with aquaporins and desaturases, have been identified as promising candidates for future functional analyses to better understand membrane remodelling during cellular dehydration.

  9. Freeze. How you can help prevent nuclear war

    International Nuclear Information System (INIS)

    In their book the Senators Kennedy and Hatfield prove that the United States will not be able to survive a nuclear war. The report on the freeze movement is followed by a chapter on the history of the efforts for disarmament which had been abruptly ended by President Reagan's call for the enhanced modernization of nuclear arms. But ''we have reached the unique moment in the history of the atomic age where it is possible and where it must be tried to freeze nuclear armament'', as Kennedy and Hatfield write, for ''the present nuclear balance is relatively stable''. Only by freezing the standard of armament can this balance which decides on worldwide peace be granted. (orig.)

  10. Arsenic resistance and cycling in earthworms residing at a former gold mine in Canada

    International Nuclear Information System (INIS)

    Earthworms (Lumbricus castaneous and Dendrodrilus rubidus), their host soils and leaf litter were collected from a former gold mine with widespread arsenic (As) contamination in Nova Scotia, Canada and determined for total and speciated As. Resistance to As toxicity was investigated by measurement of DNA damage in exposed earthworm populations using the comet assay. Arsenobetaine (AB) was observed at low concentration in the earthworms but not in the host soil or leaf litter. Several different organoarsenic species were observed in the leaf litter and only inorganic As was found in the host soils. The results suggest that 1) adaptation to As toxicity in earthworms is widespread and not particular to a single species, 2) AB originates in the earthworm and not the consumed soil or leaf litter and 3) as previously hypothesised (), biotransformation of inorganic As to AB is not likely involved in the adaptation. - Highlights: ? Adaptation to toxicity and cycling of arsenic in earthworms investigated at Canadian gold mine. ? Earthworms resistant to highly contaminated, genotoxic soils. ? Arsenobetaine present in earthworms but not soil or leaf litter. ? Arsenic resistance in earthworms is widespread and not species specific. - Adaptation of earthworms to arsenic contaminated soils is widespread and not species specific.

  11. Earthworm bioturbation influences the phytoavailability of metals released by particles in cultivated soils

    International Nuclear Information System (INIS)

    The influence of earthworm activity on soil-to-plant metal transfer was studied by carrying out six weeks mesocosms experiments with or without lettuce and/or earthworms in soil with a gradient of metal concentrations due to particles fallouts. Soil characteristics, metal concentrations in lettuce and earthworms were measured and soil porosity in the mesocosms was determined. Earthworms increased the soil pH, macroporosity and soil organic matter content due to the burying of wheat straw provided as food. Earthworm activities increased the metals concentrations in lettuce leaves. Pb and Cd concentrations in lettuce leaves can increase up to 46% with earthworm activities … These results and the low correlation between estimated by CaCl2 and EDTA and measured pollutant phytoavailability suggest that earthworm bioturbation was the main cause of the increase. Bioturbation could affect the proximity of pollutants to the roots and soil organic matter. - Highlights: • Earthworm bioturbation increases phytoavailability of Pb, Cd, Zn and Cu. • Earthworm activity influences soil structure and increases pH. • Plant metal uptake was not correlated with CaCl2, EDTA estimated phytoavailability. • Increased metal phytoavailability with bioturbation could increase human exposure. - Earthworm activities can increase metal phytoavailability and subsequent human exposure to metals in consumed vegetables

  12. Invasion by Exotic Earthworms Alters Biodiversity and Communities of Litter- and Soil-dwelling Oribatid Mites

    Directory of Open Access Journals (Sweden)

    John C. Maerz

    2011-03-01

    Full Text Available Exotic earthworms are drivers of biotic communities in invaded North American forest stands. Here we used ecologically important oribatid mite (Arachnida: Acari communities, as model organisms to study the responses of litter- and soil-dwelling microarthropod communities to exotic earthworm invasion in a northern temperate forest. Litter- and soil-dwelling mites were sampled in 2008–2009 from forest areas: (1 with no earthworms; (2 those with epigeic and endogeic species, including Lumbricus rubellus Hoffmeister; and (3 those with epigeic, endogeic, and anecic earthworms including L. terrestris L. Species richness and diversity of litter- and soil-dwelling (0–2 cm soil depth oribatid mites was 1–2 times higher in sites without earthworms than in sites with worms. Similarly, litter-dwelling oribatid mites were between 72 and 1,210 times more abundant in earthworm-free sites than in sites with worms. Among earthworm invaded sites, abundance of litter-dwelling oribatid mites in sites without the anecic L. terrestris was twice as high in May and 28 times higher in October, compared to sites with L. terrestris. Species richness, diversity, and abundance of oribatid mites were greater in litter-layers than in the soil-layers that showed a varied response to earthworm invasion. Species compositions of both litter- and soil-dwelling oribatid mite communities of forests with no earthworms were markedly different from those with earthworms. We conclude that exotic earthworm invasions are associated with significant declines of species diversity, numbers, and compositional shifts in litter- and soil-inhabiting communities. These faunal shifts may contribute to earthworm effects on soil processes and food web dynamics in historically earthworm-free, northern temperate forests.

  13. Earthworm assemblages in pasture soils affected by cattle overwintering.

    Czech Academy of Sciences Publication Activity Database

    Pižl, Václav

    Brno : Ústav biologie obratlovc? AV?R, 2014. s. 158-159. ISBN 978-80-87189-16-0. [Zoologické dny Ostrava 2014. 06.02.2014-07.02.2014, Ostrava] Institutional support: RVO:60077344 Keywords : Earthworm assemblages * pasture soils * cattle overwintering Subject RIV: EH - Ecology, Behaviour

  14. Diversity and host specificity of the Verminephrobacter–earthworm symbiosis

    DEFF Research Database (Denmark)

    Lund, Marie Braad; Davidson, Seana

    2010-01-01

    Symbiotic bacteria of the genus Verminephrobacter (Betaproteobacteria) were detected in the nephridia of 19 out of 23 investigated earthworm species (Oligochaeta: Lumbricidae) by 16S rRNA gene sequence analysis and fluorescence in situ hybridization (FISH). While all four Lumbricus species and three out of five Aporrectodea species were densely colonized by a mono-species culture of Verminephrobacter, other earthworm species contained mixed bacterial populations with varying proportions of Verminephrobacter; four species did not contain Verminephrobacter at all. The Verminephrobacter symbionts could be grouped into earthworm species-specific sequence clusters based on their 16S rRNA and RNA polymerase subunit B (rpoB) genes. Closely related host species harboured more closely related symbionts than did distantly related hosts. Co-diversification of the symbiotic partners could not be demonstrated unambiguously due to the poor resolution of the host phylogeny [based on histone H3 and cytochrome c oxidase subunit I (COI) gene sequence analyses]. However, there was a pattern of symbiont diversification within four groups of closely related hosts. The mean rate of symbiont 16S rRNA gene evolution was determined using a relaxed clock model, and the rate was calibrated with paleogeographical estimates of the time of origin of Lumbricid earthworms. The calibrated rates of symbiont 16S rRNA gene evolution are 0.012–0.026 substitutions per site per 50 million years and thus similar to rates reported from other symbiotic bacteria.

  15. Partitioning of habitable pore space in earthworm burrows.

    Science.gov (United States)

    Gorres, Josef H; Amador, Jose A

    2010-03-01

    Earthworms affect macro-pore structure of soils. However, some studies suggest that earthworm burrow walls and casts themselves differ greatly in structure from surrounding soils, potentially creating habitat for microbivorours nematodes which accelerate the decomposition and C and N mineralization. In this study aggregates were sampled from the burrow walls of the anecic earthworm Lumbricus terrestris and bulk soil (not altered by earthworms) from mesocosm incubated in the lab for 0, 1, 3, 5 and 16 weeks. Pore volumes and pore sizes were measured in triplicate with Mercury Intrusion Porosimetry (MIP). This method is well suited to establish pore size structure in the context of habitat, because it measures the stepwise intrusion of mercury from the outside of the aggregate into ever smaller pores. The progress of mercury into the aggregate interior thus resembles potential paths of a nematode into accessible habitable pore spaces residing in an aggregate. Total specific pore volume, V(s), varied between 0.13 and 0.18 mL/g and increased from 3 to 16 weeks in both burrow and bulk soil. Differences between total V(s) of bulk and burrow samples were not significant on any sampling date. However, differences were significant for pore size fractions at the scale of nematode body diameter. PMID:22736839

  16. FREEZE DRYING PROCESS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Soham Shukla

    2011-12-01

    Full Text Available Among the various methods of drying, this article has mentioned only one most important method, “Freeze drying”. This method is mainly used for the drying of thermo labile materials. This method works on the principle of sublimation. This method is divided into 3 steps for its better understanding; these are Freezing, Primary drying, and secondary drying. There are many advantages and disadvantages of this method, but still this is the most useful drying method nowadays.

  17. Gut wall bacteria of earthworms: a natural selection process.

    Science.gov (United States)

    Thakuria, Dwipendra; Schmidt, Olaf; Finan, Dillon; Egan, Damian; Doohan, Fiona M

    2010-03-01

    Earthworms and microorganisms are interdependent and their interactions regulate the biogeochemistry of terrestrial soils. Investigating earthworm-microorganism interactions, we tested the hypothesis that differences in burrowing and feeding habits of anecic and endogeic earthworms are reflected by the existence of ecological group-specific gut wall bacterial communities. Bacterial community was detected using automated ribosomal intergenic spacer analysis of 16S and 23S genes and ribotype data was used to assess diversity and community composition. Using soil and earthworm samples collected from adjacent wheat-barley and grass-clover fields, we found that the anecic Lumbricus terrestris and L. friendi, the endogeic Aporrectodea caliginosa and A. longa (classically defined as anecic, but now known to possess endogeic characteristics) contain ecological group-specific gut wall-associated bacterial communities. The abundance of specific gut wall-associated bacteria (identified by sequence analysis of ribotype bands), including Proteobacteria, Firmicutes and an actinobacterium, was ecological group dependent. A microcosm study, conducted using A. caliginosa and L. terrestris and five different feeding regimes, indicated that food resource can cause shifts in gut wall-associated bacterial community, but the magnitude of these shifts did not obscure the delineation between ecological group specificity. Using A. caliginosa and A. longa samples collected in six different arable fields, we deduced that, within an ecological group, habitat was a more important determinant of gut wall-associated bacterial community composition than was host species. Hence, we conclude that the selection of bacteria associated with the gut wall of earthworms is a natural selection process and the strongest determinant of this process is in the order ecological group>habitat>species. PMID:19924156

  18. Heavy Metals Bioaccumulation by Iranian and Australian Earthworms (Eisenia fetida in the Sewage Sludge Vermicomposting

    Directory of Open Access Journals (Sweden)

    MR Shahmansouri, H Pourmoghadas, AR Parvaresh, H Alidadi

    2005-01-01

    Full Text Available Vermicomposting of organic waste has an important part to play in an integrated waste management strategy. In this study, the possibility of heavy metals accumulation with two groups of Iranian and Australian earthworms in sewage sludge vermicompost was investigated. Eisenia fetida was the species of earthworms used in the vermicomposting process. The bioaccumulation of Cr, Cd, Pb, Cu, and Zn as heavy metals by Iranian and Australian earthworms was studied. The results indicated that heavy metals concentration decreased with increasing vermicomposting time. Comparison of the two groups of earthworms showed that the Iranian earthworms consumed higher quantities of micronutrients such as Cu and Zn comparing with the Australian earthworms, while the bioaccumulation of non-essential elements such as Cr, Cd, and Pb by the Australian group was higher. The significant decrease in heavy metal concentrations in the final vermicompost indicated the capability of both Iranian and Australian E.fetida species in accumulating heavy metals in their body tissues.

  19. Potential utilization of bagasse as feed material for earthworm Eisenia fetida and production of vermicompost.

    Science.gov (United States)

    Bhat, Sartaj Ahmad; Singh, Jaswinder; Vig, Adarsh Pal

    2015-01-01

    In the present work bagasse (B) i.e waste of the sugar industry, was fed to Eisenia fetida with cattle dung (CD) support as feed material at various ratios (waste: CD) of 0:100 (B0), 25:75 (B25), 50:50 (B50), 75:25 (B75) and 100:0 (B100) on dry weight basis. Co-composting with cattle dung helped to improve their acceptability for E. fetida and also improved physico-chemical characteristics. Best appropriate ratio for survival, maximum growth and population buildup of E. fetida was determined by observing population buildup, growth rate, biomass, mortality and cocoon formation. Minimum mortality and highest population size of worms was observed in 50:50 (B50) ratio. Increasing concentrations of wastes significantly affected the growth and reproduction of worms. Nutrients like nitrogen, phosphorus and sodium increased from pre-vermicompost to post-vermicompost, while organic carbon, and C:N ratio decreased in all the end products of post-vermicomposting. Heavy metals decreased significantly from initial except zinc, iron and manganese which increased significantly. Scanning electron microscopy (SEM) was used to recognize the changes in texture in the pre and post-vermicomposted samples. The post-vermicomposted ratios in the presence of earthworms validate more surface changes that prove to be good manure. The results observed from the present study indicated that the earthworm E. fetida was able to change bagasse waste into nutrient-rich manure and thus play a major role in industrial waste management. PMID:25625035

  20. Effect of earthworm feeding guilds on ingested dissimilatory nitrate reducers and denitrifiers in the alimentary canal of the earthworm.

    Science.gov (United States)

    Depkat-Jakob, Peter S; Hilgarth, Maik; Horn, Marcus A; Drake, Harold L

    2010-09-01

    The earthworm gut is an anoxic nitrous oxide (N(2)O)-emitting microzone in aerated soils. In situ conditions of the gut might stimulate ingested nitrate-reducing soil bacteria linked to this emission. The objective of this study was to determine if dissimilatory nitrate reducers and denitrifiers in the alimentary canal were affected by feeding guilds (epigeic [Lumbricus rubellus], anecic [Lumbricus terrestris], and endogeic [Aporrectodea caliginosa]). Genes and gene transcripts of narG (encodes a subunit of nitrate reductase and targets both dissimilatory nitrate reducers and denitrifiers) and nosZ (encodes a subunit of N(2)O reductase and targets denitrifiers) were detected in guts and soils. Gut-derived sequences were similar to those of cultured and uncultured soil bacteria and to soil-derived sequences obtained in this study. Gut-derived narG sequences and narG terminal restriction fragments (TRFs) were affiliated mainly with Gram-positive organisms (Actinobacteria). The majority of gut- and uppermost-soil-derived narG transcripts were affiliated with Mycobacterium (Actinobacteria). In contrast, narG sequences indicative of Gram-negative organisms (Proteobacteria) were dominant in mineral soil. Most nosZ sequences and nosZ TRFs were affiliated with Bradyrhizobium (Alphaproteobacteria) and uncultured soil bacteria. TRF profiles indicated that nosZ transcripts were more affected by earthworm feeding guilds than were nosZ genes, whereas narG transcripts were less affected by earthworm feeding guilds than were narG genes. narG and nosZ transcripts were different and less diverse in the earthworm gut than in mineral soil. The collective results indicate that dissimilatory nitrate reducers and denitrifiers in the earthworm gut are soil derived and that ingested narG- and nosZ-containing taxa were not uniformly stimulated in the guts of worms from different feeding guilds. PMID:20656855

  1. EVALUATION OF EARTHWORM POWDER (EUDRILUS EUGENIAE) AND ITS APPLICATION IN COTTON CREPE BANDAGE

    OpenAIRE

    Anjana Jc, Sruthy Pb

    2013-01-01

    From time immemorial earthworms have been used as therapeutic agents. Earthworm possess rich natural sources of antioxidants and are used with other herbs to treat a wide variety of conditions ranging from spasms and convulsions to pain relief, treatment of fever and certain types of arthritis. Focusing this, in our present study, the earthworm powder was prepared and its glucose, protein, lipid, phenol contents were analyzed. The minimum inhibitory concentration and antimicrobial assays were...

  2. Heavy Metals Bioaccumulation by Iranian and Australian Earthworms (Eisenia fetida) in the Sewage Sludge Vermicomposting

    OpenAIRE

    Shahmansouri, H. Pourmoghadas

    2005-01-01

    Vermicomposting of organic waste has an important part to play in an integrated waste management strategy. In this study, the possibility of heavy metals accumulation with two groups of Iranian and Australian earthworms in sewage sludge vermicompost was investigated. Eisenia fetida was the species of earthworms used in the vermicomposting process. The bioaccumulation of Cr, Cd, Pb, Cu, and Zn as heavy metals by Iranian and Australian earthworms was studied. The results indicated that heavy me...

  3. Impact of soil management on earthworm diversity according to differential plowing and plant residue incorporation

    OpenAIRE

    Lemtiri, Aboulkacem; Alabi, Taofic; Zirbes, Lara; Bodson, Bernard; Brostaux, Yves; Colinet, Gilles; Destain, Marie-france; Aubinet, Marc; Vandenbol, Micheline; Portetelle, Daniel; Haubruge, Eric; Francis, Fre?de?ric

    2012-01-01

    Earthworms are largely distributed in terrestrial ecosystems and their abundance and diversity in soils are significantly affected by biotic (macro- and micro-organisms) and abiotic factors: soil properties (pH, texture, structure…); agricultural management system and climate change. Here, tillage effect of earthworm population combined with crops residual management was investigated and correlated with soils properties. From wheat experimental field plots, the diversity of earthworm accord...

  4. Impacts of epigeic, anecic and endogeic earthworms on metal and metalloid mobility and availability

    OpenAIRE

    Sizmur, Tom; Tilston, Emma L.; Charnock, John; Palumbo-roe, Barbara; Watts, Michael J.; Hodson, Mark E.

    2011-01-01

    The introduction of earthworms into soils contaminated with metals and metalloids has been suggested to aid restoration practices. Eisenia veneta (epigeic), Lumbricus terrestris (anecic) and Allolobophora chlorotica (endogeic) earthworms were cultivated in columns containing 900 g soil with 1130, 345, 113 and 131 mg kg1 of As, Cu, Pb and Zn, respectively, for up to 112 days, in parallel with earthworm-free columns. Leachate was produced by pouring water on the soil surface to satu...

  5. Soil pH governs production rate of calcium carbonate secreted by the earthworm Lumbricus terrestris

    OpenAIRE

    Lambkin, Denise C.; Gwilliam, K. H.; Layton, C.; Canti, M. G.; Piearce, T. G.; Hodson, Mark E.

    2011-01-01

    Lumbricus terrestris earthworms exposed to 11 soils of contrasting properties produced, on average, 0.8 ± 0.1 mgCaCO3 earthworm?1 day?1 in the form of granules up to 2 mm in diameter. Production rate increased with soil pH (r2 = 0.68, p < 0.01). Earthworms could be a significant source of calcite in soils.

  6. Residue incorporation depth is a controlling factor of earthworm-induced nitrous oxide emissions

    OpenAIRE

    Paul, B. K.; Lubbers, I. M.; Groenigen, J. W.

    2012-01-01

    Earthworms can increase nitrous oxide (N2O) emissions, particularly in no-tillage systems where earthworms are abundant. Here, we study the effect of residue incorporation depth on earthworm-induced N2O emissions. We hypothesized that cumulative N2O emissions decrease with residue incorporation depth, because (i) increased water filled pore space (WFPS) in deeper soil layers leads to higher denitrification rates as well as more complete denitrification; and (ii) the longer upward diffusion pa...

  7. Invasion by Exotic Earthworms Alters Biodiversity and Communities of Litter- and Soil-dwelling Oribatid Mites

    OpenAIRE

    Maerz, John C.; Milanovich, Joseph R.; Gandhi, Kamal J. K.; Fisk, Melany C.; Burke, Jordan L.

    2011-01-01

    Exotic earthworms are drivers of biotic communities in invaded North American forest stands. Here we used ecologically important oribatid mite (Arachnida: Acari) communities, as model organisms to study the responses of litter- and soil-dwelling microarthropod communities to exotic earthworm invasion in a northern temperate forest. Litter- and soil-dwelling mites were sampled in 2008–2009 from forest areas: (1) with no earthworms; (2) those with epigeic and endogeic species, including Lumbr...

  8. Earthworms, soil aggregates and organic matter decomposition in agro-ecosystems in The Netherlands.

    OpenAIRE

    Marinissen, J. C. Y.

    1995-01-01

    The relationships between earthworm populations, soil aggregate stability and soil organic matter dynamics were studied at an experimental farm in The Netherlands.Arable land in general is not favourable for earthworm growth. In the Lovinkhoeve fields under conventional management earthworm populations were brought to the verge of extinction in a few years. Main causes are soil fumigation against nematodes and unfavourable food conditions. Organic matter inputs and N-contents of the organic m...

  9. Earthworms - role in soil fertility to the use in medicine and as a food

    Directory of Open Access Journals (Sweden)

    M Grdiša

    2013-04-01

    Full Text Available Earthworms are important regulators of soil structure and dynamics of soil organic matter. They are a major component of soil fauna communities in most ecosystems and comprise a large proportion of macro fauna biomass. Their activities are beneficial because they can enhance soil nutrient cycling through the rapid incorporation of detritus into mineral soil. However, mucus production associated with water excretion in earthworm guts also enhances the activity of other beneficial soil microorganisms. Earthworms alter soil structure, water movement, nutrient dynamics and plant growth. The medical value of earthworms has been known for centuries. The extracts prepared from earthworm tissues have been used for the treatment of numerous diseases since they are valuable source of proteins, peptides, enzymes and physiologically active substances. Several studies have shown that the earthworm extracts contain different macromolecules which exhibited the variety of activities, such as antioxidative, antibacterial, antiinflammatory, anticancer etc. Some of these activities are involved in wound healing process, using the earthworm preparation. In some countries the earthworms are used as a part of healthy food. They have very high nutritive value because their bodies contain the high percentage of various proteins. Besides the human food, the earthworms are used in the feeding of animals (fish, chicken, etc..

  10. Accumulation of mercury and methylmercury by mushrooms and earthworms from forest soils

    International Nuclear Information System (INIS)

    Accumulation of total and methyl-Hg by mushrooms and earthworms was studied in thirty-four natural forest soils strongly varying in soil physico-chemical characteristics. Tissue Hg concentrations of both receptors did hardly correlate with Hg concentrations in soil. Both total and methyl-Hg concentrations in tissues were species-specific and dependent on the ecological groups of receptor. Methyl-Hg was low accounting for less than 5 and 8% of total Hg in tissues of mushrooms and earthworms, respectively, but with four times higher concentrations in earthworms than mushrooms. Total Hg concentrations in mushrooms averaged 0.96 mg Hg kg-1 dw whereas litter decomposing mushrooms showed highest total Hg and methyl-Hg concentrations. Earthworms contained similar Hg concentrations (1.04 mg Hg kg-1 dw) whereas endogeic earthworms accumulated highest amounts of Hg and methyl-Hg. - Highlights: ? Hg and MeHg concentrations in mushrooms and earthworms at unpolluted forest soils. ? Mushrooms and earthworms contained similar Hg concentrations. ? MeHg was present in traces but four times higher in earthworms than in mushrooms. ? Ecophysiological group influenced Hg and MeHg concentration in both receptors. - Accumulation of Hg and methyl-Hg by mushrooms and earthworms is species- and ecophysiological group dependent.

  11. In Vivo Emission of Dinitrogen by Earthworms via Denitrifying Bacteria in the Gut

    OpenAIRE

    Horn, Marcus A.; Mertel, Ralph; Gehre, Matthias; Ka?stner, Matthias; Drake, Harold L.

    2006-01-01

    Earthworms emit the greenhouse gas nitrous oxide (N2O), and ingested denitrifiers in the gut appear to be the main source of this N2O. The primary goal of this study was to determine if earthworms also emit dinitrogen (N2), the end product of complete denitrification. When [15N]nitrate was injected into the gut, the earthworms Aporrectodea caliginosa and Lumbricus terrestris emitted labeled N2 (and also labeled N2O) under in vivo conditions; emission of N2 by these two earthworms was relative...

  12. Effect of temperature and season on reproduction, neutral red retention and metallothionein responses of earthworms exposed to metals in field soils

    International Nuclear Information System (INIS)

    This study investigated the short-term survival, reproduction and physiological (lysosomal membrane stability, metallothionein transcript copy number, body tissue metal concentrations) responses of Lumbricus rubellus exposed to metal contaminated field soils under different laboratory temperatures (10, 15 and 20 oC) and physiological responses of earthworms collected from the field in three different seasons (spring, autumn, winter). In the laboratory, metal contaminated soils had significant effects on reproduction (p < 0.001), metallothionein-2 (MT-2) expression (p = 0.033) and earthworm As (p = 0.003), Cd (p = 0.001), Pb (p < 0.001) and Zn (p < 0.001) concentration, but not lysosomal membrane stability and tissue Hg and Cu. No effect of temperature was found for any parameter. Principal component analysis of extractable and tissue metal concentrations indicated PC1 as a measure of metal stress. Both cocoon production (r = - 0.75) and MT-2 induction (r = 0.41) were correlated with PC1. A correlation was also found between cocoon production and MT-2 expression (r = - 0.41). Neutral red retention and MT-2 measurements in worms collected from the field sites in three seasons confirmed the absence of a temperature effect on these responses. - Laboratory and field studies demonstrate metal effects on earthworm life-cycle and biochemical responses are not influenced by temperature regime

  13. Surviving the cold: molecular analyses of insect cryoprotective dehydration in the Arctic springtail Megaphorura arctica (Tullberg)

    OpenAIRE

    Clark, Melody S.; Thorne, Michael A. S.; Purac?, Jelena; Burns, Gavin; Hillyard, Guy; Popovic?, Z?eljko D.; Grubor-lajs?ic?, Gordana; Worland, Michael Roger

    2009-01-01

    Background: Insects provide tractable models for enhancing our understanding of the physiological and cellular processes that enable survival at extreme low temperatures. They possess three main strategies to survive the cold: freeze tolerance, freeze avoidance or cryoprotective dehydration, of which the latter method is exploited by our model species, the Arctic springtail Megaphorura arctica, formerly Onychiurus arcticus (Tullberg 1876). The physiological mechanisms underlying cryoprotectiv...

  14. Earthworm activities in cassava and egusi melon fields in the transitional zone of Benin: linking farmers' perceptions with field studies

    OpenAIRE

    Sai?dou, A.; Kossou, D.; Brussaard, L.; Richards, P.; Kuyper, T. W.

    2008-01-01

    Farmers' perceptions of earthworm activities were studied in the transitional zone of Benin and linked to scientific explanations of earthworm casting activities. Earthworm activity was assessed in farmers' fields with three different cassava cultivars and in a field experiment with three different egusi melon species. The experiment included plots with cowpea and maize. The study also comprised group discussions and a survey with 91 individual farmers. All farmers were aware of earthworms, b...

  15. Freeze Protection in Gas Holders

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Duursma, Gail

    2008-01-01

    In cold weather, the water seals of gasholders need protection from freez- ing to avoid compromising the seal. These holders have a large reservoir of “tank water” at the base which is below ground. At present freeze- protection is achieved by external heating of the seal water which is in a slotted channel called a cup. Electrical heating or circulation of heated tank water to the cup are examples of systems presently used. The tank water has a large thermal capacity and National Grid wishes to inves- tigate whether circulation of the tank water without external heating could provide su?cient energy input to avoid freezing. Only tanks in which the tank water is below ground are investigated in the report. The soil temperature under the reservoir at depth of 10m and lower is almost constant.

  16. Patterns of litter disappearance in a northern hardwood forest invaded by exotic earthworms.

    Science.gov (United States)

    Suárez, Esteban R; Fahey, Timothy J; Yavitt, Joseph B; Groffman, Peter M; Bohlen, Patrick J

    2006-02-01

    A field study was conducted to evaluate the effects of exotic earthworm invasions on the rates of leaf litter disappearance in a northern hardwood forest in southcentral New York, USA. Specifically, we assessed whether differences in litter quality and the species composition of exotic earthworm communities affected leaf litter disappearance rates. Two forest sites with contrasting communities of exotic earthworms were selected, and disappearance rates of sugar maple and red oak litter were estimated in litter boxes in adjacent earthworm-free, transition, and earthworm-invaded plots within each site. After 540 days in the field, 1.7-3 times more litter remained in the reference plots than in the earthworm-invaded plots. In the earthworm-invaded plots, rates of disappearance of sugar maple litter were higher than for oak litter during the first year, but by the end of the experiment, the amount of sugar maple and oak litter remaining in the earthworm-invaded plots was identical within each site. The composition of the earthworm communities significantly affected the patterns of litter disappearance. In the site dominated by the anecic earthworm Lumbricus terrestris and the endogeic Aporrectodea tuberculata, the percentage of litter remaining after 540 days (approximately 17%) was significantly less than at the site dominated by L. rubellus and Octolasion tyrtaeum (approximately 27%). This difference may be attributed to the differences in feeding behavior of the two litter-feeding species: L. terrestris buries entire leaves in vertical burrows, whereas L. rubellus usually feeds on litter at the soil surface, leaving behind leaf petioles and veins. Our results showed that earthworms not only accelerate litter disappearance rates, but also may reduce the differences in decomposition rates that result from different litter qualities at later stages of decay. Similarly, our results indicate that earthworm effects on decomposition vary with earthworm community composition. Furthermore, because earthworm invasion can involve a predictable shift in community structure along invasion fronts or through time, the community dynamics of invasion are important in predicting the spatial and temporal effects of earthworm invasion on litter decomposition, especially at later stages of decay. PMID:16705969

  17. NUTRITIONAL AND ANTIOXIDANT EVALUATION OF EARTHWORM POWDER (Eudrillus euginae

    Directory of Open Access Journals (Sweden)

    J. Anitha

    2012-02-01

    Full Text Available Studies have been made to understand the nutritional, aminoacids and antioxidant concentrations in the dried powder of Eudrillus euginae, an African soil dweller. The nutritional factors such as carbohydrate, glucose, total free aminoacids, protein, vitamin A, and total phenol were determined. The individual aminoacids includes Histidine, Serine, Arginine, Methionine, Proline, Tryptophan, and Lysine was also quantified. The enzymatic antioxidants, such as Glutathione S transferase (GST, Glutathione reductase (GR, Glutathione Peroxidase (GPx, Superoxide Dismutase (SOD and Catalase (CAT and the non-enzymatic antioxidant like Reduced Glutathione (GSH, Vitamin C and Vitamin E were assayed. The findings of the present study reveals that the earthworm is rich in protein, carbohydrate, fat and rich antioxidants suggest that this earthworm can be used as animal protein with good source of antioxidants.

  18. Earthworm-mycorrhiza interactions can affect the diversity, structure and functioning of establishing model grassland communities.

    Science.gov (United States)

    Zaller, Johann G; Heigl, Florian; Grabmaier, Andrea; Lichtenegger, Claudia; Piller, Katja; Allabashi, Roza; Frank, Thomas; Drapela, Thomas

    2011-01-01

    Both earthworms and arbuscular mycorrhizal fungi (AMF) are important ecosystem engineers co-occurring in temperate grasslands. However, their combined impacts during grassland establishment are poorly understood and have never been studied. We used large mesocosms to study the effects of different functional groups of earthworms (i.e., vertically burrowing anecics vs. horizontally burrowing endogeics) and a mix of four AMF taxa on the establishment, diversity and productivity of plant communities after a simulated seed rain of 18 grassland species comprising grasses, non-leguminous forbs and legumes. Moreover, effects of earthworms and/or AMF on water infiltration and leaching of ammonium, nitrate and phosphate were determined after a simulated extreme rainfall event (40 l m(-2)). AMF colonisation of all three plant functional groups was altered by earthworms. Seedling emergence and diversity was reduced by anecic earthworms, however only when AMF were present. Plant density was decreased in AMF-free mesocosms when both anecic and endogeic earthworms were active; with AMF also anecics reduced plant density. Plant shoot and root biomass was only affected by earthworms in AMF-free mesocosms: shoot biomass increased due to the activity of either anecics or endogeics; root biomass increased only when anecics were active. Water infiltration increased when earthworms were present in the mesocosms but remained unaffected by AMF. Ammonium leaching was increased only when anecics or a mixed earthworm community was active but was unaffected by AMF; nitrate and phosphate leaching was neither affected by earthworms nor AMF. Ammonium leaching decreased with increasing plant density, nitrate leaching decreased with increasing plant diversity and density. In order to understand the underlying processes of these interactions further investigations possibly under field conditions using more diverse belowground communities are required. Nevertheless, this study demonstrates that belowground-aboveground linkages involving earthworms and AMF are important mediators of the diversity, structure and functioning of plant communities. PMID:22216236

  19. Earthworms newly from Mongolia (Oligochaeta, Lumbricidae, Eisenia)

    OpenAIRE

    Robert Blakemore

    2013-01-01

    Two new megadrile earthworms from the steppes, the first species wholly from Outer Mongolia, are ascribed to the partially parthenogenetic Eisenia nordenskioldi (Eisen, 1879) species-complex. Taxonomic justification of sympatric Eisenia nordenskioldi mongol and Eisenia nordenskioldi onon ssp. n. are supported by mtDNA COI barcodes. The unreliability of molecular differentiation based on voucher names compared to definitive types is again demonstrated, as pertains to the ultimate Eisenia an...

  20. Second contribution to the knowledge of earthworms (Lumbricidae) in Montenegro

    OpenAIRE

    Stojanovi? Mirjana M.; Karaman Spasenija D.

    2003-01-01

    This paper contains the results of qualitative analysis of Lumbricidae (Oligochaeta) in Montenegro, during the period 1997-2003. The research has included natural and cultivated biotopes. The presence of 15 species was established and the habitats, localities and their zoogeographical position are given. In Montenegro we found four species for the first time Dendrobaena jastrebensis, D. vejdovskyi, Octodrilus bretcheri and Lumbricus terrestris. The complete list of earthworm species in Monten...

  1. Effects of Earthworms on Phosphorus Dynamics – A Review

    OpenAIRE

    Le Bayon, Rene?e-claire; Milleret, Roxane

    2009-01-01

    Belowground biotic interactions are known to influence soil fertility and plant growth by changing the physical environment and the soil nutrient cycles. Among the great diversity of soil biota, earthworms are keystone soil organisms in regulating nutrient cycling through: (i) their own metabolism that leads to high availability of carbon (C) and nitrogen (N) from metabolic wastes such as urine, mucus and tissue, (ii) the dispersal and the stimulation of soil microorganism activity associated...

  2. Comparative Genomics of Symbiotic Bacteria in Earthworm Nephridia

    DEFF Research Database (Denmark)

    Kjeldsen, Kasper Urup; Pinel, Nicolas

    The excretory and osmoregulatory organs (nephridia) of lumbricid earthworms are densely colonized by extracellular bacterial symbionts belonging to the newly established betaproteobacterial genus Verminephrobacter. The nephridial symbiont of the earthworm Eisenia fetida was subjected to full genome sequencing along with two of its closest relatives; the plant pathogenic Acidovorax avena subsp. citrulli and the free-living Acidovorax sp. JS42. In addition, the genome of the nephridial symbiont of the earthworm Aporrectodea tuberculata was partially sequenced. In order to resolve the functional and evolutionary basis of the symbiosis we annotated and compared the genomes. The genomes ranged in size from 4.4 to 5.6 Mbp, the E. fetida symbiont genome being the largest. The symbiont genomes showed no evidence of gene-loss related to any particular type of functional gene category. In contrast, genes predicted to be involved in transport processes were highly overrepresented in the symbiont genomes due to massive paralogous expansion of genes encoding ABC-type amino acid and peptide uptake systems. Thus, symbionts seem well-adapted to the nephridial environment being able to profit from proteinaceous excretion products. Gene order was highly conserved between the genomes of Acidovorax avena and Acidovorax sp. JS42, whereas the E. fetida symbiont genome held very little conservation of gene order compared to either of the latter two. Repetitive sequences were excessively abundant throughout the genomes of both symbionts. Together, this is indicative of high recombinatorial frequency in the symbiont genomes the function of which is presently poorly understood.

  3. Earthworm-produced calcite granules: A new terrestrial palaeothermometer?

    Science.gov (United States)

    Versteegh, Emma A. A.; Black, Stuart; Canti, Matthew G.; Hodson, Mark E.

    2013-12-01

    In this paper we show for the first time that calcite granules, produced by the earthworm Lumbricus terrestris, and commonly recorded at sites of archaeological interest, accurately reflect temperature and soil water ?18O values. Earthworms were cultivated in an orthogonal combination of two different (granule-free) soils moistened by three types of mineral water and kept at three temperatures (10, 16 and 20 °C) for an acclimatisation period of three weeks followed by transfer to identical treatments and cultivation for a further four weeks. Earthworm-secreted calcite granules were collected from the second set of soils. ?18O values were determined on individual calcite granules (?18Oc) and the soil solution (?18Ow). The ?18Oc values reflect soil solution ?18Ow values and temperature, but are consistently enriched by 1.51 (± 0.12)‰ in comparison to equilibrium in synthetic carbonates. The data fit the equation 1000 ln ? = [20.21 ± 0.92] (103 T-1) - [38.58 ± 3.18] (R2 = 0.95; n = 96; p < 0.0005). As the granules are abundant in modern soils, buried soils and archaeological contexts, and can be dated using U-Th disequilibria, the developed palaeotemperature relationship has enormous potential for application to Holocene and Pleistocene time intervals.

  4. Inheritance of freezing resistance in tuber-bearing Solanum species: evidence for independent genetic control of nonacclimated freezing tolerance and cold acclimation capacity.

    OpenAIRE

    Stone, J. M.; Palta, J. P.; Bamberg, J. B.; Weiss, L. S.; Harbage, J. F.

    1993-01-01

    Frost or winter survival is regarded as a complex trait with polygenic inheritance. Two major components of this survival in crop plants are freezing tolerance in the nonacclimated state and cold acclimation capacity. To date researchers have not distinguished the two components as separate heritable traits. The mode of inheritance of these two traits was investigated in F1 and backcross populations of two wild diploid potato species (Solanum commersonii and Solanum cardiophyllum) exhibiting ...

  5. Effects of low voltage electrolysis and freezing on coliform content of contaminated water

    International Nuclear Information System (INIS)

    A sewage sample was mixed with drinking water and subjected to low voltage (15V) electrolysis in the presence of 1% NaCl. The prepared sample was also kept in freezer with and without the presence of sodium chloride for 4-hours. Among these treatments the electrolysis proved to kill the coliforms, while the freezing reduced the bacterial content. Antibiotics sensitivity patterns revealed that certain of the coliform strains survived the freezing and thawing shocks. Nature of such surviving bacteria and need to study chemical parameters of electrolyzed water are discussed. (author)

  6. Interactions of earthworms with Atrazine-degrading bacteria in an agricultural soil.

    Science.gov (United States)

    Kersanté, Anne; Martin-Laurent, Fabrice; Soulas, Guy; Binet, Françoise

    2006-08-01

    In the last 10 years, accelerated mineralization of Atrazine (2-chloro-ethylamino-6-isopropylamino-s-triazine) has been evidenced in agricultural soils repeatedly treated with this herbicide. Here, we report on the interaction between earthworms, considered as soil engineers, and the Atrazine-degrading community. The impact of earthworm macrofauna on Atrazine mineralization was assessed in representative soil microsites of earthworm activities (gut contents, casts, burrow linings). Soil with or without earthworms, namely the anecic species Lumbricus terrestris and the endogenic species Aporrectodea caliginosa, was either inoculated or not inoculated with Pseudomonas sp. ADP, an Atrazine-degrading strain, and was either treated or not treated with Atrazine. The structure of the bacterial community, the Atrazine-degrading activity and the abundance of atzA, B and C sequences in soil microsites were investigated. Atrazine mineralization was found to be reduced in representative soil microsites of earthworm activities. Earthworms significantly affected the structure of soil bacterial communities. They also reduced the size of the inoculated population of Pseudomonas sp. ADP, thereby contributing to the diminution of the Atrazine-degrading genetic potential in representative soil microsites of earthworm activities. This study illustrates the regulation produced by the earthworms on functional bacterial communities involved in the fate of organic pollutants in soils. PMID:16867138

  7. Earthworms as phoretic hosts for Steinernema carpocapsae and Beauveria bassiana: Implications for enhanced biological control

    Science.gov (United States)

    Prior research indicated that earthworms may serve as phoretic hosts to entomopathogenic nematodes. Therefore, we hypothesized that biocontrol efficacy of nematodes could be enhanced in the presence of earthworms based on increased nematode dispersal through the soil. We also hypothesized that ear...

  8. Temperature-dependent alterations in metabolic enzymes and proteins of three ecophysiologically different species of earthworms

    Scientific Electronic Library Online (English)

    G, Tripathi; N., Kachhwaha; I., Dabi; N., Bandooni.

    2011-08-01

    Full Text Available The effects of varying temperatures (12 - 44° C) on the specific activity of cytoplasmic malate dehydrogenase ((cMDH), mitochondrial malate dehydrogenase (mMDH) and lactate dehydrogenase (LDH) of some earthworms (Metaphire posthuma, Perionyx sansibaricus and Lampito mauritii) were studied. The effec [...] ts of different temperatures on supernatant and mitochondrial protein contents were also investigated. The specific activities of cMDH, mMDH and LDH of the earthworms decreased gradually as a function of increasing temperature from 12 to 44°C. Higher metabolic energy was needed to maintain the activity at low temperatures. Hence, the earthworms showed increased enzyme specific activity at low temperatures. However, the protein content increased upto 28°C. Afterwards, with the increase in the temperature from 28 to 42°C, the proteins in the earthworms showed a significant decrease. The temperature-associated changes in the protein content could be explained by the fact that protein synthesizing capacity was hampered above and below the optimum temperature range. The most pronounced effects of varying temperatures were on P. sansibaricus. It might be due to the epigeic nature of the earthworm species. Then minimum effect was on the endogeic earthworm M. posthuma. Virtually, the differences in the enzymes physiology were associated with the differences in the ecological categories of the earthworms. This clearly demonstrate a possible link between the physiology and ecology at aerobic (cMDH, mMDH) and anaerobic (LDH) levels in the tropical earthworms.

  9. Influence of earthworm mucus and amino acids on tomato seedling growth and cadmium accumulation

    International Nuclear Information System (INIS)

    The effects on the growth of tomato seedlings and cadmium accumulation of earthworm mucus and a solution of amino acids matching those in earthworm mucus was studied through a hydroponic experiment. The experiment included four treatments: 5 mg Cd L-1 (CC), 5 mg Cd L-1 + 100 mL L-1 earthworm mucus (CE), 5 mg Cd L-1 + 100 mL L-1 amino acids solution (CA) and the control (CK). Results showed that, compared with CC treatment, either earthworm mucus or amino acids significantly increased tomato seedling growth and Cd accumulation but the increase was much higher in the CE treatment compared with the CA treatment. This may be due to earthworm mucus and amino acids significantly increasing the chlorophyll content, antioxidative enzyme activities, and essential microelement uptake and transport in the tomato seedlings. The much greater increase in the effect of earthworm mucus compared with amino acid treatments may be due to IAA-like substances in earthworm mucus. - Earthworm mucus increased tomato seedlings growth and Cd accumulation through increasing chlorophyll content, antioxidative enzyme activities, and essential microelement accumulation.

  10. USING THE EARTHWORM, EISENIA FETIDA, TO ASSESS THE ECOTOXICITY OF WASTE FOUNDRY SANDS

    Science.gov (United States)

    Earthworms are often used to monitor the toxicity of contaminated soils. In this experiment, the earthworm, Eisenia fetida, was utilized to assess the ecotoxicity of waste foundry sands. Each year the U.S. foundry industry generates several million tons of waste sand that is no longer useful to pr...

  11. Phagocytosis in earthworms: An environmentally acceptable endpoint to assess immunotoxic potential of contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Giggleman, M.A.; Fitzpatrick, L.C.; Goven, A.J. [Univ. of North Texas, Denton, TX (United States). Dept. of Biological Sciences; Venables, B.J. [TRAC Labs., Inc., Denton, TX (United States); Callahan, C.A. [Environmental Protection Agency, San Francisco, CA (United States)

    1995-12-31

    Phagocytosis, a host-defense mechanism phylogenetically conserved throughout the animal kingdom, by earthworm (Lumbricus terrestris) coelomocytes has potential as a surrogate for vertebrates to be used as an environmentally acceptable endpoint to assess sublethal immunotoxic risks of contaminated soils to environmental (eg. higher wildlife) and public health. Coelomocytes can be exposed in vivo to complex contaminated parent soils by placing earthworms in situ at hazardous waste sites (HWS) or into soil samples and their dilutions with artificial soil (AS) in the laboratory, or in vitro to soil extracts and their fractionations. Here the authors report on phagocytosis by coelomocytes in earthworms exposed to pentachlorophenol (PCP) contaminated soils from a wood treatment HWS, PCP-spiked AS and PCP treated filter paper (FP). HWS soil was diluted to 25% with AS to a sublethal concentration (ca. 125 mg kg{sup {minus}1}) and earthworms exposed for 14d at 10 C under light conditions. AS was spiked at ca. 125 mg kg{sup {minus}1} PCP and earthworms were similarly exposed. Controls for both consisted of earthworms exposed to 100% AS. Earthworms were exposed to FP treated with a sublethal PCP concentration (15 {micro}g cm{sup {minus}2}) at 10 C under dark conditions for 96H. Controls were similarly exposed without PCP. Phagocytosis by coelomocytes in earthworms exposed to HWS soil, spiked AS and treated FP was suppressed 37, 41 and 29%, respectively. Results are discussed in terms of PCP body burdens and exposure protocols.

  12. Earthworm species composition affects the soil bacterial community and net nitrogen mineralization

    OpenAIRE

    Postma-blaauw, M. B.; Bloem, J.; Faber, J. H.; Groenigen, J. W.; Goede, R. G. M.; Brussaard, L.

    2006-01-01

    Knowledge of the effects of species diversity within taxonomic groups on nutrient cycling is important for understanding the role of soil biota in sustainable agriculture. We hypothesized that earthworm species specifically affect nitrogen mineralization, characteristically for their ecological group classifications, and that earthworm species interactions would affect mineralization through competition and facilitation effects. A mesocosm experiment was conducted to investigate the effect of...

  13. Mutualism between common earthworm (Lumbricus terrestris) and giant ragweed (Ambrosia trifida) varies between Ohio and Illinois

    Science.gov (United States)

    Seed caching of giant ragweed by common earthworm has been found to contribute to giant ragweed recruitment success in Ohio (OH) by protecting the seeds from postdispersal predation at a depth in the earthworm midden that is also suitable for germination. The objective of this study was to quantify ...

  14. Effect of Earthworm Feeding Guilds on Ingested Dissimilatory Nitrate Reducers and Denitrifiers in the Alimentary Canal of the Earthworm ? †

    OpenAIRE

    Depkat-jakob, Peter S.; Hilgarth, Maik; Horn, Marcus A.; Drake, Harold L.

    2010-01-01

    The earthworm gut is an anoxic nitrous oxide (N2O)-emitting microzone in aerated soils. In situ conditions of the gut might stimulate ingested nitrate-reducing soil bacteria linked to this emission. The objective of this study was to determine if dissimilatory nitrate reducers and denitrifiers in the alimentary canal were affected by feeding guilds (epigeic [Lumbricus rubellus], anecic [Lumbricus terrestris], and endogeic [Aporrectodea caliginosa]). Genes and gene transcripts of narG (encodes...

  15. Distribution of bacteria and fungi in the earthworm Libyodrillus violaceous (Annelida: Oligochaeta, a native earthworm from Nigeria

    Directory of Open Access Journals (Sweden)

    A. B Idowu

    2006-03-01

    Full Text Available Earthworms are soil invertebrates that play a key role in recycling organic matter in soils.In Nigeria, earthworms include Libyodrillus violaceous. Aerobic and anaerobic bacterial counts, as well as fungal counts of viable microorganisms in soils and gut sections, were made on twenty L. violaceous collected from different sites on the campus of the University of Agriculture, Abeokuta, Nigeria. The samples were collected between April and November, 2002. Numbers of microorganisms were higher in castings and gut sections than in uningested soil samples. The guts and their contents also had higher moisture and total nitrogen contents than the uningested soils. Bacteria and fungi isolated from the samples were identified by standard microbiological procedures on the bases of their morphological and biochemical characteristics. Isolated bacteria were identified as Staphylococcus, Bacillus spp., Pseudomonas aeruginosa, Streptococcus mutans, Clostridium, Spirocheata spp., Azotobacter spp., Micrococcus lylae, Acinetobacter spp., Halobacterium for bacteria. Yeast isolates were identified as Candida spp., Zygosaccharomyces spp., Pichia spp., and Saccharomyces spp while molds were identified as, Aspergillus spp., Pytium spp., Penicillium spp., Fusarium spp and Rhizopus spp. Of the five locations examined, the refuse dump area had the highest numbers of both aerobic and anaerobic organisms, followed by the arboretum while the cultivated land area recorded the lowest counts. The higher numbers of microorganisms observed in the gut sections and casts of the earthworms examined in this work reinforce the general concept that the gut and casts of earthworms show higher microbial diversity and activity than the surrounding soil. Rev. Biol. Trop. 54 (1: 49-58. Epub 2006 Mar 31.

  16. Distribution of bacteria and fungi in the earthworm Libyodrillus violaceous (Annelida: Oligochaeta), a native earthworm from Nigeria

    Scientific Electronic Library Online (English)

    A. B, Idowu; M. O, Edema; A. O, Adeyi.

    2006-03-01

    Full Text Available SciELO Costa Rica | Language: English Abstract in english Earthworms are soil invertebrates that play a key role in recycling organic matter in soils.In Nigeria, earthworms include Libyodrillus violaceous. Aerobic and anaerobic bacterial counts, as well as fungal counts of viable microorganisms in soils and gut sections, were made on twenty L. violaceous c [...] ollected from different sites on the campus of the University of Agriculture, Abeokuta, Nigeria. The samples were collected between April and November, 2002. Numbers of microorganisms were higher in castings and gut sections than in uningested soil samples. The guts and their contents also had higher moisture and total nitrogen contents than the uningested soils. Bacteria and fungi isolated from the samples were identified by standard microbiological procedures on the bases of their morphological and biochemical characteristics. Isolated bacteria were identified as Staphylococcus, Bacillus spp., Pseudomonas aeruginosa, Streptococcus mutans, Clostridium, Spirocheata spp., Azotobacter spp., Micrococcus lylae, Acinetobacter spp., Halobacterium for bacteria. Yeast isolates were identified as Candida spp., Zygosaccharomyces spp., Pichia spp., and Saccharomyces spp while molds were identified as, Aspergillus spp., Pytium spp., Penicillium spp., Fusarium spp and Rhizopus spp. Of the five locations examined, the refuse dump area had the highest numbers of both aerobic and anaerobic organisms, followed by the arboretum while the cultivated land area recorded the lowest counts. The higher numbers of microorganisms observed in the gut sections and casts of the earthworms examined in this work reinforce the general concept that the gut and casts of earthworms show higher microbial diversity and activity than the surrounding soil. Rev. Biol. Trop. 54 (1): 49-58. Epub 2006 Mar 31.

  17. Time dependence of immersion freezing

    Directory of Open Access Journals (Sweden)

    A. Welti

    2012-05-01

    Full Text Available The time dependence of immersion freezing was studied for temperatures between 236 K and 243 K. Droplets with single immersed, size-selected 400 nm and 800 nm kaolinite particles were produced at 300 K, cooled down to supercooled temperatures typical for mixed-phase cloud conditions, and the fraction of frozen droplets with increasing residence time was detected. To simulate the conditions of immersion freezing in mixed-phase clouds we used the Zurich Ice Nucleation Chamber (ZINC and its vertical extension, the Immersion Mode Cooling chAmber (IMCA. We observed that the frozen fraction of droplets increased with increasing residence time in the chamber. This suggests that there is a time dependence of immersion freezing and supports the importance of a stochastic component in the ice nucleation process. The rate at which droplets freeze was observed to decrease towards higher temperatures and smaller particle sizes. Comparison of the laboratory data with four different ice nucleation models, three based on classical nucleation theory with different representations of the particle surface properties and one singular, suggest that the classical, stochastic approach combined with a distribution of contact angles is able to reproduce the ice nucleation observed in these experiments most accurately. Using the models to calculate the increase in frozen fraction at typical mixed-phase cloud temperatures over an extended period of time, yields an equivalent effect of ?1 K temperature shift and an increase in time scale by a factor of ~10.

  18. Mercury, cadmium and lead concentrations in different ecophysiological groups of earthworms in forest soils

    International Nuclear Information System (INIS)

    Bioaccumulation of Hg, Cd and Pb by eight ecophysiologically distinct earthworm species was studied in 27 polluted and uncontaminated forest soils. Lowest tissue concentrations of Hg and Cd occurred in epigeic Lumbricus rubellus and highest in endogeic Octolasion cyaneum. Soils dominated by Dendrodrilus rubidus possess a high potential of risk of Pb biomagnification for secondary predators. Bioconcentration factors (soil-earthworm) followed the sequence ranked Cd > Hg > Pb. Ordination plots of redundancy analysis were used to compare HM concentrations in earthworm tissues with soil, leaf litter and root concentrations and with soil pH and CEC. Different ecological categories of earthworms are exposed to Hg, Cd and Pb in the topsoil by atmospheric deposition and accumulate them in their bodies. Species differences in HM concentrations largely reflect differences in food selectivity and niche separation. - Accumulation of non-essential heavy metals by earthworms is species-dependent and is affected by soil characteristics in natural forest soils

  19. Earthworm responses to different reclamation processes in post opencast mining lands during succession.

    Science.gov (United States)

    Hlava, Jakub; Hlavová, Anna; Hakl, Josef; Fér, Miroslav

    2015-01-01

    This study provides earthworm population data obtained from localities with a substantial anthropogenic impact spoils. The spoil heaps were reclaimed at the end of an opencast brown coal mining period. We studied spoils reclaimed by the two most commonly used reclamation processes: forestry and agricultural. The results show the significance of the locality age and the utilized reclamation process and treatment and their effect on earthworm communities. Our data indicate that apart from soil physical and chemical properties, the reclamation process itself may also induce viability and distribution of earthworm communities. Under standardized soil properties, the changes in earthworm populations during the succession were larger within the agricultural reclamation process as opposed to the forestry reclamation process for earthworm ecological groups and individual species. PMID:25380717

  20. Microflora dynamics in earthworms casts in an artificial soil (biosynthesol containing lactic acid oligomers

    Directory of Open Access Journals (Sweden)

    Alauzet Nathalie

    2001-01-01

    Full Text Available Studies were performed to appreciate the presence of micro-organisms able to degrade OLA, in earthworms casts or in the surroundings. Worms were grown in biosynthesol, an artificial soil. The counting of bacteria and fungi in earthworms casts and in biosynthesol without earthworms suggested that earthworms ate some of the micro-organisms. The main filamentous fungi genera found were Aspergillus, Trichoderma, Fusarium and Penicillium. Previous results in the literature have shown that some species from the Aspergillus and Fusarium genera were able to degrade OLA and other aliphatic esters. It could be suggested that these two genera and some bacteria were responsible for the pre-degradation of OLA, and that earthworms might eat them.

  1. Mercury, cadmium and lead concentrations in different ecophysiological groups of earthworms in forest soils

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Gregor; Zimmermann, Stefan [Soil Sciences, Swiss Federal Research Institute WSL, Zuercherstrasse 111, CH-8903 Birmensdorf (Switzerland); Christie, Peter [Agricultural and Environmental Science Department, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX (United Kingdom); Frey, Beat [Soil Sciences, Swiss Federal Research Institute WSL, Zuercherstrasse 111, CH-8903 Birmensdorf (Switzerland)], E-mail: beat.frey@wsl.ch

    2008-12-15

    Bioaccumulation of Hg, Cd and Pb by eight ecophysiologically distinct earthworm species was studied in 27 polluted and uncontaminated forest soils. Lowest tissue concentrations of Hg and Cd occurred in epigeic Lumbricus rubellus and highest in endogeic Octolasion cyaneum. Soils dominated by Dendrodrilus rubidus possess a high potential of risk of Pb biomagnification for secondary predators. Bioconcentration factors (soil-earthworm) followed the sequence ranked Cd > Hg > Pb. Ordination plots of redundancy analysis were used to compare HM concentrations in earthworm tissues with soil, leaf litter and root concentrations and with soil pH and CEC. Different ecological categories of earthworms are exposed to Hg, Cd and Pb in the topsoil by atmospheric deposition and accumulate them in their bodies. Species differences in HM concentrations largely reflect differences in food selectivity and niche separation. - Accumulation of non-essential heavy metals by earthworms is species-dependent and is affected by soil characteristics in natural forest soils.

  2. Effect of different feed types on growth, spawning, hatching and larval survival in angel fish (Pterophyllum scalare Lictenstein, 1823

    Directory of Open Access Journals (Sweden)

    Amin Farahi

    2010-12-01

    Full Text Available In this study effects of commercial extruder diet (T1, earthworm (T2, 50 % commercialextruder diet + 50 % earthworm (T3 on growth, spawning, hatching and larval survival of angel fish(average weight 4.06 g (Pterophyllum scalare Lictenstein, 1823 were investigated. The experimentalgroups were fed for 60 days. According to the results of this study, the best spawning and hatching werefound in group T3 but there was no significant difference with other groups (p>0.05. Also larval survivalrate in group T3 showed significant difference with group T2 (p1 as it showed significant difference withgroup T2 (p<0.05.

  3. Theoretical analysis of specimen cooling rate during impact freezing and liquid-jet freezing of freeze-etch specimens.

    OpenAIRE

    Kopstad, G.; Elgsaeter, A.

    1982-01-01

    We have carried out a theoretical analysis of specimen cooling rate under ideal conditions during impact freezing and liquid-jet freezing. The analysis shows that use of liquid helium instead of liquid nitrogen as cooling medium during impact freezing results in an increase in a specimen cooling rate of no more than 30-40%. We have further shown that when both impact freezing and liquid-jet freezing are conducted at liquid nitrogen temperature, the two methods give approximately the same spec...

  4. Non-native earthworms in riparian soils increase nitrogen flux into adjacent aquatic ecosystems.

    Science.gov (United States)

    Costello, David M; Lamberti, Gary A

    2008-12-01

    Riparian zones are an important transition between terrestrial and aquatic ecosystems, and they function in nutrient cycling and removal. Non-native earthworms invading earthworm-free areas of North America can affect nutrient cycling in upland soils and have the potential to affect it in riparian soils. We examined how the presence of earthworms can affect riparian nutrient cycling and nutrient delivery to streams. Two mesocosm experiments were conducted to determine how (1) the biomass of earthworms and (2) earthworm species can affect nutrient flux from riparian zones to nearby streams and how this flux can affect streamwater nutrients and periphyton growth. In separate experiments, riparian soil cores were amended with one of four mixed earthworm biomasses (0, 4, 10, or 23 g m(-2) ash-free dry mass) or with one of three earthworm species (Aporrectodea caliginosa, Lumbricus terrestris, L. rubellus) or no earthworm species. Riparian soil cores were coupled to artificial streams, and over a 36-day period, we measured nutrient leaching rates, in-stream nutrient concentrations, and periphyton growth. Ammonium leaching increased with increasing biomass and was greatest from the A. caliginosa treatments. Nitrate leaching increased through time and increased at a greater rate with higher biomass and from cores containing A. caliginosa. We suggest that the overall response of increased nitrate leaching [90% of total nitrogen (N)] was due to a combination of ammonium excretion and burrowing by earthworms, which increased nitrification rates. During both experiments, periphyton biomass increased through time but did not differ across treatments despite high in-stream inorganic N. Through time, in-stream phosphorus (P) concentration declined to <5 microg l(-1), and periphyton growth was likely P-limited. We conclude that activities of non-native earthworms (particularly A. caliginosa) can alter biogeochemical cycling in riparian zones, potentially reducing the N-buffering capacity of riparian zones and altering stoichiometric relationships in adjacent aquatic ecosystems. PMID:18825416

  5. Earthworms influenced by reduced tillage, conventional tillage and energy forest in Swedish agricultural field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lagerloef, Jan (SLU, Department of Ecology, Swedish University of Agricultural Sciences, Uppsala (Sweden)), Email: Jan.Lagerlof@ekol.slu.se; Paalsson, Olof; Arvidsson, Johan (SLU, Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala (Sweden))

    2012-03-15

    We compared earthworm density, depth distribution and species composition in three soil cultivation experiments including the treatments ploughless tillage and mouldboard ploughing. Sampling was done in September 2005 and for one experiment also in 1994. By yearly sampling 1995-2005, earthworms in an energy forest of Salix viminalis were compared with those in an adjacent arable field. Sampling method was digging of soil blocks and hand sorting and formalin sampling in one cultivation experiment. Both methods were used in the energy forest and arable land comparison. In two soil cultivation experiments, highest abundances or biomass were found in ploughless tillage. Earthworm density was higher in the upper 10 cm, especially in the ploughless tillage. Earthworm density was significantly higher in the energy forest than in the arable field. Formalin sampling revealed c. 36% of the earthworm numbers found by digging in the energy forest and gave almost no earthworms in the arable field. In all treatments with soil cultivation, species living and feeding in the rhizosphere and soil dominated. One such species, Allolobophora chlorotica, was more abundant under mouldboard ploughing than ploughless tillage. Lumbricus terrestris, browsing on the surface and producing deep vertical burrows, was more common in the ploughless tillage. Species living and feeding close to the soil surface were almost only found in the energy forest, which had not been soil cultivated since 1984. The findings support earlier studies pointing out possibilities to encourage earthworms by reduced soil cultivation. This is one of the first published studies that followed earthworm populations in an energy forest plantation during several years. Explanation of earthworm reactions to management and environmental impacts should be done with consideration of the ecology of species or species groups. Earthworm sampling by formalin must always be interpreted with caution and calibrated by digging and hand-sorting sampling

  6. Comparison of direct, indirect, and ecosystem engineering effects of an earthworm on the red-backed salamander.

    Science.gov (United States)

    Ransom, Tami S

    2012-10-01

    In addition to creating or modifying habitat, ecosystem engineers interact with other species as predators, prey, or competitors. The earthworm, Lumbricus terrestris, interacts with the common woodland salamander, Plethodon cinereus, via: (1) ecosystem engineering, by providing burrows that are used as a refuge, (2) direct effects as a prey item, and (3) indirectly, by competing with microinvertebrates, another prey item for P. cinereus. Using enclosures in the forest, I examined the relative strengths of these component pathways between seasons and salamander age classes. I found that the relative strength (partial eta2) of the positive direct (trophic) effect of L. terrestris on the change in mass of P. cineresus was greater than that of the negative indirect effect, but only in summer. Positive effects of ecosystem engineering were only evident over the winter as increased adult survival. This research has implications for how habitat provisioning complements more well-studied species interactions, such as competition and predation, within communities. PMID:23185881

  7. A survey of Pb, Cu, Zn, Cd, Cr, As, and Se in earthworms and soil from diverse sites

    Science.gov (United States)

    Beyer, W.N.; Cromartie, E.J.

    1987-01-01

    Earthworms and soils were collected from 20 diverse sites in Maryland, Pennsylvania, and Virginia, and were analyzed for Pb, Cu, Zn, Cd, Cr, As, and Se. Correlation coefficients relating Iconcentrations of the elements in earthworms to concentrations in soil were low (-0.20Zn (1600 ppm), Cd (23 ppm) and Se (7.6 ppm) detected in earthworms were in the range reported to be toxic to animals fed diets containing these elements; however, even in the absence of any environmental contamination, some species of earthworms may contain high concentrations of Pb, Zn, and Se. Earthworms of the genus Eisenoides, for example, were exceptional in their ability to concentrate Pb. When earthworms are used as indicators of environmental contamination, it is important to identify the species, to report the soil characteristics, and to collect similar earthworms from very similar but uncontaminated soil.

  8. Boar semen can tolerate rapid cooling rates prior to freezing.

    Science.gov (United States)

    Juarez, Jorge D; Parrilla, Inma; Vazquez, Juan M; Martinez, Emilio A; Roca, Jordi

    2011-01-01

    Two experiments were performed in the present study that demonstrated that boar spermatozoa are capable of surviving rapid cooling rates within a range of 15-5 °C before freezing. Boar ejaculates diluted in Beltsville thawing solution (BTS) (1:1, v/v) were held at 17-20 °C and shipped over a 24-h time period from two AI centres to a cryobiology laboratory, where they were pooled (Experiment 1) or cryopreserved individually (Experiment 2) using a standard 0.5-mL straw freezing protocol. The effects of cooling before freezing were assessed after thawing through the objective evaluation of sperm motility and flow cytometric analysis of membrane integrity, acrosomal status, changes in membrane lipid architecture monitored by merocyanine and annexin V binding and intracellular production of reactive oxygen species. In Experiment 1 (six replicates), two semen pools (five ejaculates per pool) were cooled from 15 to 5 °C at rates of 0.08, 0.13, 0.40 and 1.50 °C min(-1). These cooling rates did not result in any significant differences (P>0.05) in any of the post-thaw sperm assessments, even in thawed samples incubated under capacitation conditions. In Experiment 2, three individual ejaculates from 16 boars were slowly (0.08 °C min(-1)) or rapidly (1.5 °C min(-1)) cooled before freezing. A consistent interboar variability (Psamples that had been cooled slowly. These findings demonstrate that boar spermatozoa undergoing cryopreservation can withstand rapid cooling rates before freezing. PMID:21635817

  9. A case study on stress preconditioning of a Lactobacillus strain prior to freeze-drying.

    Science.gov (United States)

    Bergenholtz, Åsa Schoug; Wessman, Per; Wuttke, Anne; Håkansson, Sebastian

    2012-06-01

    Freeze-drying of bacterial cells with retained viability and activity after storage requires appropriate formulation, i.e. mixing of physiologically adapted cell populations with suitable protective agents, and control of the freeze-drying process. Product manufacturing may alter the clinical effects of probiotics and it is essential to identify and understand possible factor co-dependencies during manufacturing. The physical solid-state behavior of the formulation and the freeze-drying parameters are critical for bacterial survival and thus process optimization is important, independent of strain. However, the maximum yield achievable is also strain-specific and strain survival is governed by e.g. medium, cell type, physiological state, excipients used, and process. The use of preferred compatible solutes for cross-protection of Lactobacilli during industrial manufacturing may be a natural step to introduce robustness, but knowledge is lacking on how compatible solutes, such as betaine, influence formulation properties and cell survival. This study characterized betaine formulations, with and without sucrose, and tested these with the model lactic acid bacteria Lactobacillus coryniformis Si3. Betaine alone did not act as a lyo-protectant and thus betaine import prior to freeze-drying should be avoided. Differences in protective agents were analyzed by calorimetry, which proved to be a suitable tool for evaluating the characteristics of the freeze-dried end products. PMID:22266474

  10. Freeze chromatography method and apparatus

    Science.gov (United States)

    Scott, C.D.

    1987-04-16

    A freeze chromatography method and apparatus are provided which enable separation of the solutes contained in a sample. The apparatus includes an annular column construction comprising cylindrical inner and outer surfaces defining an annular passage therebetween. One of the surfaces is heated and the other cooled while passing an eluent through the annular passageway so that the eluent in contact with the cooled surface freezes and forms a frozen eluent layer thereon. A mixture of solutes dissolved in eluent is passed through the annular passageway in contact with the frozen layer so that the sample solutes in the mixture will tend to migrate either toward or away the frozen layer. The rate at which the mixture flows through the annular passageway is controlled so that the distribution of the sample solutes approaches that at equilibrium and thus a separation between the sample solutes occurs. 3 figs.

  11. Clostridiaceae and Enterobacteriaceae as active fermenters in earthworm gut content.

    Science.gov (United States)

    Wüst, Pia K; Horn, Marcus A; Drake, Harold L

    2011-01-01

    The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H(2)) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut content of the anecic earthworm Lumbricus terrestris by 16S ribosomal RNA (rRNA)-based stable isotope probing, with [(13)C]glucose as a model substrate. Glucose consumption in anoxic gut content microcosms was rapid and yielded soluble organic compounds (acetate, butyrate, formate, lactate, propionate, succinate and ethanol) and gases (carbon dioxide and H(2)), products indicative of diverse fermentations in the alimentary canal. Clostridiaceae and Enterobacteriaceae were users of glucose-derived carbon. On the basis of the detection of 16S rRNA, active phyla in gut contents included Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Proteobacteria, Tenericutes and Verrucomicrobia, taxa common to soils. On the basis of a 16S rRNA gene similarity cutoff of 87.5%, 82 families were detected, 17 of which were novel family-level groups. These findings (a) show the large diversity of soil taxa that might be active during gut passage, (b) show that Clostridiaceae and Enterobacteriaceae (fermentative subsets of these taxa) are selectively stimulated by glucose and might therefore be capable of consuming mucus- and plant-derived saccharides during gut passage and (c) indicate that ingested obligate anaerobes and facultative aerobes from soil can concomitantly metabolize the same source of carbon. PMID:20613788

  12. Metabolic changes during estivation in the common earthworm Aporrectodea caliginosa

    DEFF Research Database (Denmark)

    Bayley, Mark; Overgaard, Johannes

    2010-01-01

    The common earthworm Aporrectodea caliginosa survives drought by forming estivation chambers in the topsoil under even very slight reductions in soil water activity. We induced estivation in a soil of a consistency that allowed the removal of intact soil estivation chambers containing a single worm. These estivation chambers were exposed to 97% relative humidity for 30 d to simulate the effect of a severe summer drought. Gas exchange, body fluid osmolality, water balance, urea, and alanine were quantified, and whole?body homogenates were screened for changes in small organic molecules via 1H-nuclear magnetic resonance (NMR). Formation of estivation chambers was associated with a dramatic increase in body fluid osmolality, from 175 to 562 mOsm kg-1, accompanied by a 20% increase in water content. Dehydration for 1 mo caused a further increase to 684 mOsm kg-1, while the worms lost 50% of their water content. Gas exchange was depressed by 50% after worms entered estivation and by 80% after a further 30 d of dehydration. Urea concentrations increased from 0.3 to 1 ?mol g-1 dry mass during this time. Although 1H?NMR did not provide the identity of the osmolytes responsible for the initial increase in osmolality after estivation, it showed that alanine increased to more than 80 mmol L-1 in the long?term?estivation group. We propose that alanine functions as a nitrogen depot during dehydration and is not an anaerobe product in this case.

  13. Effects of heavy metals on the litter consumption by the earthworm Lumbricus rubellus in field soils

    Science.gov (United States)

    Hobbelen, P.H.F.; Koolhaas, J.E.; van Gestel, C.A.M.

    2006-01-01

    Aim of this study was to determine effects of heavy metals on litter consumption by the earthworm Lumbricus rubellus in National Park the "Brabantsche Biesbosch", the Netherlands. Adult L. rubellus were collected from 12 polluted and from one unpolluted field site. Earthworms collected at the unpolluted site were kept in their native soil and in soil from each of the 12 Biesbosch sites. Earthworms collected in the Biesbosch were kept in their native soils. Non-polluted poplar (Populus sp.) litter was offered as a food source and litter consumption and earthworm biomass were determined after 54 days. Cd, Cu and Zn concentrations were determined in soil, pore water and 0.01 M CaCl2 extracts of the soil and in earthworms. In spite of low available metal concentrations in the polluted soils, Cd, Cu and Zn concentrations in L. rubellus were increased. The litter consumption rate per biomass was positively related to internal Cd and Zn concentrations of earthworms collected from the Biesbosch and kept in native soil. A possible explanation is an increased demand for energy, needed for the regulation and detoxification of heavy metals. Litter consumption per biomass of earthworms from the reference site and kept in the polluted Biesbosch soils, was not related to any of the determined soil characteristics and metal concentrations. ?? 2005 Elsevier GmbH. All rights reserved.

  14. How within field abundance and spatial distribution patterns of earthworms and macropores depend on soil tillage

    Science.gov (United States)

    van Schaik, Loes; Palm, Juliane; Schröder, Boris

    2014-05-01

    Earthworms play a key role in soil systems. They are ecosystem engineers affecting soil structure as well as the transport and availability of water and solutes through their burrowing behaviour. There are three different ecological earthworm types with different burrowing behaviour that can result in varying local infiltration patterns: from rapid deep vertical infiltration to a stronger diffuse distribution of water and solutes in the upper soil layers. The small scale variation in earthworm abundance is often very high and within fields earthworm population processes might result in an aggregated pattern. The question arises how the local distribution of earthworms affects spatial distributions of macroporosity and how both are influenced by soil tillage. Therefore we performed a total number of 430 earthworm samplings on four differently tilled agricultural fields in the Weiherbach catchment (South East Germany). Additionally, at a limited amount of 32 locations on two of the fields we performed sprinkling experiments with brilliant blue and excavated the soil to count macropores at different soil depths (10 cm, 30 cm and 50 cm) to compare macropore distributions to the earthworm distributions.

  15. Antioxidant defense system responses and DNA damage of earthworms exposed to Perfluorooctane sulfonate (PFOS)

    International Nuclear Information System (INIS)

    The use of earthworms as a sublethal endpoint has significantly contributed to the ecological risk assessment of contaminated soils. Few studies have focused on the potential toxicity of PFOS to earthworms in the soil. In this work, artificial soils were tested, and contact filter paper studies were used. The results showed that earthworm growth was generally inhibited. The antioxidant activities of the enzymes superoxide dismutase, peroxidase, catalase and glutathione peroxidase were initially activated and then inhibited. Reduced glutathione content was observed, and malondialdehyde content was elevated over the duration of the exposure. These results suggested that PFOS induced oxidative stress in earthworms. In addition, the values of olive tail moment, tail DNA% and tail length using SCGE showed similar frequency distributions and increased with increases in the PFOS concentration. These results suggest that all concentrations of PFOS cause DNA damage. Highlights: ? We studied the potential ecotoxicity of PFOS to earthworm in soil. ? Eisenia foetida was used as a model organism and its growth was generally inhibited. ? Antioxidant enzyme activities were initially activated and then inhibited. ? Reduced glutathione content was observed and malondialdehyde content was elevated. ? PFOS induced DNA damage in earthworms. -- Perfluorooctane sulfonate (PFOS) induced oxidative stress and DNA damage in earthworms

  16. Impact of earthworms on trace element solubility in contaminated mine soils amended with green waste compost

    Energy Technology Data Exchange (ETDEWEB)

    Sizmur, Tom, E-mail: t.p.sizmur@reading.ac.uk [Soil Research Centre, Dept. Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading, RG6 6DW (United Kingdom); Palumbo-Roe, Barbara [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham, NG12 5GG (United Kingdom); Hodson, Mark E. [Soil Research Centre, Dept. Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading, RG6 6DW (United Kingdom)

    2011-07-15

    The common practice of remediating metal contaminated mine soils with compost can reduce metal mobility and promote revegetation, but the effect of introduced or colonising earthworms on metal solubility is largely unknown. We amended soils from an As/Cu (1150 mgAs kg{sup -1} and 362 mgCu kg{sup -1}) and Pb/Zn mine (4550 mgPb kg{sup -1} and 908 mgZn kg{sup -1}) with 0, 5, 10, 15 and 20% compost and then introduced Lumbricus terrestris. Porewater was sampled and soil extracted with water to determine trace element solubility, pH and soluble organic carbon. Compost reduced Cu, Pb and Zn, but increased As solubility. Earthworms decreased water soluble Cu and As but increased Pb and Zn in porewater. The effect of the earthworms decreased with increasing compost amendment. The impact of the compost and the earthworms on metal solubility is explained by their effect on pH and soluble organic carbon and the environmental chemistry of each element. - Graphical abstract: Display Omitted Highlights: > Compost reduced the mobility of Cu, Pb and Zn. > Compost increased the mobility of As. > Earthworms decreased water soluble As and Cu but increased Pb and Zn in porewater. > These effects are explained by the impact of the earthworms and compost on pH and DOC. - The effect of earthworms on metal solubility was due to changes in dissolved organic carbon and pH but was reduced with increasing compost amendments.

  17. Impact of earthworms on trace element solubility in contaminated mine soils amended with green waste compost

    International Nuclear Information System (INIS)

    The common practice of remediating metal contaminated mine soils with compost can reduce metal mobility and promote revegetation, but the effect of introduced or colonising earthworms on metal solubility is largely unknown. We amended soils from an As/Cu (1150 mgAs kg-1 and 362 mgCu kg-1) and Pb/Zn mine (4550 mgPb kg-1 and 908 mgZn kg-1) with 0, 5, 10, 15 and 20% compost and then introduced Lumbricus terrestris. Porewater was sampled and soil extracted with water to determine trace element solubility, pH and soluble organic carbon. Compost reduced Cu, Pb and Zn, but increased As solubility. Earthworms decreased water soluble Cu and As but increased Pb and Zn in porewater. The effect of the earthworms decreased with increasing compost amendment. The impact of the compost and the earthworms on metal solubility is explained by their effect on pH and soluble organic carbon and the environmental chemistry of each element. - Graphical abstract: Display Omitted Highlights: ? Compost reduced the mobility of Cu, Pb and Zn. ? Compost increased the mobility of As. ? Earthworms decreased water soluble As and Cu but increased Pb and Zn in porewater. ? These effects are explained by the impact of the earthworms and compost on pH and DOC. - The effect of earthworms on metal solubility was due to changes in dissolved organic carbon and pH but was reduced with increasing compost amendments.

  18. Warming shifts `worming': effects of experimental warming on invasive earthworms in northern North America

    Science.gov (United States)

    Eisenhauer, Nico; Stefanski, Artur; Fisichelli, Nicholas A.; Rice, Karen; Rich, Roy; Reich, Peter B.

    2014-11-01

    Climate change causes species range shifts and potentially alters biological invasions. The invasion of European earthworm species across northern North America has severe impacts on native ecosystems. Given the long and cold winters in that region that to date supposedly have slowed earthworm invasion, future warming is hypothesized to accelerate earthworm invasions into yet non-invaded regions. Alternatively, warming-induced reductions in soil water content (SWC) can also decrease earthworm performance. We tested these hypotheses in a field warming experiment at two sites in Minnesota, USA by sampling earthworms in closed and open canopy in three temperature treatments in 2010 and 2012. Structural equation modeling revealed that detrimental warming effects on earthworm densities and biomass could indeed be partly explained by warming-induced reductions in SWC. The direction of warming effects depended on the current average SWC: warming had neutral to positive effects at high SWC, whereas the opposite was true at low SWC. Our results suggest that warming limits the invasion of earthworms in northern North America by causing less favorable soil abiotic conditions, unless warming is accompanied by increased and temporally even distributions of rainfall sufficient to offset greater water losses from higher evapotranspiration.

  19. The Role of Earthworms in Tropics with Emphasis on Indian Ecosystems

    International Nuclear Information System (INIS)

    The paper highlights the research carried out by different scientists in India on aspects of earthworm population dynamics and species diversity, associated with other soil fauna and microflora. It also deals with the importance of earthworm activity on physicochemical properties of soil with reference to India and other tropical countries. Stress is laid on the earthworm plant association and importance of the secretions of earthworms as plant growth stimulators. Moreover, the earthworm species reported and being utilized for vermicomposting in India are discussed, since vermicomposting is the ultimate technology which renders for the improvement of soil fertility status and plant growth. Earthworms serve as indicators of soil status such as the level of contamination of pollutants: agrochemicals, heavy metals, toxic substances, and industrial effluents; human-induced activities: land-management practices and forest degradation. In all these fields there is lacuna with respect to contributions from India when compared to the available information from other tropical countries. There is lot of scope in the field of research on earthworms to unravel the importance of these major soil macro fauna from holistic ecological studies to the molecular level.

  20. Polychlorinated biphenyls (PCBs) depress allogeneic natural cytotoxicity by earthworm coelomocytes

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.M.; Cooper, E.L. [Univ. of California, Los Angeles, CA (United States). Lab. of Comparative Immunology; Eyambe, G.S.; Goven, A.J.; Fitzpatrick, L.C. [Univ. of North Texas, Denton, TX (United States). Dept. of Biological Sciences; Venables, B.J. [Univ. of North Texas, Denton, TX (United States). Dept. of Biological Sciences]|[TRAC Labs., Denton, TX (United States)

    1995-10-01

    Coelomocytes of the earthworm Lumbricus terrestris caused significant spontaneous allogeneic cytotoxicity in a 24-h trypan blue assay, but not in an assay using lactate dehydrogenase (LDH) release. Allogeneic cytotoxicity assays using cells from worms exposed to polychlorinated biphenyls (PCBs) suggest that PCBs can suppress a natural killing (NK-like) reaction. The implications of this work are twofold: understanding the evolution of natural killing (NK-like) activity and providing preliminary information on how spontaneous killing, a component of cellular immunity, may be compromised by pollutants.

  1. Co-Speciation of Earthworms and their nephridial symbionts, Acidovorax Spp

    DEFF Research Database (Denmark)

    Lund, Marie Braad; Fritz, Michael

    2006-01-01

    Earthworms (Annelida; Lumbricidae) harbour species-specific symbiotic bacteria in their nephridia (excretory organs) where the symbionts densely colonize a specific part of the nephridia called the ampulla [1]. The symbiosis is universal among earthworms, the symbionts form a monophyletic cluster within the genus Acidovorax [2], and they are transmitted vertically [3]. For these reasons, we suggest that the earthworm-Acidovorax association has evolved by co-speciation. This hypothesis was tested by a comparative study of earthworm and symbiont phylogeny. Different earthworm species were collected in Denmark and DNA was extracted from their nephridia. Earthworm phylogeny was resolved on the basis of mitochondrial cytochrome c oxidase subunit I (COI) by direct PCR amplification and sequencing from the nephridial DNA extract. Symbiont 16S rRNA gene sequences were retrieved by cloning and sequencing the extracted DNA. The presence of the symbionts in the ampulla was verified by performing fluorescence in situ hybridization (FISH) on all worm species using an Acidovorax-specific probe. Earthworm and symbiont phylogeny was largely congruent, indicating that host and symbiont have indeed co-evolved since the initial bacterial colonization of an ancestral lumbricid worm. However, the association is complicated by the recent discovery of additional, putative symbiotic bacteria which have been detected in the ampulla of several earthworms by FISH. Identity, distribution among earthworms, and function of these non-Acidovorax symbionts are still to be investigated. [1] Knop, J. 1926. Z Morph Ökol Tiere, 6(3):588-624. [2] Schramm, A. et al. 2003. Environ Microbiol 5(9):804-809. [3] Davidson, S.K. & Stahl, D.A. 2006. Appl Environ Microbiol 72(1):769-775.

  2. Automated Analysis of Two-Dimensional Positions and Body Lengths of Earthworms (Oligochaeta); MimizuTrack

    Science.gov (United States)

    Yonemura, Seiichiro; Kaneda, Satoshi; Ohashi, Mizue; Ikeno, Hidetoshi

    2014-01-01

    Earthworms are important soil macrofauna inhabiting almost all ecosystems. Their biomass is large and their burrowing and ingestion of soils alters soil physicochemical properties. Because of their large biomass, earthworms are regarded as an indicator of “soil heath”. However, primarily because the difficulties in quantifying their behavior, the extent of their impact on soil material flow dynamics and soil health is poorly understood. Image data, with the aid of image processing tools, are a powerful tool in quantifying the movements of objects. Image data sets are often very large and time-consuming to analyze, especially when continuously recorded and manually processed. We aimed to develop a system to quantify earthworm movement from video recordings. Our newly developed program successfully tracked the two-dimensional positions of three separate parts of the earthworm and simultaneously output the change in its body length. From the output data, we calculated the velocity of the earthworm's movement. Our program processed the image data three times faster than the manual tracking system. To date, there are no existing systems to quantify earthworm activity from continuously recorded image data. The system developed in this study will reduce input time by a factor of three compared with manual data entry and will reduce errors involved in quantifying large data sets. Furthermore, it will provide more reliable measured values, although the program is still a prototype that needs further testing and improvement. Combined with other techniques, such as measuring metabolic gas emissions from earthworm bodies, this program could provide continuous observations of earthworm behavior in response to environmental variables under laboratory conditions. In the future, this standardized method will be applied to other animals, and the quantified earthworm movement will be incorporated into models of soil material flow dynamics or behavior in response to chemical substances present in the soil. PMID:24886977

  3. Impacts of epigeic, anecic and endogeic earthworms on metal and metalloid mobility and availability.

    Science.gov (United States)

    Sizmur, Tom; Tilston, Emma L; Charnock, John; Palumbo-Roe, Barbara; Watts, Michael J; Hodson, Mark E

    2011-02-01

    The introduction of earthworms into soils contaminated with metals and metalloids has been suggested to aid restoration practices. Eisenia veneta (epigeic), Lumbricus terrestris (anecic) and Allolobophora chlorotica (endogeic) earthworms were cultivated in columns containing 900 g soil with 1130, 345, 113 and 131 mg kg(-1) of As, Cu, Pb and Zn, respectively, for up to 112 days, in parallel with earthworm-free columns. Leachate was produced by pouring water on the soil surface to saturate the soil and generate downflow. Ryegrass was grown on the top of columns to assess metal uptake into biota. Different ecological groups affected metals in the same way by increasing concentrations and free ion activities in leachate, but anecic L. terrestris had the greatest effect by increasing leachate concentrations of As by 267%, Cu by 393%, Pb by 190%, and Zn by 429% compared to earthworm-free columns. Ryegrass grown in earthworm-bearing soil accumulated more metal and the soil microbial community exhibited greater stress. Results are consistent with earthworm enhanced degradation of organic matter leading to release of organically bound elements. The degradation of organic matter also releases organic acids which decrease the soil pH. The earthworms do not appear to carry out a unique process, but increase the rate of a process that is already occurring. The impact of earthworms on metal mobility and availability should therefore be considered when inoculating earthworms into contaminated soils as new pathways to receptors may be created or the flow of metals and metalloids to receptors may be elevated. PMID:21161093

  4. Survival analysis

    International Nuclear Information System (INIS)

    The primary endpoint in the majority of the studies has been either disease recurrence or death. This kind of analysis requires a special method since all patients in the study experience the endpoint. The standard method for estimating such survival distribution is Kaplan Meier method. The survival function is defined as the proportion of individuals who survive beyond certain time. Multi-variate comparison for survival has been carried out with Cox's proportional hazard model

  5. Acute toxicity of virgin and used engine oil enriched with copper nano particles in the earthworm

    Energy Technology Data Exchange (ETDEWEB)

    Khodabandeh, M; Koohi, M K; Shahroziyan, E; Badri, B; Pourfallah, A; Shams, Gh; Sadeghi-Hashjin, G [Faculty of Veterinary Medicine, University of Tehran, Tehran (Iran, Islamic Republic of); Roshani, A [Industrial and Environmental Protection Division, Research Institute of Petroleum Industry (RRIPI), Tehran (Iran, Islamic Republic of); Hobbenaghi, R, E-mail: gsadeghi@ut.ac.ir [Faculty of Veterinary Medicine, Urmia University, Urmia (Iran, Islamic Republic of)

    2011-07-06

    In spite of development of nanotechnology and creation of new opportunities for industry, new applications and products initiated by this technology may cause harmful effects on human health and environment. Unfortunately, there is no sufficient information on the harmful effects caused by application of some nano materials; the current knowledge in this field is limited solely to the nano particles but not the final products. Nano cupper particles, as one of the common materials produced in industrial scale is widely used as additives into engine oil to reduce friction and improve lubrication. However, the difference between the effects of virgin and used conventional engine oil (CEO) and the engine oil containing cupper nano particles (NEO) on the environment is not known. Earthworm, as a one of the species which could live and survive in different sorts of earth and has a certain role in protecting the soil structure and fertility, was used in this experiment. In accordance with the recommended method of OECD.1984, Filter Paper test in 24 and 48 h based on 8 concentrations in the range of 3x10{sup -3} - 24x10{sup -3} ml/cm{sup 2} and Artificial Soil test in 7 and 14 days based on 7 concentrations in the range of 0.1 mg/kg - 100 g/kg were carried out to study earthworms in terms of lifetime (LC50), morphology and pathology. It was shown that the 48 h LC50 for virgin CEO, virgin NEO, used CEO(8000 km) and used NEO (8000 km) were 6x10{sup -3}, 23x10{sup -3}, 24x10{sup -3} and 16x10{sup -3} ml/cm{sup 2} respectively. Furthermore, 14-day LC50 in artificial soil for all cases were above 100 g/kg. It is concluded that virgin CEO is more toxic than virgin NEO. Meanwhile, the CEO shows significant reduction in toxicity after consumption and the used NEO shows more toxicity in comparison to virgin product. It seems that more investigations on the effects of final products specifically after consumption is necessary because the products after consumption have the most contact with environment and subsequently human health.

  6. Acute toxicity of virgin and used engine oil enriched with copper nano particles in the earthworm

    Science.gov (United States)

    Khodabandeh, M.; Koohi, M. K.; Roshani, A.; Shahroziyan, E.; Badri, B.; Pourfallah, A.; Shams, Gh; Hobbenaghi, R.; Sadeghi-Hashjin, G.

    2011-07-01

    In spite of development of nanotechnology and creation of new opportunities for industry, new applications and products initiated by this technology may cause harmful effects on human health and environment. Unfortunately, there is no sufficient information on the harmful effects caused by application of some nano materials; the current knowledge in this field is limited solely to the nano particles but not the final products. Nano cupper particles, as one of the common materials produced in industrial scale is widely used as additives into engine oil to reduce friction and improve lubrication. However, the difference between the effects of virgin and used conventional engine oil (CEO) and the engine oil containing cupper nano particles (NEO) on the environment is not known. Earthworm, as a one of the species which could live and survive in different sorts of earth and has a certain role in protecting the soil structure and fertility, was used in this experiment. In accordance with the recommended method of OECD.1984, Filter Paper test in 24 and 48 h based on 8 concentrations in the range of 3×10-3 - 24×10-3 ml/cm2 and Artificial Soil test in 7 and 14 days based on 7 concentrations in the range of 0.1 mg/kg - 100 g/kg were carried out to study earthworms in terms of lifetime (LC50), morphology and pathology. It was shown that the 48 h LC50 for virgin CEO, virgin NEO, used CEO(8000 km) and used NEO (8000 km) were 6×10-3, 23×10-3, 24×10-3 and 16×10-3 ml/cm2 respectively. Furthermore, 14-day LC50 in artificial soil for all cases were above 100 g/kg. It is concluded that virgin CEO is more toxic than virgin NEO. Meanwhile, the CEO shows significant reduction in toxicity after consumption and the used NEO shows more toxicity in comparison to virgin product. It seems that more investigations on the effects of final products specifically after consumption is necessary because the products after consumption have the most contact with environment and subsequently human health.

  7. Contact freezing: a review of experimental studies

    Directory of Open Access Journals (Sweden)

    L. A. Ladino Moreno

    2013-10-01

    Full Text Available This manuscript compiles both theoretical and experimental information on contact freezing with the aim to better understand this potentially important but still not well quantified heterogeneous freezing mode. There is no complete theory that describes contact freezing and how the energy barrier has to be overcome to nucleate an ice crystal by contact freezing. Experiments on contact freezing conducted using the cold plate technique indicate that it can initiate ice formation at warmer temperatures than immersion freezing. Additionally, a qualitative difference in the freezing temperatures between contact and immersion freezing has been found using different instrumentation and different ice nuclei. There is a lack of data on collision rates in most of the reported data, which inhibits a quantitative calculation of the freezing efficiencies. Thus, new or modified instrumentation to study contact nucleation in the laboratory and in the field are needed to identify the conditions at which contact nucleation could occur in the atmosphere. Important questions concerning contact freezing and its potential role for ice cloud formation and climate are also summarized.

  8. Soil Chemical Weathering and Nutrient Budgets along an Earthworm Invasion Chronosequence in a Northern Minnesota Forest

    Science.gov (United States)

    Resner, K. E.; Yoo, K.; Sebestyen, S. D.; Aufdenkampe, A. K.; Lyttle, A.; Weinman, B. A.; Blum, A.; Hale, C. M.

    2011-12-01

    We are investigating the impact of exotic earthworms on the rate of nutrient and ion release from soil chemical weathering along an ~200 m invasion chronosequence in a northern Minnesota sugar maple forest. The earthworms belong to three ecological groups that represent different feeding and burrowing behaviors, all of which were introduced from Europe to the previously earthworm-free Great Lakes Region through fishing and agricultural activities. As earthworms digest and mix the soil, we hypothesize that they significantly alter chemical weathering processes by incorporating mineral surfaces to new geochemical environments in their intestines and at different soil depths. The effect of mixing on soil morphology is dramatic, but biogeochemical changes remain largely unknown and therefore are poorly coupled to the current and potential changes in forest ecosystems under the threat of exotic earthworms. We analyze the activities of short-lived isotopes 137-Cs and 210-Pb along with the inorganic chemistry of soil, water, and leaf litter across an invasion transect and link these measurements to the biomass and species composition of exotic earthworms. Earthworms vertically relocate minerals and organic matter largely within the top ~10 cm, which is reflected in the depth profiles of the short-lived isotopes. Among the inorganic nutrients analyzed, Ca is of particular interest due to sugar maple's aptitude for recycling Ca. Fractional mass loss values (tau) of Ca, relative to the soil's parent material, show an enrichment factor of 14 in the least invaded A horizon soils. However, such a high enrichment factor declines dramatically in the heavily invaded soils, suggesting that earthworm activities contribute to leaching Ca. In contrast, the enrichment factor of Fe increases with greater degrees of earthworm invasion, which is consistent with the extraction chemistry data showing greater quantities of pedogenic crystalline iron oxides and greater mineral specific surface area (presumably due to the crystalline iron oxides) in the heavily invaded soils. Water chemistry of lysimeter samples show a similar trend: the heavily invaded soils show a lower solute concentration of Ca but higher concentrations of Fe. These data indicate that exotic earthworms, while significantly affecting chemical weathering processes in the soils, are seriously altering (1) the budgets of inorganic nutrient in these hardwood forests and (2) the minerals' potential capacity to complex carbon on their surface area. Our ongoing work includes the use of optically stimulated luminescence (OSL) dating which may complement the 137-Cs and 210-Pb data in constraining soil mixing. Additionally, we will incorporate leaf litter chemistry and continue water and earthworm sampling to understand the degree that exotic earthworms contribute to chemical weathering in the Great Lakes hardwood ecosystems.

  9. Putrescine is involved in Arabidopsis freezing tolerance and cold acclimation by regulating Abscisic acid levels in response to low temperature

    OpenAIRE

    Cuevas, Juan Cruz; Lo?pez-cobollo, Rosa Mari?a; Alcazar, Rube?n; Zarza, Xavier; Koncz, Csaba S.; Altabella, Teresa; Salinas, Julio; Tiburcio, Antonio Ferna?ndez; Ferrando, Alejandro

    2008-01-01

    The levels of endogenous polyamines have been shown to increase in plant cells challenged with low temperature; however, the functions of polyamines in the regulation of cold stress responses are unknown. Here, we show that the accumulation of putrescine under cold stress is essential for proper cold acclimation and survival at freezing temperatures because Arabidopsis (Arabidopsis thaliana) mutants defective in putrescine biosynthesis (adc1, adc2) display reduced freezing tolerance compared ...

  10. Scaling of the hydrostatic skeleton in the earthworm Lumbricus terrestris.

    Science.gov (United States)

    Kurth, Jessica A; Kier, William M

    2014-06-01

    The structural and functional consequences of changes in size or scale have been well studied in animals with rigid skeletons, but relatively little is known about scale effects in animals with hydrostatic skeletons. We used glycol methacrylate histology and microscopy to examine the scaling of mechanically important morphological features of the earthworm Lumbricus terrestris over an ontogenetic size range from 0.03 to 12.89 g. We found that L. terrestris becomes disproportionately longer and thinner as it grows. This increase in the length to diameter ratio with size means that, when normalized for mass, adult worms gain ~117% mechanical advantage during radial expansion, compared with hatchling worms. We also found that the cross-sectional area of the longitudinal musculature scales as body mass to the ~0.6 power across segments, which is significantly lower than the 0.66 power predicted by isometry. The cross-sectional area of the circular musculature, however, scales as body mass to the ~0.8 power across segments, which is significantly higher than predicted by isometry. By modeling the interaction of muscle cross-sectional area and mechanical advantage, we calculate that the force output generated during both circular and longitudinal muscle contraction scales near isometry. We hypothesize that the allometric scaling of earthworms may reflect changes in soil properties and burrowing mechanics with size. PMID:24871920

  11. The binding interactions of imidacloprid with earthworm fibrinolytic enzyme

    Science.gov (United States)

    Wang, Yan-Qing; Zhang, Hong-Mei; Chen, Tao

    2014-08-01

    In this paper, several studies were conducted to elucidate the binding mechanism of earthworm fibrinolytic enzyme (EFE) with imidocloprid (IMI) by using theoretical calculation, fluorescence, UV-vis, circular dichroism spectroscopy and an enzymatic inhibition assay. The spectral data showed that the binding interactions existed between IMI and EFE. The binding constants, binding site, thermodynamic parameters and binding forces were analyzed in detail. The results indicate a single class of binding sites for IMI in EFE and that this binding interaction is a spontaneous process with the estimated enthalpy and entropy changes being 2.195 kJ mol-1 and 94.480 J mol-1 K-1, respectively. A single class of binding site existed for IMI in EFE. The tertiary or secondary structure of EFE was partly destroyed by IMI. The visualized binding details were also exhibited by the theoretical calculation and the results indicated that the interaction between IMI and Phe (Tyr, or Trp) or EFE occurred. Combining the experimental data with the theoretical calculation data, we showed that the binding forces between IMI and EFE were mainly hydrophobic force accompanied by hydrogen binding, and ?-? stacking. In addition, IMI did not obviously influence the activity of EFE. In a word, the above analysis offered insights into the binding mechanism of IMI with EFE and could provide some important information for the molecular toxicity of IMI for earthworms.

  12. [Social egg freezing: which problems?].

    Science.gov (United States)

    Belaisch-Allart, J; Brzakowski, M; Chouraqui, A; Grefenstette, I; Mayenga, J-M; Muller, E; Belaid, Y; Kulski, O

    2013-09-01

    In today's society, many women push pregnancy further away from the "right" childbearing age. Assisted reproduction, except egg donation, is unable to fully overcome the effect of age on fertility loss. The effectiveness of oocyte vitrification is demonstrated, and oocyte vitrification is allowed in the French Bioethics law of 2011. In the French law, oocyte' s cryopreservation is proposed to oocyte donors without child. Social egg freezing for non-medical reason is already legal in some countries, but leads to new debates and discussions. PMID:23972923

  13. Hot big bang or slow freeze?

    OpenAIRE

    Wetterich, C.

    2014-01-01

    We confront the big bang for the beginning of the universe with an equivalent picture of a slow freeze - a very cold and slowly evolving universe. In the freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The freeze and big bang pictures both describe the same observations or physical reality. We present a simple "crossover model" without a big bang singularit...

  14. Glyphosate herbicide affects belowground interactions between earthworms and symbiotic mycorrhizal fungi in a model ecosystem

    Science.gov (United States)

    Zaller, Johann G.; Heigl, Florian; Ruess, Liliane; Grabmaier, Andrea

    2014-07-01

    Herbicides containing glyphosate are widely used in agriculture and private gardens, however, surprisingly little is known on potential side effects on non-target soil organisms. In a greenhouse experiment with white clover we investigated, to what extent a globally-used glyphosate herbicide affects interactions between essential soil organisms such as earthworms and arbuscular mycorrhizal fungi (AMF). We found that herbicides significantly decreased root mycorrhization, soil AMF spore biomass, vesicles and propagules. Herbicide application and earthworms increased soil hyphal biomass and tended to reduce soil water infiltration after a simulated heavy rainfall. Herbicide application in interaction with AMF led to slightly heavier but less active earthworms. Leaching of glyphosate after a simulated rainfall was substantial and altered by earthworms and AMF. These sizeable changes provide impetus for more general attention to side-effects of glyphosate-based herbicides on key soil organisms and their associated ecosystem services.

  15. Earthworm Casts (Pheretema sp. Nutrient Contents of Nampong Soil Series (Ustoxic Quartzipsamment in Northeast Thailand

    Directory of Open Access Journals (Sweden)

    T. Chuasavathi

    2001-01-01

    Full Text Available This earthworm cast experiment was carried out at four different sites of Nampong soil series (Ustoxic quartzipsamment namely dipterocarp forest, tamarind orchard farm, grazing pasture, and sugarcane plantation. The results showed that earthworm casts of the four locations contented different levels of nutrients. The highest nutrient contents were found with Tamarind orchard farm followed by Dipterocarp forest, grazing pasture, and sugarcane plantation, respectively. Data on nutrient contents (NPK, Ca, Mg, and Na of earthworm casts of each location were much higher than that of their respective soils. Earthworm casts could help to improve soil properties particularly Nampong soil series, which contented low level of soil fertility. This may help to improve crop yield for sustainable agriculture.

  16. Earthworm activity in a simulated landfill cover soil shifts the community composition of active methanotrophs.

    Science.gov (United States)

    Kumaresan, Deepak; Héry, Marina; Bodrossy, Levente; Singer, Andrew C; Stralis-Pavese, Nancy; Thompson, Ian P; Murrell, J Colin

    2011-12-01

    Landfills represent a major source of methane in the atmosphere. In a previous study, we demonstrated that earthworm activity in landfill cover soil can increase soil methane oxidation capacity. In this study, a simulated landfill cover soil mesocosm (1 m × 0.15 m) was used to observe the influence of earthworms (Eisenia veneta) on the active methanotroph community composition, by analyzing the expression of the pmoA gene, which is responsible for methane oxidation. mRNA-based pmoA microarray analysis revealed that earthworm activity in landfill cover soil stimulated activity of type I methanotrophs (Methylobacter, Methylomonas, Methylosarcina spp.) compared to type II methanotrophs (particularly Methylocystis spp.). These results, along with previous studies of methanotrophs in landfill cover soil, can now be used to plan in situ field studies to integrate earthworm-induced methanotrophy with other landfill management practises in order to maximize soil methane oxidation and reduce methane emissions from landfills. PMID:21925596

  17. Inhibition effect of glyphosate on the acute and subacute toxicity of cadmium to earthworm Eisenia fetida.

    Science.gov (United States)

    Zhou, Chui-Fan; Wang, Yu-Jun; Sun, Rui-Juan; Liu, Cun; Fan, Guang-Ping; Qin, Wen-Xiu; Li, Cheng-Cheng; Zhou, Dong-Mei

    2014-10-01

    The acute and subacute toxicities of cadmium (Cd) to earthworm Eisenia fetida in the presence and absence of glyphosate were studied. Although Cd is highly toxic to E. fetida, the presence of glyphosate markedly reduced the acute toxicity of Cd to earthworm; both the mortality rate of the earthworms and the accumulation of Cd decreased with the increase of the glyphosate/Cd molar ratio. The subcellular distribution of Cd in E. fetida tissues showed that internal Cd was dominant in the intact cells fraction and the heat-stable proteins fraction. The presence of glyphosate reduced the concentration of Cd in all fractions, especially the intact cells. During a longer period of exposure, the weight loss of earthworm and the total Cd absorption was alleviated by glyphosate. Thus, the herbicide glyphosate can reduce the toxicity and bioavailability of Cd in the soil ecosystems at both short- and long-term exposures. PMID:25043609

  18. Predicting Arabidopsis Freezing Tolerance and Heterosis in Freezing Tolerance from Metabolite Composition

    OpenAIRE

    Korn, Marina; Ga?rtner, Tanja; Erban, Alexander; Kopka, Joachim; Selbig, Joachim; Hincha, Dirk K.

    2009-01-01

    Heterosis, or hybrid vigor, is one of the most important tools in plant breeding and has previously been demonstrated for plant freezing tolerance. Freezing tolerance is an important trait because it can limit the geographical distribution of plants and their agricultural yield. Plants from temperate climates increase in freezing tolerance during exposure to low, non-freezing temperatures in a process termed ‘cold acclimation’. Metabolite profiling has indicated a major reprogramming of p...

  19. Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils.

    Science.gov (United States)

    Sizmur, Tom; Palumbo-Roe, Barbara; Watts, Michael J; Hodson, Mark E

    2011-03-01

    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota. PMID:21185630

  20. Breeding of Freeze-tolerant Yeast and the Mechanisms of Stress-tolerance

    Science.gov (United States)

    Hino, Akihiro

    Frozen dough method have been adopted in the baking industry to reduce labor and to produce fresh breads in stores. New freeze-tolerant yeasts for frozen dough preparations were isolated from banana peel and identified. To obtain strains that have fermentative ability even after several months of frozen storage in fermented dough, we attempted to breed new freeze-tolerantstrain. The hybrid between S.cerevisiae, which is a isolated freeze-tolerant strain, and a strain isolated from bakers' yeast with sexual conjugation gave a good quality bread made from frozen dough method. Freeze-tolerant strains showed higher surviving and trehalose accumulating abilities than freeze-sensitive strains. The freeze tolerance of the yeasts was associated with the basal amount of intracellular trehalose after rapid degradation at the onset of the prefermentation period. The complicated metabolic pathway and the regulation system of trehalose in yeast cells are introduced. The trehalose synthesis may act as a metabolic buffer system which contribute to maintain the intracellular inorganic phosphate and as a feedback regulation system in the glycolysis. However, it is not known enough how the trehalose protects yeast cells from stress.

  1. Earthworms (Millsonia anomala, Megascolecidae) do not increase rice growth through enhanced nitrogen mineralization

    OpenAIRE

    Blouin, Manuel; Barot, Se?bastien; Lavelle, Patrick

    2006-01-01

    Earthworms have been shown to increase plant growth in 75% of the experiments that have compared plant growth in their presence and absence. However, the relative importance of the different mechanisms advanced to explain such a stimulatory effect has never been tested. In a laboratory experiment, we observed increased growth of rice plants in the presence of earthworms (Millsonia anomala, Megascolecidae) and demonstrated that enhanced nitrogen release (generally considered as the principal m...

  2. Soil structure and earthworm activity in an marine silt loam under pasture versus arable land

    OpenAIRE

    Jongmans, A. G.; Pulleman, M. M.; Marinissen, J. C. Y.

    2001-01-01

    Agricultural management influences soil organic matter (SOM) and earthworm activity which interact with soil structure. We aimed to describe the change in earthworm activity and related soil (micro)structure and SOM in a loamy Eutrodept as affected by permanent pasture (PP) and conventional arable (CA). Thin sections were studied and biogenic calcite spheroids, worm casts, infillings and groundmass coatings were quantified. In both soils, sedimentary stratification was absent up till 50 cm de...

  3. Earthworms - role in soil fertility to the use in medicine and as a food

    OpenAIRE

    Grdis?a, M.; Grs?ic?, K.; Md, Grdis?a

    2013-01-01

    Earthworms are important regulators of soil structure and dynamics of soil organic matter. They are a major component of soil fauna communities in most ecosystems and comprise a large proportion of macro fauna biomass. Their activities are beneficial because they can enhance soil nutrient cycling through the rapid incorporation of detritus into mineral soil. However, mucus production associated with water excretion in earthworm guts also enhances the activity of other beneficial soil microorg...

  4. Earthworm communities in alluvial forests: Influence of altitude, vegetation stages and soil parameters

    OpenAIRE

    Salome?, Cle?mence; Guenat, Claire; Bullinger-weber, Ge?raldine; Gobat, Jean-michel; Le Bayon, Rene?e-claire

    2011-01-01

    In many terrestrial ecosystems, soil parameters usually regulate the distribution of earthworm communities.In alluvial ecosystems, few studies have investigated the impact of periodic floods and alluvium deposition on soil fauna. In this context, we assumed that earthworm communities may vary depending on altitude (alpine, subalpine, mountain and hill levels), forest successional stage (post-pioneer to mature forests) and some soil parameters. Our results demonstrated that the composition of ...

  5. Radioresistance of aboriginal earthworms of Absheron peninsula in radioactive model systems

    International Nuclear Information System (INIS)

    Full text : Soil animals are the most suitable biological indicators of radioactive pollution because they are parts of nutritional chains and webs, occur in relatively high numbers and can be collected during most parts of the year. The use of earthworms in the soils from Ramana (Baku) iodine plant area of Absheron peninsula, which is rich with radionuclide and in the soil mixed with RaCl2 and UO2SO4 salt solutions in different concentrations, for resistance to ionizing radiation in soil is reviewed. Effect of radionuclides on vital functions of earthworms and determination of radionuclides (before and after experiments) in contaminated soils by ?-spectrometer were carried out in laboratory condition during a month. Regarding to ?-spectrometric results there were determined that earthworms had absorbed most of radioactive elements and allocated them as coprogenous substances on the upper layer of soil. In Ramana soils mostly the 238U radionuclides were highly accumulated in gut cells of the earthworms. By the influence of radioactive elements it was shown that the earthworms from Ramana iodine plant territory variants had proved particularly sensitive to an increased Ra-radiation background and to iodine factor. It was interestingly established the proportional dependence between rising level of accumulation in earthworms body and in their coprolites and increasing of radioactive salts containing in the soils treated by UO22SO4 and RaCl2 solutions. Thus there is different level of radioresistance for earthworms and they are among the best bioindicators of polluted soils. There was an obvious perspective of using of earthworms as bioremediators in polluted soil with radionuclides in future as well.

  6. Radioresistance of aboriginal earthworms of Absheron peninsula in radioactive model systems

    International Nuclear Information System (INIS)

    Full tex:Soil animals are the most suitable biological indicators of radioactive pollution because they are parts of nutritional chains and webs, occur in relatively high numbers and can be collected during most parts of the year.The use of earthworms in the soils from Ramana iodine plant area of Absheron peninsula, which is rich with radionuclide and in the soil mixed with RaCl2 and UO2SO4 salt solutions in different concentrations, for resistance to ionizing radiation in soil is reviewed.Effect of radionuclides on vital functions of earthworms and determination of radionuclides (before and after experiments) in contaminated soils by ?-spectrometer were carried out in laboratory condition during a month. Regarding to ?-spectrometric results there were determined that earthworms had absorbed most of radioactive elements and allocated them as coprogenous substances on the upper layer of soil. In Ramana soils mostly the 238U radionuclides were highly accumulated in gut cells of the earthworms. By the influence of radioactive elements it was shown that the earthworms from Ramana iodine plant territory variants had proved particularly sensitive to an increased Ra-radiation background and to iodine factor.It was interestingly established the proportional dependence between rising level of accumulation in earthworms' body and in their coprolites and increasing of radioactive salts containing in the soils treated by UO2SO4 and RaCl2 solutions.Thus there is different level ofsolutions.Thus there is different level of radioresistance for earthworms and they are among the best bioindicators of polluted soils. There was an obvious perspective of using of earthworms as bioremediators in polluted soil with radionuclides in future as well.

  7. Earthworms as Ecosystem Engineers and the Most Important Detritivors in Forest Soils

    OpenAIRE

    Yahya Kooch; Hamid Jalilvand

    2008-01-01

    Earthworms are considered as soil engineers because of their effects on soil properties and their influence on the availability of resources for other organisms, including microorganisms and plants. However, the links between their impacts on the soil environment and the resulting modification of natural selection pressures on engineer as well as on other organisms have received little attention. Earthworms are known to have a positive influence on the soil fabric and on the decompositi...

  8. Soil organic matter distribution as influenced by enchytraeid and earthworm activity

    OpenAIRE

    Koutika, L. S.; Didden, W. A. M.; Marinissen, J. C. Y.

    2001-01-01

    Loam and sandy soils, and the earthworm casts produced with 14C-labelled plant material in both soils, were incubated in airtight glass vessels with and without enchytraeids to evaluate the effects of soil fauna on the distribution and fragmentation of organic matter. After 1, 3, and 6 weeks, the amount of C mineralised was determined in soils and earthworm casts, and the soil was fractionated into particulate organic matter (POM), the most active pool of soil organic matter, after complete p...

  9. Earthworms and management affect organic matter incorporation and microaggregate formation in agricultural soils

    OpenAIRE

    Pulleman, M. M.; Six, J.; Uyl, A.; Marinissen, J. C. Y.; Jongmans, A. G.

    2005-01-01

    Through their feeding activities and cast production, earthworms influence both aggregate turnover and soil organic matter (SOM) dynamics. We studied the impact of earthworm activity on soil macro- and microaggregation and SOM incorporation in different farming systems. Dry-sieved aggregates (4¿12.5 mm) of a permanent pasture (PP), a conventional arable field (CA) and an organic arable field (OA) (0¿10 and 10¿20 cm depth) were separated into different aggregate fractions, which were analyz...

  10. Quantitative arsenic speciation in two species of earthworms from a former mine site

    OpenAIRE

    Watts, Michael; Button, Mark; Brewer, T. S.; Jenkin, G. W. T.; Harrington, C. F.

    2008-01-01

    The relationship between the total arsenic concentration and the chemical speciation of arsenic in two species of earthworm (Lumbricus rubellus and Dendrodillus rubidus) in relation to the host soil, was investigated for 13 sites of varying arsenic content, including a 10 background level garden soil and a former mine site at the Devon Great Consols, UK. Earthworms were collected with the host soil (As soil concentration range 16 - 12,466 mg kg-1 dry weight) and measured for th...

  11. Diversity of glycosyl hydrolases from cellulose-depleting communities enriched from casts of two earthworm species

    OpenAIRE

    Beloqui, Ana; Nechitaylo, Taras Y.; Lopez-cortes, Nieves; Ghazi, Azam; Guazzaroni, Mari?a-eugenia; Polaina, Julio; Strittmatter, Axel W.; Reva, Oleg N.; Waliczek, Agnes; Yakimov, Michail M.; Golyshina, Olga V.; Ferrer, Manuel; Golyshin, Peter N.

    2010-01-01

    The guts and casts of earthworms contain microbial assemblages that process large amounts of organic polymeric substrates from plant litter and soil; however, the enzymatic potential of these microbial communities remains largely unexplored. In the present work, we retrieved carbohydrate-modifying enzymes through the activity screening of metagenomic fosmid libraries from cellulose-depleting microbial communities established with the fresh casts of two earthworm species, Aporrectodea caligino...

  12. Screening of actinomycetes from earthworm castings for their antimicrobial activity and industrial enzymes

    OpenAIRE

    Vijay Kumar; Alpana Bharti; Yogesh Kumar Negi; Omprakash Gusain; Piyush Pandey; Gajraj Singh Bisht

    2012-01-01

    Actinomycetes from earthworm castings were isolated and screened for their antimicrobial activity and industrial enzymes. A total of 48 isolates were obtained from 12 samples of earthworm castings. Highest numbers of isolates were recovered from forest site (58.33 %) as compared to grassland (25%) and agricultural land (16.66%). The growth patterns, mycelial coloration of abundance actinomycetes were documented. The dominant genera Identified by cultural, morphological and physiological chara...

  13. Plasmid Transfer between Spatially Separated Donor and Recipient Bacteria in Earthworm-Containing Soil Microcosms

    OpenAIRE

    Daane, L. L.; Molina, J.; Sadowsky, M. J.

    1997-01-01

    Most gene transfer studies have been performed with relatively homogeneous soil systems in the absence of soil macrobiota, including invertebrates. In this study we examined the influence of earthworm activity (burrowing, casting, and feeding) on transfer of plasmid pJP4 between spatially separated donor (Alcaligenes eutrophus) and recipient (Pseudomonas fluorescens) bacteria in nonsterile soil columns. A model system was designed such that the activity of earthworms would act to mediate cell...

  14. Influence of earthworm activity on gene transfer from Pseudomonas fluorescens to indigenous soil bacteria.

    OpenAIRE

    Daane, L. L.; Molina, J. A.; Berry, E. C.; Sadowsky, M. J.

    1996-01-01

    We have developed a model system to assess the influence of earthworm activity on the transfer of plasmid pJP4 from an inoculated donor bacterium, Pseudomonas fluorescens C5t (pJP4), to indigenous soil microorganisms. Three different earthworm species (Lumbricus terrestris, Lumbricus rubellus, and Aporrectodea trapezoides), each with unique burrowing, casting, and feeding behaviors, were evaluated. Soil columns were inoculated on the surface with 10(8) cells per g of soil of the donor bacteri...

  15. A simple and effective method to keep earthworms confined to open-top mesocosms

    OpenAIRE

    Lubbers, I. M.; Groenigen, J. W.

    2013-01-01

    Earthworms can have a profound effect on a myriad of soil physical, chemical and microbial parameters. To better understand their role in the soil, they are often studied under controlled conditions. However, a persistent problem in such controlled experiments is the ability of earthworms to escape from experimental units with open tops (e.g. for plant growth). Here, we tested whether adhesive hook tape applied to the inside of mesocosms is effective in confining them to their experimental un...

  16. Influence of ground cover on earthworm communities in an unmanaged beech forest: linear gradient studies

    OpenAIRE

    Campana, Cyril; Gauvin, Ste?phanie; Ponge, Jean-franc?ois

    2002-01-01

    Micro-scale changes in earthworm communities and ground cover types were studied along five transect lines in an unmanaged beech forest (Fontainebleau forest, France). Spatial patterns were interpreted in the light of interactions between earthworm species and forest architecture, ground vegetation and quantity as well as quality of litter. The anecic Lumbricus terrestris was associated with patches of the grass Melica uniflora, with poor litter cover, while most epigeic species were favoured...

  17. Complete mitochondrial genome of a Pheretimoid earthworm Metaphire vulgaris (Oligochaeta: Megascolecidae).

    Science.gov (United States)

    Zhang, Liangliang; Jiang, Jibao; Dong, Yan; Qiu, Jiangping

    2014-03-11

    Abstract We have determined the mitochondrial genome of the first Pheretimoid earthworm, Metaphire vulgaris (Chen, 1930). This mitogenome is 15,061?bp in length containing 37 genes typical of other annelid. All genes are encoded by the same strand, ATP8 is not adjacent to ATP6, all 13 PCGs use ATG as a start codon. These features are consistent with first determined earthworm Lumbricus terrestris, but unusual among animal mtDNAs. PMID:24617491

  18. How insects survive the cold: molecular mechanisms - a review

    OpenAIRE

    Clark, Melody S.; Worland, M. Roger

    2008-01-01

    Insects vary considerably in their ability to survive low temperatures. The tractability of these organisms to experimentation has lead to considerable physiology-based work investigating both the variability between species and the actual mechanisms themselves. This has highlighted a range of strategies including freeze tolerance, freeze avoidance, protective dehydration and rapid cold hardening, which are often associated with the production of specific chemicals such as antifreezes and pol...

  19. Earthworm Ecology in the Northern Part of Iran: With an Emphasis on Compost Worm Eisenia fetida

    OpenAIRE

    Omrani, G. A.; Zamanzadeh, M.; Maleki, A.; Ashori, Y.

    2005-01-01

    In the present study, Northern part of Iran was chosen as study area. Four hundred samples of earthworms were collected by three methods (hand-sorting, chemical and heat extraction) of which 352 and 20 were mature and immature earthworms, respectively from different parts of the area. Following the method introduced by Graff the earthworms were placed in formaldehyde (5 and 10%) and ethyl alcohol (60%). The morphological observations showed the presence of eight species including seven specim...

  20. Metallothionein Induction in the Coelomic Fluid of the Earthworm Lumbricus terrestris following Heavy Metal Exposure: A Short Report

    OpenAIRE

    Calisi, A.; Lionetto, M. G.; Lorenzis, E.; Leomanni, A.; Schettino, T.

    2014-01-01

    Earthworms are useful bioindicator organisms for soil biomonitoring. Recently the use of pollution biomarkers in earthworms has been increasingly investigated for soil monitoring and assessment. Earthworm coelomic fluid is particularly interesting from a toxicological perspective, because it is responsible for pollutant disposition and tissue distribution to the whole organism. The aim of the present work was to study the effect of heavy metal exposure on metallothionein (Mt) induction in the...

  1. Influence of plant-earthworm interactions on SOM chemistry and p,p'-DDE bioaccumulation.

    Science.gov (United States)

    Kelsey, Jason W; Slizovskiy, Ilya B; Petriello, Michael C; Butler, Kelly L

    2011-05-01

    Laboratory experiments assessed how bioaccumulation of weathered p,p'-DDE from soil and humic acid (HA) chemistry are affected by interactions between the plants Cucurbita pepo ssp. pepo and ssp. ovifera and the earthworms Eisenia fetida, Lumbricus terrestris, and Apporectodea caliginosa. Total organochlorine phytoextraction by ssp. pepo increased at least 25% in the presence of any of the earthworm species (relative to plants grown in isolation). Uptake of the compound by ssp. ovifera was unaffected by earthworms. Plants influenced earthworm bioaccumulation as well. When combined with pepo, p,p'-DDE levels in E. fetida decreased by 50%, whereas, in the presence of ovifera, bioconcentration by L. terrestris increased by more than 2-fold. Spectral analysis indicated a decrease in hydrophobicity of HA in each of the soils in which both pepo and earthworms were present. However, HA chemistry from ovifera treatments was largely unaffected by earthworms. Risk assessments of contaminated soils should account for species interactions, and SOM chemistry may be a useful indictor of pollutant bioaccumulation. PMID:21421253

  2. Earthworms as Ecosystem Engineers and the Most Important Detritivors in Forest Soils

    Directory of Open Access Journals (Sweden)

    Yahya Kooch

    2008-01-01

    Full Text Available Earthworms are considered as soil engineers because of their effects on soil properties and their influence on the availability of resources for other organisms, including microorganisms and plants. However, the links between their impacts on the soil environment and the resulting modification of natural selection pressures on engineer as well as on other organisms have received little attention. Earthworms are known to have a positive influence on the soil fabric and on the decomposition and mineralization of litter by breaking down organic matter and producing large amounts of fasces, thereby mixing litter with the mineral soil. Therefore, they play an important part in changes from one humus from to another according to forest succession patterns. Consequently, they are also expected to be good bio-indicators for forest site quality and are thus useful when planning forest production improvement. Earthworm`s populations are as indicator that in exploited regions is destruction indicator and reclamation plans is nature return indicator. In this study we summarized the current knowledge in relation to earthworm`s ecology in forest soils as ecosystem engineers.

  3. Enantioselective toxicity, bioaccumulation and degradation of the chiral insecticide fipronil in earthworms (Eisenia feotida).

    Science.gov (United States)

    Qu, Han; Wang, Peng; Ma, Rui-xue; Qiu, Xing-xu; Xu, Peng; Zhou, Zhi-qiang; Liu, Dong-hui

    2014-07-01

    The enantioselective acute toxicity to earthworms of racemic fipronil and its individual enantiomers was studied. R-(-)-fipronil was approximately 1.5 times more toxic than the racemate and approximately 2 times more toxic than S-(+)-fipronil after 72 and 96 h of exposure, respectively. Assays of fipronil enantiomer bioaccumulation and degradation in earthworms were conducted. The bio-concentration factors (BCFs) were slightly different between the two enantiomers. The enantiomeric fraction (EF) values in earthworms in the bioaccumulation period were approximately 0.5, which indicated there was no enantioselective bioaccumulation. In contrast, the degradation of fipronil in earthworms was enantioselective: the t1/2 values for R- and S-fipronil were 3.3 and 2.5 days, respectively, in natural soil, and 2.1 and 1.4 days, respectively, in artificial soil. The results of soil analyses showed that the degradation of fipronil was not enantioselective, which suggested that the enantioselectivity of fipronil in earthworms results from the organism's metabolism. The study also demonstrated that the presence of earthworms could accelerate the degradation of fipronil in soil. PMID:24742550

  4. Invasive earthworms interact with abiotic conditions to influence the invasion of common buckthorn (Rhamnus cathartica).

    Science.gov (United States)

    Roth, Alexander M; Whitfeld, Timothy J S; Lodge, Alexandra G; Eisenhauer, Nico; Frelich, Lee E; Reich, Peter B

    2014-12-01

    Common buckthorn (Rhamnus cathartica L.) is one of the most abundant and ecologically harmful non-native plants in forests of the Upper Midwest United States. At the same time, European earthworms are invading previously glaciated areas in this region, with largely anecdotal evidence suggesting they compound the negative effects of buckthorn and influence the invasibility of these forests. Germination and seedling establishment are important control points for colonization by any species, and manipulation of the conditions influencing these life history stages may provide insight into why invasive species are successful in some environments and not others. Using a greenhouse microcosm experiment, we examined the effects of important biotic and abiotic factors on the germination and seedling establishment of common buckthorn. We manipulated light levels, leaf litter depth and earthworm presence to investigate the independent and interactive effects of these treatments on buckthorn establishment. We found that light and leaf litter depth were significant predictors of buckthorn germination but that the presence of earthworms was the most important factor; earthworms interacted with light and leaf litter to increase the number and biomass of buckthorn across all treatments. Path analysis suggested both direct and moisture-mediated indirect mechanisms controlled these processes. The results suggest that the action of earthworms may provide a pathway through which buckthorn invades forests of the Upper Midwest United States. Hence, researchers and managers should consider co-invasion of plants and earthworms when investigating invasibility and creating preemptive or post-invasion management plans. PMID:25481818

  5. Aporrectodea caliginosa, a suitable earthworm species for field based genotoxicity assessment?

    International Nuclear Information System (INIS)

    There is a growing interest for the application of biomakers to field-collected earthworms. Therefore we have evaluated the usability of native populations of endogeic, widely distributed earthworm Aporrectodea caliginosa in the assessment of soil genotoxicity using the Comet assay. Validation of the Comet assay on earthworm coelomocytes has been established using commercially available Eisenia fetida exposed to copper, cadmium, and pentachlorophenol, along with A. caliginosa exposed to copper in a filter paper contact test. Neutral red retention time (NRRT) assay was conducted on copper exposed and field-collected earthworms. Significant DNA and lysosomal damage was measured using Comet and NRRT assays in native populations of A. caliginosa sampled from the polluted soils in the urban area in comparison to the earthworms from the reference site. The results of this study confirm the employment of A. caliginosa as a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Research highlights: ? Native A. caliginosa has shown significant biological effect measured by the Comet and NRRT assays. ? The Comet assay on A. caliginosa and E. fetida has shown to be of similar sensitivity as the NRRT assay. ? A. caliginosa is a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Native populations of endogeic earthworm Aporrectodea caliginosa can be successfully applied in the genotoxicity field surveys using Comet assaicity field surveys using Comet assay.

  6. Impact of land protection in soil quality properties and in earthworm biomass in Venezuelan savannas

    Scientific Electronic Library Online (English)

    D, López-Hernández; L, Hernández; A, Ojeda; E, Quintero; S, Caipo.

    2014-12-01

    Full Text Available We studied soil parameters and the earthworm biomass and density in a protected savanna (PS) from fire and cattle raising for more than forty years located at Estación Biológica de los Llanos, Venezuela (EBLL), and an adjacent non-protected savanna (NS) under frequent burning and agricultural activi [...] ties, located less than 1 km apart. Earthworm sampling was carried out at the end of the dry season (April), and at the peak of the wet season (July-August) using a hand sorting extraction method. In each plot, five to seven sampling units were selected corresponding to soil monoliths of 25x25x30 cm. The main physical, chemical, microbial (biomass) and enzymatic activities of soils in both systems were estimated. Thepresence of an abundant litter layer under the tree canopies in the PS have increased the soil water retention capacity, the organic-C, C-microbial biomass, dehydrogenase activity and fertility levels respect NS. This may allow for an increase in the density and biomass of earthworms in the PS compared with the adjacent NS. The systems were characterized by abundance in juvenile individuals belonging to the Glossoscolecidae family; two different morphotypes of the genus Aicodrilus were registered. Earthworms found were located in an endo-anecic ecological category. Results suggest that, agricultural management in savannas by modification of physical and biochemical soil properties can decrease an important fraction of pedofauna, particularly their earthworm communities. However, earthworm populations and soil quality indicators can be restored after long-term protection.

  7. Radiocesium (137Cs) from the Chernobyl reactor in Eurasian woodcock and earthworms in Norway

    International Nuclear Information System (INIS)

    To understand the ecological effects of the Chernobyl reactor accident, we investigated radiocesium (137Cs) levels in Eurasian woodcock (Scolopax rusticola), earthworms (Lambricidae), litter (dead organic materials lying on the ground), humus (beneath litter 2 cm deep), and mineral soil samples (3-6 cm deep) from a heavily effected (20-60 kBq/m2[1 Bq = 1 nuclear fission/sec]) area in Norway. The highest concentrations measured in earthworms (1988 median = 142 Bq/Kg) and woodcock (1986 median = 730 Bq/kg) for human food (600 Bq/kg fresh mass) only were found in woodcock during 1986. Radiocesium concentrations decreased (P < 0.001) in earthworms (40%) and woodcock (95%) from 1986 to 1990. There was no reduction in total radiocesium in soil over the same period. The relatively high radiocesium concentrations in woodcock during 1986 and the decreasing radiocesium ratio in woodcock to earthworms during the first years following fallout could have been caused by woodcock ingesting abiotic radiocesium with earthworms. The decrease in radiocesium in woodcock and earthworms during the study (1986-90) probably resulted from decreasing bioavailability of radiocesium during the first years after fallout rather than by radiocesium disappearing from the ecosystem. 38 refs., 3 figs., 2 tabs

  8. The “deduction” approach: A non-invasive method for estimating secondary production of earthworm communities

    Science.gov (United States)

    Eriksen-Hamel, Nikita S.; Whalen, Joann K.

    2009-05-01

    Secondary production is an important parameter for the study of population dynamics and energy flow through animal communities. Secondary production of earthworm communities has been determined with the size-frequency and instantaneous growth rate methods, whereby earthworm populations are repeatedly sampled at regular intervals and the change in biomass of cohorts or individuals between sampling dates is determined. The major disadvantage of repeated sampling is that it disturbs the soil and permanently removes earthworms from the study area. The " deduction" approach is a theoretical model that partitions individuals into defined pools and makes assumptions about the growth, recruitment and mortality of each pool. In 2004 and 2005, earthworms were added to undisturbed field enclosures and the " deduction" approach was used to estimate secondary production of the indigenous and added earthworm populations during the crop growing period (17-18 weeks) in each year. Secondary production estimates made by the " deduction" approach were similar to estimates from direct earthworm sampling in temperate agroecosystems. The "deduction" approach is an indirect method that estimates population dynamics and secondary production, and is appropriate for manipulation experiments where removal of organisms and physical disturbance of the habitat by repeated sampling could bias results.

  9. Physical and chemical characterization of earthworms and humus obtained by vertical vermicomposting

    Directory of Open Access Journals (Sweden)

    Lucélia Hoehne

    2013-01-01

    Full Text Available Earthworms culture are usually made horizontally and it is necessary a lot of area. In order to minimize the size of earthworms culture and the possibility to be applied in residences, this paper proposed evaluate conditions for vertical vermicomposting. For this, were purchased vertical boxes and organic matter. The earthworms of species Eisenia andrei, california red earthworms, were used. There were evaluated the adaptation of earthworms and physical and chemical characterization of the humus. Results showed that there was a good adaptation of earthworms in this configuration, minimizing the space required, and it is one technique for environmentally friendly recycling of organic waste, creating a bio-product wich can used as fertilizers.Resumo Minhocários são normalmente feitoshorizontalmente sendo necessária uma área grande. A fim de minimizar o tamanho da cultura de minhocas e a possibilidade de ser aplicado em residências, este trabalho propõe avaliar as condições de vermicompostagem vertical. Para isso, foram adquiridas caixas verticais e matéria orgânica. Foram usadas minhocas da espécie Eisenia andrei, minhocas vermelhas da califórmia. Foi avaliada a adaptação das minhocas e caracterização físico-química do húmus gerado. Os resultados mostraram que houve uma boa adaptação das minhocas nesta configuração, minimizando o espaço utilizado, e é uma técnica de reciclagem ecológica de resíduos orgânicos, a criação de umbioproduto o qual pode ser usado como adubo.

  10. Response of Nitrous Oxide Flux to Addition of Anecic Earthworms to an Agricultural Field

    Directory of Open Access Journals (Sweden)

    José A. Amador

    2013-05-01

    Full Text Available The burrowing and feeding activities of earthworms may have a strong effect on the flux of N2O from agricultural soils. As such, shifts to agricultural management practices that increase the number of earthworms require an understanding of the role of earthworms in N2O dynamics. We conducted a field experiment to examine the effects of addition of anecic earthworms (Lumbricus terrestris on N2O flux in a field previously planted with corn (Zea mays in southern Rhode Island, USA. Plots were amended with (15NH42SO4 and either 0 (CTL or 48 L. terrestris m-2 (EW. The flux of N2O, 15N2O and 15N2 was measured over 28 days between October and November 2008. The EW treatment had a significantly higher flux of N2O and 15N2O 1 - 3 days after 15NH4 addition. No treatment effects were observed on 15N2 flux. The addition of earthworms significantly increased (Day 1 and decreased (Day 12 the mole fraction of N2O relative to the CTL. Our results suggest that anecic earthworm additions can increase N2O flux from inorganic fertilizer N amendments, but the effects appear to short-lived.

  11. To freeze or not to freeze: adaptations for overwintering by hatchlings of the North American painted turtle.

    Science.gov (United States)

    Packard, Gary C; Packard, Mary J

    2004-08-01

    Many physiologists believe that hatchling painted turtles (Chrysemys picta) provide a remarkable, and possibly unique, example of 'natural freeze-tolerance' in an amniotic vertebrate. However, the concept of natural freeze-tolerance in neonatal painted turtles is based on results from laboratory studies that were not placed in an appropriate ecological context, so the concept is suspect. Indeed, the weight of current evidence indicates that hatchlings overwintering in the field typically withstand exposure to ice and cold by avoiding freezing altogether and that they do so without benefit of an antifreeze to depress the equilibrium freezing point for bodily fluids. As autumn turns to winter, turtles remove active nucleating agents from bodily fluids (including bladder and gut), and their integument becomes a highly efficient barrier to the penetration of ice into body compartments from frozen soil. In the absence of a nucleating agent or a crystal of ice to 'catalyze' the transformation of water from liquid to solid, the bodily fluids remain in a supercooled, liquid state. The supercooled animals nonetheless face physiological challenges, most notably an increased reliance on anaerobic metabolism as the circulatory system first is inhibited and then caused to shut down by declining temperature. Alterations in acid/base status resulting from the accumulation of lactic acid may limit survival by supercooled turtles, and sublethal accumulations of lactate may affect behavior of turtles after the ground thaws in the spring. The interactions among temperature, circulatory function, metabolism (both aerobic and anaerobic), acid/base balance and behavior are fertile areas for future research on hatchlings of this model species. PMID:15277545

  12. Cryoprotectants and Extreme Freeze Tolerance in a Subarctic Population of the Wood Frog

    Science.gov (United States)

    Costanzo, Jon P.; Reynolds, Alice M.; do Amaral, M. Clara F.; Rosendale, Andrew J.; Lee, Richard E.

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 ?mol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 ?mol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 ?mol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to –8°C, either directly or following three cycles of freezing/thawing between –4 and 0°C, or –16°C increased the liver’s synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica. PMID:25688861

  13. Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.

    Science.gov (United States)

    Costanzo, Jon P; Reynolds, Alice M; do Amaral, M Clara F; Rosendale, Andrew J; Lee, Richard E

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 ?mol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 ?mol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 ?mol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica. PMID:25688861

  14. Macropores and earthworm species affected by agronomic intensification

    DEFF Research Database (Denmark)

    Krogh, Paul Henning; Pérès, Guénola

    Soil ecosystem services depend on water regulation both to retain soil moisture and to eliminate water excess without harmful loss of particles and nutrients. As such the combination of soil physical properties that support soil hydrological functioning is a well-recognized service delivered by soil. There is widespread recognition of soil biodiversity and biological activities that are needed to sustain soil structural properties. The detrimental consequences of a weakened functionality have been stressed in the EU Soil Strategy and hydrology in particular is related to all soil threats. Biopores and soil aggregate formation have been shown to be crucial results of soil macroorganism activities contributing to soil hydrology. In collaboration between the French “Observatoire de Recherche en Environnement – Agro-écosystèmes, Cycles Biogéochimiques et Biodiversité” (ORE-ACBB) and the FP7 EU project EcoFINDERS we investigated the relationsship between earthworm biodiversity, macropores and three agricultural landuse types. A field campaign was conducted in October-November 2011. Earthworm burrow distribution was quantified at 10, 20, 30, 50 and 100 20 cm horizontal layer intervals down the soil profile to 1 meter depth and correlated with the earthworm community consisting of 12 species dominated by the endogeics Aporrectodea caliginosa and Aporrectodea chlorotica and the anecics Aporrectodea longa and Lumbricus centralis. Medium-small macropores in the ploughing layer with diameters (Ø) less than 5 mm were significantly more abundant in permanent grassland compared to conventional rotation system with annual crops. An intermediate system with 3 year grass and 3 years with annuals was also intermediate between the two other systems. At 30 cm's depth we found no large macropores, Ø >7 mm, in the system with annuals, but increasingly more in rotations with grass. Addition of frequencies of macropores with Ø>7 mm retains the significant difference between annual and the permanent grass system. Moreover, all the large burrows, >5 mm Ø, follow this pattern and are significantly more numerous in permanent grass to annuals (P<3%). At depth 100 cm total number of macropores were more abundant in the annual crops compared with permanent grass (P=5%), due to a larger number of macropores <7 mm. We present an interpretation of the macropore patterns in relation to the anecic and endogeic lifeforms and their established role in creating burrows of different spatial distribution and density.

  15. Repeatability and randomness in heterogeneous freezing nucleation

    Directory of Open Access Journals (Sweden)

    G. Vali

    2008-02-01

    Full Text Available This study is aimed at clarifying the relative importance of the specific character of the nuclei and of the duration of supercooling in heterogeneous freezing nucleation by immersed impurities. Laboratory experiments were carried out in which sets of water drops underwent multiple cycles of freezing and melting. The drops contained suspended particles of mixtures of materials; the resulting freezing temperatures ranged from ?6°C to ?24°C. Rank correlation coefficients between observed freezing temperatures of the drops in successive runs were >0.9 with very high statistical significance, and thus provide strong support for the modified singular model of heterogeneous immersion freezing nucleation. For given drops, changes in freezing temperatures between cycles were relatively small (<1°C for the majority of the events. These frequent small fluctuations in freezing temperatures are interpreted as reflections of the random nature of embryo growth and are associated with a nucleation rate that is a function of a temperature difference from the characteristic temperatures of nuclei. About a sixth of the changes were larger, up to ±5°C, and exhibited some systematic patterns. These are thought to arise from alterations of the nuclei, some being permanent and some transitory. The results are used to suggest ways of describing ice initiation in cloud models that account for both the temperature and the time dependence of freezing nucleation.

  16. Repeatability and randomness in heterogeneous freezing nucleation

    Directory of Open Access Journals (Sweden)

    G. Vali

    2008-08-01

    Full Text Available This study is aimed at clarifying the relative importance of the specific character of the nuclei and of the duration of supercooling in heterogeneous freezing nucleation by immersed impurities. Laboratory experiments were carried out in which sets of water drops underwent multiple cycles of freezing and melting. The drops contained suspended particles of mixtures of materials; the resulting freezing temperatures ranged from ?6°C to ?24°C. Rank correlation coefficients between observed freezing temperatures of the drops in successive runs were >0.9 with very high statistical significance, and thus provide strong support for the modified singular model of heterogeneous immersion freezing nucleation. For given drops, changes in freezing temperatures between cycles were relatively small (<1°C for the majority of the events. These frequent small fluctuations in freezing temperatures are interpreted as reflections of the random nature of embryo growth and are associated with a nucleation rate that is a function of a temperature difference from the characteristic temperatures of nuclei. About a sixth of the changes were larger, up to ±5°C, and exhibited some systematic patterns. These are thought to arise from alterations of the nuclei, some being permanent and some transitory. The results are used to suggest ways of describing ice initiation in cloud models that account for both the temperature and the time dependence of freezing nucleation.

  17. Fish With Nature's Anti-freeze

    Science.gov (United States)

    Using this material, students will discover that under special experimental conditions, fish have been observed functioning in ice-free cold salt water at a temperature of -6 degrees Centigrade. Research has found that these fish have eight types of anti-freeze molecules which bathe the interior surface of their skin, acting as a barrier to ice propagating in from outside. When the anti-freeze molecules are not present, ice filters through their skin at these temperatures and crystallizes (freezes) their blood and tissues. Students will experiment with lowering the freezing point of a substance, thus causing it to remain liquid at a temperature when it is normally solid. Students will compare their findings with facts about Antarctic ice-fish, which have bodily fluids that remain liquid at temperatures below freezing.

  18. Freeze concentration of lime juice

    Directory of Open Access Journals (Sweden)

    Ampawan Tansakul

    2008-11-01

    Full Text Available The main objective of this research was to study the effects of processing conditions, i.e. cooling medium temperature (-6, -12 and -18?C and scraper blade rotational speed (50, 100 and 150 rpm on the freeze concentration of lime juice. The initial soluble solid content of lime juice was 7.6? Brix. Results showed that soluble solid content of lime juice increased as cooling medium temperature decreased while scraper blade rotational speed increased. It was also found that the processing condition with -18?C cooling medium temperature and 150 rpm rotational speed of the scraper blade was the best among all studied conditions, although the loss of the soluble solids with ice crystals during ice separation was relatively high at 35%.

  19. Escape and avoidance learning in the earthworm Eisenia hortensis

    Directory of Open Access Journals (Sweden)

    W. Jeffrey Wilson

    2014-01-01

    Full Text Available Interest in instrumental learning in earthworms dates back to 1912 when Yerkes concluded that they can learn a spatial discrimination in a T-maze. Rosenkoetter and Boice determined in the 1970s that the “learning” that Yerkes observed was probably chemotaxis and not learning at all. We examined a different form of instrumental learning: the ability to learn both to escape and to avoid an aversive stimulus. Freely moving “master” worms could turn off an aversive white light by increasing their movement; the behavior of yoked controls had no effect on the light. We demonstrate that in as few as 12 trials the behavior of the master worms comes under the control of this contingency.

  20. Earthworms newly from Mongolia (Oligochaeta, Lumbricidae, Eisenia

    Directory of Open Access Journals (Sweden)

    Robert Blakemore

    2013-04-01

    Full Text Available Two new megadrile earthworms from the steppes, the first species wholly from Outer Mongolia, are ascribed to the partially parthenogenetic Eisenia nordenskioldi (Eisen, 1879 species-complex. Taxonomic justification of sympatric Eisenia nordenskioldi mongol and E. nordenskioldi onon ssp. n. are supported by mtDNA COI barcodes. The unreliability of molecular differentiation based on voucher names compared to definitive types is again demonstrated, as pertains to the ultimate Eisenia andrei Bouché, 1972 synonym of the E. fetida (Savigny, 1826 sibling species-complex composed of more than a dozen prior names. Similar species described from Northeast China [formerly Manchuria] and North Korea are briefly considered, albeit they are intermittently held in synonymy of cosmopolitan Aporrectodea rosea (Savigny, 1826 along with many other taxa including some exotic lumbricids initially found in India. Japanese and North American lumbricids are also mentioned. Distributions are discussed and an annotated checklist of all nine Siberian/sub-arctic E. nordenskioldi ssp. is appended.

  1. A novel fibrinolytic enzyme extracted from the earthworm, Lumbricus rubellus.

    Science.gov (United States)

    Mihara, H; Sumi, H; Yoneta, T; Mizumoto, H; Ikeda, R; Seiki, M; Maruyama, M

    1991-01-01

    A strong fibrinolytic enzyme was readily obtained in saline extracts of the earthworm, Lumbricus rubellus. It hydrolyzed not only plasminogen-rich fibrin plates, but also plasminogen-free fibrin plates. The average fibrinolytic activity was about 100 CU (plasmin units) or 250 IU (urokinase units)/g wet weight. The molecular weight and isoelectric point were about 20,000 and 3.4, respectively. The enzyme was heat-stable and displayed a very broad optimal pH range. DFP and SBTI strongly inhibited the enzyme, but the anti-plasmin agent, t-AMCHA, exerted little effect under the same conditions. Purification of the enzyme was performed and three partially purified fractions were obtained. These three fractions were further subdivided. The first fraction (F-I) was divided into three fractions (F-I-0, F-I-1, and F-I-2), which exhibited similar biochemical characteristics. The second fraction (F-II) could not be subdivided. The third fraction (F-III) was divided into two fractions (F-III-1 and F-III-2). Based on results for their enzymatic activities against various substrates, the fraction I enzymes are thought to represent a chymotrypsin-like enzyme and the fraction III enzymes to represent a trypsin-like enzyme. The fraction II enzyme appears to be neither a trypsin- or chymotrypsin-like enzyme nor an elastase. The amino acid compositions of the six enzymes were estimated. Compared with other serine enzymes, these enzymes contained very abundant asparagine or aspartic acid, and there was very little proline or lysine. From the above data, these enzymes are regarded as novel fibrinolytic enzymes, and we name them collectively as Lumbrokinase from the generic name of the earthworm. PMID:1960890

  2. Cryopreservation of porcine spermatogonial stem cells by slow-freezing testis tissue in trehalose.

    Science.gov (United States)

    Lee, Y-A; Kim, Y-H; Ha, S-J; Kim, K-J; Kim, B-J; Kim, B-G; Choi, S-H; Kim, I-C; Schmidt, J A; Ryu, B-Y

    2014-03-01

    Spermatogonial stem cells provide the foundation for continued adult spermatogenesis and their manipulation can facilitate assisted reproductive technologies or the development of transgenic animals. Because the pig is an important agricultural and biomedical research animal, the development of practical application techniques to manipulate the pig Spermatogonial stem cell is needed. The ability to preserve porcine Spermatogonial stem cell or testis tissue long term is one of these fundamental techniques. The objective of this study was to optimize methods to cryopreserve porcine Spermatogonial stem cell when freezing testis cells or testis tissue. To identify the most efficient cryopreservation technique, porcine testis cells (cell freezing) or testis tissue (tissue freezing) were frozen in medium containing dimethyl sulfoxide (DMSO) and fetal bovine serum (FBS) or DMSO, FBS, and various concentrations of trehalose (50, 100, or 200 mM). After thawing, undifferentiated germ cells were enriched and treatments were evaluated for cryopreservation efficiency. The tissue freezing method resulted in significantly greater germ cell recovery (P = 0.041) and proliferation capacity (P < 0.001) compared to the cell freezing treatment. Regardless of freezing method (cell vs. tissue), addition of 200 mM trehalose to freezing medium increased germ cell recovery and proliferation capacity compared to cells frozen using the same freezing method without trehalose. Interestingly, addition of trehalose to the tissue freezing medium significantly increased germ cell recovery (P = 0.012) and proliferation capacity (P = 0.004) compared to the cell freezing treatment supplemented with trehalose. To confirm that cryopreservation in trehalose improves the survival of Spermatogonial stem cell, testis cells enriched for undifferentiated germ cells were xenotransplanted into recipient mouse testes. Germ cells recovered from tissue frozen with 200 mM trehalose generated significantly more (P < 0.001) donor derived colonies than tissue frozen without trehalose. Regardless of cryopreservation medium or freezing method, testis cell recovery, viability, and proliferation capacity of germ cells after thawing were significantly lower compared to those of untreated fresh control. Nevertheless, these data demonstrate that undifferentiated porcine germ cells can be efficiently cryopreserved in the presence of 200 mM trehalose. PMID:24504041

  3. Modelling spatiotemporal distribution patterns of earthworms in order to indicate hydrological soil processes

    Science.gov (United States)

    Palm, Juliane; Klaus, Julian; van Schaik, Loes; Zehe, Erwin; Schröder, Boris

    2010-05-01

    Soils provide central ecosystem functions in recycling nutrients, detoxifying harmful chemicals as well as regulating microclimate and local hydrological processes. The internal regulation of these functions and therefore the development of healthy and fertile soils mainly depend on the functional diversity of plants and animals. Soil organisms drive essential processes such as litter decomposition, nutrient cycling, water dynamics, and soil structure formation. Disturbances by different soil management practices (e.g., soil tillage, fertilization, pesticide application) affect the distribution and abundance of soil organisms and hence influence regulating processes. The strong relationship between environmental conditions and soil organisms gives us the opportunity to link spatiotemporal distribution patterns of indicator species with the potential provision of essential soil processes on different scales. Earthworms are key organisms for soil function and affect, among other things, water dynamics and solute transport in soils. Through their burrowing activity, earthworms increase the number of macropores by building semi-permanent burrow systems. In the unsaturated zone, earthworm burrows act as preferential flow pathways and affect water infiltration, surface-, subsurface- and matrix flow as well as the transport of water and solutes into deeper soil layers. Thereby different ecological earthworm types have different importance. Deep burrowing anecic earthworm species (e.g., Lumbricus terrestris) affect the vertical flow and thus increase the risk of potential contamination of ground water with agrochemicals. In contrast, horizontal burrowing endogeic (e.g., Aporrectodea caliginosa) and epigeic species (e.g., Lumbricus rubellus) increase water conductivity and the diffuse distribution of water and solutes in the upper soil layers. The question which processes are more relevant is pivotal for soil management and risk assessment. Thus, finding relevant environmental predictors which explain the distribution and dynamics of different ecological earthworm types can help us to understand where or when these processes are relevant in the landscape. Therefore, we develop species distribution models which are a useful tool to predict spatiotemporal distributions of earthworm occurrence and abundance under changing environmental conditions. On field scale, geostatistical distribution maps have shown that the spatial distribution of earthworms depends on soil parameters such as food supply, soil moisture, bulk density but with different patterns for earthworm stages (adult, juvenile) and ecological types (anecic, endogeic, epigeic). On landscape scales, earthworm distribution seems to be strongly controlled by management/disturbance-related factors. Our study shows different modelling approaches for predicting distribution patterns of earthworms in the Weiherbach area, an agricultural site in Kraichtal (Baden-Württemberg, Germany). We carried out field studies on arable fields differing in soil management practices (conventional, conservational), soil properties (organic matter content, texture, soil moisture), and topography (slope, elevation) in order to identify predictors for earthworm occurrence, abundance and biomass. Our earthworm distribution models consider all ecological groups as well as different life stages, accounting for the fact that the activity of juveniles is sometimes different from those of adults. Within our BIOPORE-project it is our final goal to couple our distribution models with population dynamic models and a preferential flow model to an integrated ecohydrological model to analyse feedbacks between earthworm engineering and transport characteristics affecting the functioning of (agro-) ecosystems.

  4. Soil Aggregate Stability in the Presence of Earthworms (Lumbricus terrestris L. and Different Organic Materials in a Calcareous Soil

    Directory of Open Access Journals (Sweden)

    F. S. Moosavi

    2011-01-01

    Full Text Available Although the crucial function of earthworms in improvement of soil physical properties is well -know, but very little is known of the interactive influence of earthworms and organic materials on soil properties such as soil aggregate stability, particularly in arid and semi-arid soils. The low organic matter content and the significant role of earthworms in improving physical properties of arid and semi-arid soils necessitate studying the interactive effects of organic materials and earthworms. Thus, the main objective of this study was to identify the interactive effects of anecic earthworm (Lumbricus terrestris L. and various organic residues (including alfalfa, compost, mixture of alfalfa and compost and cow dung on soil aggregate stability expressed as the Mean Weight Diameter (MWD, Geometric Mean Diameter (GMD and Aggregation Ratio (AR, and furthermore soil Ca and Mg contents. The experiment consisted of a 2×5 factorial treatment organized in a completely randomized design with four replications under controlled greenhouse conditions, lasted for 150 days. Results showed that earthworm inoculation and organic materials addition alone increased significantly all the indices of soil aggregation and aggregate stability, and Ca and Mg contents. However, the combined use of earthworms and organic residues resulted in more stable aggregates. Results indicated that earthworm inoculation in the presence of organic materials resulted in 39, 58, 2, 67, 43 and 74% increases, respectively in MWD, AR, GMD, Ca, Mg and macroaggregates whereas microaggregates were reduced by 13.5% in earthworm-worked soils. We observed a significant relationship (R2=0.945 between soil Ca content and MWD, demonstrating that earthworms apparently excrete calcite that helps bonding clay particles and soil organic matter via cationic (Ca+2 bridging. In summary, results of this study show that the simultaneous applications of anecic earthworms and organic materials may considerably help in improving the structure of arid and semi-arid soils with low carbon level.

  5. The wonders of earthworms & its vermicompost in farm production: Charles Darwin’s ‘friends of farmers’, with potential to replace destructive chemical fertilizers

    OpenAIRE

    Dalsukh Valani; Krunal Chauhan; Sunita Agarwal; Sinha, Rajiv K.

    2010-01-01

    Earthworms and its excreta (vermicast) promises to usher in the ‘Second Green Revolution’ by completely replacing the destructive agro chemicals which did more harm than good to both the farmers and their farmland. Earthworms restore & improve soil fertility and significantly boost crop productivity. Earthworms excreta (vermicast) is a nutritive ‘organic fertilizer’ rich in humus, NKP, micronutrients, beneficial soil microbes—‘nitrogenfixing & phosphate solubilizing bacter...

  6. Surfactant-facilitated remediation of metal-contaminated soils: efficacy and toxicological consequences to earthworms.

    Science.gov (United States)

    Slizovskiy, Ilya B; Kelsey, Jason W; Hatzinger, Paul B

    2011-01-01

    The effectiveness of surfactant formulations to remove aged metals from a field soil and their influence on soil toxicity was investigated. Batch studies were conducted to evaluate the efficacy of cationic (1-dodecylpyridinium chloride; DPC), nonionic (oleyl dimethyl benzyl ammonium chloride; trade name Ammonyx KP), and anionic (rhamnolipid biosurfactant blend; trade name JBR-425) surfactants for extracting Zn, Cu, Pb, and Cd from a soil subjected to more than 80 years of metal deposition. All three surfactants enhanced removal of the target metals. The anionic biosurfactant JBR-425 was most effective, reducing Zn, Cu, Pb, and Cd in the soil by 39, 56, 68, and 43%, respectively, compared with less than 6% removal by water alone. Progressive acidification of the surfactants with citric acid buffer or addition of ethylenediaminetetra-acetic acid (EDTA) further improved extraction efficiency, with more than 95% extraction of all four metals by surfactants acidified to pH 3.6 and generally greater than 90% removal of all metals with addition of 0.1?M EDTA. In two species of earthworm, Eisenia fetida and Lumbricus terrestris, metal bioaccumulation was reduced by approximately 30 to 80%, total biomass was enhanced by approximately threefold to sixfold, and survival was increased to greater than 75% in surfactant-remediated soil compared with untreated soil. The data indicate that surfactant washing may be a feasible approach to treat surface soils contaminated with a variety of metals, even if those metals have been present for nearly a century, and that the toxicity and potential for metal accumulation in biota from the treated soils may be significantly reduced. PMID:20853447

  7. Plant genetic variation mediates an indirect ecological effect between belowground earthworms and aboveground aphids.

    Science.gov (United States)

    Singh, Akanksha; Braun, Julia; Decker, Emilia; Hans, Sarah; Wagner, Agnes; Weisser, Wolfgang W; Zytynska, Sharon E

    2014-10-21

    BackgroundInteractions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. Many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. We used an earthworm-plant-aphid model system with two aphid species (Aphis fabae and Acyrthosiphon pisum) to test the effect of host-plant (Vicia faba) genetic variation on the indirect interaction between the belowground earthworms (Eisenia veneta) on the aboveground aphid populations.ResultsOur data shows that host-plant variety mediated an indirect ecological effect of earthworms on generalist black bean aphids (A. fabae), with earthworms increasing aphid growth rate in three plant varieties but decreasing it in another variety. We found no effect of earthworms on the second aphid species, the pea aphid (A. pisum), and no effect of competition between the aphid species. Plant biomass was increased when earthworms were present, and decreased when A. pisum was feeding on the plant (mediated by plant variety). Although A. fabae aphids were influenced by the plants and worms, they did not, in turn, alter plant biomass.ConclusionsPrevious work has shown inconsistent effects of earthworms on aphids, but we suggest these differences could be explained by plant genetic variation and variation among aphid species. This study demonstrates that the outcome of belowground-aboveground interactions can be mediated by genetic variation in the host-plant, but depends on the identity of the species involved. PMID:25331082

  8. Avoidance behaviour response and esterase inhibition in the earthworm, Lumbricus terrestris, after exposure to chlorpyrifos.

    Science.gov (United States)

    Martínez Morcillo, S; Yela, J L; Capowiez, Y; Mazzia, C; Rault, M; Sanchez-Hernandez, Juan C

    2013-05-01

    The avoidance response of earthworms to polluted soils has been standardised using a simple and low-cost test, which facilitates soil toxicity screening. In this study, the avoidance response of Lumbricus terrestris was quantified in chlorpyrifos-spiked soils, depending on the pesticide concentration and exposure duration. The inhibition of acetylcholinesterase (AChE) and carboxylesterase (CbE) activities was also determined as indirect measures of pesticide bioavailability. The effects of different chlorpyrifos concentrations were examined in a standardised test (two-chamber system) with 0.6, 3 and 15 mg/kg chlorpyrifos. A modification of the test involved a pre-exposure step (24, 48 or 72 h) in soils spiked with 15 mg/kg. In both protocols, earthworms were unable to avoid the contaminated soils. However, the esterase activities showed that all earthworms were exposed to chlorpyrifos. Acetylcholinesterase activity did not change in earthworms in the standardised behavioural test (0.58 ± 0.20 U/mg protein, mean ± SD; n = 72), whereas the CbE activity was significantly inhibited (62-87 % inhibition) in earthworms exposed to 3 and 15 mg/kg. In the modified test, earthworms had greatly inhibited AChE activity (0.088 ± 0.034 U/mg protein, n = 72), which was supported by reactivation of the inhibited enzyme activity in the presence of pralidoxime (2-PAM). Similarly, the CbE activity was significantly inhibited in earthworms with all treatments. This study suggests that the avoidance behaviour test for organophosphorus-contaminated soils could be supported by specific biomarkers to facilitate a better understanding of pesticide exposure and toxicity during this test. PMID:23435687

  9. Rapid cold-hardening increases the freezing tolerance of the Antarctic midge Belgica antarctica.

    Science.gov (United States)

    Lee, Richard E; Elnitsky, Michael A; Rinehart, Joseph P; Hayward, Scott A L; Sandro, Luke H; Denlinger, David L

    2006-02-01

    Rapid cold-hardening (RCH) is well known to increase the tolerance of chilling or cold shock in a diverse array of invertebrate systems at both organismal and cellular levels. Here, we report a novel role for RCH by showing that RCH also increases freezing tolerance in an Antarctic midge, Belgica antarctica (Diptera, Chironomidae). The RCH response of B. antarctica was investigated under two distinct physiological states: summer acclimatized and cold acclimated. Summer-acclimatized larvae were less cold tolerant, as indicated by low survival following exposure to -10 degrees C for 24 h; by contrast, nearly all cold-acclimated larvae survived -10 degrees C, and a significant number could survive -15 degrees C. Cold-acclimated larvae had higher supercooling points than summer larvae. To evaluate the RCH response in summer-acclimatized midges, larvae and adults, maintained at 4 degrees C, were transferred to -5 degrees C for 1 h prior to exposures to -10, -15 or -20 degrees C. RCH significantly increased survival of summer-acclimatized larvae frozen at -10 degrees C for 1 h compared with larvae receiving no cold-hardening treatment, but adults, which live for only a week or so in the austral summer, lacked the capacity for RCH. In cold-acclimated larvae, RCH significantly increased freeze tolerance to both -15 and -20 degrees C. Similarly, RCH significantly increased cellular survival of fat body, Malpighian tubules and gut tissue from cold-acclimated larvae frozen at -20 degrees C for 24 h. These results indicate that RCH not only protects against non-freezing injury but also increases freeze tolerance. PMID:16424090

  10. Exploring the Nature of Contact Freezing

    Science.gov (United States)

    Kiselev, A. A.; Hoffmann, N.; Duft, D.; Leisner, T.

    2012-12-01

    The freezing of supercooled water droplets upon contact with aerosol particles (contact nucleation of ice) is the least understood mechanism of ice formation in atmospheric clouds. Although experimental evidences suggest that some aerosols can be better IN in the contact than in the immersion mode (that is, triggering ice nucleation at higher temperature), no final explanation of this phenomena currently exists. On the other hand, the contact freezing is believed to be responsible for the enhanced rate of secondary ice formation occasionally observed in LIDAR measurements in the cold mixed phase clouds. Recently we have been able to show that the freezing of supercooled droplets electrodynamically levitated in the laminar flow containing mineral dust particles (kaolinite) is a process solely governed by a rate of collisions between the supercooled droplet and the aerosol particles. We have shown that the probability of droplet freezing on a single contact with aerosol particle may differ over an order of magnitude for kaolinite particles having different genesis and morphology. In this presentation we extend the study of contact nucleation of ice and compare the IN efficiency measured for DMA-selected kaolinite, illite and hematite particles. We show that the freezing probability increases towards unity as the temperature decreases and discuss the functional form of this temperature dependence. We explore the size dependence of the contact freezing probability and show that it scales with the surface area of the particles, thus resembling the immersion freezing behavior. However, for all minerals investigated so far, the contact freezing has been shown to dominate over immersion freezing on the short experimental time scales. Finally, based on the combined ESEM and electron microprobe analysis, we discuss the significance of particle morphology and variability of chemical composition on its IN efficiency in contact mode.

  11. Simple improvement in freeze-tolerance of bakers' yeast with poly-gamma-glutamate.

    Science.gov (United States)

    Yokoigawa, Kumio; Sato, Machiko; Soda, Kenji

    2006-09-01

    We examined the effect of poly-gamma-glutamate (PGA) on the freeze-tolerance of four types of commercial bakers' yeast (freeze-tolerant, osmotic-tolerant, low-temperature-sensitive, and ordinary bakers' yeasts). The survival ratio of ordinary bakers' yeast cells frozen at -30 degrees C for 3 d in a medium (0.5% yeast extract, 0.5% peptone, and 2% glucose: YPD medium) was improved by adding more than 1% PGA to the medium; the survival ratio increased from about 10% to more than 70%. All PGA preparations, which differed in average molecular mass (50, 2,000, 4,000, 6,000, 8,000, and 10,000 kDa), showed a similar cryoprotecive effect on the cells. Similar results were also obtained with other types of bakers' yeast, sake yeast and beer yeast. When the four types of bakers' yeast cell were frozen at -30 degrees C for 3 d in dough supplemented with more than 1% PGA, the cells (after freezing and thawing) showed higher leavening ability than those frozen in dough without PGA, irrespective of the molecular mass of PGA. Thus, PGA appears to protect bakers' yeast from lethal freeze injury, leading to a high leavening ability after freezing and thawing. PGA did not decrease the original leavening ability of the bakers' yeast, and was not decomposed by the yeast cells. PGA suppressed the decrease in leavening ability during a prolonged fermentation time, probably because PGA adsorbed inhibitory metabolites accumulated in the dough. PGA could prove useful for improving the freeze-tolerance of bakers' yeast by its addition to dough. PMID:17046536

  12. Surviving Winter

    Science.gov (United States)

    WGBH Educational Foundation

    2010-12-13

    In this lesson designed to enhance literacy skills, students learn about the varied physical and behavioral adaptations that animals rely on to help them survive changing environmental conditions, such as the arrival of winter.

  13. Hot big bang or slow freeze?

    Science.gov (United States)

    Wetterich, C.

    2014-09-01

    We confront the big bang for the beginning of the universe with an equivalent picture of a slow freeze - a very cold and slowly evolving universe. In the freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The freeze and big bang pictures both describe the same observations or physical reality. We present a simple “crossover model” without a big bang singularity. In the infinite past space-time is flat. Our model is compatible with present observations, describing the generation of primordial density fluctuations during inflation as well as the present transition to a dark energy-dominated universe.

  14. POPULATION DYNAMICS OF AMBIENT AND ALTERED EARTHWORM COMMUNITIES IN ROW-CROP AGROECOSYSTEMS IN THE MIDWESTERN U.S.

    Science.gov (United States)

    Although earthworms affect agroecosystem processes, few studies have addressed population dynamics when earthworms are intentionally introduced. Therefore, handsorting and formalin extraction were used semi-annually from fall 1994 to fall 1997 to measure populations in ambient and addition plots in ...

  15. Mutual impacts of wheat (Triticum aestivum L.) and earthworms (Eisenia fetida) on the bioavailability of perfluoroalkyl substances (PFASs) in soil

    International Nuclear Information System (INIS)

    Wheat and earthworms were exposed individually and together to soils contaminated with 11 perfluoroalkyl substances (PFASs). Wheat accumulated PFASs from soil with root concentration factors and bioconcentration factors that decreased as the number of perfluorinated carbons in the molecule increased. Earthworms accumulated PFASs from soil with biota-to-soil accumulation factors that increased with the number of carbons. Translocation factors (TF) of perfluorinated carboxylates (PFCAs) in wheat peaked at perfluorohexanoic acid and decreased significantly as the number of carbons increased or decreased. Perfluorohexane sulfonate produced the greatest TF of the three perfluorinated sulfonates (PFSAs) examined. Wheat increased the bioaccumulation of all 11 PFASs in earthworms and earthworms increased the bioaccumulation in wheat of PFCAs containing seven or less perfluorinated carbons, decreased bioaccumulation of PFCAs with more than seven carbons, and decreased bioaccumulation of PFSAs. In general, the co-presence of wheat and earthworms enhanced the bioavailability of PFASs in soil. -- Highlights: • PFASs can be taken up by root of wheat from soil and translocated to shoot. • The RCFs and BCFs of PFASs in wheat decreased with perfluorinated carbon chain length. • PFHxA had the highest TF, which decreased exponentially with the carbon chain length. • The BSAFs in earthworm increased with carbon chain length. • The co-presence of wheat and earthworm enhanced the bioavailability of PFASs in soil. -- PFASs can be uptake by root of wheat from soil and translocated to shoot and co-presence of wheat and earthworm enhance the bioavailability of PFASs in soil

  16. Assessing soil ecotoxicity of methyl tert-butyl ether using earthworm bioassay; closed soil microcosm test for volatile organic compounds

    International Nuclear Information System (INIS)

    An earthworm bioassay was conducted to assess ecotoxicity in methyl tert-butyl ether (MTBE)-amended soils. Ecotoxicity of MTBE to earthworms was evaluated by a paper contact method, natural field soil test, and an OECD artificial soil test. All tests were conducted in closed systems to prevent volatilization of MTBE out of test units. Test earthworm species were Perionyx excavatus and Eisenia andrei. Mortality and abnormal morphology of earthworms exposed to different concentrations of MTBE were examined. MTBE was toxic to both earthworm species and the severity of response increased with increasing MTBE concentrations. Perionyx excavatus was more sensitive to MTBE than Eisenia andrei in filter papers and two different types of soils. MTBE toxicity was more severe in OECD artificial soils than in field soils, possibly due to the burrowing behavior of earthworms into artificial soils. The present study demonstrated that ecotoxicity of volatile organic compounds such as MTBE can be assessed using an earthworm bioassay in closed soil microcosm with short-term exposure duration. - Earthworm bioassay can be a good protocol to assess soil ecotoxicity of volatile organic compounds such as MTBE

  17. DNA damage in earthworms (Eisenia spp.) as an indicator of environmental stress in the industrial zone of Coatzacoalcos, Veracruz, Mexico.

    Science.gov (United States)

    Espinosa-Reyes, Guillermo; Ilizaliturri, Cesar A; Gonzalez-Mille, Donaji J; Costilla, Rogelio; Diaz-Barriga, Fernando; Carmen Cuevas, Maria Del; Martinez, Miguel Angel; Mejia-Saavedra, Jesus

    2010-01-01

    Coatzacoalcos, Veracruz is one of the major industrial areas of Mexico. Presently, the Coatzacoalcos River and the areas surrounding the industrial complex are considered by various authors to be some of most polluted sites in Mexico. The objective of this study was to determine if earthworms could be used as indicators of environmental stress in the Coatzacoalcos industrial zone. Often, detritivores and decomposers such as earthworms are the first to be affected when the soil is contaminated. We collected soil samples to be used for persistent organic pollutants (POPs) quantification by gas chromatography. Concentrations of hexachlorobenzene, lindane and total polychlorinated biphenyls (PCBs) in the soil were above the maximum permissible limits of the Canadian Environmental Quality Guidelines (CEQG). Comet assay was conducted in coelomocytes of wild earthworms collected in Coatzacoalcos and compared with the control earthworms. We found DNA damage in earthworms from Coatzacoalcos that was significantly higher (P < 0.05) in comparison to laboratory earthworms. Earthworms are an appropriate organism to use as an indicator of environmental impact in contaminated sites. DNA damage recorded in the earthworms provides clear evidence of environmental impacts by the chemical industry on the wildlife of this region. PMID:20390841

  18. DNA damage in earthworms from highly contaminated soils: assessing resistance to arsenic toxicity by use of the Comet assay.

    Science.gov (United States)

    Button, Mark; Jenkin, Gawen R T; Bowman, Karen J; Harrington, Chris F; Brewer, Tim S; Jones, George D D; Watts, Michael J

    2010-02-01

    Earthworms native to the former mine site of Devon Great Consols (DGC), UK reside in soils highly contaminated with arsenic (As). These earthworms are considered to have developed a resistance to As toxicity. The mechanisms underlying this resistance however, remain unclear. In the present study, non-resistant, commercially sourced Lumbricus terrestris were exposed to a typical DGC soil in laboratory mesocosms. The earthworms bio-accumulated As from the soil and incurred DNA-damage levels significantly above those observed in the control mesocosm (assessed using the Comet assay). A dose response was observed between DNA damage (% tail DNA) and As concentration in soil (control, 98, 183, 236, 324 and 436mgkg(-1)). As-resistant earthworms (Lumbricus rubellus, Dendrodrilus rubidus and L. terrestris) collected from contaminated soils at DGC (203 to 9025mgkg(-1) As) had also bio-accumulated high levels of As from their host soils, yet demonstrated low levels of DNA damage compared with earthworms from uncontaminated sites. The results demonstrate that the As-contaminated soils at DGC are genotoxic to non-native earthworms and much less so to earthworms native to DGC, thus providing further evidence of an acquired resistance to As toxicity in the native earthworms. PMID:20015476

  19. Assessing ecotoxicity and uptake of metals and metalloids in relation to two different earthworm species (Eiseina hortensis and Lumbricus terrestris)

    International Nuclear Information System (INIS)

    Due to diffuse atmospheric fallouts of process particles enriched by metals and metalloids, polluted soils concern large areas at the global scale. Useful tools to assess ecotoxicity induced by these polluted soils are therefore needed. Earthworms are currently used as biotest, however the influence of specie and earthworm behaviour, soil characteristics are poorly highlighted. Our aim was therefore to assess the toxicity of various polluted soils with process particles enriches by metals and metalloids (Pb, Cd, Cu, Zn, As and Sb) collected from a lead recycling facility on two earthworm species belonging to different ecological types and thus likely to have contrasted behavioural responses (Eiseina hortensis and Lumbricus terrestris). The combination of behavioural factors measurements (cast production and biomass) and physico-chemical parameters such as metal absorption, bioaccumulation by earthworms and their localization in invertebrate tissues provided a valuable indication of pollutant bioavailability and ecotoxicity. Soil characteristics influenced ecotoxicity and metal uptake by earthworms, as well as their soil bioturbation. -- Highlights: •Historically polluted soils collected from a lead recycling facility were studied. •Cast production is a sensitive parameter to assess ecotoxicity on earthworms. •Both soil parameters, like organic matter content and pH and earthworm specie influence metal uptake and ecotoxicity. -- Behavioural factors and inorganic pollutant uptake by earthworms provide a valuable indication of bioavailability and ecotoxicity

  20. Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Sizmur, Tom, E-mail: t.p.sizmur@reading.ac.uk [Soil Research Centre, Department of Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom); Palumbo-Roe, Barbara; Watts, Michael J. [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Hodson, Mark E. [Soil Research Centre, Department of Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom)

    2011-03-15

    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota. - Research highlights: > Earthworms increase the mobility and availability of metals and metalloids in soils. > We incubated L. terrestris in three soils contaminated with As, Cu, Pb and Zn. > Earthworms increased the mobility of As, Cu, Pb and Zn in their casts. > The mechanisms for this could be explained by changes in pH or organic carbon. - Lumbricus terrestris change the partitioning of metal(loid)s between soil constituents and increase the mobility of metal(loid)s in casts and pore water.

  1. The second wave of earthworm invasion: soil organic matter dynamics from the stable isotope perspective

    Science.gov (United States)

    Chang, C.; Szlavecz, K. A.; Bernard, M.; Pitz, S.

    2013-12-01

    Through transformation of plant litter into soil organic matter (SOM) and translocation of ingested organic material among different soil depths, soil organisms, especially earthworms, are one of the major factors affecting SOM dynamics. In North America temperate soil, historical human activity has lead to invasion of European earthworms into habitats that were previously earthworm-free or inhabited only by native species. By consuming leaf litter and SOM, burrowing, and casting, invasive earthworms have been known for reducing the understory vegetation and leaf litter layer while increasing the thickness of organic soil, causing changes in the soil habitat and the distribution of SOM. Recently, another group of invasive earthworm, namely Amynthas from Asia, has been reported invading habitats already dominated by European species, causing a 'second wave of invasion' where the soil ecosystem, already modified by European species, is going through another transition. The mechanisms through which these functionally (ecologically) different species affect C and N transformation could be better understood by tracing the carbon and nitrogen derived from 13C- and 15N-labeled leaf litter into earthworm tissues and SOM. The objective of this study is to understand how earthworm species that differ ecologically, including the Asian Amynthas, interact with each other and how these interactions affect SOM dynamics. We hypothesized that 1) species feeding on different food resources will have different isotopic signature and their tissue 13C and 15N values will change due to facilitation or interspecific competition on food resources, and 2) the short-term fate of litter-derived carbon differs depending on the presence or absence of different earthworm species. These hypotheses were tested by field sampling and lab mesocosm experiments using 13C and 15N double-enriched Tulip Poplar leaf litter (mean 13C = 124‰, mean 15N = 1667‰) produced from tree saplings growing in an airtight chamber. Stable isotope mass balance calculation is used to estimate the recovery of litter-derived carbon from three pools (earthworm tissue, SOM, remaining litter), the loss of litter-derived carbon through soil respiration, and the contribution of different carbon sources to soil CO2 efflux in different earthworm treatments. Our results show that earthworm species recognized as 'soil feeders' have 13C and 15N values that are 1.2‰ and 3.8‰ higher than those of 'litter feeders', and 15N also differ significantly amount different soil feeders, suggesting different food resource usage even within the same functional group. There are strong species effects on both leaf litter disappearance rate and CO2 efflux rate, both being high when Amynthas earthworms are present. Our results suggest that changing earthworm species composition leads to changing resource use, which alters the fate of organic carbon in the forest floor and soil and could potentially affect long-term SOM dynamics in temperate forests.

  2. Biochar and earthworm effects on soil nitrous oxide and carbon dioxide emissions.

    Science.gov (United States)

    Augustenborg, Cara A; Hepp, Simone; Kammann, Claudia; Hagan, David; Schmidt, Olaf; Müller, Christoph

    2012-01-01

    Biochar is the product of pyrolysis produced from feedstock of biological origin. Due to its aromatic structure and long residence time, biochar may enable long-term carbon sequestration. At the same time, biochar has the potential to improve soil fertility and reduce greenhouse gas (GHG) emissions from soils. However, the effect of biochar application on GHG fluxes from soil must be investigated before recommendations for field-scale biochar application can be made. A laboratory experiment was designed to measure carbon dioxide (CO) and nitrous oxide (NO) emissions from two Irish soils with the addition of two different biochars, along with endogeic (soil-feeding) earthworms and ammonium sulfate, to assist in the overall evaluation of biochar as a GHG-mitigation tool. A significant reduction in NO emissions was observed from both low and high organic matter soils when biochars were applied at rates of 4% (w/w). Earthworms significantly increased NO fluxes in low and high organic matter soils more than 12.6-fold and 7.8-fold, respectively. The large increase in soil NO emissions in the presence of earthworms was significantly reduced by the addition of both biochars. biochar reduced the large earthworm emissions by 91 and 95% in the low organic matter soil and by 56 and 61% in the high organic matter soil (with and without N fertilization), respectively. With peanut hull biochar, the earthworm emissions reduction was 80 and 70% in the low organic matter soil, and only 20 and 10% in the high organic matter soil (with and without N fertilization), respectively. In high organic matter soil, both biochars reduced CO efflux in the absence of earthworms. However, soil CO efflux increased when peanut hull biochar was applied in the presence of earthworms. This study demonstrated that biochar can potentially reduce earthworm-enhanced soil NO and CO emissions. Hence, biochar application combined with endogeic earthworm activity did not reveal unknown risks for GHG emissions at the pot scale, but field-scale experiments are required to confirm this. PMID:22751063

  3. Cryoprotectant and freezing-process alter the ability of chicken sperm to acrosome react.

    Science.gov (United States)

    Mocé, E; Grasseau, I; Blesbois, E

    2010-12-01

    Sperm surviving after freezing-thawing is usually 40-50% of the initial population. Damage during this process affects both fertilizing ability and its duration in avian species. However, the effect of cryopreservation on the sperm ability to undergo the acrosome reaction, the initial event of fertilization, is still in question in birds. In this paper, the influence of cryoprotectant (glycerol and dimethylacetamide-DMA) and of two different cryopreservation processes (pellets or straws) on the ability of rooster sperm to acrosome react (AR measured with PNA-FITC) was studied. Motility parameters (CASA) and plasma membrane integrity (propidium iodide exclusion) were also measured. The addition of cryoprotectants (CPA) immediately provoked a dramatic decrease in the ability of sperm to undergo the acrosome reaction, glycerol being more harmful than DMA. The cryoprotectant removal was also harmful. The other parts of the freezing process further decreased the ability to AR. Motility was affected to a lesser extent by CPA presence although plasma membrane integrity was not altered. The DMA/rapid freezing procedure was the most harmful for plasma membrane integrity. Taken together, these results show that AR is more dramatically altered by CPA presence than motility and membrane integrity and CPA provokes a more pronounced effect than the freezing-thawing process especially in the case of using glycerol/slow freezing process. PMID:21115311

  4. Improvement of the resistance of Lactobacillus delbrueckii ssp. bulgaricus to freezing by natural selection.

    Science.gov (United States)

    Monnet, C; Béal, C; Corrieu, G

    2003-10-01

    Lactic acid bacteria are often produced as frozen or freeze-dried cultures that can be used for the direct inoculation of milk in cheese and fermented milk production processes. The objective of this study was to investigate whether the resistance of Lactobacillus delbrueckii ssp. bulgaricus to freezing could be improved by natural selection. Three parallel cultures of strain CFL1 were propagated for 30 cycles in which each cycle involved three serial transfers through milk, one freezing step, and one thawing step. The concentration in viable cells after thawing as well as the acidifying activity of the thawed cultures increased dramatically throughout the experiment. This may be explained by the random appearance of better-adapted mutants that can outcompete the other genotypes. However, after 30 cycles of subcultivation, freezing, and thawing, all the cultures contained subpopulations having different survival rates to freezing. Our results show that serial transfer culture experiments may be used to improve technological properties of lactic acid bacteria. Furthermore, investigation of the mutations that are responsible for an increased cryotolerance may help to define new targets for improving the resistance of lactic acid bacteria to several stresses. PMID:14594221

  5. Bioaccumulation of perfluoroalkyl carboxylates (PFCAs) and perfluoroalkane sulfonates (PFSAs) by earthworms (Eisenia fetida) in soil

    International Nuclear Information System (INIS)

    Earthworms were exposed to artificially contaminated soils with ten perfluoroalkyl substances (PFASs). PFASs with longer perfluorinated carbon chain displayed higher uptake rate coefficients (ku), longer half-life (t1/2) and time to steady-state (tss) but lower elimination rate coefficients (ke) than the shorter ones. Similarly, perfluorosulfonates acids (PFSAs) displayed higher ku, longer t1/2 and tss but lower ke than perflurocarboxylic acids (PFCAs) with the same perfluorinated chain length. All the studied PFASs, including those with seven or less perfluorinated carbons, were bioaccumulated in the earthworms and the biota-to-soil accumulation factors (BSAFs) increased with perfluorinated carbon chain length and were greater for PFSAs than for PFCAs of equal perfluoroalkyl chain length. The BSAFs were found to be dependent on the concentrations of PFASs in soil and decreased as the level of PFASs in soil increased. -- Highlights: •PFASs with seven or less perfluoroalkyl carbons were bioaccumulated in earthworm. •The BSAFs of PFASs in earthworm increased with perfluoroalkyl chain length. •The BSAFs of PFSAs were greater than PFCAs of equal perfluoroalkyl chain length. •The ku increased with perfluorinated chain length while ke decreased. •The BSAFs of PFASs decreased as their concentrations in soil increased. -- Perfluoroalkyl substances (PFASs) can be effectively bioaccumulated in earthworms including those with seven or less perfluoroalkyl carbon chain length

  6. Biomarker responses in earthworms (Eisenia fetida) to soils contaminated with di-n-butyl phthalates.

    Science.gov (United States)

    Du, Li; Li, Guangde; Liu, Mingming; Li, Yanqiang; Yin, Suzhen; Zhao, Jie

    2015-03-01

    Di-n-butyl phthalates (DBP) are recognized as ubiquitous contaminants in soil and adversely impact the health of organisms. Changes in the activity of antioxidant enzymes and levels of glutathione-S-transferase (GST), glutathione (GSH), and malondialdehyde (MDA) were used as biomarkers to evaluate the impact of DBP on earthworms (Eisenia fetida) after exposure to DBP for 28 days. DBP was added to artificial soil in the amounts of 0, 5, 10, 50, and 100 mg kg(-1) of soil. Earthworm tissues exposed to each treatment were collected on the 7th, 14th, 21st, and 28th day of the treatment. We found that superoxide dismutase (SOD) and catalase (CAT) levels were significantly inhibited in the 100 mg kg(-1) treatment group on day 28. After 21 days of treatment, GST activity in 10-50 mg kg(-1) treatment groups was markedly stimulated compared to the control group. MDA content in treatment groups was higher than in the control group throughout the exposure time, suggesting that DBP may lead to lipid peroxidation (LPO) in cells. GSH content increased in the treatment group that received 50 mg kg(-1) DBP from 7 days of exposure to 28 days. These results suggest that DBP induces serious oxidative damage on earthworms and induce the formation of reactive oxygen species (ROS) in earthworms. However, DBP concentration in current agricultural soil in China will not constitute any threat to the earthworm or other animals in the soil. PMID:25328097

  7. Enantioselective bioaccumulation and toxic effects of metalaxyl in earthworm Eisenia foetida.

    Science.gov (United States)

    Xu, Peng; Diao, Jinling; Liu, Donghui; Zhou, Zhiqiang

    2011-05-01

    Knowledge about the enantioselective bioavailability of chiral pesticides in soil invertebrates facilitates more accurate interpretation of their environmental behaviors. In this study, the acute toxicities of R-metalaxyl and rac-metalaxyl to earthworm (Eisenia foetida) were assayed by filter paper contact test. After 48 h of exposure, the calculated LC(50) values for R- and rac-metalaxyl were 0.052 and 0.022 mg cm(-2), respectively, resulting in a two fold difference in toxicity. For uptake experiment, earthworms were exposed in soil at two dose levels (10 and 50 mg kg(dwt)(-1)). The concentrations of two enantiomers in soil and earthworm were determined by high-performance liquid chromatography based on cellulose tri-(3,5-dimethylphenyl-carbamate) chiral stationary phase. The results showed that metalaxyl was taken up by earthworm rapidly, and the bioaccumulation of metalaxyl in earthworm was enantioselective with preferential accumulation of S-enantiomer. In addition, biota to soil accumulation factor (BSAF) used to express the bioaccumulation of metalaxyl enantiomers was investigated, and significant difference was observed between rac-metalaxyl and R-metalaxyl. PMID:21315406

  8. Changes in forest floor composition and chemistry along an invasive earthworm gradient in a hardwood forest

    Science.gov (United States)

    Jourdain, J. N.; Filley, T. R.; Top, S. M.; Thayer, C.; Johnson, A.; Jenkins, M.; Welle, P.; Zurn-Birkhimer, S.; Kroeger, T.; Gemscholars

    2010-12-01

    Recent studies have demonstrated how invasive European earthworm species have caused large and long lasting perturbations to forest floor dynamics and soil composition in many northern hardwood forests. The type of perturbation is driven primarily by the composition and activity of the invasive species and the original state of the forest system. Over the past 4 years we have investigated an invasive earthworm front moving through the Ojibwa Red Lake Reservation (Minnesota). Significant shifts in litter and organic horizon mass were observed, similar to other gradients identified in the region, but the species of earthworms exhibited differences compared to other reservation lands in the region--possibly driven by the availability of recreation fishing near to the sites. Sharp gradients in earthworm abundance were observed exhibiting shifts from 600- 900 individuals per meter square to no observed worms within only 500 meters. The gradients in earthworm activity also influenced decay rates of litter, as was observed by placement of litter decay bags across the gradient. Our findings demonstrate the tenuous nature of many tribal reservation forests and point to the need for policies to address spread on such species to minimize impacts to soil carbon stocks as well as culturally important plant species.

  9. Subacute toxicity of copper and glyphosate and their interaction to earthworm (Eisenia fetida)

    International Nuclear Information System (INIS)

    Glyphosate (GPS) and copper (Cu) are common pollutants in soils, and commonly co-exist. Due to the chemical structure of GPS, it can form complexes of heavy metals and interface their bioavailability in soil environment. In order to explore the interactions between GPS and Cu, subacute toxicity tests of Cu and GPS on soil invertebrate earthworms (Eisenia fetida) were conducted. The relative weight loss and whole-worm metal burdens increased significantly with the increasing exposure concentration of Cu, while the toxicity of GPS was insignificant. The joint toxicity data showed that the relative weight loss and the uptake of Cu, as well as the superoxide dismutase, catalase and malondialdehyde activities, were significantly alleviated in the present of GPS, which indicated that GPS could reduce the toxicity and bioavailability of Cu in the soil because of its strong chelating effects. Highlights: •Cu markedly increased the weight loss ratio of earthworm. •Cu decreased the cocoon production of earthworm. •The toxicity of GPS on earthworm was insignificant. •The presence of GPS could reduce the toxicity of Cu on earthworm. -- The presence of glyphosate could reduce the toxicity and bioavailability of Cu in the soil because of its strong chelating effects

  10. Edaphic factors affecting the toxicity and accumulation of arsenate in the earthworm Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Meharg, A.A.; Shore, R.F.; Broadgate, K. [Inst. of Terrestrial Ecology, Huntingdon (United Kingdom)

    1998-06-01

    The toxicity and accumulation of arsenate was determined in the earthworm Lumbricus terrestris in soil from different layers of a forest profile. Toxicity increased fourfold between 2 and 10 d. Edaphic factors (pH, soil organic matter, and depth in soil profile) also affected toxicity with a three fold decrease in the concentration that causes 50% mortality with increasing depth in soil. In a 4-d exposure study, there was no evidence of arsenic bioconcentration in earthworm tissue, although bioaccumulation was occurring. There was a considerable difference in tissue residues between living and dead earthworms, with dead worms having higher concentrations. This difference was dependent on both soil arsenate concentration and on soil type. Over a wide range of soil arsenate concentrations, earthworm arsenic residues are homeostatically maintained in living worms, but this homeostasis breaks down during death. Alternatively, equilibration with soil residues may occur via accumulation after death. In long-term accumulation studies in soils dosed with a sublethal arsenate concentration, bioconcentration of arsenate did not occur until day 12, after which earthworm concentrations rose steadily above the soil concentration, with residues in worms three fold higher than soil concentrations by the termination of the study. This bioconcentration only occurred in depurated worms over the time period of the study. Initially, depurated worms had lower arsenic concentrations than undepurated until tissue concentrations were equivalent to the soil concentration. Once tissue concentration was greater than soil concentration, depurated worms had higher arsenic residues than undepurated.

  11. Cellular biomarkers for measuring toxicity of xenobiotics: Effects of polychlorinated biphenyls on earthworm Lumbricus terrestris coelomocytes

    Energy Technology Data Exchange (ETDEWEB)

    Goven, A.J.; Fitzpatrick, L.C. (Univ. of North Texas, Denton (United States)); Eyambe, G.S. (Texas Tech Univ., Lubbock (United States)); Venables, B.J. (TRAC Labs., Denton, TX (United States)); Cooper, E.L. (Univ. of California, Los Angeles (United States))

    1993-05-01

    Acute toxicity in earthworms (Lumbricus terrestris) was assayed immediately after 5-d filter paper exposure to the polychlorinated biphenyl (PCB) Aroclor 1254, using coelomocyte viability, total extruded cell counts (ECC), differential cell counts (DCC), and formation of erythrocyte (ER) and secretory rosettes (SR) with, and phagocytosis of, antigenic rabbit red blood cells (RRBC). Chronic toxicity was assayed using rates by which earthworms replaced viable immunoactive coelomocytes, removed noninvasively immediately after exposure, over an 18-week depuration period. All cytological parameters, except ECC, were acutely affected immediately after exposure, when tissue concentrations were ([anti X] [plus minus] SE) 91.2 [plus minus] 8.19 [mu]g PCB per gram dry mass. Replacement of viable immunoactive coelomocytes occurred within six weeks in unexposed control earthworms. Exposed earthworms showed significant alteration in viability, ECC, DCC, ER, and SR formation, and phagocytosis at 6 and 12 weeks when PCB tissue concentrations were 41 [plus minus] 0.31 and 30.2 [plus minus] 0.88 [mu]g/g dry mass, respectively. Replacement of extruded coelomocytes with normal DCC of viable immunocompetent cells was not observed until week 18, when PCB had decreased to 15.7 [plus minus] 0.83 [mu]g/g dry mass. Low inherent natural variability in coelomocyte viability, ECC, DCC, rosette formation, and phagocytosis, and their sensitivity to sublethal PCB body burdens, indicated that earthworm coelomocytes have potential as nonmammalian biomarkers for assaying acute and chronic sublethal toxicity of xenobiotics.

  12. The Mechanics and Energetics of Soil Bioturbation by Plant Roots and Earthworms - Plastic Deformation Considerations

    Science.gov (United States)

    Ruiz, Siul; Or, Dani; Schymanski, Stanislaus

    2014-05-01

    Soil structure plays a critical factor in the agricultural, hydrological and ecological functions of soils. These services are adversely impacted by soil compaction, a damage that could last for many years until functional structure is restored. An important class of soil structural restoration processes are related to biomechanical activity associated with burrowing of earthworms and root proliferation in impacted soil volumes. We study details of the mechanical processes and energetics associated with quantifying the rates and mechanical energy required for soil structural restoration. We first consider plastic cavity expansion to describe earthworm and plant root radial expansion under various conditions. We then use cone penetration models as analogues to wedging induced by root tip growth and worm locomotion. The associated mechanical stresses and strains determine the mechanical energy associated with bioturbation for different hydration conditions and root/earthworm geometries. Results illustrate a reduction in strain energy with increasing water content and trade-offs between pressure and energy investment for various root and earthworm geometries. The study provides the basic building blocks for estimating rates of soil structural alteration, the associated energetic requirements (soil carbon, plant assimilates) needed to sustain structure regeneration by earthworms and roots, and highlights potential mechanical cut-offs for such activities.

  13. Remediation of polychlorinated biphenyl-contaminated soil by using a combination of ryegrass, arbuscular mycorrhizal fungi and earthworms.

    Science.gov (United States)

    Lu, Yan-Fei; Lu, Mang; Peng, Fang; Wan, Yun; Liao, Min-Hong

    2014-07-01

    In this work, a laboratory experiment was performed to investigate the influences of inoculation with the arbuscular mycorrhizal fungus (AMF) Glomus caledoniun L. and/or epigeic earthworms (Eisenia foetida) on phytoremediation of a PCB-contaminated soil by ryegrass grown for 180d. Planting ryegrass, ryegrass inoculated with earthworms, ryegrass inoculated with AMF, and ryegrass co-inoculated with AMF and earthworms decreased significantly initial soil PCB contents by 58.4%, 62.6%, 74.3%, and 79.5%, respectively. Inoculation with AMF and/or earthworms increased the yield of plants, and the accumulation of PCBs in ryegrass. However, PCB uptake by ryegrass accounted for a negligible portion of soil PCB removal. The number of soil PCB-degrading populations increased when ryegrass was inoculated with AMF and/or earthworms. The data show that fungal inoculation may significantly increase the remedial potential of ryegrass for soil contaminated with PCBs. PMID:24457052

  14. Assessing ecotoxicity and uptake of metals and metalloids in relation to two different earthworm species (Eiseina hortensis and Lumbricus terrestris).

    Science.gov (United States)

    Leveque, Thibaut; Capowiez, Yvan; Schreck, Eva; Mazzia, Christophe; Auffan, Mélanie; Foucault, Yann; Austruy, Annabelle; Dumat, Camille

    2013-08-01

    Due to diffuse atmospheric fallouts of process particles enriched by metals and metalloids, polluted soils concern large areas at the global scale. Useful tools to assess ecotoxicity induced by these polluted soils are therefore needed. Earthworms are currently used as biotest, however the influence of specie and earthworm behaviour, soil characteristics are poorly highlighted. Our aim was therefore to assess the toxicity of various polluted soils with process particles enriches by metals and metalloids (Pb, Cd, Cu, Zn, As and Sb) collected from a lead recycling facility on two earthworm species belonging to different ecological types and thus likely to have contrasted behavioural responses (Eiseina hortensis and Lumbricus terrestris). The combination of behavioural factors measurements (cast production and biomass) and physico-chemical parameters such as metal absorption, bioaccumulation by earthworms and their localization in invertebrate tissues provided a valuable indication of pollutant bioavailability and ecotoxicity. Soil characteristics influenced ecotoxicity and metal uptake by earthworms, as well as their soil bioturbation. PMID:23688736

  15. Improvement of parameters of freezing medium and freezing protocol for bull sperm using two osmotic supports.

    OpenAIRE

    Chaveiro, A.; Machado, A. L.; Frijters, A.; Engel, B.; Woelders, H.

    2006-01-01

    The aim of this study was to improve the freezing protocol of bull sperm, by investigating the influence on sperm viability after freeze/thawing of different freezing medium components, as well as the effect of cooling rates in the different stages of the cooling protocol, in single factor experiments. The experimental variables were: (1) salt-based versus a sugar-based medium (Tris versus sucrose); (2) glycerol concentration; (3) detergent (Equex) concentration; (4) presence of bicarbonate; ...

  16. Glutathione Protects Lactobacillus sanfranciscensis against Freeze-Thawing, Freeze-Drying, and Cold Treatment?

    OpenAIRE

    Zhang, Juan; Du, Guo-cheng; Zhang, Yanping; Liao, Xian-yan; Wang, Miao; Li, Yin; Chen, Jian

    2010-01-01

    Lactobacillus sanfranciscensis DSM20451 cells containing glutathione (GSH) displayed significantly higher resistance against cold stress induced by freeze-drying, freeze-thawing, and 4°C cold treatment than those without GSH. Cells containing GSH were capable of maintaining their membrane structure intact when exposed to freeze-thawing. In addition, cells containing GSH showed a higher proportion of unsaturated fatty acids in cell membranes upon long-term cold treatment. Subsequent studies r...

  17. Surface freezing of n-octane nanodroplets

    Science.gov (United States)

    Modak, Viraj; Pathak, Harshad; Thayer, Mitchell; Singer, Sherwin; Wyslouzil, Barbara

    2013-05-01

    Surface freezing, at temperatures up to a few degrees above the equilibrium melting point, has been observed for intermediate chain length (16? i? 50) n-alkanes [B. M. Ocko, X. Z. Wu, E. B. Sirota, S. K. Sinha, O. Gang and M. Deutsch, Phys. Rev. E, 1997, 55, 3164-3182]. Our recent experimental results suggest that surface freezing is also the first step when highly supercooled nanodroplets of n-octane crystallize. Our data yield surface and bulk nucleation rates on the order of ˜1015/cm2.s and ˜1022/cm3.s, respectively. Complementary molecular dynamics simulations also show that the surface of the droplet freezes almost immediately, and freezing of the remainder of the droplet progresses in a layer-by-layer manner.

  18. Freezing and Thawing Human Embryonic Stem Cells

    Science.gov (United States)

    Kent, Lia

    Lia Kent, of Stemgent's Research and Development team, has created this video to demonstrate "the proper technique for rapidly thawing hES cells from liquid nitrogen stocks, plating them on mouse embryonic feeder cells, and slowly freezing them for long-term storage." The video is also accompanied by protocols for thawing and freezing hES cells, discussion, materials, references, a forum for comments, and a PDF of the full text.

  19. Redistribution and Destabilization of Forest Soil Carbon by Earthworm Invasion

    Science.gov (United States)

    Swanston, C. W.; Torn, M. S.; Allen, L.; Lilleskov, E. A.; Maggi, F.

    2008-12-01

    Soils of temperate forests in the northern Great Lakes region have developed in the absence of earthworms, which were largely eradicated during the last ice age. European earthworms, such as Lumbricus terrestris, are spreading and their effect on forest soil C has not been widely studied. We examined soils along a chronosequence of worm activity (wormosequence) ranging from no apparent activity (Low) to high activity over several decades (High). In the soil profile, including organic horizons, there was only a small loss (4%) of C with high worm activity. There was a 71% decrease in the Oe and no remaining Oa in the High site. Conversely, the mineral soil contained 25% more C in the High site, with most of that in the top 20 cm. We densimetrically separated the mineral soil into primarily organic free light fraction (FLF) and occluded light fraction (OLF), a mineral-associated intermediate fraction (IF), and a mineral-associated dense fraction (DF). We measured fraction mass, C, nitrogen, and 14C content. In comparison to Low sites, each depth of High worm soil had less FLF C and more IF C. With worms, more C was stored in aggregates in the upper soil but less in the lower soil. The presence of worms had a very large effect on the 14C content of soil organic matter, with shifts of > 60 per mil in several fractions presumably due to a combination of vertical redistribution and more rapid transfer into and out of some fractions. For example, from the Low to High sites OLF 14C increased 100 per mil at 0-10 cm depth, while DF 14C decreased 80 per mil at 20-50 cm. The effect of worms on C cycling can be explored using a multi-pool, multi-depth model that treats 14C as a conservative (i.e., stable) tracer. Our results suggest that worms play a major role in redistributing soil C in these forest soils by pathways that differ with depth: the upper soil loses FLF C and incorporates organic horizon C into OLF and IF, whereas in the lower depths FLF is lost and the previously stable OLF C pool is redistributed into IF and DF. We conclude that the introduction of worms to these forest soils has fundamentally changed the storage, distribution, and turnover of soil organic C.

  20. Hydrocarbon exclusion from ground water during freezing

    International Nuclear Information System (INIS)

    Bench-scale studies were conducted using a constant-head ground-water flow chamber and natural soil. Initial experiments with chlorides and dye were conducted to test the hydraulic and adsorptive characteristics of the chamber. A constant flow of phenol was then introduced into the chamber and contaminant movement with time was monitored under freezing and nonfreezing conditions. The chamber was located in a controlled-temperature room, and freezing fronts were induced from the soil surface downward using cooled Freon circulated through freezer pads placed on the surface of the soil. The results conclusively demonstrate that phenol is excluded from the freezing front and pushed downward through the system. Extensive exclusion of the chemical occurs even though the freezing point of phenol (43 C) is significantly higher than water. The information gained through this research is applicable in cold regions outside Alaska and the Arctic where ground water systems may undergo periodic freezing, and may also be of extreme importance in artificial-freezing scenarios such as those currently being investigated by the Environmental Protection Agency (EPA) as a method of contaminant containment

  1. RAPD and freezing resistance in Eucalyptus globulus

    Scientific Electronic Library Online (English)

    Marta, Fernández R.; Sofía, Valenzuela A.; Claudio, Balocchi L..

    2006-06-01

    Full Text Available SciELO Chile | Language: English Abstract in english Eucalyptus globulus is the second most important forest species in Chile, after Pinus radiata. The main advantages of E. globulus are its fast growth (25 m³/ha/year) and its excellent wood quality for kraft pulp production. On the negative side, its low freezing tolerance has been an obstacle for th [...] e expansion of plantations, specifically on the foothills of the Andes. The difference in the freezing resistance between clones of E. globulus has a genetic base and, therefore, it could be detected through DNA molecular markers. Fifteen clones of E. globulus, eight classified as freezing resistant and seven as freezing sensitive were analyzed using the technique of RAPD, in order to obtain molecular markers that could differentiate between freezing sensitive and resistant clones. Eighteen primers amplified reproducible bands. Three bands were only present in freezing resistant clones, two bands of 768 bp, 602 bp obtained with UBC 218 primer and one band of 248 bp obtained with UBC 237 primer. The preliminary results indicate that polymorphism can be observed with the primers employed, but it is not possible to associate the bands with the cold resistance or susceptibility in E. globulus.

  2. Soil physical ambient and its relation ships with the earthworm's biomass in some Colombian Andean hillsides

    International Nuclear Information System (INIS)

    The work presented here describes on the one hand the relationship between diversity, density and biomass of the earthworm's side and humidity, total porosity and resistance to penetration in the hillsides soils (secondary forest, Inceptisol and Pennsisetum clandestinum pastured, Andisol) on the other hand side. Results indicate that there were significant differences between sites for density and biomass of earthworms, and that their presence was affected by the physical parameters. Resistance to soil penetrability and humidity were significantly different only in the first 20 cm; while in deeper soil layers these were no such difference between sites, this is of importance, since the surface of the soil suffers changes due to the management, thus affecting the conditions that regulate the earthworm populations

  3. DNA Repair Inhibition by Mercuric Chloride in Earthworms after Exposure to Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Tae Ho; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain); An, Kwang Guk [Chungnam National University, Daejeon (Korea, Republic of)

    2011-10-15

    All organisms are being exposed to harmful factors present in the environment. Ionizing radiation can damage DNA through a series of molecular events depending on the radiation energy. The biological effects due to the combined action of ionizing radiation with the other factor are hard to estimate and predict in advance. Recently International Commission on Radiological Protection (ICRP) requires the effect data of ionizing radiation on non-human biota for the radiological protection of the environment. Earthworms have been identified by the ICRP as one of the reference animals and plants to be used in environmental radiation protection. Particularly, the earthworm Eisenia fetida can be used as a bio-indicator of pollution in soil. This study was performed to investigate the acute genotoxic effects of radiation and the synergistic effects between radiation and mercury in earthworm, E. fetida

  4. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    International Nuclear Information System (INIS)

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slope < 1) related to the total concentration in soil, while risk assessment procedures often assume the biota-soil accumulation factor (BSAF) to be constant. Although predicted internal concentrations of all metals are generally within a factor 5 compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. - Earthworm metal concentrations are less than linearly related to total soil concentrations and predicted pore water concentrations

  5. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    Energy Technology Data Exchange (ETDEWEB)

    Veltman, Karin [Department of Environmental Science, Institute for Wetland and Water Research, Radboud University (Russian Federation) Nijmegen, P.O. Box 9010, Toernooiveld 1, 6500 GL Nijmegen (Netherlands)]. E-mail: k.veltman@science.ru.nl; Huijbregts, Mark A.J. [Department of Environmental Science, Institute for Wetland and Water Research, Radboud University (RU) Nijmegen, P.O. Box 9010, Toernooiveld 1, 6500 GL Nijmegen (Netherlands)]. E-mail: m.a.j.huijbregts@science.ru.nl; Vijver, Martina G. [Institute for Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA Leiden (Netherlands)]. E-mail: vijver@cml.leidenuniv.nl; Peijnenburg, Willie J.G.M. [National Institute for Public Health and the Environment (RIVM), Laboratory for Ecotoxicology, P.O. Box 1, 3720 BA Bilthoven (Netherlands)]. E-mail: wjgm.peijnenburg@rivm.nl; Hobbelen, Peter H.F. [US Geological Survey, Biological Resources Division, National Wildlife Health Center, 6006 Schroeder Road, Madison WI 53711-6223 (United States)]. E-mail: phobbelen@usgs.gov; Koolhaas, Josee E. [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Gestel, Cornelis A.M. van [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)]. E-mail: kees.van.gestel@ecology.falw.vu.nl; Vliet, Petra C.J. van [Section Soil Quality Wageningen University, Bode 5, P.O. Box 8005, 6700 EC Wageningen (Netherlands)]. E-mail: petra.vanvliet@wur.nl; Jan Hendriks, A. [Department of Environmental Science, Institute for Wetland and Water Research, Radboud University (RU) Nijmegen, P.O. Box 9010, Toernooiveld 1, 6500 GL Nijmegen (Netherlands)]. E-mail: a.j.hendriks@science.ru.nl

    2007-03-15

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slope < 1) related to the total concentration in soil, while risk assessment procedures often assume the biota-soil accumulation factor (BSAF) to be constant. Although predicted internal concentrations of all metals are generally within a factor 5 compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. - Earthworm metal concentrations are less than linearly related to total soil concentrations and predicted pore water concentrations.

  6. DNA Repair Inhibition by Mercuric Chloride in Earthworms after Exposure to Radiation

    International Nuclear Information System (INIS)

    All organisms are being exposed to harmful factors present in the environment. Ionizing radiation can damage DNA through a series of molecular events depending on the radiation energy. The biological effects due to the combined action of ionizing radiation with the other factor are hard to estimate and predict in advance. Recently International Commission on Radiological Protection (ICRP) requires the effect data of ionizing radiation on non-human biota for the radiological protection of the environment. Earthworms have been identified by the ICRP as one of the reference animals and plants to be used in environmental radiation protection. Particularly, the earthworm Eisenia fetida can be used as a bio-indicator of pollution in soil. This study was performed to investigate the acute genotoxic effects of radiation and the synergistic effects between radiation and mercury in earthworm, E. fetida

  7. Increased susceptibility to repeated freeze-thaw cycles in Escherichia coli following long-term evolution in a benign environment

    Directory of Open Access Journals (Sweden)

    Lenski Richard E

    2006-12-01

    Full Text Available Abstract Background In order to study the dynamics of evolutionary change, 12 populations of E. coli B were serially propagated for 20,000 generations in minimal glucose medium at constant 37°C. Correlated changes in various other traits have been previously associated with the improvement in competitive fitness in the selective environment. This study examines whether these evolved lines changed in their ability to tolerate the stresses of prolonged freezing and repeated freeze-thaw cycles during adaptation to a benign environment. Results All 12 lines that evolved in the benign environment for 20,000 generations are more sensitive to freeze-thaw cycles than their ancestor. The evolved lines have an average mortality rate of 54% per daily cycle, compared to the ancestral rate of 34%. By contrast, there was no significant difference between the evolved lines and their ancestor in mortality during prolonged freezing. There was also some variability among the evolved lines in susceptibility to repeated freeze-thaw cycles. Those lines that had evolved higher competitive fitness in the minimal glucose medium at 37°C also had higher mortality during freeze-thaw cycles. This variability was not associated, however, with differences among lines in DNA repair functionality and mutability. Conclusion The consistency of the evolutionary declines in freeze-thaw tolerance, the correlation between fitness in glucose medium at 37°C and mortality during freeze-thaw cycles, and the absence of greater declines in freeze-thaw survival among the hypermutable lines all indicate a trade-off between performance in minimal glucose medium at 37°C and the capacity to tolerate this stress. Analyses of the mutations that enhance fitness at 37°C may shed light on the physiological basis of this trade-off.

  8. Effects of freezing on soil temperature, freezing front propagation and moisture redistribution in peat: laboratory investigations

    Directory of Open Access Journals (Sweden)

    R. M. Nagare

    2012-02-01

    Full Text Available There are not many studies that report water movement in freezing peat. Soil column studies under controlled laboratory settings can help isolate and understand the effects of different factors controlling freezing of the active layer in organic covered permafrost terrain. In this study, four peat Mesocosms were subjected to temperature gradients by bringing the Mesocosm tops in contact with sub-zero air temperature while maintaining a continuously frozen layer at the bottom (proxy permafrost. Soil water movement towards the freezing front (from warmer to colder regions was inferred from soil freezing curves, liquid water content time series and from the total water content of frozen core samples collected at the end of freezing cycle. A substantial amount of water, enough to raise the upper surface of frozen saturated soil within 15 cm of the soil surface at the end of freezing period appeared to have moved upwards during freezing. Diffusion under moisture gradients and effects of temperature on soil matric potential, at least in the initial period, appear to drive such movement as seen from analysis of freezing curves. Freezing front (separation front between soil zones containing and free of ice propagation is controlled by latent heat for a long time during freezing. A simple conceptual model describing freezing of an organic active layer initially resembling a variable moisture landscape is proposed based upon the results of this study. The results of this study will help in understanding, and ultimately forecasting, the hydrologic response of wetland-dominated terrain underlain by discontinuous permafrost.

  9. Effects of earthworm invasion on plant species richness in northern hardwood forests.

    Science.gov (United States)

    Holdsworth, Andrew R; Frelich, Lee E; Reich, Peter B

    2007-08-01

    The invasion of non-native earthworms (Lumbricus spp.) into a small number of intensively studied stands of northern hardwood forest has been linked to declines in plant diversity and the local extirpation of one threatened species. It is unknown, however, whether these changes have occurred across larger regions of hardwood forests, which plant species are most vulnerable, or with which earthworm species such changes are associated most closely. To address these issues we conducted a regional survey in the Chippewa and Chequamegon national forests in Minnesota and Wisconsin (U.S.A.), respectively. We sampled earthworms, soils, and vegetation, examined deer browse in 20 mature, sugar-maple-dominated forest stands in each national forest, and analyzed the relationship between invasive earthworms and vascular plant species richness and composition. Invasion by Lumbricus was a strong indicator of reduced plant richness in both national forests. The mass of Lumbricus juveniles was significantly and negatively related to plant-species richness in both forests. In addition, Lumbricus was a significant factor affecting plant richness in a full model that included multiple variables. In the Chequamegon National Forest earthworm mass was associated with higher sedge cover and lower cover of sugar maple seedlings and several forb species. The trends were similar but not as pronounced in Chippewa, perhaps due to lower deer densities and different earthworm species composition. Our results provide regional evidence that invasion by Lumbricus species may be an important mechanism in reduced plant-species richness and changes in plant communities in mature forests dominated by sugar maples. PMID:17650250

  10. Impact of land protection in soil quality properties and in earthworm biomass in Venezuelan savannas

    Scientific Electronic Library Online (English)

    D, López-Hernández; L, Hernández; A, Ojeda; E, Quintero; S, Caipo.

    Full Text Available SciELO Chile | Language: English Abstract in english We studied soil parameters and the earthworm biomass and density in a protected savanna (PS) from fire and cattle raising for more than forty years located at Estación Biológica de los Llanos, Venezuela (EBLL), and an adjacent non-protected savanna (NS) under frequent burning and agricultural activi [...] ties, located less than 1 km apart. Earthworm sampling was carried out at the end of the dry season (April), and at the peak of the wet season (July-August) using a hand sorting extraction method. In each plot, five to seven sampling units were selected corresponding to soil monoliths of 25x25x30 cm. The main physical, chemical, microbial (biomass) and enzymatic activities of soils in both systems were estimated. Thepresence of an abundant litter layer under the tree canopies in the PS have increased the soil water retention capacity, the organic-C, C-microbial biomass, dehydrogenase activity and fertility levels respect NS. This may allow for an increase in the density and biomass of earthworms in the PS compared with the adjacent NS. The systems were characterized by abundance in juvenile individuals belonging to the Glossoscolecidae family; two different morphotypes of the genus Aicodrilus were registered. Earthworms found were located in an endo-anecic ecological category. Results suggest that, agricultural management in savannas by modification of physical and biochemical soil properties can decrease an important fraction of pedofauna, particularly their earthworm communities. However, earthworm populations and soil quality indicators can be restored after long-term protection.

  11. Rock phosphate solubilizing and cellulolytic actinomycete isolates of earthworm casts

    Science.gov (United States)

    Mba, Caroline C.

    1994-03-01

    Four microbial isolates, OP2, OP3, OP6, and OP7, of earthworm casts of Pontoscolex corethrurus were found to be acid tolerant actinomycetes and efficient rock phosphate (RP) solubilizers that could grow fast on NH4Cl-enriched or N-free carboxymethyl cellulose or glucose as sole carbon source. CMC (carboxymethyl cellulose) induced production of extracellular cellulase enzyme and the production of reducing sugar in all the isolates. RP solubilizing power was observed to be inversely related to glucose consumption. The most efficient RP solubilizer was found to consume the least glucose. Growth was faster on cellulose than on glucose media. N-free CMC induced greater glucose production than NH4Cl-enriched CMC medium. Both CMC and glucose media were acidified by all the isolates, however, RP solubilizing power decreased with acidification. Solubilization power was greatest with isolate OP7, which also produced the greatest amount of reducing sugar per gram CMC. Both RP solubilizing power and the cellulolytic efficiency varied among isolates. A minimum of 631 µg P/0.1 g RP and a maximum of 951.4 µg P/0.1 g RP was recorded.

  12. Neurotropic and neuroprotective activities of the earthworm peptide Lumbricusin.

    Science.gov (United States)

    Kim, Dae Hong; Lee, Ik Hwan; Nam, Seung Taek; Hong, Ji; Zhang, Peng; Hwang, Jae Sam; Seok, Heon; Choi, Hyemin; Lee, Dong Gun; Kim, Jae Il; Kim, Ho

    2014-06-01

    We recently isolated a polypeptide from the earthworm Lumbricus terrestris that is structurally similar to defensin, a well-known antibacterial peptide. An 11-mer antibacterial peptide (NH2-RNRRWCIDQQA), designated Lumbricusin, was synthesized based on the amino acid sequence of the isolated polypeptide. Since we previously reported that CopA3, a dung beetle peptide, enhanced neuronal cell proliferation, we here examined whether Lumbricusin exerted neurotropic and/or neuroprotective effects. Lumbricusin treatment induced a time-dependent increase (?51%) in the proliferation of human neuroblastoma SH-SY5Y cells. Lumbricusin also significantly inhibited the apoptosis and decreased viability induced by treatment with 6-hydroxy dopamine, a Parkinson's disease-mimicking agent. Immunoblot analyses revealed that Lumbricusin treatment increased ubiquitination of p27(Kip1) protein, a negative regulator of cell-cycle progression, in SH-SY5Y cells, and markedly promoted its degradation. Notably, adenoviral-mediated over-expression of p27(Kip1) significantly blocked the antiapoptotic effect of Lumbricusin in 6-hydroxy dopamine-treated SH-SY5Y cells. These results suggest that promotion of p27(Kip1) degradation may be the main mechanism underlying the neuroprotective and neurotropic effects of Lumbricusin. PMID:24796676

  13. Cryopreservation of platelets using trehalose: the role of membrane phase behavior during freezing.

    Science.gov (United States)

    Gläfke, Christiane; Akhoondi, Maryam; Oldenhof, Harriëtte; Sieme, Harald; Wolkers, Willem F

    2012-01-01

    In blood banks, platelets are stored at 20-24 °C, which limits the maximum time they can be stored. Platelets are chilling sensitive, and they activate when stored at temperatures below 20 °C. Cryopreservation could serve as an alternative method for long term storage of platelet concentrates. Recovery rates using dimethyl sulfoxide (DMSO) as cryoprotective agent, however, are low, and removal of DMSO is required before transfusion. In this study, we have explored the use of trehalose for cryopreservation of human platelets while using different cooling rates. Recovery of membrane intact cells and the percentage of nonactivated platelets were used as a measure for survival. In all cases, survival was optimal at intermediate cooling rates of 20 °C min(-1). Cryopreservation using DMSO resulted in high percentages of activated platelets; namely 54% of the recovered 94%. When using trehalose, 98% of the platelets had intact membranes after freezing and thawing, whereas 76% were not activated. Using Fourier transform infrared spectroscopy, subzero membrane phase behavior of platelets has been studied in the presence of trehalose and DMSO. Furthermore, membrane hydraulic permeability parameters were derived from these data to predict the cell volume response during cooling. Both trehalose and DMSO decrease the activation energy for subzero water transport across cellular membranes. Platelets display a distinct lyotropic membrane phase transition during freezing, irrespective of the presence of cryoprotective agents. We suggest that concomitant uptake of trehalose during freezing could explain the increased survival of platelets cryopreserved with trehalose. PMID:22837111

  14. Natural freeze-tolerance in hatchling painted turtles?

    Science.gov (United States)

    Packard, Gary C; Packard, Mary J

    2003-02-01

    Hatchlings of the North American painted turtle (Family Emydidae: Chrysemys picta) typically spend their first winter of life inside a shallow, subterranean hibernaculum (the natal nest) where life-threatening conditions of ice and cold commonly occur. Although a popular opinion holds that neonates exploit a tolerance for freezing to survive the rigors of winter, hatchlings are more likely to withstand exposure to ice and cold by avoiding freezing altogether-and to do so without the benefit of an antifreeze. In the interval between hatching by turtles in late summer and the onset of wintery weather in November or December, the integument of the animals becomes highly resistant to the penetration of ice into body compartments from surrounding soil, and the turtles also purge their bodies of catalysts for the formation of ice. These two adjustments, taken together, enable the animals to supercool to temperatures below those that they routinely experience in nature. However, cardiac function in hatchlings is diminished at subzero temperatures, thereby compromising the delivery of oxygen to peripheral tissues and eliciting an increase in reliance by those tissues on anaerobic metabolism for the provision of ATP. The resulting increase in production of lactic acid may disrupt acid/base balance and lead to death even in animals that remain unfrozen. Although an ability to undergo supercooling may be key to survival by overwintering turtles in northerly populations, a similar capacity to resist inoculation and undergo supercooling characterizes animals from a population near the southern limit of distribution, where winters are relatively benign. Thus, the suite of characters enabling hatchlings to withstand exposure to ice and cold may have been acquired prior to the northward dispersal of the species at the end of the Pleistocene, and the characters may not have originated as adaptations specifically to the challenges of winter. PMID:12547253

  15. Survival Analysis

    CERN Document Server

    Miller, Rupert G

    2011-01-01

    A concise summary of the statistical methods used in the analysis of survival data with censoring. Emphasizes recently developed nonparametric techniques. Outlines methods in detail and illustrates them with actual data. Discusses the theory behind each method. Includes numerous worked problems and numerical exercises.

  16. Space-time dynamics in situ of earthworm casts under temperate cultivated soils

    OpenAIRE

    Binet, Franc?oise; Le Bayon, Rene?e-claire

    2009-01-01

    Soil does not always benefit from disturbance by earthworms. We investigated whether (under a temperate climate and in maize growing in rows running down-hill) earthworm casts could contribute to soil erosion and losses of nutrients in runoff water. Observations of casts were made in compacted (wheel-tracks) and non-compacted (untrafficked) inter-rows, for a 2-month period in spring. Estimates of surface-cast production in a temperate maize crop ranged between 2.5 to 3.2 kg (d.w soil) m?2 y...

  17. Background internal dose rates of earthworm and arthropod species in the forests of Aomori, Japan

    International Nuclear Information System (INIS)

    We measured naturally occurring radionuclides in samples from an earthworm species and 11 arthropod species collected in coniferous forests in Rokkasho, Aomori, Japan, to assess background internal radiation dose rates. The rates were calculated from the measured concentrations of the radionuclides and dose coefficients from the literature. The mean internal dose rate of composite earthworm samples was 0.35 ?Gy h-1, whereas the mean dose rates of the arthropod samples ranged from 36 nGy h-1 to 0.79 ?Gy h-1. Polonium-210 was the radionuclide with the highest contribution to the internal dose rate for all the species, except the longhorn beetle. (author)

  18. Background internal dose rates of earthworm and arthropod species in the forests of Aomori, Japan

    International Nuclear Information System (INIS)

    In this study, we measured the concentrations of several natural radionuclides in samples of one earthworm species and 11 arthropod species collected from four coniferous forests in Rokkasho, Aomori Prefecture, Japan, and we assessed the background internal radiation dose rate for each species. Dose rates were calculated by using the radionuclide concentrations in the samples and dose conversion coefficients obtained from the literature. The mean internal dose rate in the earthworm species was 0.28 ?Gy h-1, and the mean internal dose rates in the arthropod species ranged between 0.036 and 0.69 ?Gy h-1. (author)

  19. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    Science.gov (United States)

    Veltman, K.; Huijbregts, M.A.J.; Vijver, M.G.; Peijnenburg, W.J.G.M.; Hobbelen, P.H.F.; Koolhaas, J.E.; van Gestel, C.A.M.; van Vliet, P.C.J.; Jan, Hendriks A.

    2007-01-01

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slope compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. ?? 2006 Elsevier Ltd. All rights reserved.

  20. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data.

    Science.gov (United States)

    Veltman, Karin; Huijbregts, Mark A J; Vijver, Martina G; Peijnenburg, Willie J G M; Hobbelen, Peter H F; Koolhaas, Josee E; van Gestel, Cornelis A M; van Vliet, Petra C J; Hendriks, A Jan

    2007-03-01

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slopeBSAF) to be constant. Although predicted internal concentrations of all metals are generally within a factor 5 compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. PMID:16938367

  1. Effects of zinc exposure on earthworms, Lumbricus terrestris, in an artificial soil.

    Science.gov (United States)

    Lev, Steven M; Matthies, Nick; Snodgrass, Joel W; Casey, Ryan E; Ownby, David R

    2010-06-01

    Earthworms have the potential to act as trophic links for pollutants that accumulate in urban soils. However, many pollutants may act as micronutrients at low concentrations and toxins at higher concentration. When pollutants are also micronutrients, bioaccumulations may initially increase trophic transfer as pollutant concentration increase, but at higher levels toxic effects may limit population size and the potential for trophic transfer. We found support for this model among earthworms exposed to a range of soil Zn levels. Worms showed increasing bioaccumulation of Zn with increasing Zn soil concentrations, but at higher Zn levels worm growth rates decreased. PMID:20431863

  2. Earthworm activity in a simulated landfill cover soil shifts the community composition of active methanotrophs

    OpenAIRE

    Kumaresan, Deepak; He?ry, Marina; Bodrossy, Levente; Singer, Andrew C.; Stralis-pavese, Nancy; Thompson, Ian P.; Murrell, J. Colin

    2011-01-01

    Landfills represent a major source of methane into the atmosphere. In a previous study, we demonstrated that earthworm activity in landfill cover soil can increase soil methane oxidation capacity (Héry et al., 2008). In this study, a simulated landfill cover soil mesocosm (1 m x 0.15 m) was used to observe the influence of earthworms (Eisenia veneta) on the active methanotroph community composition, by analyzing the expression of the pmoA gene, which is responsible for methane oxidation. mR...

  3. Survival strategies of Listeria monocytogenes - roles of regulators and transporters

    OpenAIRE

    Wemekamp-kamphuis, H. H.

    2003-01-01

    Outbreaks of the food-borne pathogen Listeria monocytogenes are mainly associated with ready-to-eatfoods. Survival strategies of L. monocytogenes in relation to minimally processed foods were studied.L.monocytogenespossesses several mechanisms to regulate transcription, e.g. the cold-shock proteins and the alternative sigma factorsB. Studies showed thatsBplays a crucial role in survival and adaptation to acidic conditions, HHP treatment and freezing by inducing the transcription of several ge...

  4. Preservation of functionality of Bifidobacterium animalis subsp. lactis INL1 after incorporation of freeze-dried cells into different food matrices.

    Science.gov (United States)

    Vinderola, G; Zacarías, M F; Bockelmann, W; Neve, H; Reinheimer, J; Heller, K J

    2012-05-01

    The aim of this work was to investigate how production and freeze-drying conditions of Bifidobacterium animalis subsp. lactis INL1, a probiotic strain isolated from breast milk, affected its survival and resistance to simulated gastric digestion during storage in food matrices. The determination of the resistance of bifidobacteria to simulated gastric digestion was useful for unveiling differences in cell sensitivity to varying conditions during biomass production, freeze-drying and incorporation of the strain into food products. These findings show that bifidobacteria can become sensitive to technological variables (biomass production, freeze-drying and the food matrix) without this fact being evidenced by plate counts. PMID:22265312

  5. Effectivity of the Earthworms Pheretima hupiensis, Eudrellus sp. and Lumbricus sp. on the Organic Matter Decomposition Process

    Directory of Open Access Journals (Sweden)

    Ea Kosman Anwar

    2009-05-01

    Full Text Available The earthworms are the one of soil fauna component in soil ecosystem have an important role in organic matter decomposition procces. The earthworm feed plant leaf and plant matter up to apart and dissolved. Earthworm metabolisms produce like faeces that mixed with decomposed organic matter mean vermicompost. The vermicompost fertility varies because of some kind of earthworm differ in “niche” and attitude. The experiment was to study the effectivity of earthworm on organic matter decomposition which has been conducted in Soil Biological and Healthy Laboratory and Green House of Soil Research Institute Bogor, during 2006 Budget Year. The three kind of earthworms i.e Pheretima hupiensis, Lumbricus sp. and Eudrellus sp. combined with three kind of organic matter sources i.e rice straw, trash and palm oil plant waste (compost heap. The result shows that the Lumbricus sp. are the most effective decomposer compared to Pheretima hupiensis and Eudrellus sp. and the organic matter decomposed by Lumbricus sp. as followed: market waste was decomposed of 100%, palm oil empty fruit bunch (compost heap 95.8 % and rice straw 84.9%, respectively. Earthworm effectively decreased Fe, Al, Mn, Cu dan Zn.

  6. Effect of earthworm Eisenia fetida and wetland plants on nitrification and denitrification potentials in vertical flow constructed wetland.

    Science.gov (United States)

    Xu, Defu; Li, Yingxue; Howard, Alan; Guan, Yidong

    2013-06-01

    The response of nitrification potentials, denitrification potentials, and N removal efficiency to the introduction of earthworms and wetland plants in a vertical flow constructed wetland system was investigated. Addition of earthworms increased nitrification and denitrification potentials of substrate in non-vegetated constructed wetland by 236% and 8%, respectively; it increased nitrification and denitrification potentials in rhizosphere in vegetated constructed wetland (Phragmites austrail, Typha augustifolia and Canna indica), 105% and 5%, 187% and 12%, and 268% and 15% respectively. Denitrification potentials in rhizosphere of three wetland plants were not significantly different, but nitrification potentials in rhizosphere followed the order of C. indica>T. augustifolia>P. australis when addition of earthworms into constructed wetland. Addition of earthworms to the vegetated constructed significantly increased the total number of bacteria and fungi of substrates (P<0.05). The total number of bacteria was significantly correlated with nitrification potentials (r=913, P<0.01) and denitrification potentials (r=840, P<0.01), respectively. The N concentration of stems and leaves of C. indica were significantly higher in the constructed wetland with earthworms (P<0.05). Earthworms had greater impact on nitrification potentials than denitrification potentials. The removal efficiency of N was improved via stimulated nitrification potentials by earthworms and higher N uptake by wetland plants. PMID:23591133

  7. Cryoprotective dehydration and the resistance to inoculative freezing in the Antarctic midge, Belgica antarctica.

    Science.gov (United States)

    Elnitsky, Michael A; Hayward, Scott A L; Rinehart, Joseph P; Denlinger, David L; Lee, Richard E

    2008-02-01

    During winter, larvae of the Antarctic midge, Belgica antarctica (Diptera, Chironomidae), must endure 7-8 months of continuous subzero temperatures, encasement in a matrix of soil and ice, and severely desiccating conditions. This environment, along with the fact that larvae possess a high rate of water loss and are extremely tolerant of desiccation, may promote the use of cryoprotective dehydration as a strategy for winter survival. This study investigates the capacity of larvae to resist inoculative freezing and undergo cryoprotective dehydration at subzero temperatures. Slow cooling to -3 degrees C in an environment at equilibrium with the vapor pressure of ice reduced larval water content by approximately 40% and depressed the body fluid melting point more than threefold to -2.6 degrees C. This melting point depression was the result of the concentration of existing solutes (i.e. loss of body water) and the de novo synthesis of osmolytes. By day 14 of the subzero exposure, larval survival was still >95%, suggesting larvae have the capacity to undergo cryoprotective dehydration. However, under natural conditions the use of cryoprotective dehydration may be constrained by inoculative freezing as result of the insect's intimate contact with environmental ice. During slow cooling within a substrate of frozen soil, the ability of larvae to resist inoculative freezing and undergo cryoprotective dehydration was dependent upon the moisture content of the soil. As detected by a reduction of larval water content, the percentage of larvae that resisted inoculative freezing increased with decreasing soil moisture. These results suggest that larvae of the Antarctic midge have the capacity to resist inoculative freezing at relatively low soil moisture contents and likely undergo cryoprotective dehydration when exposed to subzero temperatures during the polar winter. PMID:18245628

  8. Cryopreservation for bovine embryos in serum-free freezing medium containing silk protein sericin.

    Science.gov (United States)

    Isobe, Tomohiro; Ikebata, Yoshihisa; Onitsuka, Takeshi; Do, Lanh Thi Kim; Sato, Yoko; Taniguchi, Masayasu; Otoi, Takeshige

    2013-10-01

    Because the use of serum in the embryo cryopreservation increases the probability of animal health problems such as bovine spongiform encephalopathy (BSE) and viral infections, this study was conducted to examine the effects of sericin supplementation for serum-free freezing medium on the survival and development of bovine embryos after freezing-thawing and direct transfer to recipients. When in vitro-produced bovine embryos were frozen conventionally in the freezing medium supplemented with various concentrations (0.1%, 0.5%, and 1.0%) of sericin, the percentages of damaged zona pellucida, survival, and development of frozen-thawed embryos were similar to those of embryos frozen in freezing medium supplemented with 0.4% bovine serum albumin (BSA) and 20% fetal bovine serum (FBS) (0.4BSA/20F; control). When in vivo-derived embryos were frozen with 0.4BSA/20F (control), 0.5% sericin +20% FBS (0.5S/20F) or 0.5% sericin (0.5S) and were subsequently transferred directly to recipients, the percentages of recipients with pregnancy and normal calving in the 0.5S/20F group were higher than those in the control group (47.3% vs. 40.1% and 94.6% vs. 87.3%, respectively). Moreover, the percentages of recipients with pregnancy and normal calving (42.2% and 92.4%, respectively) in the 0.5S group were similar with those of other groups. In conclusion, these results indicate that serum-free freezing medium supplemented with sericin is available for the cryopreservation of bovine embryos and that it is beneficial for the elimination of a potential source of biological contamination by serum or BSA. PMID:23850826

  9. Determining the bioavailability and toxicity of lead contamination to earthworms requires using a combination of physicochemical and biological methods

    International Nuclear Information System (INIS)

    This study aimed at assessing the bioavailability and toxicity of lead to Eisenia andrei in shooting range soils representing different land uses (forest, grassland, bullet plot). Soils contained 47–2398 mg Pb/kg dry weight (dw), but also had different pH-CaCl2 (3.2–6.8) and organic matter contents (3.8–13%). Therefore artificial soils with different pH and organic matter contents and two natural soils were included as control soils. Earthworms were exposed for 28 days and toxicity and uptake of Pb were related to total, water and 0.01 M CaCl2 extractable and porewater Pb concentrations as well as to soil characteristics. Pb uptake in the earthworms linearly increased with increasing soil concentrations. At >2000 mg Pb/kg dw and pH 3.3–3.5, high earthworm mortality with significant weight loss and complete inhibition of reproduction were recorded. At <1000 mg/kg dw, earthworm reproduction was more related to differences in pH and other soil characteristics than to Pb. -- Highlights: • Availability and earthworm toxicity of Pb determined in field-contaminated soils. • Earthworm toxicity of most-polluted soils explained from available Pb levels. • Earthworm response in less polluted soils mainly determined by soil pH. • Earthworm toxicity correlated with Pb uptake from the soil. • Soil properties explained differences in earthworm Pb uptake and effects. -- Combination of physicochemical and biological assays helped explaining Pb toxicity in shooting range soils from available Pb concentrations and soil characteristics

  10. Radiocesium concentrations in epigeic earthworms at various distances from the Fukushima Nuclear Power Plant 6 months after the 2011 accident

    International Nuclear Information System (INIS)

    We investigated the concentrations of radiocesium in epigeic earthworms, litter, and soil samples collected from forests in Fukushima Prefecture 6 months after the Fukushima Dai-ichi Nuclear Power Plant accident in 2011. Radiocesium concentrations in litter accumulated on the forest floor were higher than those in the soil (0–5 cm depth). The highest average 134+137Cs concentrations in earthworms (approximately 19 Bq g?1 of wet weight with gut contents and 108 Bq g?1 of dry weight without gut contents) were recorded from a plot that experienced an air dose rate of 3.1 ?Sv h?1, and earthworm concentrations were found to increase with litter and/or soil concentrations. Average 134Cs and 137Cs concentrations (with or without gut contents) were intermediate between accumulated litter and soil. Different species in the same ecological groups on the same plots had similar concentrations because of their use of the same habitats or their similar physiological characteristics. The contribution of global fallout 137Cs to earthworms with gut contents was calculated to be very low, and most 137Cs in earthworms was derived from the Fukushima accident. Transfer factors from accumulated litter to earthworms, based on their dry weights, ranged from 0.21 to 0.35, in agreement with previous field studies. -- Highlights: • Radiocesium concentrations in earthworms were intermediate between litter and soil. • Three earthworm species in epigeic groups had similar radiocesium concentrations. • Transfer factors from accumulated litter to earthworms ranged from 0.21 to 0.35

  11. Biotic interactions modify the transfer of cesium-137 in a soil-earthworm-plant-snail food web.

    Science.gov (United States)

    Fritsch, Clémentine; Scheifler, Renaud; Beaugelin-Seiller, Karine; Hubert, Philippe; Coeurdassier, Michaël; de Vaufleury, Annette; Badot, Pierre-Marie

    2008-08-01

    The present study investigated the possible influence of the earthworm Aporrectodea tuberculata on the transfer of cesium-137 ((137)Cs) from a contaminated (130 Bq/kg) deciduous forest soil to the lettuce Lactuca sativa and to the snail Cantareus aspersus (formerly Helix aspersa) in two laboratory experiments. In the first experiment, the International Organization for Standardization 15952 test was used to expose snails for five weeks to contaminated soil with or without earthworms. In these conditions, the presence of earthworms caused a two- to threefold increase in (137)Cs concentrations in snails. Transfer was low in earthworms as well as in snails, with transfer factors (TFs) lower than 3.7 x 10(-2). Activity concentrations were higher in earthworms (2.8- 4.8 Bq/kg dry mass) than in snails (<1.5 Bq/kg). In the second experiment, microcosms were used to determine the contribution of soil and lettuce in the accumulation of (137)Cs in snails. Results suggest that the contribution of lettuce and soil is 80 and 20%, respectively. Microcosms also were used to study the influence of earthworms on (137)Cs accumulation in snail tissues in the most ecologically relevant treatment (soil-earthworm-plant-snail food web). In this case, soil-to-plant transfer was high, with a TF of 0.8, and was not significantly modified by earthworms. Conversely, soil-to-snail transfer was lower (TF, approximately 0.1) but was significantly increased in presence of earthworms. Dose rates were determined in the microcosm study with the EDEN (elementary dose evaluation for natural environment) model. Dose rates were lower than 5.5 x 10(-4) mGy/d, far from values considered to have effects on terrestrial organisms (1 mGy/d). PMID:18266477

  12. Wolf Survival

    Science.gov (United States)

    Eduweb

    2012-01-01

    In this activity, some learners pretend to be wolves, while the other learners pretend to be the prey of the wolf. The goal of the simulation is to have the wolves work together to survive. This activity works best with a larger group of at least 25 learners, but can work with smaller groups of at least 16 learners. Use this activity to discuss predator/prey relationships and the importance of communication for both animals and people.

  13. Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens

    Directory of Open Access Journals (Sweden)

    Inge-Marie Petzer

    2012-02-01

    Full Text Available The aim of this study was to compare the effects of cryopreservation at approximately -196 °C in liquid nitrogen (N and freezing at approximately -20 °C in a freezer, on the viability and survival of eight different mastitogenic bacteria inoculated in milk. Bacteria were frozen at approximately -20 °C in a freezer and cryopreserved at approximately -196 °C in liquid nitrogen. An effective preservation method was needed for follow-up samples from cows identified in the South African National Milk Recording Scheme (NMRS with somatic cell counts above 250 000 cells/mL milk. The organisation responsible for sample collection of the NMRS milk samples also provides producers with liquid nitrogen for their semen flasks at the collection sites. This existing mode of storage and transport could therefore be utilised.

    Ten samples of each organism were thawed and cultured bi-weekly until week 18 for both temperature treatments. An additional sampling was performed at week 30 for samples frozen at approximately -20 °C. Freezing and cryopreservation did not impair subsequent isolation of Streptococcus dysgalactiae, Streptococcus uberis, Enterococcus faecalis, Staphylococcus aureus (STH (phage type lytic group III or Sta. aureus (STA (phage typed, other than lytic group III. Survival was indicated by the isolation of bacteria from samples, and viability by the strength of growth of the bacteria isolated. The survival of Streptococcus agalactiae decreased after week 12 and Escherichia coli after week 16 of freezing, but both organisms survived under cryogenic preservation until week 18. Coagulase-negative staphylococci survived until week 18 for both freezing and cryogenic preservation.

    Both storage methods could thus contribute to the improvement of a pro-active approach towards udder health management in South African dairy herds.

    How to cite this article: Petzer, I.M., Karzis, J., Van der Schans, T.J., Watermeyer, J.C., Mitchell-Innes, N., Eloff, S. & Fosgate, G.T., 2012, ‘Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens’, Onderstepoort Journal of Veterinary Research 79(1, Art. #343, 6 pages. http://dx.doi.org/10.4102/ojvr.v79i1.343

  14. N2O-Producing Microorganisms in the Gut of the Earthworm Aporrectodea caliginosa Are Indicative of Ingested Soil Bacteria

    OpenAIRE

    Ihssen, Julian; Horn, Marcus A.; Matthies, Carola; Go?ßner, Anita; Schramm, Andreas; Drake, Harold L.

    2003-01-01

    The main objectives of this study were (i) to determine if gut wall-associated microorganisms are responsible for the capacity of earthworms to emit nitrous oxide (N2O) and (ii) to characterize the N2O-producing bacteria of the earthworm gut. The production of N2O in the gut of garden soil earthworms (Aporrectodea caliginosa) was mostly associated with the gut contents rather than the gut wall. Under anoxic conditions, nitrite and N2O were transient products when supplemental nitrate was redu...

  15. Effects of non-native earthworms on on below- and aboveground processes in the Mid-Atlantic region

    Science.gov (United States)

    Szlavecz, K. A.; McCormick, M. K.; Xia, L.; Pitz, S.; O'Neill, J.; Bernard, M.; Chang, C.; Whigham, D. F.

    2011-12-01

    Many biotic and abiotic disturbances have shaped the structure of the deciduous forests in the Mid-Atlantic region. One major anthropogenic factor is land use history. Agricultural practices in the past undoubtedly facilitated non-native earthworm colonization and establishment. Today most secondary forests are dominated by European lumbricid earthworms, although native species also occur in some habitats. To investigate how earthworm community composition and abundance affect belowground processes and tree seedling growth we set up a field manipulation experiment at the Smithsonian Environmental Research Center in Edgewater, MD. A total of 66 experimental plots were set up in successional (70 yrs) and mature (150 yrs) Tulip-poplar-Oak associations. We manipulated earthworm abundance and leaf litter input, and planted seedlings of Tulip poplar, Red maple, Red oak, and American beech. The experiment lasted for two years during which we regularly monitored density, biomass and species composition of earthworm assemblages and measured soil respiration. Soil moisture, temperature and air temperature were also continuously monitored using a wireless sensor network. At harvest, soil bulk density, pH, N pools, C:N ratio, potential N-mineralization rates, and enzyme activity were determined. We used quantitative PCR to assess the community composition of soil fungi. We also determined the extent of mycorrhizal colonization and biomass of roots, shoots and leaves. We conducted likelihood ratio tests for random and fixed effects based on mixed model analyses of variance. Differences between soil depths and among sites and plots accounted for a large portion of the variation in many soil properties. Litter quality affected soil pH and N mineralization. Earthworm densities affected bulk density, inorganic N content, and N mineralization. Both mycorrhizal groups were more abundant in mature than in successional forests. Both ectomycorrhizal (ECM) and arbuscular (AM) fungi were less abundant in the earthworm removal plots. There was a significant positive earthworm effect on the rate and thermal sensitivity of soil respiration. Soil respiration was consistently higher in plots with tulip poplar litter than those with beech litter, indicating a strong influence of plant residue quality. However, the differences were smaller in the second year than in the first one indicating an adaptation of the soil system. Oak and beech seedlings were smaller in high density earthworm plots, while the reverse was true for maple and tulip poplar seedlings. Non-native earthworms affect below- and aboveground processes, however, these effects depend on forest type and land use history. The earthworm effects also appear to be dynamic, as witnessed by a recent invasion of an Asian earthworm species in one of our forest stands.

  16. Heat transfer coefficient of cryotop during freezing.

    Science.gov (United States)

    Li, W J; Zhou, X L; Wang, H S; Liu, B L; Dai, J J

    2013-01-01

    Cryotop is an efficient vitrification method for cryopreservation of oocytes. It has been widely used owing to its simple operation and high freezing rate. Recently, the heat transfer performance of cryotop was studied by numerical simulation in several studies. However, the range of heat transfer coefficient in the simulation is uncertain. In this study, the heat transfer coefficient for cryotop during freezing process was analyzed. The cooling rates of 40 percent ethylene glycol (EG) droplet in cryotop during freezing were measured by ultra-fast measurement system and calculated by numerical simulation at different value of heat transfer coefficient. Compared with the results obtained by two methods, the range of the heat transfer coefficient necessary for the numerical simulation of cryotop was determined, which is between 9000 W/(m(2)·K) and 10000 W/(m (2)·K). PMID:23812315

  17. UltraViolet Freeze-in

    CERN Document Server

    Elahi, Fatemeh; Unwin, James

    2014-01-01

    If dark matter is thermally decoupled from the visible sector, the observed relic density can potentially be obtained via freeze-in production of dark matter. Typically in such models it is assumed that the dark matter is connected to the thermal bath through feeble renormalisable interactions. Here, rather, we consider the case in which the hidden and visible sectors are coupled only via non-renormalisable operators. This is arguably a more generic realisation of the dark matter freeze-in scenario, as it does not require the introduction of diminutive renormalisable couplings. We examine general aspects of freeze-in via non-renormalisable operators in a number of toy models and present several motivated implementations in the context of Beyond the Standard Model physics. Specifically, we study models related to the Peccei-Quinn mechanism and Z' portals.

  18. Hot big bang or slow freeze?

    CERN Document Server

    Wetterich, C

    2014-01-01

    We confront the hot big bang for the beginning of the universe with an equivalent picture of a slow freeze - a very cold and slowly evolving universe. In the slow freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The slow freeze and hot big bang pictures both describe the same observations or physical reality. We present a simple three-parameter "crossover model" without a "big bang singularity". In the infinite past space-time is flat. Our model is compatible with all present observations, describing the generation of primordial density fluctuations during inflation as well as the present transition to a dark energy dominated universe.

  19. Effects of the geophagous earthworm Metaphire guillelmi on sorption, mineralization, and bound-residue formation of 4-nonylphenol in an agricultural soil

    International Nuclear Information System (INIS)

    Effects of earthworms on fate of nonylphenol (NP) are obscure. Using 14C-4-NP111 as a representative, we studied the fate of 4-NP in an agricultural soil with or without the earthworm Metaphire guillelmi and in fresh cast of the earthworm. Sorption of 4-NP on the cast (Kd 1564) was significantly higher than on the parent soil (Kd 1474). Mineralization of 4-NP was significantly lower in the cast (13.2%) and the soil with earthworms (10.4%) than in the earthworm-free soil (16.0%). One nitro metabolite of 4-NP111 (2-nitro-4-NP111) was identified in the soil and cast, and the presence of the earthworm significantly decreased its amounts. The presence of earthworm also significantly decreased formation of bound residues of 4-NP in the soil. Our results demonstrate that earthworms could significantly change the fate of 4-NP, underlining that earthworm effects should be considered when evaluating behavior and risk of 4-NP in soil. - Highlights: • The earthworm Metaphire guillelmi inhibited mineralization of 4-NP in the soil. • A less-polar metabolite of 4-NP (2-nitro-4-NP111) was detected in the soil and cast. • The presence of earthworm reduced the amount of 2-nitro-4-NP111 in the soil. • M. guillelmi significantly reduced formation of bound residues of 4-NP in the soil. - Earthworms significantly changed the fate of 4-NP, highlighting that effects of earthworm should be considered when evaluating the behavior and risk of 4-NP in soil

  20. Reproducing Black's experiments: freezing point depression and supercooling of water

    International Nuclear Information System (INIS)

    We carried out two historical experiments referred to by Joseph Black, one on freezing mixtures of salted water with ice and another on freezing supercooled pure water by a small disturbance. The results confirm thermodynamical predictions for the depression of the freezing point of salted water and for the latent heat of freezing of supercooled water respectively, which came after Black. The depression of the freezing point can hardly be fitted in the framework of the caloric theory of heat, which was taken for granted by Black, and the instantaneous freezing of supercooled water also poses some difficulties for that theory. (author)

  1. The influence of earthworms on the mobility of microelements in soil and their availability for plants

    Science.gov (United States)

    Bityutskii, N. P.; Kaidun, P. I.

    2008-12-01

    The influence of earthworms ( Aporrectodea caliginosa, Lumbricus rubellus, L. terrestris, and Eisenia fetida) on the mobility of microelements and their availability for plants was studied. The contents of water-soluble Fe and Mn compounds extracted from the coprolites were 5-10 times higher than that in the soil (enriched in calcium carbonate and dried) consumed by the earthworms. This digestion-induced effect became higher with the age of the coprolites (up to 9 days) and took place under their alkalization. In the excreta (surface + enteric) of earthworms, the Fe concentration exceeded those of Mn and Zn by many times. Iron and manganese were mostly concentrated (>80% and >60%, respectively) in the organic part of the excrements. In the tests with hydroponics, the excreta were found to be a source of iron compounds available for plants that were similar to Fe2(SO4)3 or Fe-citrate by their physiological effect in the case when the Fe concentration in the excretions was above 0.7 ?M. However, the single application of excreta of different earthworm species into the CaCO3 enriched soil did not significantly affect the plant (cucumber) nutrition. The analysis of the transport of microelements with xylem sap showed that this fact appeared to be due to the absence of an Fe deficit in the cucumber plants because of their high capability for the absorption of weakly soluble iron compounds.

  2. Characterization of the organic fraction of earthworm humus and composts taken place starting from different substrates

    International Nuclear Information System (INIS)

    In order to evaluate the quality and the humification degree of different composted materials, the organic fraction of earthworm humus obtained from kitchen and farm residues, coffee pulp, biodegradable garbage and roses residues and of composts from roses and carnation residues were characterized chemically. Thus, determination and analysis of the C/N ratio, as well as the fractionation of the organic matter and the purification and characterization of the humic acids by C, H, N, 0 elemental analysis, UV-VIS spectroscopy were done and different humification parameters were found. The fractionation of the organic matter showed a low content of extracted carbon with respect to the normal content found in the soil humus. The elemental analysis data of the humic acids from the composts and the earthworm humus did not reveal important differences between these materials, while the E4/E6 ratio provided more evident changes. The results showed that the C/N ratio is not an absolute indicative of the Maturity State of the studied materials. The best parameters to estimate the maturity degree of the composts and the earthworm humus turned out to be the polymerization ratio, the humification index and the extracted carbon/non extracted carbon ratio. Among the evaluated materials, the earthworm of roses residues showed the best conditions with respect to content and quality of the organic matter to be added to a soil

  3. Effect of soil properties on lead bioavailability and toxicity to earthworms.

    Science.gov (United States)

    Bradham, Karen D; Dayton, Elizabeth A; Basta, Nicholas T; Schroder, Jackie; Payton, Mark; Lanno, Roman P

    2006-03-01

    Soil properties are important factors modifying metal bioavailability to ecological receptors. Twenty-one soils with a wide range of soil properties (USA; http://soils.usda.gov/technical/classification/taxonomy/) were amended with a single concentration of Pb (2,000 mg/kg) to determine the effects of soil properties on Pb bioavailability and toxicity to earthworms. Earthworm mortality ranged from 0 to 100% acute mortality following exposure to the same total concentration of Pb (2,000 mg/kg) in amended field soils. Internal Pb concentrations in earthworms ranged from 28.7 to 782 mg/kg, with a mean of 271 mg/kg. Path analysis was used to partition correlations in an attempt to discern the relative contribution of each soil property. Results of path analysis indicated that pH was the most important soil property affecting earthworm mortality (p FEAL). Because FEAL is rich in pH-dependent cation-exchange sites, several soil properties, including pH, FEAL, and cation-exchange capacity, have a causal effect on Pb adsorption and soluble Pb. Path analysis is useful for assessing contaminated soils with a wide range of soil properties and can assist in ecological risk assessment and remediation decisions for contaminated sites. Soil properties are important factors modifying metal bioavailability and toxicity and should be considered during the ecological risk assessment of metals in contaminated soils. PMID:16566162

  4. Earthworms and Plant Residues Modify Nematodes in Tropical Cropping Soils (Madagascar): A Mesocosm Experiment

    International Nuclear Information System (INIS)

    Free-living nematodes present several characteristics that have led to their use as bio indicators of soil quality. Analyzing the structure of nematofauna is a pertinent way to understand soil biological processes. Earthworms play an important role in soil biological functioning and organic matter dynamics. Their effects on soil nematofauna have seldom been studied. We studied the effect of the tropical endogeic earthworm, Pontoscolex corethrurus, on nematode community structure in a 5-month field mesocosm experiment conducted in Madagascar. Ten different treatments with or without earthworms and with or without organic residues (rice, soybean) were compared. Organic residues were applied on the soil surface or mixed with the soil. The abundance of nematodes (bacterial and fungal feeders) was higher in presence of P. corethrurus than in their absence. The type of plant residues as well as their localisation had significant effects on the abundance and composition of soil nematodes. The analysis of nematode community structure showed that earthworm activity led to an overall activation of the microbial compartment without specific stimulation of the bacterial or fungal compartment.

  5. Toxicological Effects of Organophosphate Pesticide on Ceolomocytes Viability of Earthworm E. Foetida Using NRRA

    Directory of Open Access Journals (Sweden)

    Sameena Farrukh

    2015-03-01

    Full Text Available Background: In recent years, there has been a growing interest in the development of sub-lethal earthworm biomarkers as they are relevant indicators of environmental change and they are among the five key indicators for ecotoxicological testing of industrial chemicals determined by the OECD. In the present study, the effects of an organophosphate pesticide dichlorovos on lysosomes of coelomocytes of earthworm E. foetida are studied using Neutral Red Retention Assay (NRRA. Methods: Earthworms were exposed to three sub-lethal concentrations of the pesticide for 7, 14, 21, and 28 days and neutral red retention assay was done following the method employed by Weeks and Sevendsen and Booth et al. Results: It was observed that the pesticide significantly affected the coelomocyte viability within 28 days of exposure. The neutral red retention time of lysosomal membrane significantly decreased at all concentrations when compared with well-matched controls. Conclusion: After the analysis of results, it was concluded that the neutral red retention time assay in earthworms can be used to link changes in the permeability of lysosomal membranes to ecologically relevant life cycle effects caused by such toxic substances.

  6. Interactions between earthworms and arsenic in the soil environment: a review

    International Nuclear Information System (INIS)

    Relationships between earthworms and As-rich soils are discussed, examining mechanisms of tolerance, soil factors and possible trophic transfers. - Chemical pollution of the environment has become a major source of concern. In particular, many studies have investigated the impact of pollution on biota in the environment. Studies on metalliferous contaminated mine spoil wastes have shown that some soil organisms have the capability to become resistant to metal/metalloid toxicity. Earthworms are known to inhabit arsenic-rich metalliferous soils and, due to their intimate contact with the soil, in both the solid and aqueous phases, are likely to accumulate contaminants present in mine spoil. Earthworms that inhabit metalliferous contaminated soils must have developed mechanisms of resistance to the toxins found in these soils. The mechanisms of resistance are not fully understood; they may involve physiological adaptation (acclimation) or be genetic. This review discusses the relationships between earthworms and arsenic-rich mine spoil wastes, looking critically at resistance and possible mechanisms of resistance, in relation to soil edaphic factors and possible trophic transfer routes

  7. Earthworms as ecosystem engineers and the most important detritivors in forest soils.

    Science.gov (United States)

    Kooch, Yahya; Jalilvand, Hamid

    2008-03-15

    Earthworms are considered as soil engineers because of their effects on soil properties and their influence on the availability of resources for other organisms, including microorganisms and plants. However, the links between their impacts on the soil environment and the resulting modification of natural selection pressures on engineer as well as on other organisms have received little attention. Earthworms are known to have a positive influence on the soil fabric and on the decomposition and mineralization of litter by breaking down organic matter and producing large amounts of fasces, thereby mixing litter with the mineral soil. Therefore, they play an important part in changes from one humus from to another according to forest succession patterns. Consequently, they are also expected to be good bio-indicators for forest site quality and are thus useful when planning forest production improvement. Earthworm's populations are as indicator that in exploited regions is destruction indicator and reclamation plans is nature return indicator. In this study we summarized the current knowledge in relation to earthworm's ecology in forest soils as ecosystem engineers. PMID:18814642

  8. Earthworm species and burrows related to agricultural management of grass-clover in rotation

    DEFF Research Database (Denmark)

    Krogh, Paul Henning; Lamandé, Mathieu

    2014-01-01

    Grass-clover is an important element in crop rotations due to its beneficial agronomic properties including nitrogen build-up, biodiversity stimulation and maintenance of soil macropores and it produces very high levels of earthworm biomass. We studied the relationship between crucial elements of grass-clover management in a crop rotation and earthworm diversity and macropore depth distribution. The dominance of anecics increased from an annual crop to the perennial grass-clover. Aporrectodea tuberculata decreased significantly from annuals to 3 year grass-clover. Cattle grazing favours the occurrence of coarse macropores (>5 mm ?) made by anecics, Aporrectodea longa and Lumbricus terrestris, while otherwise decreasing the number of fine-medium macropores (<5 mm ?) below the topsoil. Our study stresses the importance of considering subsoil macropores to complete the picture of earthworm influence on soil hydrology. The anecics are responsible for coarse macropores, while the smaller endogeic A. tuberculata isless important for coarse macropores and even negatively correlated with the abundant anecics and sensitive to the presence of grazing cattle compacting the topsoil. The detailed species-specific functional properties are crucial for successfully predicting the contribution to soil ecosystem services by earthworms.

  9. Effects of the endemic earthworm Allolobophora hrabei (?ernosvitov, 1935) on soil microbial communities of steppe grasslands.

    Czech Academy of Sciences Publication Activity Database

    Jirout, Ji?í; Pižl, Václav

    2014-01-01

    Ro?. 76, September (2014), s. 249-256. ISSN 0038-0717 R&D Projects: GA ?R GAP504/12/0536 Institutional support: RVO:60077344 Keywords : bacteria * archaea * fungi * community composition * DGGE * earthworm Subject RIV: EH - Ecology, Behaviour Impact factor: 4.410, year: 2013

  10. Nitric oxide production in celomocytes of the earthworm Eisenia hortensis following bacterial challenge

    Directory of Open Access Journals (Sweden)

    SR Cook

    2015-02-01

    Full Text Available In this in vitro investigation, nitric oxide (NO production was induced within celomocytes of the earthworm Eisenia hortensis following microbial challenge. Celomocytes were pre-loaded with the fluorescent indicator 4-amino-5-methylamino-2’, 7’-difluorofluorescein diacetate (DAF-FM DA in order to detect the presence of intracellular nitric oxide subsequent to a 16 h incubation with chemically-fixed soil bacteria including Bacillus megaterium, Arthrobacter globiformis, Pseudomonas stutzeri, and Azotobacter chroococcum at a range of multiplicities of infection (MOIs. Flow cytometric analysis measuring increases in relative fluorescence intensity (RFI, which is directly proportional to the amount of intracellular NO produced, permitted determination of statistical significance (p < 0.05 of exposed celomocytes compared to baseline controls. Significant increases in NO were detected reproducibly in celomocytes treated with all bacterial species used. The most prominent results were observed after exposure to Gram positive B. megaterium and A. globiformis where 100 % of earthworms tested exhibited statistically significant increases of RFI at MOIs of 100:1 and 500:1, respectively. Furthermore, significant decreases in NO production in bacteria-stimulated earthworm celomocytes incubated with the NOS inhibitor aminoguanidine hydrochloride were observed. These results demonstrate microbial induction of NO synthesis in earthworms and provide evidence of an antimicrobial role of NO in the innate immune system.

  11. Characterization, molecular cloning and localization of calreticulin in Eisenia fetida earthworms.

    Czech Academy of Sciences Publication Activity Database

    Šilerová, Marcela; Kauschke, E.; Kohlerová, Petra; Josková, Radka; Tu?ková, Ludmila; Bilej, Martin

    2007-01-01

    Ro?. 397, - (2007), s. 169-177. ISSN 0378-1119 R&D Projects: GA ?R GD310/03/H147; GA AV ?R IAA5020208; GA MŠk 2B06155 Institutional research plan: CEZ:AV0Z50200510 Keywords : earthworms * annelids * invertebrates Subject RIV: EE - Microbiology, Virology Impact factor: 2.871, year: 2007

  12. Detrimental Influence of Invasive Earthworms on North American Cold-Temperate Forest Soils

    Science.gov (United States)

    Enerson, Isabel

    2012-01-01

    The topic of invasive earthworms is a timely concern that goes against many preconceived notions regarding the positive benefits of all worms. In the cold-temperate forests of North America invasive worms are threatening forest ecosystems, due to the changes they create in the soil, including decreases in C:N ratios and leaf litter, disruption of…

  13. Effect of the earthworms Lumbricus terrestris and Aporrectodea caliginosa on bacterial diversity in soil.

    Science.gov (United States)

    Nechitaylo, Taras Y; Yakimov, Michail M; Godinho, Miguel; Timmis, Kenneth N; Belogolova, Elena; Byzov, Boris A; Kurakov, Alexander V; Jones, David L; Golyshin, Peter N

    2010-04-01

    Earthworms ingest large amounts of soil and have the potential to radically alter the biomass, activity, and structure of the soil microbial community. In this study, the diversity of eight bacterial groups from fresh soil, gut, and casts of the earthworms Lumbricus terrestris and Aporrectodea caliginosa were studied by single-strand conformation polymorphism (SSCP) analysis using both newly designed 16S rRNA gene-specific primer sets targeting Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, Bacteroidetes, Verrucomicrobia, Planctomycetes, and Firmicutes and a conventional universal primer set for SSCP, with RNA and DNA as templates. In parallel, the study of the relative abundance of these taxonomic groups in the same samples was performed using fluorescence in situ hybridization. Bacteroidetes, Alphaproteobacteria, and Betaproteobacteria were predominant in communities from the soil and worm cast samples. Representatives of classes Flavobacteria and Sphingobacteria (Bacteroidetes) and Pseudomonas spp. (low-abundant Gammaproteobacteria) were detected in soil and worm cast samples with conventional and taxon-targeting SSCP and through the sequence analysis of 16S rRNA clone libraries. Physiologically active unclassified Sphingomonadaceae (Alphaproteobacteria) and Alcaligenes spp. (Betaproteobacteria) also maintained their diversities during transit through the earthworm intestine and were found on taxon-targeting SSCP profiles from the soil and worm cast samples. In conclusion, our results suggest that some specific bacterial taxonomic groups maintain their diversity and even increase their relative numbers during transit through the gastrointestinal tract of earthworms. PMID:19888626

  14. Impact of earthworms on trace element solubility in contaminated mine soils amended with green waste compost.

    Science.gov (United States)

    Sizmur, Tom; Palumbo-Roe, Barbara; Hodson, Mark E

    2011-07-01

    The common practice of remediating metal contaminated mine soils with compost can reduce metal mobility and promote revegetation, but the effect of introduced or colonising earthworms on metal solubility is largely unknown. We amended soils from an As/Cu (1150 mg As kg(-1) and 362 mg Cu kg(-1)) and Pb/Zn mine (4550 mg Pb kg(-1) and 908 mg Zn kg(-1)) with 0, 5, 10, 15 and 20% compost and then introduced Lumbricus terrestris. Porewater was sampled and soil extracted with water to determine trace element solubility, pH and soluble organic carbon. Compost reduced Cu, Pb and Zn, but increased As solubility. Earthworms decreased water soluble Cu and As but increased Pb and Zn in porewater. The effect of the earthworms decreased with increasing compost amendment. The impact of the compost and the earthworms on metal solubility is explained by their effect on pH and soluble organic carbon and the environmental chemistry of each element. PMID:21501909

  15. Earthworms and legumes control litter decomposition in a plant diversity gradient.

    Science.gov (United States)

    Milcu, Alexandru; Partsch, Stephan; Scherber, Christoph; Weisser, Wolfgang W; Scheu, Stefan

    2008-07-01

    The role of species and functional group diversity of primary producers for decomposers and decomposition processes is little understood. We made use of the "Jena Biodiversity Experiment" and tested the hypothesis that increasing plant species (1, 4, and 16 species) and functional group diversity (1, 2, 3, and 4 groups) beneficially affects decomposer density and activity and therefore the decomposition of plant litter material. Furthermore, by manipulating the densities of decomposers (earthworms and springtails) within the plant diversity gradient we investigated how the interactions between plant diversity and decomposer densities affect the decomposition of litter belonging to different plant functional groups (grasses, herbs, and legumes). Positive effects of increasing plant species or functional group diversity on earthworms (biomass and density) and microbial biomass were mainly due to the increased incidence of legumes with increasing diversity. Neither plant species diversity nor functional group diversity affected litter decomposition, However, litter decomposition varied with decomposer and plant functional group identity (of both living plants and plant litter). While springtail removal generally had little effect on decomposition, increased earthworm density accelerated the decomposition of nitrogen-rich legume litter, and this was more pronounced at higher plant diversity. The results suggest that earthworms (Lumbricus terrestris L.) and legumes function as keystone organisms for grassland decomposition processes and presumably contribute to the recorded increase in primary productivity with increasing plant diversity. PMID:18705374

  16. Earthworms facilitate carbon sequestration through unequal amplification of carbon stabilization compared with mineralization

    Science.gov (United States)

    A recent review concluded that earthworm presence increases CO2 emissions by 33% but does not affect soil organic carbon stocks. However, the findings are controversial and raise new questions. Here we hypothesize that neither an increase in CO2 emission nor in stabilized carbon...

  17. APPLICATION OF PLANT AND EARTHWORM BIOASSAYS TO EVALUATE REMEDIATION OF A LEAD-CONTAMINATED SOIL

    Science.gov (United States)

    Earthworm acute toxicity, plant seed germination/root elongation (SG/RE) and plant genotoxicity bioassays were employed to evaluate the remediation of a lead-contaminated soil. The remediation involved removal of heavy metals by a soil washing/soil leaching treatment process. A p...

  18. Dissecting the multi-scale spatial relationship of earthworm assemblages with soil environmental variability.

    Science.gov (United States)

    Jiménez, Juan J; Decaëns, Thibaud; Lavelle, Patrick; Rossi, Jean-Pierre

    2014-12-01

    BackgroundStudying the drivers and determinants of species, population and community spatial patterns is central to ecology. The observed structure of community assemblages is the result of deterministic abiotic (environmental constraints) and biotic factors (positive and negative species interactions), as well as stochastic colonization events (historical contingency). We analyzed the role of multi-scale spatial component of soil environmental variability in structuring earthworm assemblages in a gallery forest from the Colombian ¿Llanos.¿ We aimed to disentangle the spatial scales at which species assemblages are structured and determine whether these scales matched those expressed by soil environmental variables. We also tested the hypothesis of the ¿single tree effect¿ by exploring the spatial relationships between root-related variables and soil nutrient and physical variables in structuring earthworm assemblages. Multivariate ordination techniques and spatially explicit tools were used, namely cross-correlograms, Principal Coordinates of Neighbor Matrices (PCNM) and variation partitioning analyses.ResultsThe relationship between the spatial organization of earthworm assemblages and soil environmental parameters revealed explicitly multi-scale responses. The soil environmental variables that explained nested population structures across the multi-spatial scale gradient differed for earthworms and assemblages at the very-fine- (30 m), fine (10¿20 m) and very fine scales (<10 m). Variation partitioning analysis revealed that the soil environmental variability explained from less than 1% to as much as 48% of the observed earthworm spatial variation.ConclusionsA large proportion of the spatial variation did not depend on the soil environmental variability for certain species. This finding could indicate the influence of contagious biotic interactions, stochastic factors, or unmeasured relevant soil environmental variables. PMID:25476419

  19. Importância ecológica e ambiental das minhocas / Environmental and ecological importance of earthworms

    Scientific Electronic Library Online (English)

    Gerusa Pauli Kist, Steffen; Zaida Inês, Antoniolli; Ricardo Bemfica, Steffen; Rodrigo Josemar Seminoti, Jacques.

    2013-04-01

    Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese As minhocas correspondem a um dos principais grupos de organismos edáficos atuantes nos processos de movimenta­ção de partículas e ciclagem de nutrientes. Este trabalho tem como objetivos discutir a importância das minhocas para a melhoria e manutenção da sustentabilidade dos agroecossistemas, salie [...] ntando as formas de avaliação da comunidade de minhocas no solo e sua utilização como ferramenta em avaliações ambientais. Através da constante movimentação e atividade de ingestão de solo e resíduos orgânicos, constroem galerias que contribuem com o aumento da aeração e da taxa de infiltração de água no solo. A liberação de excrementos na superfície e no interior do solo modifica positiva­mente sua estrutura e fertilidade. A densidade e diversidade de minhocas em agroecossistemas pode ser determinada por diferentes métodos de extração. Algumas espécies de minhocas, por apresentarem sensibilidade a alterações de uso e manejo do solo, são excelentes bioindicadoras ambientais, representando importante ferramenta para avaliação de impactos em ecossistemas. Abstract in english The earthworms represent a major group of soil organisms active in the process of moving particles and nutrient cycling. This paper aims to discuss the importance of earthworms to improve and maintain the sustainability of agroecosystems, emphasizing forms of community assessment of earthworms in th [...] e soil and its use as a tool in environmental assess­ments. Through constant movement and activity of soil ingestion and organic waste, they build galleries that contribute to increase the aeration and water infiltration in the soil. The release of faeces on the surface and within the soil positively modify its structure and fertility. The density and diversity of earthworms in agroecosystems can be determined by dif­ferent extraction methods. Some species of earthworms, because they are excellen to changes in land use and management, are sensitive environmental bioindicators, representing an important tool to asses impacts on ecosystems.

  20. Earthworms as bio-indicators of metal pollution in dump sites of Abeokuta City, Nigeria

    Directory of Open Access Journals (Sweden)

    O. Bamgbose

    2000-03-01

    Full Text Available Metal concentrations (Zn, Pb, Mn, Cu, Cd and Cr and contents were measured in earthworms (Libyodrilus violaceus and soil samples from three non-contaminated sites and ten dump sites located in Abeokuta, Nigeria. Samples from control sites show (in general levels of metals to be higher in earthworms than in soil samples, as shown by the mean concentrations, (earthworms-soil: - Zn:7.02, 6.74, Pb:5.04, 4.94, Mn 10.54, 10.41, Cu:1.03, 1.60., Cd: 0.80, 0.81 and Cr:0.55, 0.49 µg/g while for samples from dump sites, irrespective of the degree of pollution, the ratio of metal concentration in earthworms to soil samples were less than unity with the exception of Cd and Cr. The availability of metals in soils was also co-determined by the soil pH and soil organic matter which accounted for the trend of metal concentration at the various dump sites. For the control sites, the pH ranged from 5.40 - 6.74 and soil organic matter from 3.25% to 3.40%, while for the dump sites, values of 7.44-10.10 and 5.79% - 7.59% were obtained for soil pH and soil organic matter respectively. The metal ion concentration in both soil and earthworm samples followed the trend Pb > Zn > Mn > Cu > Cr > Cd. Dump sites with high levels of Pb were located by roadsides of busy highways.

  1. 7 CFR 58.638 - Freezing the mix.

    Science.gov (United States)

    2010-01-01

    ...false Freezing the mix. 58.638 Section...Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT...UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE...638 Freezing the mix. After the...

  2. Unitarity Constraints on Asymmetric Freeze-In

    Energy Technology Data Exchange (ETDEWEB)

    Hook, Anson; /SLAC

    2011-08-15

    This paper considers unitarity and CPT constraints on asymmetric freeze-in, the use of freeze-in to store baryon number in a dark sector. In this scenario, Sakharov's out of equilibrium condition is satisfied by placing the visible and hidden sectors at different temperatures while a net visible baryon number is produced by storing negative baryon number in a dark sector. It is shown that unitarity and CPT lead to unexpected cancellations. In particular, the transfer of baryon number cancels completely at leading order. This note has shown that if two sectors are in thermal equilibrium with themselves, but not with each other, then the leading effect transferring conserved quantities between the two sectors is of order the the weak coupling connecting them to the third power. When freeze-in is used to produce a net baryon number density, the leading order effect comes from {Omicron}({lambda}{sup 3}) diagrams where the intermediate state that goes on-shell has a different visible baryon number than the final state visible baryon number. Models in which the correct baryon number is generated with freeze-in as the dominant source of abundance, typically require {lambda} {approx}> 10{sup -6} and m{sub bath} {approx}> TeV. m{sub bath} is the mass of the visible particle which communicates with the hidden sector. The lower window is potentially observable at the LHC.

  3. Fundamental aspects of the freezing of cells, with emphasis on mammalian ova and embryos

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, P.

    1980-01-01

    The problem in cryobiology is how to cool cells to -196/sup 0/C and return them to normal temperatures without killing them. One important factor is the presence of a protective additive like glycerol or dimethyl sulfoxide. Mammalian cells rarely survive freezing to below -40/sup 0/C in its absence. In the presence of an additive, survival is critically dependent on the cooling rate. Supraoptimal rates and suboptimal rates are both damaging. Death at supraoptimal rates is the result of the formation of intracellular ice and its recrystallization during warming. Death at suboptimal rates is a consequence of the major alterations in aqueous solutions produced by ice formation. The chief effects are a major reduction in the fraction of the solution remaining unfrozen at a given temperature and a major increase in the solute concentration of that fraction. The introduction of molar concentrations of additive greatly reduces both the fraction frozen and the concentration of electrolytes in the unfrozen channels and in the cell interior. Usually, freezing either kills cells outright or it results in survivors that retain full capacity to function. But there is the possibility that in some cases survivors may in fact be impaired genetically or physiologically. All evidence indicates that genetic damage does not occur. But there are clear examples in which freezing does induce nonlethal physiological damage. (ERB)

  4. Viability of ligaments after freezing: an experimental study in a rabbit model

    International Nuclear Information System (INIS)

    Our purpose in this study was to assess ligament fibroblast viability after freezing by quantifying the subsequent ability of fibroblasts to synthesize collagen in vitro. Both medial collateral ligament (MCL) complexes from 40 adolescent rabbits were studied. Collagen production was determined by in vitro incubation of ligaments in 3H-proline (a collagen precursor) and subsequent analysis of 3H-hydroxyproline (a marker of newly synthesized collagen). Autoradiographs determined the distributions of ligament cell activity. All right MCL complexes served as fresh controls, providing a baseline of collagen production. Each left MCL was assigned to an experimental group and was either incubated fresh (10 animals); killed by drying, multiple freeze thawing, or cycloheximide (six animals); or slowly frozen at -70 degrees C without cryoprotection (24 animals). Collagen production of rapidly thawed ligaments was studied by proline incubation at 1 day, 9 days, or 6 weeks after freezing and was compared with that of contralateral fresh controls. Results demonstrate that some cells in the substance of these rabbit ligaments retained the ability to synthesize collagen in vitro after being frozen for up to 6 weeks. Mean collagen production of frozen ligaments was decreased, but tests of mean and median values as well as ratios were statistically similar to fresh contralateral ligaments in all animals. This postfreezing ligament cell survival and collagen produ ligament cell survival and collagen production after -70 degrees C storage may have implications for ligament transplantation

  5. Earthworm biomass as additional information for risk assessment of heavy metal biomagnification: a case study for dredged sediment-derived soils and polluted floodplain soils

    International Nuclear Information System (INIS)

    The important role of earthworms in the biomagnification of heavy metals in terrestrial ecosystems is widely recognised. Differences in earthworm biomass between sites is mostly not accounted for in ecological risk assessment. These differences may be large depending on soil properties and pollution status. A survey of earthworm biomass and colonisation rate was carried out on dredged sediment-derived soils (DSDS). Results were compared with observations for the surrounding alluvial plains. Mainly grain size distribution and time since disposal determined earthworm biomass on DSDS, while soil pollution status of the DSDS was of lesser importance. Highest earthworm biomass was observed on sandy loam DSDS disposed at least 40 years ago. - Polluted clayey dredged sediment-derived soils have a relatively low risk for heavy metal biomagnification due to slow earthworm colonisation

  6. Effect of acute gamma radiation and protective action of different concentration of extracts of safora japonica and hypericum perforatum on the life of aboriginal earthworms of Absheron

    International Nuclear Information System (INIS)

    Full text : As atomic power is increasingly recognized as a potential energy source to sustain future human development, radiological protection of the environment will become an even more important environmental safety concern. Thus, an understanding of the effects of ionizing radiation on non-human biota is required by the International Commission on Radiological Protection for the radiological protection of the environment. Soil processes are vital to sustainable terrestrial ecosystems, and soil invertebrates play an important role in nutrient cycling by feeding on microbiota. Because of their ecological importance, soil invertebrates are used for ecological impact assessments of terrestrial ecosystem pollutants. For chemical substances, single-species laboratory tests are used to understand toxicity. Standard tests using earthworms and spring tails have been developed by the Organization for Economic Co-operation and Development (OECD) and the International Organization for Standardization (ISO). Laboratory toxicity tests are also applicable in field contamination monitoring to determine if test organisms have been exposed to field-corrected soils. In such assays, gene expression as a biomarker has been receiving increased attention as it may produce fast, sensitive and diagnostic assays. A similar use of laboratory tests can be applied to assess the environmental impact of ionizing radiation. An understanding of the dose-effect relations of ionising radiation foreffect relations of ionising radiation for non-human biota establishes important baselines for radiobiological protection of ecosystems. We used standard laboratory tests to examine dose-effect relationships of gamma radiation on the survival, biomass changing, feeding activity, coprolite excretion of aboriginal earthworms

  7. BIOCONVERSION OFWATER HYACINTH (EICHHORNIA CRASSIPES) TO VERMICOMPOST BY THE EARTHWORM EUDRILUS EUGENIAE: AN IDEAL METHOD FOR SOLID WASTE MANAGEMENT

    OpenAIRE

    Rao, K. R.; Mushan, L. C.; Kale, P. V.; Ankaram, S. R.

    2013-01-01

    Vermicomposting is a process in which organic waste can be converted to an energy rich byproduct by the action of microbial population present in the gut flora of earthworms. Earthworms are considered as bioengineers as they enrich the soil by adding micronutrient and macronutrients through their cast. This enriched soil will be useful for getting higher yield in the agricultural crops. The vermibiotechnology facilitates the recycling of industrial, agricultural, domestic an...

  8. Effect of earthworms on plant Lantana camara Pb-uptake and on bacterial communities in root-adhering soil.

    Science.gov (United States)

    Jusselme, My Dung; Poly, Franck; Miambi, Edouard; Mora, Philippe; Blouin, Manuel; Pando, Anne; Rouland-Lefèvre, Corinne

    2012-02-01

    The present study aimed to assess the potential abilities of Lantana camara, an invasive plant species for phytoremediation in the presence of earthworm Pontoscolex corethrurus. Effects of earthworm on growth and lead (Pb) uptake by L. camara plant were studied in soil artificially contaminated at 500 or 1000mg of Pb kg(-1) soil. This species has a promising value for phytoremediation because it can uptake as much as 10% of 1000mgkg(-1) of Pb per year. Moreover, the presence of earthworms enhanced plant biomass by about 1.5-2 times and increased the uptake of lead by about 2-3 times. In the presence of earthworm, L. camara was thus able to uptake up 20% of Pb presence in the soil, corresponding to remediation time of 5 years if all organs are removed. As soil microorganisms are known to mediate many interactions between earthworms and plants, we documented the effect of earthworms on the bacterial community of root-adhering soil of L. camara. Cultivable bacterial biomass of root-adhering soil increased in the presence of earthworms. Similar trend was observed on bacterial metabolic activities. The increase of lead concentrations from 500 to 1000mgkg(-1) did not have any significant effect either on plant growth or on bacterial biomass and global activities but affected the structure and functional diversity of the bacterial community. These results showed that we should broaden the ecological context of phytoremediation by considering plant/microbial community/earthworm interactions that influence the absorption of heavy metals. PMID:22221873

  9. Design and experimental gait analysis of a multi-segment in-pipe robot inspired by earthworm's peristaltic locomotion

    Science.gov (United States)

    Fang, Hongbin; Wang, Chenghao; Li, Suyi; Xu, Jian; Wang, K. W.

    2014-03-01

    This paper reports the experimental progress towards developing a multi-segment in-pipe robot inspired by earthworm's body structure and locomotion mechanism. To mimic the alternating contraction and elongation of a single earthworm's segment, a robust, servomotor based actuation mechanism is developed. In each robot segment, servomotor-driven cords and spring steel belts are utilized to imitate the earthworm's longitudinal and circular muscles, respectively. It is shown that the designed segment can contract and relax just like an earthworm's body segment. The axial and radial deformation of a single segment is measured experimentally, which agrees with the theoretical predictions. Then a multisegment earthworm-like robot is fabricated by assembling eight identical segments in series. The locomotion performance of this robot prototype is then extensively tested in order to investigate the correlation between gait design and dynamic locomotion characteristics. Based on the principle of retrograde peristalsis wave, a gait generator is developed for the multi-segment earthworm-like robot, following which gaits of the robot can be constructed. Employing the generated gaits, the 8-segment earthworm-like robot can successfully perform both horizontal locomotion and vertical climb in pipes. By changing gait parameters, i.e., with different gaits, locomotion characteristics including average speed and anchor slippage can be significantly tailored. The proposed actuation method and prototype of the multi-segment in-pipe robot as well as the gait generator provide a bionic realization of earthworm's locomotion with promising potentials in various applications such as pipeline inspection and cleaning.

  10. Root, mycorrhiza and earthworm interactions: their effects on soil structuring processes, plant and soil nutrient concentration and plant biomass

    OpenAIRE

    Milleret, Roxane; Le Bayon, Rene?e-claire; Gobat, Jean-michel

    2009-01-01

    Earthworms, arbuscular mycorrhiza fungi (AMF) and roots are important components of the belowground part of terrestrial ecosystem. However, their interacting effects on soil properties and plant growth are still poorly understood. A compartmental experimental design was used in a climate chamber in order to investigate, without phosphorus (P) addition, the single and combined effects of earthworms (Allolobophora chlorotica), AMF (Glomus intraradices) and roots (Allium porrum) on soil structur...

  11. 90Sr accumulation of the earthworms and the influence of those upon the radionuclide dissipation in the soil

    International Nuclear Information System (INIS)

    The study is aimed at the obtaining of quantitative characteristics of 90Sr accumulation process by puberal earthworms (Nicodrilius caliginosus Savigny) when they dwell in soils of different types (grey forest and leached black earth, and to evaluate the purticipation of earthworms in the processes of radiostrontium redistribution over the soil priofile. In the experiments on the study of accumulation dynamics it is shown, that in the first days after earthworm entrance into contaminated soil the intensive accumulation of the radionuclide by the animals takes place, at that, the rate of 90Sr concentrating in the variant with grey forrest soil is 2.6 times lower, than in the case of leached black earth, and, it is somewhat lower to the end of the first stage. Stabilization of radiostrontium concentration in the earthworm organism took place in both variants of the experiment practically at the same level (KH=0.75). Radioactivity of caprolytes of the earthworms increased rapidly and all over the observation period it exceeded the radioactivity of soil on the average by 1.2-1.9. Experiments with the radionuclide redistribution have shown, that in experimental plastic vessels earthworms quite activily dispersed 90Sr. In the variant with ''contaminated'' lower soil the earthworms in time transferred approximately 11% 90Sr to the upper ''pure layers'', when the radionuclide was introduced in the upper layers of soil in ''non-contaminated'' loswer layers of soil approximately 8% 90Sr was introduced. According to preliminary calculations the rate of 90Sr dispersion by earthworms in soil constitutes approximately 0.003 cm/day and, provided the rate is constant, gradual distribution of the radionuclide over the soil profile under experimental conditions will take place in 55 years

  12. Rediscovery of Fimoscolex sporadochaetus Michaelsen 1918 (Clitellata: Glossoscolecidae), and considerations on the endemism and diversity of Brazilian earthworms / Redescubrimiento de Fimoscolex Sporadochaetus Michaelsen 1918 (clitellata: glossoscolecidae), y consideraciones sobre el endemismo y la diversidad de lombrices de tierra brasileñas

    Scientific Electronic Library Online (English)

    Samuel W., JAMES; George G., BROWN.

    Full Text Available SciELO Mexico | Language: English Abstract in spanish En Brasil hay aproximadamente 305 especies de lombrices de tierra, de las cuales 260 (85%) son nativas e 46 (15%) exóticas. La mayor parte de las especies nativas (80%) es conocida de apenas una o dos localidades y dos especies fueron consideradas como extintas por el Ministerio del Medio Ambiente d [...] e Brasil en 2003, debido a la falta de registros, destrucción de hábitat y distribución limitada (endemismo). Una de ellas es Fimoscolex sporadochaetus Michaelsen 1918, que fue recién encontrada en una reserva de Bosque Atlántico (Parque Estatal de Itacolomi) próximo al Embalse del Custodio, en el municipio de Ouro Preto, Minas Gerais. Basándonos en los datos de colectas de lombrices de tierra realizadas en Brasil hasta el momento, creemos que el estado de las especies amenazadas y "extintas" debe ser revisado y que mayores esfuerzos de colecta son necesarios para determinar la biodiversidad de lombrices en el país y su estado actual de amenaza. Abstract in english Brazil hosts approximately 305 earthworm species, of which 260 (85%) are native and 46 (15%) exotic. Most of the native species (80%) are known from only one or a few sites, and two species were considered as extinct by the Ministry of Environment of Brazil in 2003, due to lack of sightings, habitat [...] destruction and a limited prior known distribution (endemism). One of these, Fimoscolex spora-dochaetus Michaelsen, 1918 was recently found in a forest reserve (Parque Estadual do Itacolomi), near the reservoir Bacio do Custódio in Ouro Preto, Minas Gerais. With this finding, and based on earthworm collection data in Brazil up to now, we believe that the endangered and "extinct" species should have their status reviewed, and that further collecting efforts are urgently necessary to adequately determine the extent of earthworm biodiversity in Brazil and the present level of threat to their survival.

  13. Controlling the freezing process: a robotic device for rapidly freezing biological tissues with millisecond time resolution.

    Science.gov (United States)

    Tikunov, Boris A; Rome, Lawrence C

    2007-10-01

    A robotic cryogenic device was developed which allows freezing of thick biological tissues with millisecond time resolution. The device consists of two horizontally oriented hammers (pre-cooled with liquid N(2)) driven by two linear servo-motors. The tissue sample is bathed in Ringers contained in a chamber which drops rapidly out of the way just as the hammers approach. A third linear motor is vertically oriented, and permits the rapidly dropping chamber to smoothly decelerate. All movements were performed by the three motors and four solenoids controlled by a PC. Mechanical adjustments, that change the size of the gap between the hammers at the end position, permit the final thickness of the frozen tissue to be varied. Here we show that the freezing time increased with the square of the final thickness of the frozen bundle. However, when bundles of different original thicknesses (up to at least 1mm) were compressed to the same final thickness (e.g., 0.2mm), they exhibited nearly equal freezing times. Hence, by being able to adjust the final thickness of the frozen bundles, the device not only speeds the rate of freezing, but standardizes the freezing time for different diameter samples. This permits the use of freezing for accurate determination of the kinetics of cellular processes in biological tissue. PMID:17640628

  14. Bioaccumulation of 14C60 by the earthworm Eisenia fetida.

    Science.gov (United States)

    Li, Dong; Fortner, John D; Johnson, David R; Chen, Chun; Li, Qilin; Alvarez, Pedro J J

    2010-12-01

    Carbon fullerenes, including buckminsterfullerene (C(60)), are increasingly available for numerous applications, thus increasing the likelihood of environmental release. This calls for information about their bioavailability and bioaccumulation potential. In this study, (14)C-labeled C(60) and (14)C-phenanthrene (positive control) were added separately to soils of varying composition and organic carbon content (OC), and their bioaccumulation in the earthworm Eisenia fetida was compared. Biota-sediment accumulation factors (BSAF) were measured after 24 h depuration in soils with high C(60) dosages (60, 100, and 300 mg-C(60) kg(-1) dry soil), which exceed the soil sorption capacity, as well as in soils with a low C(60) dose (0.25 mg kg(-1)) conducive to a high fraction of sorbed molecular C(60). The BSAF value for the low-dose soil (0.427) was 1 order of magnitude lower than for less hydrophobic phenanthrene (7.93), inconsistent with the equilibrium partition theory that suggests that BSAF should be constant and independent of the K(OW) value of the chemical. Apparently, the large molecular size of C(60) hinders uptake and bioaccumulation. Lower BSAF values (0.065-0.13) were measured for high-dose soils, indicating that C(60) bioaccumulates more readily when a higher fraction of molecular C(60) (rather than larger precipitates) is available. For the high-dose tests (heterogeneous C(60) system), soil OC content did not significantly affect the extent of C(60) bioaccumulation after 28 d of incubation, although higher OC content resulted in faster initial bioaccumulation. For low-dose soils, C(60) BSAF decreased with increasing soil OC, as commonly reported for hydrophobic chemicals due to partitioning into soil OC. There was no detectable transformation of (14)C(60) in either soil or worm tissue. Overall, the relatively low extent but rapid bioaccumulation of C(60) in E. fetida suggests the need for further studies on the potential for trophic transfer and biomagnification. PMID:21049992

  15. Sampling of resident earthworms using mustard expellant to evaluate ecological risk at a mixed hazardous and radioactive waste site

    Energy Technology Data Exchange (ETDEWEB)

    Stair, D.M. Jr.; Keller, L.J. [Bechtel Environmental Inc., Oak Ridge, TN (United States). Oak Ridge Remediation Center; Hensel, T.W. [OGDEN Environmental and Energy Services, Inc., Oak Ridge, TN (United States)

    1994-12-31

    As residents of contaminated soils and as prey for many species of wildlife, earthworms can serve as integrative biomonitors of soil contamination, which is biologically available to the terrestrial food chain. The assessment of contaminants within earthworm tissue provides a more realistic measurement of the potential biological hazards and ecological risks than physical and chemical measurements of soil. A unique sampling procedure using a mixture of ground mustard powder and water was implemented for cost-effectively collecting earthworms without digging; the procedure minimized occupational exposure to soil contaminants and reduced the quantity of investigation-derived wastes. The study site is located at a closed burial ground for low-level radioactive waste and transuranic waste that lies within the Valley and Ridge Physiographic Province of East Tennessee. Earthworms were maintained in the laboratory for four days to allow passage of the contents of the digestive tract. Earthworm body burdens, castings, and soil were analyzed for gamma-emitting radioisotopes (potassium 40, cobalt 60, cesium 137), strontium 90, trace metals (arsenic, cadmium, chromium, mercury, lead, and selenium), and polychlorinated biphenyls (PCBs). Ecological effects of soil contamination on the earthworms were also assessed through analysis of weight, abundance, and reproductive success.

  16. Sampling of resident earthworms using mustard expellant to evaluate ecological risk at a mixed hazardous and radioactive waste site

    International Nuclear Information System (INIS)

    As residents of contaminated soils and as prey for many species of wildlife, earthworms can serve as integrative biomonitors of soil contamination, which is biologically available to the terrestrial food chain. The assessment of contaminants within earthworm tissue provides a more realistic measurement of the potential biological hazards and ecological risks than physical and chemical measurements of soil. A unique sampling procedure using a mixture of ground mustard powder and water was implemented for cost-effectively collecting earthworms without digging; the procedure minimized occupational exposure to soil contaminants and reduced the quantity of investigation-derived wastes. The study site is located at a closed burial ground for low-level radioactive waste and transuranic waste that lies within the Valley and Ridge Physiographic Province of East Tennessee. Earthworms were maintained in the laboratory for four days to allow passage of the contents of the digestive tract. Earthworm body burdens, castings, and soil were analyzed for gamma-emitting radioisotopes (potassium 40, cobalt 60, cesium 137), strontium 90, trace metals (arsenic, cadmium, chromium, mercury, lead, and selenium), and polychlorinated biphenyls (PCBs). Ecological effects of soil contamination on the earthworms were also assessed through analysis of weight, abundance, and reproductive success

  17. Impact of gut passage and mucus secretion by the earthworm Lumbricus terrestris on mobility and speciation of arsenic in contaminated soil

    OpenAIRE

    Sizmur, Tom; Watts, Michael J.; Brown, Geoffrey D.; Palumbo-roe, Barbara; Hodson, Mark E.

    2011-01-01

    Earthworms inhabiting arsenic contaminated soils may accelerate the leaching of As into surface and ground waters. We carried out three experiments to determine the impact of passage of As contaminated soil (1150 mg As kg?1) through the gut of the earthworm Lumbricus terrestris on the mobility and speciation of As and the effects of earthworm mucus on As mobility. The concentration of water soluble As in soil increased (from 1.6 to 18 mg kg?1) after passage through the earthworm gut. Cast...

  18. Toxicokinetics of metals in the earthworm Lumbricus rubellus exposed to natural polluted soils – relevance of laboratory tests to the field situation

    International Nuclear Information System (INIS)

    The aim of this study was to estimate the bioavailability of essential (Zn, Cu) and non-essential metals (Cd, Pb) to the earthworm Lumbricus rubellus exposed to soils originating from a gradient of metal pollution in Southern Poland. Metal uptake and elimination kinetics were determined and related to soils properties. Experimental results were compared with tissue metal concentrations observed in earthworms from the studied transect. Cd and Pb were intensively accumulated by the earthworms, with very slow or no elimination. Their uptake rate constants, based on 0.01 M CaCl2-extractable concentrations in the soils, increased with soil pH. Internal concentrations of Cu and Zn were maintained by the earthworms at a stable level, suggesting efficient regulation of these metals by the animals. The estimated uptake and elimination kinetics parameters enabled fairly accurate prediction of metal concentrations reached within a life span of L. rubellus in nature. - Highlights: • We estimated bioavailability of Cd, Pb, Cu and Zn to the earthworm L. rubellus. • Earthworms intensively accumulated Cd and Pb. • Uptake rate constants of Cd and Pb increased with soil pH. • Earthworms showed efficient regulation of Cu and Zn internal concentrations. • Toxicokinetics was predictive of metal accumulation by earthworms in the field. - Toxicokinetics tests with earthworms are indicative of metal bioavailability in the field

  19. Effect of radiation and freezing on [3H]DNA of Yersinia enterocolitica

    International Nuclear Information System (INIS)

    Freezing of the enteropathogenic bacterium Yersinia enterocolitica to -18 and -750C caused 7 and 42% cell death, respectively, and 0.329 and 0.588 single-strand breaks per 108 daltons of DNA, respectively, while radiation to one D10 dose (10% cell survival) combined with freezing to 2 to 0, -18 and -750C induces 0.05, 0.75, and 5.04 single-strand breaks, respectively. The increase in the effectiveness of radiation with respect to the yield of single-strand breaks at -18 to -750C is contrary to expectation and seems to be due to arrest of repair of single-strand breaks by these low temperatures. 27 references

  20. Seasonal differences in freezing stress resistance of needles of Pinus nigra and Pinus resinosa: evaluation of the electrolyte leakage method.

    Science.gov (United States)

    Sutinen, M L; Palta, J P; Reich, P B

    1992-10-01

    Seasonal changes in freezing stress resistance of needles of red pine (Pinus resinosa Ait.) and Austrian pine (Pinus nigra Arnold) trees were measured by an electrolyte leakage method and by visual observation. During most of the year, freezing stress resistance determined by the two methods gave similar results. The electrolyte leakage method provided a good estimate of seasonal changes in freezing stress resistance except for red pine needles in their most winter-hardy state. To obtain a reliable estimate of freezing stress resistance in winter-hardy red pine needles it was necessary to combine the electrolyte leakage method with visual observations. When red pine needles survived exposure to -80 degrees C or lower, electrolyte leakage was never more than 30% even when the needles were exposed to a slow freeze-thaw stress of -196 degrees C. However, rapid freezing of red pine needles to -196 degrees C resulted in electrolyte leakage of over 80%. Red pine needles attained a much higher freezing stress resistance during the winter than Austrian pine. Red pine needles also acclimated and deacclimated faster than Austrian pine needles. An index of injury was developed based on the electrolyte leakage method ((R(2) + R(1))/2, where R(1) is the minimum % electrolyte leakage from noninjured tissue and R(2) is the maximum % electrolyte leakage at the highest injury) that reliably predicted freezing stress resistance of pine needles for most of the year. Important aspects for developing a successful index of injury for pine needles are: use of cut needles, vacuum infiltration and shaking during incubation in water.We conclude that: (1) during cold acclimation the cell wall properties of the pine needles changed and these changes, which appeared to differ in the two species, might explain the very low leakage of electrolytes from winter-hardy needles of red pine; (2) pine needles survive winter by developing the ability to tolerate extracellular ice formation, because after rapid freezing the needles were severely injured; and (3) red pine is adapted to a shorter growing season and colder winters than Austrian pine. PMID:14969949

  1. Near infrared spectroscopy for identifying the earthworm's participation to soil macroaggregation

    Science.gov (United States)

    Zangerlé, Anne; Hissler, Christophe; Lavelle, Patrick

    2014-05-01

    As ecosystem engineers, earthworms are major actors of soil aggregation, a process that drives the delivery of ecosystem services by soils. However, our inability to identify the origins of different types of macroaggregates found in soils, the macroaggregates persistence in the soil matrix, their degradation rates, and their role in the dynamics of soil organic matter (SOM) and nutrients remain poorly known. Near Infrared Spectroscopy (NIRS) was tested as a tool to discriminate between origins of macroaggregates, collected in the field at the soil surface and in the 25 first cm of the soil. In parallel, NIR spectral signatures of earthworm casts were measured, during the ageing processes of the aggregates. During the first experiment, earthworm casts of unknown origins, collected in the field, were identified by comparing their NIR spectral signatures to the signatures of macroaggregates produced by the same ecosystem engineers in laboratory conditions, living in the same soil. Principal component analysis of NIR spectra permitted us to characterize macroaggregates of each species by a specific spectral signature (psoil macroaggregates present quantitative and qualitative differences according to the earthworm species that produced them. During the second experiment, realized in laboratory conditions, NIR spectral signatures were measured in subterranean and surface casts of different earthworm species, incubated in controlled laboratory conditions for different periods of time. In parallel, dynamics of total amounts of C and N were assessed in ageing macroaggregates. As casts aged, NIR spectral signatures went through three main stages in the maturation process: (1) rapid changes in the NIR signal during the first 48 h, (2) a maturation period from days 3-30 with much slower change in NIR spectral signatures and (3) a further stage of maturation (days 45-90), where cast spectral signature and C and N contents converged towards those of the control soil. The first two axes of the PCA corresponded closely to the C and N content, respectively, of the casts. These two complementary experiments demonstrate that NIRS allows identifying origins of macroaggregates produced by various earthworm species in different environments. Other complementary experiences we realized in laboratory conditions highlight that OM modifications, caused in aging casts, are large enough to be detected by NIRS in macroaggregates and to estimate a cast's age. We propose a new method to analyse soil macroaggregates origins, to quantify the relative contribution of ecosystem engineers to soil aggregation and to evaluate soil macroaggregates dynamics in the soil structure.

  2. Integrated biomarker analysis of chlorpyrifos metabolism and toxicity in the earthworm Aporrectodea caliginosa.

    Science.gov (United States)

    Sanchez-Hernandez, Juan C; Narvaez, C; Sabat, P; Martínez Mocillo, S

    2014-08-15

    To increase our understanding about the mode of toxic action of organophosphorus pesticides in earthworms, a microcosm experiment was performed with Aporrectodea caliginosa exposed to chlorpyrifos-spiked soils (0.51 and 10 mg kg(-1) dry soil) for 3 and 21 d. Acetylcholinesterase (AChE), carboxylesterase (CbE), cytochrome P450-dependent monooxygenase (CYP450), and glutathione S-transferase (GST) activities were measured in the body wall of earthworms. With short-term exposure, chlorpyrifos inhibited CbE activity (51-89%) compared with controls in both treated groups, whereas AChE activity was depressed in the 10-mg kg(-1) group (87% inhibition). With long-term exposure, chlorpyrifos strongly inhibited all esterase activities (84-97%). Native electrophoresis revealed three AChE isozymes, two of which showed a decreased staining corresponding to the level of pesticide exposure. The impact of chlorpyrifos on CbE activity was also corroborated by zymography. CYP450 activity was low in unexposed earthworms, but it increased (1.5- to 2.4-fold compared to controls) in the earthworms exposed to both chlorpyrifos concentrations for 3d. Bioactivation of chlorpyrifos was determined by incubating the muscle homogenate in the presence of chlorpyrifos and NAD(H)2. The mean (±SD, n=40) bioactivation rate in the unexposed earthworms was 0.74±0.27 nmol NAD(H)2 oxidized min(-1) mg(-1) protein, and a significant induction was detected in the low/short-term exposure group. GST activity significantly increased (33-35% of controls) in earthworms short-term exposed to both chlorpyrifos concentrations. Current data showed that CYP450 and GST activities had a prominent role in the initial exposure to the organophosphorus. With short-term exposure, CbE activity was also a key enzyme in the non-catalytic detoxification of chlorpyrifos-oxon, thereby reducing its impact on AChE activity, before it became saturated at t=21 d. Results indicate that A. caliginosa detoxify efficiently chlorpyrifos, which would explain its tolerance to relatively high exposure levels to chlorpyrifos. PMID:24867707

  3. Cryopreservation of human failed-matured oocytes followed by in vitro maturation: vitrification is superior to the slow freezing method

    Directory of Open Access Journals (Sweden)

    Zhang ZhiGuo

    2011-12-01

    Full Text Available Abstract Background Oocyte cryopreservation is an important method used in a number of human fertility circumstances. Here, we compared the survival, in vitro maturation, fertilization, and early embryonic development rates of frozen-thawed human immature oocytes using two different cryopreservation methods. Methods A total of 454 failed-matured oocytes [germinal vesicle (GV and metaphase I (MI stages] were collected from 135 patients (mean age 33.84 +/- 5.0 y who underwent intracytoplasmic sperm injection (ICSI cycles between February 2009 and December 2009 and randomly divided into a slow freezing group [1.5 mol/L-1, 2-propanediol (PROH + 0.2 mol/l sucrose] and vitrification group [20% PROH + 20% ethylene glycol (EG + 0.5 mol/l sucrose]. Results The vitrification protocol yielded a better survival rate than the slow freezing protocol at each maturation stage assessed. Regardless of the maturation stage (GV + MI, the slow freezing protocol had a significantly lower survival rate than the vitrification protocol (p in vitro maturation (21.2 vs. 54.0%, respectively; p 0.05. For the GV-matured oocytes, no fertilized eggs were obtained in the slow-freezing group, while a 19.0% (4/21 fertilization rate was observed in the vitrification group. For the MI-matured oocytes, fertilization rates for the slow freezing and vitrified groups were 36% and 61.1%, respectively, but no significant difference was found between the two groups (PIn the Methods section in the MS, all procedures were compliant with ethical guidelines, i.e. approved by the Ethical Committee of our university and Informed Consent signed by each patient. > 0.05. In the GV vitrification group, no embryo formed; however, in the MI slow freezing group, 12 oocytes were fertilized, but only two achieved cleavage and were subsequently blocked at the 2-cell stage. In the MI vitrification group, a total of 22 embryos were obtained, five of which developed to the blastocyst stage. Conclusions Vitrification is superior to the slow freezing method in terms of the survival and developmental rates for the cryopreservation of human failed-matured oocytes. In addition, GV oocytes appeared to be more resistant than MI oocytes to the low temperature and cryoprotectant used during cryopreservation.

  4. The freezing and supercooling of garlic (Allium sativum L.)

    Energy Technology Data Exchange (ETDEWEB)

    James, Christian; Seignemartin, Violaine; James, Stephen J. [Food Refrigeration and Process Engineering Research Centre (FRPERC), University of Bristol, Churchill Building, Langford, Bristol BS40 5DU (United Kingdom)

    2009-03-15

    This work shows that peeled garlic cloves demonstrate significant supercooling during freezing under standard conditions and can be stored at temperatures well below their freezing point (-2.7 C) without freezing. The nucleation point or 'metastable limit temperature' (the point at which ice crystal nucleation is initiated) of peeled garlic cloves was found to be between -7.7 and -14.6 C. Peeled garlic cloves were stored under static air conditions at temperatures between -6 and -9 C for up to 69 h without freezing, and unpeeled whole garlic bulbs and cloves were stored for 1 week at -6 C without freezing. (author)

  5. Cryopreservation of Escherichia coli K12TG1: Protection from the damaging effects of supercooling by freezing.

    Science.gov (United States)

    Simonin, H; Bergaoui, I M; Perrier-Cornet, J M; Gervais, P

    2015-04-01

    Injuries in living cells caused by water freezing during a freeze-thaw process have been extensively reported. In particular, intracellular water freezing has long been incriminated in cell death caused by a high cooling rate, but this supposition could not always be demonstrated. This work aims to discriminate the role of water freezing, dehydration and cold-induced injuries in cellular damage occuring during cryopreservation. For this purpose, Escherichia coli K12TG1 suspensions were maintained in a supercooled or frozen state at -20°C for times ranging from 10min to 5h. The supercooled state was maintained for a long period at -20°C by applying a non-injurious isostatic pressure (Pmembrane damage were determined by agar plating and fluorescence staining with propidium iodide and bis-oxonol. It was clear that keeping the cell suspensions in the supercooled state had a detrimental effect on both viability and plasma membrane permeability. Conversely, when cells were subjected to cold stress by freezing, the survival rate remained high throughout the experiment, and the cell membranes suffered little damage. Moreover, cells subjected to 5h of osmotic treatments at -20°C, conditions that mimic cryoconcentration upon freezing, and subsequently diluted and thawed suffered little damage. Dehydration due to cryoconcentration upon freezing protects the cells against the deleterious effects of supercooling, especially in the plasma membranes. The decrease in membrane leakage upon dehydration at low temperatures could be linked to differences in the gel state of the membrane revealed by a higher Laurdan general polarization (GP) value. PMID:25542651

  6. Earthworm effects on the incorporation of litter C and N into soil organic matter in a sugar maple forest.

    Science.gov (United States)

    Fahey, Timothy J; Yavitt, Joseph B; Sherman, Ruth E; Maerz, John C; Groffman, Peter M; Fisk, Melany C; Bohlen, Patrick J

    2013-07-01

    To examine the mechanisms of earthworm effects on forest soil C and N, we double-labeled leaf litter with 13C and 15N, applied it to sugar maple forest plots with and without earthworms, and traced isotopes into soil pools. The experimental design included forest plots with different earthworm community composition (dominated by Lumbricus terrestris or L. rubellus). Soil carbon pools were 37% lower in earthworm-invaded plots largely because of the elimination of the forest floor horizons, and mineral soil C:N was lower in earthworm plots despite the mixing of high C:N organic matter into soil by earthworms. Litter disappearance over the first winter-spring was highest in the L. terrestris (T) plots, but during the warm season, rapid loss of litter was observed in both L. rubellus (R) and T plots. After two years, 22.0% +/- 5.4% of 13C released from litter was recovered in soil with no significant differences among plots. Total recovery of added 13C (decaying litter plus soil) was much higher in no-worm (NW) plots (61-68%) than in R and T plots (20-29%) as much of the litter remained in the former whereas it had disappeared in the latter. Much higher percentage recovery of 15N than 13C was observed, with significantly lower values for T than R and NW plots. Higher overwinter earthworm activity in T plots contributed to lower soil N recovery. In earthworm-invaded plots isotope enrichment was highest in macroaggregates and microaggregates whereas in NW plots silt plus clay fractions were most enriched. The net effect of litter mixing and priming of recalcitrant soil organic matter (SOM), stabilization of SOM in soil aggregates, and alteration of the soil microbial community by earthworm activity results in loss of SOM and lowering of the C:N ratio. We suggest that earthworm stoichiometry plays a fundamental role in regulating C and N dynamics of forest SOM. PMID:23967585

  7. Influence of melt freezing characteristics on steam explosion energetics

    International Nuclear Information System (INIS)

    This paper examines the freezing process of distinct melt particles interacting with water. Approximate time scales of freezing are estimated for some high-temperature melt materials that are of interest in experimental and reactor situations. Transient conduction calculations are performed to clarify the special freezing characteristics of oxidic melt materials (low conductivity) and binary melt mixtures (no definite freezing point). The transient calculations are compared with recent experiments indicating ''non-explosivity'' of Corium (UO2-ZrO2). One potential explanation, based on the freezing characteristics of binary Corium mixture, is proposed for the experimental observations. The numerical results are generalized by discussing the scaling implications of the thermal conduction analysis and by defining different freezing categories. Finally, conclusions are drawn on the potential influence of melt freezing characteristics on steam explosion energetic

  8. Freezing of water droplets colliding with kaolinite particles

    DEFF Research Database (Denmark)

    Svensson, Erik Anders; Delval, Christophe Eric Ludovic

    2009-01-01

    Contact freezing of single supercooled water droplets colliding with kaolinite dust particles has been investigated. The experiments were performed with droplets levitated in an electrodynamic balance at temperatures from 240 to 268 K. Under dry conditions freezing 5 was observed to occur below 249 K, while a freezing threshold of 267 K was observed at high relative humidity. The effect of relative humidity is attributed to an influence on the contact freezing process for the kaolinite-water droplet system, and it is not related to the lifetime of the droplets in the electrodynamic balance. Freezing probabilities per collision were derived assuming that collisions at the lowest temper10 ature employed had a probability of unity. The data recorded at high humidity should be most relevant to atmospheric conditions, and the results indicate that parameterizations currently used in modelling studies to describe freezing rates are appropriate for kaolinite aerosol particles. Mechanisms for contact freezing are briefly discussed.

  9. Study of Transient Nuclei near Freezing

    CERN Document Server

    Isobe, Masaharu

    2010-01-01

    The molasses tail in dense hard core fluids is investigated by extensive event-driven molecular dynamics simulation through the orientational autocorrelation functions. Near the fluid-solid phase transition, there exist three regimes in the relaxation of the pair orientational autocorrelation function, namely the kinetic, molasses (stretched exponential), and diffusional power decay. The density dependence of both the molasses and diffusional power regimes are evaluated and the latter compares with theoretical predictions in three dimensions. The largest cluster at the freezing density of only a few sphere diameter in size persist for only about 30 picoseconds (~ 2.8 x 10^{-11}[s]). The most striking observation through the bond orientatinal order parameter is the dramatic increase of the cluster size as the freezing density is approached.

  10. Vogel-Fulcher freezing in relaxor ferroelectrics

    International Nuclear Information System (INIS)

    A physical mechanism for the freezing of polar nanoregions (PNRs) in relaxor ferroelectrics is presented. Assuming that the activation energy for the reorientation of a cluster of PNRs scales with the mean volume of the cluster, the characteristic relaxation time ? is found to diverge as the cluster volume reaches the percolation limit. Applying the mean field theory of continuum percolation, the familiar Vogel-Fulcher equation for the temperature dependence of ? is derived

  11. Theoretical prediction of 'optimal' freezing programmes

    OpenAIRE

    Woelders, H.; Chaveiro, A.

    2004-01-01

    We have developed a quantitative description of the osmotic behaviour of cells during freezing without a presupposed value of the cooling rate. Instead, at all times the intracellular supercooling is maximised provided that it does not exceed a predetermined value 'p' (e.g., 2°C). This should preclude intracellular ice formation, but also ensures that the osmotic gradient and the CPA concentration gradient are limited, as well as the gradient driven transmembrane fluxes of water and CPA. Usi...

  12. Scaling-Up Eutectic Freeze Crystallization:

    OpenAIRE

    Genceli, F. E.

    2008-01-01

    A novel crystallization technology, Eutectic Freeze Crystallization (EFC) has been investigated and further developed in this thesis work. EFC operates around the eutectic temperature and composition of aqueous solutions and can be used for recovery of (valuable) dissolved salts (and/or or acids) and water from a wide variety of aqueous process streams. Using EFC, processes producing large quantities of saline solutions could be carried out in an ecologically and economically attractive way. ...

  13. Hot water can freeze faster than cold?!?

    OpenAIRE

    Jeng, Monwhea

    2005-01-01

    We review the Mpemba effect, where intially hot water freezes faster than initially cold water. While the effect appears impossible at first sight, it has been seen in numerous experiments, was reported on by Aristotle, Francis Bacon, and Descartes, and has been well-known as folklore around the world. It has a rich and fascinating history, which culminates in the dramatic story of the secondary school student, Erasto Mpemba, who reintroduced the effect to the twentieth cent...

  14. Astronomical bounds on future big freeze singularity

    CERN Document Server

    Yurov, Artyom V; Gonzalez-Diaz, Pedro F

    2007-01-01

    Recently it was found that dark energy in the form of phantom generalized Chaplygin gas may lead to a new form of the cosmic doomsday, the big freeze singularity. Like the big rip singularity, the big freeze singularity would also take place at a finite future cosmic time, but unlike the big rip singularity it happens for a finite scale factor.Our goal is to test if a universe filled with phantom generalized Chaplygin gas can conform to the data of astronomical observations. We shall see that if the universe is only filled with generalized phantom Chaplygin gas with equation of state $p=-c^2s^2/\\rho^{\\alpha}$ with $\\alpha<-1$, then such a model cannot be matched to the data of astronomical observations. To construct matched models one actually need to add dark matter. This procedure results in cosmological scenarios which do not contradict the data of astronomical observations and allows one to estimate how long we are now from the future big freeze doomsday.

  15. An exploration of the relationship between adsorption and bioavailability of pesticides in soil to earthworm

    Energy Technology Data Exchange (ETDEWEB)

    Yu Yunlong [Department of Plant Protection, Zhejiang University, Kaixuan Road 268, Hangzhou, Zhejiang 310029 (China)]. E-mail: ylyu@zju.edu.cn; Wu Xiaomao [Department of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025 (China); Li Shaonan [Department of Plant Protection, Zhejiang University, Kaixuan Road 268, Hangzhou, Zhejiang 310029 (China); Fang Hua [Department of Plant Protection, Zhejiang University, Kaixuan Road 268, Hangzhou, Zhejiang 310029 (China); Zhan Haiyan [Department of Plant Protection, Zhejiang University, Kaixuan Road 268, Hangzhou, Zhejiang 310029 (China); Yu Jingquan [Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China)

    2006-06-15

    A study was conducted to determine the adsorption/desorption of butachlor, myclobutanil and chlorpyrifos on five soils using a batch equilibration technique and to study the relationship between bioavailability to Allolobophora caliginosa and the adsorption/desorption of these three pesticides. The results showed that the adsorption/desorption processes of the tested compounds were mainly controlled by soil organic matter content (OM) and octanol/water-partitioning coefficient (K {sub ow}), and that the bioavailability of the pesticides was dependent on characteristics of pesticides, properties of soils, and uptake routes of earthworms. Bioconcentration of butachlor and myclobutanil was negatively correlated with Freundlich adsorption constant K {sub af} and K {sub df}. However, only a slightly positive correlation between bioconcentration and K {sub af} and K {sub df} was observed for chlorpyrifos due to its high affinity onto soil. - Bioavailability of pesticides in soil to earthworm is governed by adsorption characteristics.

  16. Expression and characterization of earthworm Eisenia foetida lumbrokinase-3 in Pichia pastoris.

    Science.gov (United States)

    Yuan, Xiaoling; Cao, Chenhua; Shan, Yajun; Zhao, Zhenhu; Chen, Jiapei; Cong, Yuwen

    2006-01-01

    Lumbrokinase-3 (LK-3, AY438622), first cloned from the earthworm Eisenia foetida in our laboratory, is a component of earthworm fibrinolytic enzymes. In this study, cDNA encoding the LK-3 gene was sub-cloned into yeast pPIC9K expression vector and transformed into the Pichia pastoris GS115 cells by electroporation. High level expression of LK-3 in yeast cells was confirmed with a different induction time. The activity of expressed LK-3 was observed in fibrin plates. In addition, the expressed LK-3 protein could dissolve fibrinogen and bovine serum albumin. The use of this system for the high level production of biological protein is implicated from this study. PMID:16707338

  17. Uptake, bioavailability and elimination of hydrophobic compounds in earthworms (Eisenia andrei) in field-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Belfroid, A.; Berg, M. van den; Seinen, W.; Hermens, J. [Univ. of Utrecht (Netherlands). Research Inst. of Toxicology; Gestel, K. van [Vrije Univ., Amsterdam (Netherlands). Dept. of Ecology and Ecotoxicology

    1995-04-01

    Uptake, accumulation, and elimination of hydrophobic organic chemicals in earthworms (Eisenia andrei) exposed to field-contaminated Volgermeerpolder soil was studied. Earthworms were able to take up chlorobenzenes and polychlorobiphenyls (PCBs), but body burdens did not exceed concentrations measured in the soil. For the chlorobenzenes, steady-state concentrations in the worms and biota-to-soil accumulation factor (BSAF) values were much smaller than expected based on earlier experiments, suggesting a decreased bioavailability in the Volgermeerpolder soil. Comparison of the PCB accumulation pattern in worms to the pattern in soil showed that biotransformation of the studied PCBs is of minor importance in this species. Elimination of all chemicals studied was monophasic, with the exception of hexachlorobenzene, which showed a biphasic elimination. The elimination half-life for the initial fast phase of this compound is comparable to the elimination measured in previous studies. Elimination rate constants decreased with increasing log K{sub ow}.

  18. Earthworm cast production as a new behavioural biomarker for toxicity testing.

    Science.gov (United States)

    Capowiez, Yvan; Dittbrenner, Nils; Rault, Magali; Triebskorn, Rita; Hedde, Mickaël; Mazzia, Christophe

    2010-02-01

    There is currently a lack of ecotoxicity tests adapted to earthworm species of higher ecological relevance and whose endpoints could be directly related to their ecological role in the soil. We propose a new and relatively simple ecotoxicity test based on the estimation of cast production (CP) by Lumbricus terrestris under laboratory conditions. CP was found to be linearly correlated to earthworm biomass and to be greatly influenced by soil water content. Azinphos-methyl had no effect on CP at all the concentrations tested. Significant decreases were observed at the normal application rate for other pesticides with (imidacloprid, carbaryl, methomyl) or without (ethyl-parathion and chlorpyrifos-ethyl) a clear concentration-effect response. For the highest concentration tested, reduction in CP varied between 35 and 67%. CP is straightforward and rapidly measured and ecologically meaningful. We thus believe it to be of great use as an endpoint in ecotoxicity testing. PMID:19783336

  19. Silver nanoparticle exposure causes apoptotic response in the earthworm Lumbricus terrestris (Oligochaeta).

    Science.gov (United States)

    Lapied, Emmanuel; Moudilou, Elara; Exbrayat, Jean-Marie; Oughton, Deborah Helen; Joner, Erik Jautris

    2010-08-01

    In terrestrial ecotoxicology there is a serious lack of data for potential hazards posed by engineered nanoparticles (ENPs). This is partly due to complex interactions between ENPs and the soil matrix, but also to the lack of suitable toxicological end points in organisms that are exposed to ENPs in a relevant manner. Earthworms are key organisms in terrestrial ecosystems, but so far only physiological end points of low sensitivity have been used in ecotoxicity studies with ENPs. We exposed the earthworm Lumbricus terrestris to silver nanoparticles and measured their impact on apoptosis in different tissues. Increased apoptotic activity was detected in a range of tissues both at acute and sublethal concentrations (down to 4 mg/kg soil). Comparing exposure in water and soil showed reduced bioavailability in soil reflected in the apoptotic response. Apoptosis appears to be a sensitive end point and potentially a powerful tool for quantifying environmental hazards of ENPs. PMID:20735231

  20. A comparison of multiple esterases as biomarkers of organophosphate exposure and effect in two earthworm species.

    Science.gov (United States)

    Henson-Ramsey, Heather; Schneider, Ashley; Stoskopf, Michael K

    2011-04-01

    Two different earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to 5 ?g/cm(2) of malathion to evaluate their usefulness as sentinels of organophosphate exposure and to assess three different esterases, as biomarkers of malathion exposure and effect. Tissue xenobiotic burdens and esterase activity were determined for each species and each esterase in order to assess variability. E. fetida exhibited 4-fold less variability in tissue burdens than did L. terrestris and had less variable basal esterase activities. An attempt was made to correlate malathion and malaoxon tissue burdens with esterase activity post-exposure. There was no malaoxon present in the earthworm tissues. No significant correlations were determined by comparing acetylcholinesterase, butyrylcholinesterase, nor carboxylesterase activities with malathion burdens. PMID:21404045

  1. Degradation of Potassium Rock by Earthworms and Responses of Bacterial Communities in Its Gut and Surrounding Substrates after Being Fed with Mineral

    Science.gov (United States)

    Liu, Dianfeng; Lian, Bin; Wang, Bin; Jiang, Guofang

    2011-01-01

    Background Earthworms are an ecosystem's engineers, contributing to a wide range of nutrient cycling and geochemical processes in the ecosystem. Their activities can increase rates of silicate mineral weathering. Their intestinal microbes usually are thought to be one of the key drivers of mineral degradation mediated by earthworms,but the diversities of the intestinal microorganisms which were relevant with mineral weathering are unclear. Methodology/Principal Findings In this report, we show earthworms' effect on silicate mineral weathering and the responses of bacterial communities in their gut and surrounding substrates after being fed with potassium-bearing rock powder (PBRP). Determination of water-soluble and HNO3-extractable elements indicated some elements such as Al, Fe and Ca were significantly released from mineral upon the digestion of earthworms. The microbial communities in earthworms' gut and the surrounding substrates were investigated by amplified ribosomal DNA restriction analysis (ARDRA) and the results showed a higher bacterial diversity in the guts of the earthworms fed with PBRP and the PBRP after being fed to earthworms. UPGMA dendrogram with unweighted UniFrac analysis, considering only taxa that are present, revealed that earthworms' gut and their surrounding substrate shared similar microbiota. UPGMA dendrogram with weighted UniFrac, considering the relative abundance of microbial lineages, showed the two samples from surrounding substrate and the two samples from earthworms' gut had similarity in microbial community, respectively. Conclusions/Significance Our results indicated earthworms can accelerate degradation of silicate mineral. Earthworms play an important role in ecosystem processe since they not only have some positive effects on soil structure, but also promote nutrient cycling of ecosystem by enhancing the weathering of minerals. PMID:22174903

  2. Searching for external sources of the riboflavin stored in earthworm eleocytes

    OpenAIRE

    Sulik, P.; Klimek, M.; Talik, P.; Kruk, J.; Aj, Morgan; Plytycz, B.

    2012-01-01

    Riboflavin (vitamin B2) is essential to maintain immune potency in animals and plants. So far is accepted that animals cannot synthesise riboflavin; they rely on plant-sourced diets and intestinal bacteria for their supplies. A unique feature of earthworm ‘hepatocyte-like’ chloragocytes and chloragocyte-derived eleocytes floating in celomic cavity is the storage of riboflavin within intracellular granules. The hypothesis was that vegetarian food-deprivation or antibiotic/antifungal treatm...

  3. Biological significance of metals partitioned to subcellular fractions within earthworms (Aporrectodea caliginosa).

    OpenAIRE

    Vijver, Martina G.; Gestel, Cornelis A. M.; Straalen, Nico M.; Lanno, Roman P.; Peijnenburg, Willie J. G. M.

    2007-01-01

    Metal ions in excess of metabolic requirements are potentially toxic and must be removed from the vicinity of important biological molecules to protect organisms from adverse effects. Correspondingly, metals are sequestrated in various forms, defining the accumulation pattern and the magnitude of steady-state levels reached. To investigate the subcellular fractions over which Ca, Mg, Fe, Cu, Zn, Cd, Pb, Ni, and As are distributed, earthworms (Aporrectodea caliginosa) collected from the field ...

  4. Molecular characterization of the iron binding protein ferritin in Eisenia andrei earthworms.

    Czech Academy of Sciences Publication Activity Database

    Procházková, Petra; Dvo?ák, Ji?í; Šilerová, Marcela; Roubalová, Radka; Škanta, František; Halada, Petr; Bilej, Martin

    2011-01-01

    Ro?. 485, ?. 2 (2011), s. 73-80. ISSN 0378-1119 R&D Projects: GA ?R GA206/07/0378; GA ?R GD310/08/H077; GA AV ?R IAA600200704; GA MŠk 2B06155; GA MŠk LC07017 Institutional research plan: CEZ:AV0Z50200510 Keywords : Earthworms * Invertebrates * Ferritin Subject RIV: EC - Immunology Impact factor: 2.341, year: 2011

  5. Underground evolution: New roots for the old tree of lumbricid earthworms.

    Science.gov (United States)

    Domínguez, Jorge; Aira, Manuel; Breinholt, Jesse W; Stojanovic, Mirjana; James, Samuel W; Pérez-Losada, Marcos

    2015-02-01

    Earthworms belonging to the family Lumbricidae are extremely abundant in terrestrial temperate regions. They affect soil properties and nutrient cycling, thus shaping plant community composition and aboveground food webs. Some lumbricids are also model organisms in ecology and toxicology. Despite the intense research efforts dedicated to lumbricids over the last 130years, the evolutionary relationships and taxonomic classification of these organisms are still subject to great debate. Resolution of their systematics is hampered by the structural simplicity of the earthworm body plan and the existence of cryptic species. We sampled 160 earthworm specimens belonging to 84 lumbricid species (28 genera) and 22 Lumbricoidea outgroups, sequenced two nuclear genes, four mitochondrial genes and seven mitochondrial tRNAs and examined 22 morphological characters. We then applied a combination of phylogenetic methods to generate the first robust genus-level phylogeny of the Lumbricidae. Our results show that the current Lumbricidae classification and the underlying hypotheses of character evolution must be revised. Our chronogram suggests that lumbricids emerged in the Lower Cretaceous in the holarctic region and that their diversification has been driven by tectonic processes (e.g. Laurasia split) and geographical isolation. Our chronogram and character reconstruction analysis reveal that spermathecae number does not follow a gradual pattern of reduction and that parthenogenesis arose from sexual relatives multiple times in the group; the same analysis also indicates that both epigeic and anecic earthworms evolved from endogeic ancestors. These findings emphasize the strong and multiple changes to which morphological and ecological characters are subjected, challenging the hypothesis of character stasis in Lumbricidae. PMID:25463017

  6. Microflora dynamics in earthworms casts in an artificial soil (biosynthesol) containing lactic acid oligomers

    Scientific Electronic Library Online (English)

    Nathalie, Alauzet; Sevastianos, Roussos; Henri, Garreau; Michel, Vert.

    2001-06-01

    Full Text Available Já mostramos que a minhoca Eisenia andrei é capaz de bioassimilar o OLA (oligomeros de ácido lático), uma vez que este último tenha sido pré-digerido por microorganismos. A fim de verificar a presênça de microorganismos capazes de degradar os oligomeros de ácido láctico (OLA), as minhocas foram cria [...] das num solo artificial, o biosintesol. O número de bactérias e fungos nas fezes de minhocas e no biosintesol sem minhoca foi estimado, assim como o gênero dos fungos filamentosos presentes. O resultado mostra uma fraca diminuição do número de microrganismos após sua passagem no instestino das minhocas, sugerindo que as minhocas digerem alguns deles. Os principais fungos filamentosos encontrados foram Aspergillus, Trichoderma, Fusarium e Penicillium. Resultados anteriores mostraram que algumas espécies dos gêneros Aspergillus e Fusarium são capazes de degradar o OLA e outros ésteres alifáticos. Sugere-se que esses 2 gêneros e algumas bactérias são responsáveis pela pré-degradação do OLA, antes que as minhocas os comam. Abstract in english Studies were performed to appreciate the presence of micro-organisms able to degrade OLA, in earthworms casts or in the surroundings. Worms were grown in biosynthesol, an artificial soil. The counting of bacteria and fungi in earthworms casts and in biosynthesol without earthworms suggested that ear [...] thworms ate some of the micro-organisms. The main filamentous fungi genera found were Aspergillus, Trichoderma, Fusarium and Penicillium. Previous results in the literature have shown that some species from the Aspergillus and Fusarium genera were able to degrade OLA and other aliphatic esters. It could be suggested that these two genera and some bacteria were responsible for the pre-degradation of OLA, and that earthworms might eat them.

  7. Composition of organic matter in earthworm casts depending on litter quality

    Science.gov (United States)

    Ellerbrock, R. H.; Gerke, H. H.; Schrader, S.; Leue, M.

    2009-04-01

    Earthworms contribute to decomposition and stabilization of organic matter (OM) in soil. The digestion during intestinal passage inside worms may lead to a change in the composition of OM. It is largely unknown if and how the type of litter the earthworm is feeding on is affecting the OM composition in the casts. Fourier Transform infrared spectroscopy (FTIR) is used to determine the hydrophobic CH- (A) and the hydrophilic CO- (B) functional groups in OM. The objective was to compare the A/B- ratios of litter samples with that of (i) the corresponding casts of the primary decomposer Lumbricus terrestris and (ii) the water contact angles of ground cast samples and at intact cast surfaces. Litter from 10 different plant species including leaves of birch, beech, oak, spruce, pear, mustard and wheat straw (3 replicates) was offered separately to L. terrestris in microcosms containing a Luvisol soil. The OM composition of litter and that of casts, collected from the soil surface after 4-weeks was analyzed with FTIR (DRIFT technique). The A/B ratio of casts was generally increased as compared to that of the soil. For most litter types, the A/B ratio of cast was relatively similar except for casts from birch (Betula pendula) and pear (Pyrus communis) where the OM show a 3-times higher A/B ratio as compared to wheat (Triticum aestivum) or beech (Fagus sylvatica) casts. The higher A/B ratios seem to be related to the relative higher C/N ratios in the casts from Betula pendula and Pyrus communis feeding experiments. The results indicate that digestion of litter by the worm may change OM composition. The assumption that earthworm casts may enrich hydrophobic OM components could be verified only partly. However particulate and soluble OM fractions in the earthworm casts could have contributed to such differentiation.

  8. A Comparison of Multiple Esterases as Biomarkers of Organophosphate Exposure and Effect in Two Earthworm Species

    OpenAIRE

    Henson-ramsey, Heather; Schneider, Ashley; Stoskopf, Michael K.

    2011-01-01

    Two different earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to 5 ?g/cm2 of malathion to evaluate their usefulness as sentinels of organophosphate exposure and to assess three different esterases, as biomarkers of malathion exposure and effect. Tissue xenobiotic burdens and esterase activity were determined for each species and each esterase in order to assess variability. E. fetida exhibited 4-fold less variability in tissue burdens than did L. terrestris and had l...

  9. Evaluation of five different suture materials in the skin of the earthworm (Lumbricus terrestris)

    OpenAIRE

    Salgado, Melissa A.; Lewbart, Gregory A.; Christian, Larry S.; Griffith, Emily H.; Law, Jerry Mchugh

    2014-01-01

    The purpose of this study was to determine which suture material is the most appropriate for dermal closure of terrestrial annelids. This paper describes the tissue reactions of the earthworm, Lumbricus terrestris, to five different types of suture materials in order to determine which suture material is the most appropriate for dermal closure. Silk, monofilament nylon, polydiaxonone, polyglactin 910, and chromic gut were studied. There was mild to moderate tissue reaction to all five suture ...

  10. Earthworms produce a collagen-like substance detected by the garter snake vomeronasal system.

    OpenAIRE

    Kirschenbaum, D. M.; Schulman, N.; Halpern, M.

    1986-01-01

    Earthworms (Lumbricus terrestris) produce a chemical substance that is readily detected by and serves as an attractant for garter snakes (Thamnophis sirtalis). This chemoattractant is sensed by the vomeronasal system of snakes. Amino acid analysis of the chemoattractant revealed a high hydroxyproline/proline ratio and large amounts of serine and threonine. More than one-third of the residues were glycine. No hydroxylysine and no cysteine were present. Carbohydrate analyses revealed a high con...

  11. Chemical and microbiological changes during vermicomposting of coffee pulp using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis) species.

    Science.gov (United States)

    Raphael, Kurian; Velmourougane, K

    2011-06-01

    Coffee pulp is the main solid residue from the wet processing of coffee berries. Due to presence of anti-physiological and anti-nutritional factors, coffee pulp is not considered as adequate substrate for bioconversion process by coffee farmers. Recent stringent measures by Pollution Control authorities, made it mandatory to treat all the solid and liquid waste emanating from the coffee farms. A study was conducted to evaluate the efficiency of an exotic (Eudrilus eugeniae) and a native earthworm (Perionyx ceylanesis) from coffee farm for decomposition of coffee pulp into valuable vermicompost. Exotic earthworms were found to degrade the coffee pulp faster (112 days) as compared to the native worms (165 days) and the vermicomposting efficiency (77.9%) and vermicompost yield (389 kg) were found to significantly higher with native worms. The multiplication rate of earthworms (280%) and worm yield (3.78 kg) recorded significantly higher with the exotic earthworms. The percentage of nitrogen, phosphorous, potassium, calcium and magnesium in vermicompost was found to increase while C:N ratio, pH and total organic carbon declined as a function of the vermicomposting. The plant nutrients, nitrogen (80.6%), phosphorus (292%) and potassium (550%) content found to increase significantly in the vermicompost produced using native earthworms as compared to the initial values, while the calcium (85.7%) and magnesium (210%) content found to increase significantly in compost produced utilizing exotic worms. Vermicompost and vermicasts from native earthworms recorded significantly higher functional microbial group's population as compared to the exotic worms. The study reveals that coffee pulp can be very well used as substrate for vermicomposting using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis). PMID:20922463

  12. Community-specific impacts of exotic earthworm invasions on soil carbon dynamics in a sandy temperate forest.

    Science.gov (United States)

    Crumsey, Jasmine M; Le Moine, James M; Capowiez, Yvan; Goodsitt, Mitchell M; Larson, Sandra C; Kling, George W; Nadelhoffer, Knute J

    2013-12-01

    Exotic earthworm introductions can alter above- and belowground properties of temperate forests, but the net impacts on forest soil carbon (C) dynamics are poorly understood. We used a mesocosm experiment to examine the impacts of earthworm species belonging to three different ecological groups (Lumbricus terrestris [anecic], Aporrectodea trapezoides [endogeic], and Eisenia fetida [epigeic]) on C distributions and storage in reconstructed soil profiles from a sandy temperate forest soil by measuring CO2 and dissolved organic carbon (DOC) losses, litter C incorporation into soil, and soil C storage with monospecific and species combinations as treatments. Soil CO2 loss was 30% greater from the Endogeic x Epigeic treatment than from controls (no earthworms) over the first 45 days; CO2 losses from monospecific treatments did not differ from controls. DOC losses were three orders of magnitude lower than CO2 losses, and were similar across earthworm community treatments. Communities with the anecic species accelerated litter C mass loss by 31-39% with differential mass loss of litter types (Acer rubrum > Populus grandidentata > Fagus grandifolia > Quercus rubra > or = Pinus strobus) indicative of leaf litter preference. Burrow system volume, continuity, and size distribution differed across earthworm treatments but did not affect cumulative CO2 or DOC losses. However, burrow system structure controlled vertical C redistribution by mediating the contributions of leaf litter to A-horizon C and N pools, as indicated by strong correlations between (1) subsurface vertical burrows made by anecic species, and accelerated leaf litter mass losses (with the exception of P. strobus); and (2) dense burrow networks in the A-horizon and the C and N properties of these pools. Final soil C storage was slightly lower in earthworm treatments, indicating that increased leaf litter C inputs into soil were more than offset by losses as CO2 and DOC across earthworm community treatments. PMID:24597228

  13. Survival strategies in arctic ungulates

    Directory of Open Access Journals (Sweden)

    N. J. C. Tyler

    1990-09-01

    Full Text Available Arctic ungulates usually neither freeze nor starve to death despite the rigours of winter. Physiological adaptations enable them to survive and reproduce despite long periods of intense cold and potential undernutrition. Heat conservation is achieved by excellent insulation combined with nasal heat exchange. Seasonal variation in fasting metabolic rate has been reported in several temperate and sub-arctic species of ungulates and seems to occur in muskoxen. Surprisingly, there is no evidence for this in reindeer. Both reindeer and caribou normally maintain low levels of locomotor activity in winter. Light foot loads are important for reducing energy expenditure while walking over snow. The significance and control of selective cooling of the brain during hard exercise (e.g. escape from predators is discussed. Like other cervids, reindeer and caribou display a pronounced seasonal cycle of appetite and growth which seems to have an intrinsic basis. This has two consequences. First, the animals evidently survive perfectly well despite enduring negative energy balance for long periods. Second, loss of weight in winter is not necessarily evidence of undernutrition. The main role of fat reserves, especially in males, may be to enhance reproductive success. The principal role of fat reserves in winter appears to be to provide a supplement to, rather than a substitute for, poor quality winter forage. Fat also provides an insurance against death during periods of acute starvation.

  14. The earthworm—Verminephrobacter symbiosis: an emerging experimental system to study extracellular symbiosis

    DEFF Research Database (Denmark)

    Lund, Marie Braad; Kjeldsen, Kasper Urup

    2014-01-01

    Almost all Lumbricid earthworms (Oligochaeta: Lumbricidae) harbor extracellular species-specific bacterial symbionts of the genus Verminephrobacter (Betaproteobacteria) in their nephridia. The symbionts have a beneficial effect on host reproduction and likely live on their host’s waste products. They are vertically transmitted and presumably associated with earthworms already at the origin of Lumbricidae 62–136 million years ago. The Verminephrobacter genomes carry signs of bottleneck-induced genetic drift, such as accelerated evolutionary rates, low codon usage bias, and extensive genome shuffling, which are characteristic of vertically transmitted intracellular symbionts. However, the Verminephrobacter genomes lack AT bias, size reduction, and pseudogenization, which are also common genomic hallmarks of vertically transmitted, intracellular symbionts. We propose that the opportunity for genetic mixing during part of the host—symbiont life cycle is the key to evade drift-induced genome erosion. Furthermore, we suggest the earthworm-Verminephrobacter association as a new experimental system for investigating host-microbe interactions, and especially for understanding genome evolution of vertically transmitted symbionts in the presence of genetic mixing.

  15. The earthworm-Verminephrobacter symbiosis : an emerging experimental system to study extracellular symbiosis

    DEFF Research Database (Denmark)

    Lund, Marie Braad; Kjeldsen, Kasper U

    2014-01-01

    ALMOST ALL LUMBRICID EARTHWORMS (OLIGOCHAETA: Lumbricidae) harbor extracellular species-specific bacterial symbionts of the genus Verminephrobacter (Betaproteobacteria) in their nephridia. The symbionts have a beneficial effect on host reproduction and likely live on their host's waste products. They are vertically transmitted and presumably associated with earthworms already at the origin of Lumbricidae 62-136 million years ago. The Verminephrobacter genomes carry signs of bottleneck-induced genetic drift, such as accelerated evolutionary rates, low codon usage bias, and extensive genome shuffling, which are characteristic of vertically transmitted intracellular symbionts. However, the Verminephrobacter genomes lack AT bias, size reduction, and pseudogenization, which are also common genomic hallmarks of vertically transmitted, intracellular symbionts. We propose that the opportunity for genetic mixing during part of the host-symbiont life cycle is the key to evade drift-induced genome erosion. Furthermore, we suggest the earthworm-Verminephrobacter association as a new experimental system for investigating host-microbe interactions, and especially for understanding genome evolution of vertically transmitted symbionts in the presence of genetic mixing.

  16. Effect of Butachlor Herbicide on Earthworm Eisenia fetidaIts Histological Perspicuity

    International Nuclear Information System (INIS)

    With the advent of the Green Revolution, there has been a quantum leap in the use of synthetic herbicides and pesticides throughout the world to sustain high yielding crop varieties. Continuous use of these synthetic chemicals leads to loss of soil fertility and soil organisms. To explore the effect of exposure to commercial herbicide (Butachlor) on the life history parameters (biomass, clitellum development, and cocoon production) and the histological changes in the earthworm Eisenia fetida over 60 days, the dried cow dung was contaminated with 0.2575 mg/ kg-1, 0.5150 mg/ kg-1, and 2.5750 mg/ kg-1 of butachlor based on the LC 50 value, and a control was maintained. The mean earthworm biomass was found to be decreased with increasing herbicide concentration. Similarly, cocoon production was also reduced by the increasing herbicide concentration. A possible explanation is an increased demand for energy, needed for the regulation and detoxification of herbicide. All earthworms in the exposed group were found to have glandular cell enlargement and to be vacuolated

  17. Effects of acute gamma radiation on the reproductive ability of the earthworm Eisenia fetida.

    Science.gov (United States)

    Sowmithra, K; Shetty, N J; Harini, B P; Jha, S K; Chaubey, R C

    2015-02-01

    Earthworms are the most suitable biological indicators of radioactive pollution because they are the parts of nutritional webs, and are present in relatively high numbers. Four months old Eisenia fetida were exposed to different doses of gamma radiation, namely 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 & 60 Gy to study the effects of radiation on different reproductive parameters. The number of cocoons laid and the hatchlings emerged were recorded for all the selected doses. There was no reduction in cocoon production, however; decreasing size and weight of the cocoons was observed from the samples exposed to 20 Gy and above doses. Significant reductions in the hatchlings were recorded in earthworms exposed to 10 Gy and above doses. The dose response curves for a percentage reduction in hatchlings were constructed. Exposure to radiation dose of 1 and 2 Gy did not show any reduction, however, there was ?10%, ?50% and ?90% decrease in the hatchlings in samples exposed to 3, 15 and 45, 50, 55 and 60 Gy doses respectively. Delayed hatchability was also reported at al exposure level. Histology of irradiated earthworms revealed that the structural damage in the seminal vesicles was prominent at the exposed dose of 3 Gy onwards with complete degeneration on exposure to 60 Gy of gamma radiation. PMID:25461510

  18. Potential of two epigeic and two anecic earthworm species in vermicomposting of water hyacinth.

    Science.gov (United States)

    Gajalakshmi, S; Ramasamy, E V; Abbasi, S A

    2001-02-01

    The potential of two epigeic species (Eudrilus eugeniae Kinberg, and Perionyx excavatus Perrier) and two anecic species (Lampito mauritii Kinberg and Drawida willsi Michaelson) of earthworms was assessed in terms of efficiency and sustainability of vermicomposting water hyacinth (Eichhornia crassipes, Mart. Solm.). In different vermireactors, each run in duplicate with one of the four species of earthworms, and 75 g of 6:1 water hyacinth:cowdung as feed, vermicasts were produced with steadily increasing output in all the reactors. E. eugeniae was by far the most efficient producer of vermicasts, followed by the other epigeic P. excavatus. The two anecics came next, with D. willsi being the least effective which could generate only about half the quantity of vermicasts achieved in a corresponding time by E. eugeniae. In all the reactors, the earthworms grew well, increasing their weights by more than 250%. The maximum net gain of weight (average 30.7 g) was by E. eugeniae, followed by P. excavatus, L. mauritii and D. willsi. This trend, which followed the efficiency of vermicast production, was also shown in terms of reproductive ability as measured by the number of offspring produced by the four species. PMID:11198167

  19. Depleted uranium mobility across a weapons testing site: isotopic investigation of porewater, earthworms, and soils.

    Science.gov (United States)

    Oliver, Ian W; Graham, Margaret C; MacKenzie, Angus B; Ellam, Robert M; Farmer, John G

    2008-12-15

    The mobility and bioavailability of depleted uranium (DU) in soils at a UK Ministry of Defence (UK MoD) weapons testing range were investigated. Soil and vegetation were collected near a test-firing position and at eight points along a transect line extending approximately 200 m down-slope, perpendicular to the firing line, toward a small stream. Earthworms and porewaters were subsequently separated from the soils and both total filtered porewater (<0.2 microm) and discrete size fractions (0.2 microm-100 kDa, 100-30 kDa, 30-3 kDa, and <3 kDa)obtainedvia centrifugal ultrafiltration were examined. Uranium concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) for soils and ICP-mass spectrometry (MS) for earthworms and porewaters, while 235U:238U atom ratios were determined by multicollector (MC)-ICP-MS. Comparison of the porewater and earthworm isotopic values with those of the soil solids indicated that DU released into the environment during weapons test-firing operations was more labile and more bioavailable than naturally occurring U in the soils at the testing range. Importantly, DU was shown to be present in soil porewater even at a distance of approximately 185 m from the test-firing position and, along the extent of the transect was apparently associated with organic colloids. PMID:19174886

  20. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

    International Nuclear Information System (INIS)

    Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. - Detoxification and accumulation of cadmium and lead by earthworms carries little energetic expenses whereas strict internal regulation of aluminium and nickel has energetic costs.

  1. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

    Energy Technology Data Exchange (ETDEWEB)

    Holmstrup, Martin, E-mail: martin.holmstrup@dmu.d [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Sorensen, Jesper G. [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Overgaard, Johannes; Bayley, Mark [Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Bindesbol, Anne-Mette [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Slotsbo, Stine; Fisker, Karina V.; Maraldo, Kristine [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Waagner, Dorthe [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Labouriau, Rodrigo [Aarhus University, Faculty of Agricultural Sciences, Department of Genetics and Biotechnology, Research Centre Foulum, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Asmund, Gert [National Environmental Research Institute, Aarhus University, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2011-01-15

    Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. - Detoxification and accumulation of cadmium and lead by earthworms carries little energetic expenses whereas strict internal regulation of aluminium and nickel has energetic costs.

  2. 1H NMR metabolomics of earthworm exposure to sub-lethal concentrations of phenanthrene in soil

    International Nuclear Information System (INIS)

    1H NMR metabolomics was used to monitor earthworm responses to sub-lethal (50-1500 mg/kg) phenanthrene exposure in soil. Total phenanthrene was analyzed via soxhlet extraction, bioavailable phenanthrene was estimated by hydroxypropyl-?-cyclodextrin (HPCD) and 1-butanol extractions and sorption to soil was assessed by batch equilibration. Bioavailable phenanthrene (HPCD-extracted) comprised ?65-97% of total phenanthrene added to the soil. Principal component analysis (PCA) showed differences in responses between exposed earthworms and controls after 48 h exposure. The metabolites that varied with exposure included amino acids (isoleucine, alanine and glutamine) and maltose. PLS models indicated that earthworm response is positively correlated to both total phenanthrene concentration and bioavailable (HPCD-extracted) phenanthrene in a freshly spiked, unaged soil. These results show that metabolomics is a powerful, direct technique that may be used to monitor contaminant bioavailability and toxicity of sub-lethal concentrations of contaminants in the environment. These initial findings warrant further metabolomic studies with aged contaminated soils. - 1H NMR metabolomics is used to directly monitor metabolic responses of Eisenia fetida after 48 h of exposure to sub-lethal concentrations of phenanthrene in soil.

  3. The Changes of Earthworm Population and Chemical Properties of Tropical Soils under Different Land Use Systems

    Directory of Open Access Journals (Sweden)

    Sri Yusnaini

    2008-05-01

    Full Text Available Hilly area Sumberjaya, West Lampung Province, South Sumatra, Indonesia, is one of the Province where deforestation increasing in the past 30 years as a result of the implementation of agricultural systems, especially coffee plantation. it is important to study the soil fauna in these natural relicts. Six sites (3 naturals and 3 managed systems were studied in order to identify earthworm species communities, using the hand sorting method and soil chemical parameters (pH, avail-P, org-C., tot-N, and cation exchange capacity (CEC. Two species were found (Pheretima sp. and Pontoscolex sp.. All land use systems had very similar soil chemical characteristics, there can be characterised as acidic (pH between 3.6 and 5.0. A high content of organic carbon was in natural sites (bush 4.0% and primary forest 3.9%, and a low content was in managed sites (coffee plantation 2.1%. Total nitrogen (0.37% and CEC (21.84 Cmol-c kg-1 was in primary forest. However, the earthworm densities were significantly lower under primary forest than in the other sites. The acidity component explained mainly the lowest earthworm population at the primary forest (soil pH 3.6. The use of succession forest (bush and mix farming showed a positive effect on soil fertility.

  4. Vermicomposting of paper mill solid waste using epigeic earthworm Eudrilus eugeniae.

    Science.gov (United States)

    Ponmani, S; Udayasoorian, C; Jayabalakrishnan, R M; Kumar, K Vinoth

    2014-07-01

    A 90 day study was conducted to evaluate the efficiency of an exotic earthworm species (Eudrilus eugeniae) for decomposition of different types of organic substrates (mixed liquor suspended solids, cow dung and leaf litter) into valuable vermicompost. Mixed liquor suspended solids (MLSS) and leaf litter (LL) were mixed with cow dung (CD) in eight different ratios with three replicates for each treatment. All vermibeds expressed a significant decrease in pH, organic carbon, C:N ratio and an increase in total nitrogen, phosphorus and potash. Overall, earthworms could maximize decomposition and mineralization efficiency in bedding with lower proportions of MLSS. Maximum value for earth worm zoo mass and higher concentration of nutrient content was observed in CD + MLSS + LL in 1:1:2 ratios. Earthworm mortality tended to increase with increasing proportion of MLSS and maximum mortality in E. eugeniae was recorded for MLSS treatment alone. Results indicate that vermicomposting might be useful for managing the energy and nutrient of MLSS on a low-input basis. Products of this process can be used for sustainable land restoration practices. PMID:25004743

  5. Enantiomer-specific toxicity and bioaccumulation of alpha-cypermethrin to earthworm Eisenia fetida.

    Science.gov (United States)

    Diao, Jinling; Xu, Peng; Liu, Donghui; Lu, Yule; Zhou, Zhiqiang

    2011-09-15

    Alpha-cypermethrin, a synthetic pyrethroid, is highly effective against a wide range of chewing and sucking insects in crops, and it is a racemic mixture of two enantiomers ((+)-1R-cis-?S+(-)-1S-cis-?R). Studies about the toxicity of alpha-cypermethrin to non-target organisms are mainly focused on aquatic organisms, whereas information regarding terrestrial organisms is relatively much less. Very little report about its enantioselective toxicity is known, so the present study tested the enantiomer-specific acute toxicity to earthworm Eisenia fetida. Experiment about bioaccumulation of two enantiomers in soil was conducted, peak-shaped accumulation curves were observed for both enantiomers, and the calculated biota to soil accumulations factor (BSAF) have significant difference between the two enantiomers. It was obvious that earthworm can uptake alpha-cypermethrin enantioselectively, preferentially accumulating (-)-(1S-cis-?R)-enantiomer. Great difference in toxicity to earthworm between two enantiomers was found, and the calculated LC(50) values for (+)-(1R-cis-?S)-, (-)-(1S-cis-?R)-, and rac-alpha-cypermethrin were 49.53, 1663.87 and 165.61 ng/cm(2), respectively. The acute toxicity of alpha-cypermethrin enantiomers was enantioselective. PMID:21724328

  6. Alternatives to herbicides in an apple orchard, effects on yield, earthworms and plant diversity

    DEFF Research Database (Denmark)

    Andersen, L.; Kuehn, Birka Falk

    2013-01-01

    tIn a newly established apple orchard eight alternative methods to weed control in the tree row werecompared to a herbicide treatment with respect to effects on tree growth, first-quality fruit yield, earth-worms and flora. All treatments were tested at two irrigation schedules, with similar amount of water ata daily or weekly basis. In general, daily irrigation reduced first-quality fruit yield compared to weeklyirrigation. Mulching with black polypropylene (MyPex®) and rape straw had a positive effect on first-quality yield and shoot growth, only black polypropylene, compared to herbicide treatment, whereasmulching with paper wool reduced first-quality fruit yield compared to herbicide treatment. Cover cropas tagetes and weed harrowing had similar yield as herbicide treatment, whereas cover crops as grassand hop medick and weed cutting reduced first-quality yield compared to herbicide treatment. Earth-worms thrived under rape straw contrary to under black polypropylene and plots with weed harrowing.Treatments had significant effects on species numbers of plants both years, and total vegetation covergenerally increased in the second year. Rape straw supported a high production of apples and a largestock of earthworms; however, its support of wild flora is poor, when it is taken into account that a largeproportion of the flora in the rape straw was rape established from seeds left with the straw

  7. Oxidative stress in earthworms short- and long-term exposed to highly Hg-contaminated soils.

    Science.gov (United States)

    Colacevich, Andrea; Sierra, María J; Borghini, Francesca; Millán, Rocio; Sanchez-Hernandez, Juan C

    2011-10-30

    Exposure to mercury is often assessed by the measurement of molecular and biochemical antioxidant defences against an excessive production of reactive oxygen species. Here we examined some selected biomarkers of oxidative stress in the earthworm Lumbricus terrestris short- (2d) and long-term (44 d) exposed to Hg-contaminated soils (up to 1287 mg/kg dry wt). This level of Hg exposure did not cause earthworm mortality, however it yielded organisms to a situation of oxidative stress which was evidenced by the time-dependent responses of biomarkers. The reduced to oxidized glutathione ratio was a sensitive and early biomarker of Hg exposure, although the glutathione reductase activity back returned their normal physiological concentrations. Metallothioneins and total glutathione seemed to have a significant role in reducing Hg-induced oxidative stress when exposure to Hg prolonged up to 44 d. We combined biomarker responses into an integrate biomarker index which positively correlated with the Hg concentrations measured in the postmitochondrial fraction of the earthworm muscle, and with the available Hg fraction in soil. Current results suggest that glutathione redox cycle can be a complementary tool in the exposure and effect assessment of Hg-polluted soils. PMID:21871720

  8. [Specific features of nitrogen transformation in the gut and coprolites of earthworms].

    Science.gov (United States)

    Umarov, M M; Striganova, B R; Kostin, N V

    2008-01-01

    It has been found that nitrogenase activity in the guts and coprolites of three earthworm species (Lumbricus terrestris, Aporrectodea rosea, and Aporrectodea caliginosa) is one to three orders of magnitude higher than that in the control soil. In A. caliginosa earthworms, the actual nitrogenase activity remains high upon keeping them in soils of different types. However, it reaches a peak in the gut lumen and decreases to a minimum on its wall, which is evidence for a major role of transitional microflora in intestinal nitrogen fixation. Nitrogen fixation activity in freshly excreted coprolites decreases to one-half or one-third of that in the gut and then increases again, reaching a peak on days 3-5 of exposure in the soil. According to the results of multisubstrate testing, the functional diversity of nitrogen-fixing soil microorganisms increases in the course of passage through the earthworm gut. Thus, the microbial community in coprolites retains its functional potential and, within a few days, shows the second peak of activity in the soil. Due to a short-term increase in the rate of nitrogen fixation, coprolites contain a pool of bound amino acids, which become involved in the formation of new humus substances. PMID:19198081

  9. Evaluation of five different suture materials in the skin of the earthworm (Lumbricus terrestris).

    Science.gov (United States)

    Salgado, Melissa A; Lewbart, Gregory A; Christian, Larry S; Griffith, Emily H; Law, Jerry McHugh

    2014-01-01

    The purpose of this study was to determine which suture material is the most appropriate for dermal closure of terrestrial annelids. This paper describes the tissue reactions of the earthworm, Lumbricus terrestris, to five different types of suture materials in order to determine which suture material is the most appropriate for dermal closure. Silk, monofilament nylon, polydiaxonone, polyglactin 910, and chromic gut were studied. There was mild to moderate tissue reaction to all five suture materials. In all of the biopsies wound-healing reaction consisted of aggregates of blastemal cells which appeared in various stages of dedifferentiation from the body wall. Inflammatory cells infiltrated the wound sites, reminiscent of the typical foreign body reaction in vertebrates. The results indicate polyglactin 910 would be the best suture material with regards to tissue security and reaction scores. Chromic gut occupies the next position but there were problems with suture security over time. This appears to be the first suture material performance study on a terrestrial invertebrate. The earthworm, Lumbricus terrestris, was chosen for its wide availability, size, and the extensive species knowledge base. The earthworm may prove to be a good surgical/suture model for economically important invertebrates such as mollusks, tunicates, and insect larval stages. PMID:25143875

  10. Incorporation of lead into calcium carbonate granules secreted by earthworms living in lead contaminated soils

    Science.gov (United States)

    Fraser, A.; Lambkin, D. C.; Lee, M. R.; Schofield, P. F.; Mosselmans, J. F. W.; Hodson, M. E.

    2011-05-01

    The influence of soil organisms on metal mobility and bioavailability in soils is not currently fully understood. We conducted experiments to determine whether calcium carbonate granules secreted by the earthworm Lumbricus terrestris could incorporate and immobilise lead in lead- and calcium-amended artificial soils. Soil lead concentrations were up to 2000 mg kg -1 and lead:calcium ratios by mass were 0.5-8. Average granule production rates of 0.39 ± 0.04 mg calcite earthworm -1 day -1 did not vary with soil lead concentration. The lead:calcium ratio in granules increased significantly with that of the soil ( r2 = 0.81, p = 0.015) with lead concentrations in granules reaching 1577 mg kg -1. X-ray diffraction detected calcite and aragonite in the granules with indications that lead was incorporated into the calcite at the surface of the granules. In addition to the presence of calcite and aragonite X-ray absorption spectroscopy indicated that lead was present in the granules mainly as complexes sorbed to the surface but with traces of lead-bearing calcite and cerussite. The impact that lead-incorporation into earthworm calcite granules has on lead mobility at lead-contaminated sites will depend on the fraction of total soil lead that would be otherwise mobile.

  11. The potential role of earthworms in toxicity assessment of terrestrial hazardous waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Goven, A.J.; Fitzpatrick, L.C. [Univ. of North Texas, Denton, TX (United States); Venables, B.J. [TRAC Labs., Inc., Denton, TX (United States)

    1994-12-31

    Understanding the toxic potential and mechanisms of action of environmental xenobiotics is fundamental for assessing risk to public and environmental health. Current established protocols with earthworms focus primarily on defining the lethal effects of chemicals associated with soil contamination. Development of sublethal assays, until recently, has been largely ignored. Here the authors develop rationale for use of earthworms as a model organism for comprehensive assessment of risks to higher wildlife from contaminated soils and hazardous waste sites. They present a panel of lethal (LC/LD50`s) and sublethal measurement endpoint biomarkers, developed within the framework of the National Toxicology Program`s tiered immunotoxicity protocol for mice and according to published criteria for good measurement endpoints, that represent sensitive phylogenetically-conserved processes. Specifically the authors discuss immunosuppressive effects of terrestrial heavy metal and organic contamination on the innate, nonspecific and specific immune responses of earthworm, Lumbricus terrestris, coelomocytes in terms of total and differential cell counts, lysozyme activity, nitroblue tetrazolium dye reduction, phagocytic activity and secretary rosette formation. Findings indicate that sensitive phylogenetically conserved immune responses present in invertebrates can be used to assess or predict risk to wildlife from contaminated soils.

  12. Suppression of immune functions by PCBs in the earthworm Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Rodriquez Grau, J.L.

    1989-01-01

    This research is part of an effort to develop non-mammalian surrogate immunoassays with the earthworm Lumbricus terrestris to assess immunotoxic potential of xenobiotics to mammals. The objective was to determine if earthworm immunoassays, namely E- and S-rosette formation and phagocytosis, are sensitive to a known mammalian immunotoxin, the PCB Aroclor 1254. Results are presented in terms of PCB exposure and tissue levels during uptake/depuration. Using 5-d filter paper contact exposure, LC{sub 50} and LD{sub 50} were 300 {mu}g/cm{sup 2} and 1140 {mu}g/g dry mass. Nominal PCB exposure concentration of 5 {mu}g/cm{sup 2} and actual tissue levels of 76 {mu}g/g dry mass were sufficient to suppress S-rosette formation, a humoral response. S-rosette suppression and return of function followed PCB levels in coelomic leukocytes, the presumed site of toxicity. Phagocytic response also showed suppressive effects but only at a nominal PCB exposure level of 10 {mu}g/cm{sup 2}, which corresponds to an actual tissue level of 185 {mu}g/g dry mass. However, PCbs had no effect on E-rosette formation with rabbit red blood cells, a component of immunity associated with surface receptor molecules. Compared to published mammalian data on PCB suppression of immunoglobulin production, the earthworm S-rosette immunoassay appeared to be more sensitive.

  13. Earthworms and Humans in Vitro: Characterizing Evolutionarily Conserved Stress and Immune Responses to Silver Nanoparticles

    DEFF Research Database (Denmark)

    Hayashi, Yuya; Engelmann, Péter

    2012-01-01

    Little is known about the potential threats of silver nanoparticles (AgNPs) to ecosystem health, with no detailed report existing on the stress and immune responses of soil invertebrates. Here we use earthworm primary cells, cross-referencing to human cell cultures with a particular emphasis on the conserved biological processes, and provide the first in vitro analysis of molecular and cellular toxicity mechanisms in the earthworm Eisenia fetida exposed to AgNPs (83 ± 22 nm). While we observed a clear difference in cytotoxicity of dissolved silver salt on earthworm coelomocytes and human cells (THP-1 cells, differentiated THP-1 cells and peripheral blood mononuclear cells), the coelomocytes and differentiated (macrophage-like) THP-1 cells showed a similar response to AgNPs. Intracellular accumulation of AgNPs in the coelomocytes, predominantly in a phagocytic population, was evident by several methods including transmission electron microscopy. Molecular signatures of oxidative stress and selected biomarker genes probed in a time-resolved manner suggest early regulation of oxidative stress genes and subsequent alteration of immune signaling processes following the onset of AgNP exposure in the coelomocytes and THP-1 cells. Our findings provide mechanistic clues on cellular innate immunity toward AgNPs that is likely to be evolutionarily conserved across the animal kingdom.

  14. Searching for external sources of the riboflavin stored in earthworm eleocytes

    Directory of Open Access Journals (Sweden)

    P Sulik

    2012-10-01

    Full Text Available Riboflavin (vitamin B2 is essential to maintain immune potency in animals and plants. So far is accepted that animals cannot synthesise riboflavin; they rely on plant-sourced diets and intestinal bacteria for their supplies. A unique feature of earthworm ‘hepatocyte-like’ chloragocytes and chloragocyte-derived eleocytes floating in celomic cavity is the storage of riboflavin within intracellular granules. The hypothesis was that vegetarian food-deprivation or antibiotic/antifungal treatment inhibits riboflavin accumulation in eleocytes of Eisenia andrei. The 7-week starvation inhibited worm body weight gain and worm reproduction but had insignificant effects on celomocytes, both amoebocytes and eleocytes, and eleocyte riboflavin accumulation. The 1 week or 3 week antibiotic exposure had insignificant effects on worm coelomocytes and riboflavin content. Thus, a vegetarian diet and intestinal bacteria are not the exclusive or perhaps even the main sources of eleocyte riboflavin. The role of endosymbionts in earthworm flavonoid economy warrants targeted investigation. Moreover, the possibility of horizontal transfer of riboflavin biosynthesis genes from bacteria/fungi to earthworm genomes cannot be neglected.

  15. Impacts of leaves, roots, and earthworms on soil organic matter composition and distribution in sycamore maple stands

    Science.gov (United States)

    Rivera, N.; Mueller, K. E.; Mueller, C. W.; Oleksyn, J.; Hale, C.; Freeman, K. H.; Eissenstat, D.

    2009-12-01

    The relative contributions of leaf and root material to soil organic matter (SOM) are poorly understood despite the importance of constraining SOM sources to conceptual and numeric models of SOM dynamics. Selective ingestion and bioturbation of litter and soil by earthworms can alter the fate and spatial distribution of OM in soils, including stabilization pathways of leaf and root litter. However, studies on the contributions of leaves, roots, and earthworms to SOM dynamics are rare. In 3 stands of sycamore maple (Acer pseudoplatanus) with minimal O horizon development and high earthworm activity, we sampled surface litter (> 2 mm) from the Oi horizon, fine roots (< 2 mm), bulk mineral soils (0-20 cm depth), and earthworm casts from Lumbricus terrestris middens. The chemical composition of these samples was estimated by wet-chemical degradation followed by GC-MS analysis. In addition, elemental analyses (C and N) were performed on bulk soils and earthworm casts, before and after physical fractionation by means of particle size and density. Relative to bulk soils, earthworm casts were highly enriched in organic matter, dominated by large particulate OM, and had lower acid to aldehyde ratios among lignin monomers (a proxy for extent of decomposition), confirming that L. terrestris casts stabilize recent plant litter inputs. Maple fine roots and surface litter were distinguished by different profiles of carboxylic acids estimated by GC-MS, facilitating interpretation of OM sources in bulk soil and earthworm casts. Earthworm casts were characterized by a distribution of carboxylic acids similar to that of surface litter while bulk soils had a carboxylic acid profile much closer to that of roots. These results confirm that L. terrestris is primarily a surface, leaf feeder and suggest that OM in the bulk soil may be dominated by root inputs. In bulk soils, the ratio of lignin to hydroxy- and diacids derived from suberin and cutin was low relative to plant litter, confirming the often-observed selective preservation of aliphatic over aromatic biomolecules. The ratio of lignin to cutin/suberin acids in earthworm casts was also low; based on the minimal extent of decomposition in casts evident by lignin acid to aldehyde ratios, we attribute this to selective ingestion by L. terrestris of leaf litter rich in aliphatic biomolecules at the expense of woody debris and petioles rich in lignin, rather than selective preservation.

  16. Effects of three pesticides on the avoidance behavior of earthworms in laboratory tests performed under temperate and tropical conditions

    International Nuclear Information System (INIS)

    Little research has been performed on the impact of pesticides on earthworms under tropical conditions. Taking into consideration the often-limited resources in tropical countries, simple screening tests are needed. Therefore, it was investigated whether three pesticides relevant for the Brazilian Amazon (benomyl, carbendazim, lambda-cyhalothrin) affect the avoidance behavior of the earthworm Eisenia fetida. The tests were performed for two days according to ISO guideline 17512 but were adapted to tropical conditions (i.e. test substrate, test organism and temperature). The results indicate that this test gives reproducible and reliable results. Toxicity values (NOEC, EC50) are lower than those determined in 14 day-acute mortality tests and are approximately in the same range such as those found in 56 day-chronic reproduction tests with the same earthworm species, which were performed in parallel. Therefore, the use of the earthworm avoidance tests is recommended as a screening tool for the risk assessment of pesticides. - The earthworm avoidance test is a practical and sensitive screening method for assessing the effects of pesticides in tropical soils

  17. Effects of three pesticides on the avoidance behavior of earthworms in laboratory tests performed under temperate and tropical conditions

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Marcos [Embrapa Amazonia Ocidental, Rod. AM-10, Km 28, 69.011-970 Manaus (Brazil); Roembke, Joerg [ECT Oekotoxikologie, Boettgerstr. 2-14, D-65439 Floersheim (Germany)], E-mail: j-roembke@ect.de; Torres de Brito, Marcus [CNPq - PIBIC/Embrapa, Rod. AM-10, Km 28, 69.011-970 Manaus (Brazil); Scheffczyk, Adam [ECT Oekotoxikologie, Boettgerstr. 2-14, D-65439 Floersheim (Germany)

    2008-05-15

    Little research has been performed on the impact of pesticides on earthworms under tropical conditions. Taking into consideration the often-limited resources in tropical countries, simple screening tests are needed. Therefore, it was investigated whether three pesticides relevant for the Brazilian Amazon (benomyl, carbendazim, lambda-cyhalothrin) affect the avoidance behavior of the earthworm Eisenia fetida. The tests were performed for two days according to ISO guideline 17512 but were adapted to tropical conditions (i.e. test substrate, test organism and temperature). The results indicate that this test gives reproducible and reliable results. Toxicity values (NOEC, EC50) are lower than those determined in 14 day-acute mortality tests and are approximately in the same range such as those found in 56 day-chronic reproduction tests with the same earthworm species, which were performed in parallel. Therefore, the use of the earthworm avoidance tests is recommended as a screening tool for the risk assessment of pesticides. - The earthworm avoidance test is a practical and sensitive screening method for assessing the effects of pesticides in tropical soils.

  18. Responses by earthworms to reduced tillage in herbicide tolerant maize and Bt maize cropping systems

    DEFF Research Database (Denmark)

    Krogh, P. H.; Griffiths, B.

    2007-01-01

    Genetically modified crops (GM) may affect earthworms either directly through the plant, its root exudates and litter, or indirectly through the agricultural management changes that are associated with GM plant production. In order to investigate such possible effects we established two field studies of Bt corn and a glufosinate ammonium tolerant corn and included a reduced tillage treatment (RT) and a conventional tillage treatment (CT) as examples of a likely concomitant change in the agricultural practise. At a French study site at Varois, (Bourgogne), a field grown with the Bt-toxin producing transgenic maize line MON810 was studied for 1 year. At a Danish study site, Foulum (Jutland), one year of Bt corn was followed by 2 years of herbicide tolerant corn. At the French study site the most prominent effects observed were due to the tillage method where RT significantly reduced the earthworm populations to levels about half of CT. At the Danish study site effects of CT complied with known reduction of anecic earthworms due to this technique and likewise effects of RT were observed for endogeic earthworms. Earthworm populations were dimin-ished with the herbicide tolerant crop, probably due to exposure to the herbicide Basta® during the two consecutive autumn seasons. This study confirms the importance of including the tillage tech-niques and pesticide usage when evaluating the environmental effects of new agricultural technologies.

  19. Interaction of citrate-coated silver nanoparticles with earthworm coelomic fluid and related cytotoxicity in Eisenia andrei.

    Science.gov (United States)

    Kwak, Jin Il; Lee, Woo-Mi; Kim, Shin Woong; An, Youn-Joo

    2014-11-01

    Understanding the interaction of nanoparticles with biological fluid is important for predicting the behavior and toxicity of nanoparticles in living systems. The earthworm Eisenia andrei was exposed to citrate-coated silver nanoparticles (cAgNPs), and the interaction of cAgNPs with earthworm coelomic fluid (ECF), the cytotoxicity of cAgNPs in earthworm coelomocytes was assessed. The neutral red retention assay showed a reduction in lysosomal stability after exposure. The toxicity of silver ions dissolved from cAgNPs in the soil medium was not significant. The aggregation and dissolution of cAgNPs increased in ECF, which contains various electrolytes that alter the properties of nanoparticles, and their subsequent toxicity. Microscopic and dissolution studies demonstrated that the aggregation of cAgNPs rapidly increased, and readily dissolved in ECF. The bioavailability of cAgNPs to earthworms induced lysosomal cytotoxicity. This is the first report to test the interaction and lysosomal cytotoxicity of nanoparticles in earthworm biofluids. PMID:24532537

  20. Combined effects of soil moisture and carbaryl to earthworms and plants: Simulation of flood and drought scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Maria P.R.; Soares, Amadeu M.V.M. [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal); Loureiro, Susana, E-mail: sloureiro@ua.pt [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)

    2011-07-15

    Studying tolerance limits in organisms exposed to climatic variations is key to understanding effects on behaviour and physiology. The presence of pollutants may influence these tolerance limits, by altering the toxicity or bioavailability of the chemical. In this work, the plant species Brassica rapa and Triticum aestivum and the earthworm Eisenia andrei were exposed to different levels of soil moisture and carbaryl, as natural and chemical stressors, respectively. Both stress factors were tested individually, as well as in combination. Acute and chronic tests were performed and results were discussed in order to evaluate the responses of organisms to the combination of stressors. When possible, data was fitted to widely employed models for describing chemical mixture responses. Synergistic interactions were observed in earthworms exposed to carbaryl and drought conditions, while antagonistic interactions were more representative for plants, especially in relation to biomass loss under flood-simulation conditions. - Highlights: > Climate variations may cause changes on chemicals' toxicity or bioavailability. > Earthworms and plants are exposed simultaneously to carbaryl and flood and drought conditions. > The IA model and possible deviations were used to evaluate combination exposures. > Synergism was observed for earthworms exposed to carbaryl and drought conditions. > Antagonistic interactions were observed for plants, in flood conditions and carbaryl. - Soil moisture can play an important role in carbaryl toxicity towards plants and earthworms.

  1. Influence of earthworm Eisenia fetida on removal efficiency of N and P in vertical flow constructed wetland.

    Science.gov (United States)

    Xu, Defu; Li, Yingxue; Howard, Alan

    2013-09-01

    This study investigates biomass, density, photosynthetic activity, and accumulation of nitrogen (N) and phosphorus (P) in three wetland plants (Canna indica, Typha augustifolia, and Phragmites austrail) in response to the introduction of the earthworm Eisenia fetida into a constructed wetland. The removal efficiency of N and P in constructed wetlands were also investigated. Results showed that the photosynthetic rate (P n), transpiration rate (T r), and stomatal conductance (S cond) of C. indica and P. austrail were (p?earthworms were present. The addition of E. fetida increased the N uptake value by above-ground of C. indica, T. augustifolia, and P. australis by 185, 216, and 108 %, respectively; and its P uptake value increased by 300, 355, and 211 %, respectively. Earthworms could enhance photosynthetic activity, density, and biomass of wetland plants in constructed wetland, resulting in the higher N and P uptake. The addition of E. fetida into constructed wetland increased the removal efficiency of TN and TP by 10 and 7 %, respectively. The addition of earthworms into vertical flow constructed wetland increased the removal efficiency of TN and TP, which was related to higher photosynthetic activity and N and P uptake. The addition of earthworms into vertical flow constructed wetland and plant harvests could be the significantly sustainable N and P removal strategy. PMID:23729029

  2. Comparative toxicity in earthworms Eisenia fetida and Lumbricus terrestris exposed to cadmium nitrate using artificial soil and filter paper protocols

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, L.C.; Goven, A.J. [Univ. of North Texas, Denton, TX (United States); Muratti-Ortiz, J.F. [City of Denton Water/Wastewater Laboratory, TX (United States); Venables, B.J. [TRAC Laboratories Inc., Denton, TX (United States)

    1996-07-01

    Earthworms are ideal soil organisms for use in terrestrial ecotoxicology. As such, several earthworm protocols have been developed for testing toxic potential of chemicals and contaminated soils. Of these, the 48-h filter paper contact (FP) and the 14-d artificial soil exposure (AS) protocols, using mortality (LC50) as the toxic endpoint and Eisenia fetida as the test species, have received the most attention, with the latter being adopted by both OECD and EEC in Europe and the Environmental Protection Agency (USEPA) in the United States. Although the FP technique, adopted by EEC, provides for inexpensive reproducible toxicity screening for chemicals (i.e. establishing relative toxicities), it has been criticized for lacking the ecotoxicological relevance of the AS protocol. Choice of earthworm species for laboratory testing also has been controversial. The manure worm, E. fetida, is criticized for not being sufficiently sensitive to chemicals or representative of {open_quotes}typical{close_quotes} earthworms. Lumbricus terrestris and Apporectodea caliginosa have been suggested as more sensitive and ecologically relevant earthworms by Dean-Ross and Martin, respectively. This paper compares the AS and FP protocols in assessing toxicity of cadminum to L. terrestris and E. fetida using LC50s and LC50s. 19 refs., 2 tabs.

  3. Incorporation of strontium in earthworm-secreted calcium carbonate granules produced in strontium-amended and strontium-bearing soil

    Science.gov (United States)

    Brinza, Loredana; Quinn, Paul D.; Schofield, Paul F.; Mosselmans, J. Frederick W.; Hodson, Mark E.

    2013-07-01

    This paper investigates the incorporation of Sr into biomineralized calcium carbonate granules secreted by the earthworm Lumbricus terrestris. Experiments were conducted using an agricultural soil amended with Sr(NO3)2 to give concentrations in the range 50-500 mg kg-1 Sr and a naturally Sr-rich, Celestine-bearing soil containing up to 11 000 mg kg-1 Sr. Granule production rates were in the range 0.26-2.3 mgCaCO3 earthworm-1 day-1; they showed no relationship with soil or soil solution Sr concentration but decreased with decreasing pH. Strong relationships exist (r2 ? 0.8, p ? 0.01) between the Sr concentrations and Sr/Ca ratios of the granules and those of the soil, soil solution and earthworms. The highest bulk Sr concentration we recorded in the calcium carbonate granules was 5.1 wt.% Sr whilst electron microprobe analysis recorded spot concentrations of up to 4.3 wt.% Sr. X-ray diffraction and X-ray absorption spectroscopy indicate that the majority of the calcium carbonate is present as Sr-bearing calcite with trace amounts of Sr-bearing vaterite also being present. The granules produced in the Sr-amended soils concentrated Sr relative to Ca from the bulk soil and the earthworms. This suggests that earthworm secreted calcium carbonate may be significant in the cycling of 90Sr released into soils via nuclear accidents or leakage from nuclear waste storage facilities.

  4. Efectos tóxicos de los insecticidas clorpirifos y teflutrina sobre la lombriz de tierra (Lumbricus terrestris L.) / Toxic effects of the insecticides chlorpyrifos and tefluthrin on earthworms (Lumbricus terrestris L.)

    Scientific Electronic Library Online (English)

    Rosana, Giménez; Angela, Della Penna; Ezequiel, Odello.

    2004-10-01

    Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Para evaluar la ecotoxicidad de clorpirifos y teflutrina sobre Lumbricus terrestris L., se realizó una prueba de laboratorio, basado en el protocolo de la Organización Internacional de Control Biológico (IOBC). Las lombrices fueron recolectadas a mano en un suelo libre de plaguicidas, en el campo de [...] la Facultad de Agronomía, Universidad de Buenos Aires, Argentina y colocadas en suelo esterilizado, en condiciones de oscuridad y 12°C durante cinco días, alimentadas con hojas secas de trébol blanco (Trifolium repens L.). Se colocó una lombriz mayor a 1,5 g sin clitelo por embudo de Daniel, con diez hojas secas de trébol blanco sobre la superficie. Los tratamientos fueron: 1) testigo, agua no clorada; 2) 30 mg L-1 de solución de cloroacetamida (97,37%); 3) clorpirifos (EC 48%) 5 L ha-1 o 50 mg L-1; 4) teflutrina (EC 5%) 2 L ha-1 o 20 mg L-1. El ensayo tuvo diseño completamente aleatorizado con diez repeticiones. Durante los 15 días de ensayo las variables analizadas fueron: variación de peso, actividad individual y supervivencia de lombrices. El incremento de peso de las lombrices fue 0,285; 0,280 y 0,300 g en 15 días en los tratamientos 1, 3 y 4 respectivamente, y no hubo diferencias significativas entre los mismos así como en la cantidad de hojas retiradas al día, que fue de 0,61; 0,369; 0,555 y 0,425, respectivamente. La supervivencia fue de 100; 20; 100; y 90% en los tratamientos 1, 2, 3 y 4, respectivamente, siendo afectada sólo por cloroacetamida. Clorpirifos y teflutrina no fueron tóxicos a las dosis evaluadas (P Abstract in english In order to evaluate the ecotoxicity of chlorpyrifos and tefluthrin on the earthworm Lumbricus terrestris L., a laboratory test was carried out based on the guidelines of the International Organization of Biological Control (IOBC). The earthworms were collected by handsorting from a soil free of pes [...] ticides of the Agronomy Faculty, University of Buenos Aires, Argentina and placed in sterilized soil, in complete darkness, at 12ºC for five days, and fed with dry white clover (Trifolium repens L.) leaves. Earthworms larger than 1.5 g without clitelum were placed in a Daniel's funnel with ten dry leaves of white clover on the surface. The treatments were: 1) control, unchlorinated water; 2) chloroacetamid solution (97.37%) 30 mg L-1; 3) chlorpyrifos (emulsifiable concentrate, EC, 48%) 5 L ha-1 or 50 mg L-1; 4) tefluthrin (EC 5%) 2 L ha-1 or 20 mg L-1. A completely randomized experimental design with ten replicates was used. During 15 days of the assay the variables analyzed were: live weight change, individual activity and earthworm survival. The increase of earthworm weight was 0.285, 0.280 and 0.300 g in the 15 days of treatments 1, 3 and 4, respectively, with no significant differences between treatments, as well as the number of leaves withdrawn per day 0.61, 0.369, 0.555, and 0.425, respectively. The survival rates were: 100, 20, 100 and 90%, in treatments 1, 2, 3 and 4, respectively, being only effected by chloroacetamid. Chlorpyrifos and tefluthrin were not toxic for L. terrestris at the current dose (P

  5. Efectos tóxicos de los insecticidas clorpirifos y teflutrina sobre la lombriz de tierra (Lumbricus terrestris L. Toxic effects of the insecticides chlorpyrifos and tefluthrin on earthworms (Lumbricus terrestris L.

    Directory of Open Access Journals (Sweden)

    Rosana Giménez

    2004-10-01

    Full Text Available Para evaluar la ecotoxicidad de clorpirifos y teflutrina sobre Lumbricus terrestris L., se realizó una prueba de laboratorio, basado en el protocolo de la Organización Internacional de Control Biológico (IOBC. Las lombrices fueron recolectadas a mano en un suelo libre de plaguicidas, en el campo de la Facultad de Agronomía, Universidad de Buenos Aires, Argentina y colocadas en suelo esterilizado, en condiciones de oscuridad y 12°C durante cinco días, alimentadas con hojas secas de trébol blanco (Trifolium repens L.. Se colocó una lombriz mayor a 1,5 g sin clitelo por embudo de Daniel, con diez hojas secas de trébol blanco sobre la superficie. Los tratamientos fueron: 1 testigo, agua no clorada; 2 30 mg L-1 de solución de cloroacetamida (97,37%; 3 clorpirifos (EC 48% 5 L ha-1 o 50 mg L-1; 4 teflutrina (EC 5% 2 L ha-1 o 20 mg L-1. El ensayo tuvo diseño completamente aleatorizado con diez repeticiones. Durante los 15 días de ensayo las variables analizadas fueron: variación de peso, actividad individual y supervivencia de lombrices. El incremento de peso de las lombrices fue 0,285; 0,280 y 0,300 g en 15 días en los tratamientos 1, 3 y 4 respectivamente, y no hubo diferencias significativas entre los mismos así como en la cantidad de hojas retiradas al día, que fue de 0,61; 0,369; 0,555 y 0,425, respectivamente. La supervivencia fue de 100; 20; 100; y 90% en los tratamientos 1, 2, 3 y 4, respectivamente, siendo afectada sólo por cloroacetamida. Clorpirifos y teflutrina no fueron tóxicos a las dosis evaluadas (P In order to evaluate the ecotoxicity of chlorpyrifos and tefluthrin on the earthworm Lumbricus terrestris L., a laboratory test was carried out based on the guidelines of the International Organization of Biological Control (IOBC. The earthworms were collected by handsorting from a soil free of pesticides of the Agronomy Faculty, University of Buenos Aires, Argentina and placed in sterilized soil, in complete darkness, at 12ºC for five days, and fed with dry white clover (Trifolium repens L. leaves. Earthworms larger than 1.5 g without clitelum were placed in a Daniel's funnel with ten dry leaves of white clover on the surface. The treatments were: 1 control, unchlorinated water; 2 chloroacetamid solution (97.37% 30 mg L-1; 3 chlorpyrifos (emulsifiable concentrate, EC, 48% 5 L ha-1 or 50 mg L-1; 4 tefluthrin (EC 5% 2 L ha-1 or 20 mg L-1. A completely randomized experimental design with ten replicates was used. During 15 days of the assay the variables analyzed were: live weight change, individual activity and earthworm survival. The increase of earthworm weight was 0.285, 0.280 and 0.300 g in the 15 days of treatments 1, 3 and 4, respectively, with no significant differences between treatments, as well as the number of leaves withdrawn per day 0.61, 0.369, 0.555, and 0.425, respectively. The survival rates were: 100, 20, 100 and 90%, in treatments 1, 2, 3 and 4, respectively, being only effected by chloroacetamid. Chlorpyrifos and tefluthrin were not toxic for L. terrestris at the current dose (P < 0.05.

  6. Mathematical Modeling of Food Freezing in Air-Blast Freezer

    Directory of Open Access Journals (Sweden)

    Guiqiang Wang

    2014-11-01

    Full Text Available A mathematical model for simulating the heat transfer during food freezing was presented. The model consists of three steps. First, the flow field inside the freezing chamber was modeled using the CFD method, based on which the freezing condition, including the temperature and velocity around the food, was calculated. Second, the heat transfer coefficient between food and air was calculated in the CFD model. Third, a finite-difference model was employed to simulate the heat transfer inside the food product. Measurements were conducted on different food products in freezing chamber to verify the mathematical model. The effects of process parameters on food freezing were also analyzed, which concludes that the air temperature has more influence on food freezing than the air velocity

  7. Anomalous freezing behavior of nanoscale liposomes

    DEFF Research Database (Denmark)

    Spangler, E. J.; Kumar, P. B. S.

    2012-01-01

    The effect of the finite size of one-component liposomes on their phase behavior is investigated via simulations of an implicit-solvent model of self-assembled lipid bilayers. We found that the high curvature of nanoscale liposomes has a significant effect on their freezing behavior. While the location of the freezing temperature of liposomes with diameters larger than 30 nm is the same as that of a planar membrane, the transition is broadened as the liposome diameters are decreased. For very small liposomes, with diameters smaller than 30 nm, the transitions of the two leaflets become increasingly decoupled, and their respective freezing temperatures become different. In particular, the outer leaflet gels at a temperature, T-g((u)), which is higher than that of the inner leaflet, T-g((i)). We argue that this decoupling is due to the difference in configurational entropies of the lipid chains in the two leaflets. At temperatures higher than T-g((u)), the liposomes are spherical and the lipids in both leafletslack both positional and chain order. At temperatures between T-g((i)) and T-g((u)), the lipids in the outer leaflet exhibit chain order but lack positional order. In contrast the lipids in the inner leaflet lack both chain order and positional order in this temperature range. In this range of temperatures, liposomes are essentially spherical. At temperatures lower than T-g((i)), lipids in both the inner and outer leaflets exhibit chain order as well as positional order, and the liposomes become faceted. The structure of the outer leaflet for T-g((i))

  8. Freezing of fluids confined between mica surfaces.

    Science.gov (United States)

    Ayappa, K G; Mishra, Ratan K

    2007-12-27

    Using grand ensemble simulations, we show that octamethyl-cyclo-tetra-siloxane (OMCTS) confined between two mica surfaces can form a variety of frozen phases which undergo solid-solid transitions as a function of the separation between the surfaces. For atomically smooth mica surfaces, the following sequence of transitions 1[triangle up] --> 1[triangle up]b --> 2B --> 2 square --> 2[triangle up] are observed in the one- and two-layered regimes, where n[triangle up], n[square], and nB denote triangular, square, and buckled phases, respectively, with the prefix n denoting the number of confined layers. The presence of potassium on mica is seen to have a strong influence on the degree of order induced in the fluid. The sequence of solid-solid transitions that occurs with the smooth mica surface is no longer observed. When equilibrated with a state point near the liquid-solid transition, a counterintuitive freezing scenario is observed in the presence of potassium. Potassium disrupts in-plane ordering in the fluid in contact with the mica surface, and freezing is observed only in the inner confined layers. The largest mica separations at which frozen phases were observed ranged from separations that could accommodate six to seven fluid layers. The extent of freezing and the square-to-triangular lattice transition was found to be sensitive to the presence of potassium as well as the thermodynamic conditions of the bulk fluid. The implications of our results on interpretation of surface force experiments as well as the generic phase behavior of confined soft spheres is discussed. PMID:18092763

  9. Investigations on freezing processes of molten cores

    International Nuclear Information System (INIS)

    In reactor safety analysis of fast breeder reactors the freezing behaviour of molten core materials plays an important role. This, and particularly the conditions under which stable crusts and melt-films exist were investigated in simulation experiments. Different structures (tubes, annuli, bundles) of stainless steel and quartz glass were used. The molten core was simulated by aluminum oxide and iron. In all experiments, including those with melting steel walls stable crusts were found and no intermixing of molten steel and streaming oxide was observed. The measured penetration depths and crust thicknesses were recalculated with a modified version of the code PLUGM. In most cases the agreement was good. (orig.)

  10. Mechano-freezing of the ambient water

    CERN Document Server

    Zhang, Xi; Zou, Bo; Sun, Chang Q

    2013-01-01

    Raman spectroscopy examination of the 25 deg-C water freezing under compression revealed transition from 1.35 GPa to 0.86 GPa upon ice being formed at continued volume change. The transition is associated with a slight blue shift of the high-frequency phonon (omiga_H ~ 3120 cm-1) and creation of the low-frequency phonons (Omiga_L ~ 200 cm-1). In the liquid and in the solid phase, the increased pressure softens the Omiga_H and stiffens the Omida_L, which indicates the presence of the inter-electron-pair repulsion in both liquid and solid water.

  11. Freeze Tolerant Radiator for an Advanced EMU

    Science.gov (United States)

    Copeland, Robert J.; Elliott, Jeannine; Weislogel, Mark

    2004-01-01

    During an Extravehicular Activity (EVA), the astronaut s metabolic heat and the heat produced by the Portable Life Support Unit (PLSS) must be rejected. This heat load is currently rejected by a sublimator, which vents up to eight pounds of water each EVA. However, for advanced space missions of the future, water venting to space needs to be minimized because resupply impacts from earth will be prohibitive. If this heat load could be radiated to space from the PLSS, which has enough surface area to radiate most of the heat, the amount of water now vented could be greatly reduced. Unfortunately, a radiator rejects heat at a relatively constant rate, but the astronauts generate a variable heat load depending on how hard they are working. Without a way to vary the heat removal rate, the astronaut would experience cold discomfort or even frostbite. A proven method allowing a radiator to be turned-down is to sequentially allow tubes that carry the heat transfer fluid to the radiator to freeze. A drawback of current freezable radiators using this method is that they are far to heavy for use on a PLSS, because they use heavy construction to prevent the tubes from bursting as they freeze and thaw. This creates the need for a large radiator to reject most of the heat but with a lightweight tube that doesn t burst as it freezes and thaws. The new freezable radiator for the Extravehicular Mobility Unit (EMU) has features to accommodate the expansion of the radiator fluid when it freezes, and still have the high tube to fin conductance needed to minimize the number and weight of the tubes. Radiator fluid candidates are water and a propylene glycol-water mixture. This design maintains all materials within their elastic limits so that large volume changes can be achieved without breaking the tube. This concept couples this elastic expansion with an extremely lightweight, extremely high conductivity carbon fiber fin that can carry the heat needed to thaw a frozen tube. By using most of the exposed surface area of the PLSS as a radiator, the system can reject about 75% of the highest heat load, and reduce the loss of water through sublimation by a factor of four. The proposed radiator and a small water tank can be no heavier than the current system.

  12. Freeze-fracture study of Trichomonas vaginalis

    Directory of Open Access Journals (Sweden)

    Marlene Benchimol

    1990-12-01

    Full Text Available The freeze-fracture technique was used to analyse the organization of the plasma membrane, as well as membranes of cytoplasmic organelles, of the pathogenic protozoan Trichomonas vaginalis. Rosettes formed by 4 to 14 intramembranous particles were seen on the fracture faces of the membrane lining the anterior flagella as well as in fracture faces of the plasma membrane enclosing the anterior region of the protozoan and in cytoplasmic organelles. Special organization of the membrane particles were also seen in the region of association of the recurrent flagellum to the cell body.

  13. Electrical Indicator of Imminent Freezing in Supercooled Water

    OpenAIRE

    Brownridge, James D.

    2002-01-01

    Data is presented that demonstrate electrical activity and evidences of dipole alignment in supercooled water and heavy water before and after the onset of freezing. Voltage signals as high as 13 mV have been recorded. In some cases up to 3 seconds before latent heat is released and freezing began. The polarity of the voltage signals is suggestive of molecule dipole alignment prior to freezing.

  14. eskimo1 mutants of Arabidopsis are constitutively freezing-tolerant

    OpenAIRE

    Xin, Zhanguo; Browse, John

    1998-01-01

    Temperate plants develop a greater ability to withstand freezing in response to a period of low but nonfreezing temperatures through a complex, adaptive process of cold acclimation. Very little is known about the signaling processes by which plants perceive the low temperature stimulus and transduce it into the nucleus to activate genes needed for increased freezing tolerance. To help understand the signaling processes, we have isolated mutants of Arabidopsis that are constitutively freezing-...

  15. Mathematical Modeling of Food Freezing in Air-Blast Freezer

    OpenAIRE

    Guiqiang Wang; Pinghua Zou

    2014-01-01

    A mathematical model for simulating the heat transfer during food freezing was presented. The model consists of three steps. First, the flow field inside the freezing chamber was modeled using the CFD method, based on which the freezing condition, including the temperature and velocity around the food, was calculated. Second, the heat transfer coefficient between food and air was calculated in the CFD model. Third, a finite-difference model was employed to simulate the heat transfer inside th...

  16. Microstructure Changes in Hardened Cement Paste after Freezing – Thawing Cycles

    OpenAIRE

    Girskas, Giedrius; Janavic?ius, Eugenijus; Skripkiu?nas, Gintautas; S?pokauskas, Algimantas; Keriene?, Jadvyga; Nagrockiene?, Dz?igita

    2013-01-01

    This article analyses the results of the freezing – thawing with deicing salt test where changes in the microstructure of the surface layer in contact with aggressive environment of hardened cement paste produced with and without sodium silicate (hereinafter NTS) admixture were observed after freeze-thaw cycles in the presence of calcium chloride. After 56 cycles of freezing – thawing with deicing salt test micro-cracks and cavities were observed in the microstructure of the surface laye...

  17. A novel technique for energy saving in freezing technology

    OpenAIRE

    Zhang, Jianyi

    1993-01-01

    In the freezing process, a single evaporating temperature is normally used in the food industry. This work proposes a new technique which uses two evaporating temperatures in freezing process. Based on the Carnot principle, the bigger the temperature difference of refrigeration, the greater the energy costs. The new technique uses a higher evaporating temperature in the first period of the new freezing process. It allows most of the refrigeration capacity to be obtained for less temperature d...

  18. Experimental Evaluation of Herbivory on Live Plant Seedlings by the Earthworm Lumbricus terrestris L. in the Presence and Absence of Soil Surface Litter

    Science.gov (United States)

    Kirchberger, Johannes; Eisenhauer, Nico; Weisser, Wolfgang W.; Türke, Manfred

    2015-01-01

    Background Recent studies suggested that the earthworm Lumbricus terrestris might act as a seedling predator by ingesting emerging seedlings, and individuals were observed damaging fresh leaves of various plant species in the field. To evaluate the significance of herbivore behavior of L. terrestris for plant and earthworm performance we exposed 23- to 33-days-old seedlings of six plant species to earthworms in two microcosm experiments. Plants belonged to the three functional groups grasses, non-leguminous herbs, and legumes. Leaf damage, leaf mortality, the number of leaves as well as mortality and growth of seedlings were followed over a period of up to 26 days. In a subset of replicates 0.1 g of soil surface litter of each of the six plant species was provided and consumption was estimated regularly to determine potential feeding preferences of earthworms. Results There was no difference in seedling growth, the number of live seedlings and dead leaves between treatments with or without worms. Fresh leaves were damaged eight times during the experiment, most likely by L. terrestris, with two direct observations of earthworms tearing off leaf parts. Another nine leaves were partly pulled into earthworm burrows. Lumbricus terrestris preferred to consume legume litter over litter of the other plant functional groups. Earthworms that consumed litter lost less weight than individuals that were provided with soil and live plants only, indicating that live plants are not a suitable substitute for litter in earthworm nutrition. Conclusion Our results demonstrate that L. terrestris damages live plants; however, this behavior occurs only rarely. Pulling live plants into earthworm burrows might induce microbial decomposition of leaves to make them suitable for later consumption. Herbivory on plants beyond the initial seedling stage may only play a minor role in earthworm nutrition and has limited potential to influence plant growth. PMID:25885861

  19. Automated assessment of Pavlovian conditioned freezing and shock reactivity in mice using the VideoFreeze system

    Directory of Open Access Journals (Sweden)

    StephanGAnagnostaras

    2010-09-01

    Full Text Available The Pavlovian conditioned freezing paradigm has become a prominent mouse and rat model of learning and memory, as well as of pathological fear. Due to its efficiency, reproducibility, and well-defined neurobiology, the paradigm has become widely adopted in large-scale genetic and pharmacological screens. However, one major shortcoming of the use of freezing behavior has been that it has required the use of tedious hand scoring, or a variety of proprietary automated methods that are often poorly validated or difficult to obtain and implement. Here we report an extensive validation of the Video Freeze system in mice, a “turn-key” all-inclusive system for fear conditioning in small animals. Using digital video and near-infrared lighting, the system achieved outstanding performance in scoring both freezing and movement. Given the large-scale adoption of the conditioned freezing paradigm, we encourage similar validation of other automated systems for scoring freezing, or other behaviors.

  20. Genotypic variation in morphology and freezing resistance of Eucalyptus globulus seedlings subjected to drought hardening in nursery

    Scientific Electronic Library Online (English)

    Rafael E, Coopman; Jorge C, Jara; Rene, Escobar; Luis J, Corcuera; Leon A, Bravo.

    2010-01-15

    Full Text Available SciELO Chile | Language: English Abstract in english Eucalyptus globulus Labill is one of the most planted species in Chile, because of its fast growth and superior pulp qualities. Nevertheless, the incidence of drought and frost damage immediately after planting is frequent. The purpose of this work was to study the effect of drought hardening on fro [...] st resistance and on variations in morphological traits that may increase drought resistance at nursery phase in four genotypes of E. globulus Labill. Drought hardening treatments consisted in induced water stress by watering restriction, until pre-dawn stem xylem water potentials (?pd) reached -0.2, -1.8 and -2.6 MPa. Two water stress-rewatering cycles were applied during 54 days of hardening. Plant and root biomasses were affected by the interaction of drought hardening and genotypes. The rest of morphological and alometrical traits were affected independently by drought or genotype. Plant height, leaf area, specific leaf area (SLA), stem, and leaf biomasses decreased with drought hardening, while collar diameter was not affected. Genotypes responded differentially to drought hardening in plant height, leaf area, SLA, and stem, and leaf biomasses. Ice nucleation temperature (INT), and freezing temperatures (FRT), and 50% freezing damage index of leaves (LT50) were affected by the interaction between drought hardening and genotypes. EG-13, EG-23 and EG-22 genotypes became freezing tolerant with drought hardening (-2.6 MPa). Additionally, EG-14 genotype increased its freezing resistance at -1.8 MPa. Therefore, freezing resistance levels and mechanism depend on genotype and drought hardening treatment. The success in tree breeding by genetic selection should be facilitated by improved understanding of the physiology of stress resistance development and survival during water supply limitations. The knowledge of morphological and freezing resistance dependency on the interaction between genotype and drought hardening may be useful nursery management information to improve plantation success.

  1. Epithelial dominant expression of antifreeze proteins in cunner suggests recent entry into a high freeze-risk ecozone.

    Science.gov (United States)

    Hobbs, Rod S; Fletcher, Garth L

    2013-01-01

    Most marine teleost fishes residing in a high freeze-risk ecozone, such as the coastal waters of Newfoundland during winter, avoid freezing by secreting high concentrations of antifreeze proteins (AFP) into their blood plasma where they can bind to and prevent the growth of ice that enter the fish. Cunner (Tautogolabrus adspersus), which overwinter in such shallow waters are the only known exception. Although this species does produce type I AFP, the plasma levels are too low to be of value as a freeze protectant. Southern and Northern blot analyses carried out in this study establish that the cunner AFP genes belong to a multigene family that is predominantly expressed in external epithelia (skin and gill filaments). These results support the hypothesis that the survival of cunner in icy waters is attributable in part to epithelial AFP that help block ice propagation into their interior milieu. In contrast to the cunner, heterospecifics occupying the same habitat have greater freeze protection because they produce AFP in the liver for export to the plasma as well as in external epithelia. Since the external epithelia would be the first tissue to come into contact with ice it is possible that one of the earliest steps involved in the evolution of freeze resistant fish could have been the expression of AFP in tissues such as the skin. We suggest that this epithelial-dominant AFP expression represents a primitive stage in AFP evolution and propose that cunner began to inhabit "freeze-risk ecozones" more recently than heterospecifics. PMID:23085291

  2. Freezing efficiency of Silver Iodide, ATD and Kaolinite in the contact freezing mode

    Science.gov (United States)

    Nagare, Baban; Marcolli, Claudia; Stetzer, Olaf; Lohmann, Ulrike

    2014-05-01

    The importance of heterogeneous ice nucleation via contact freezing is one of the open questions in the atmospheric science community. In our laboratory, we built the Collision Nucleation CHamber (CLINCH) (Ladino et al. 2011) in which falling cloud droplets can collide with aerosol particles. In this study, contact freezing experiments are conducted to investigate the ice nucleation ability of silver iodide (AgI), kaolinite and Arizona Test Dust (ATD). Silver iodide has been known for its ice nucleation ability since 1940s (Vonnegut 1947) while kaolinite is a clay mineral and known to be a moderate ice nucleus. ATD is a commercial dust sample used by many groups to compare different setups. In CLINCH, size selected aerosol particles collide with water droplets of 80 µm diameter. With the extension in chamber length it is possible to vary the interaction time of ice nuclei and the droplets. Our experiments are performed between -10 to -36 ºC for various concentrations of ice nuclei and different interaction times. The frozen fraction of the droplets is determined using the custom-made depolarization detector IODE (Nicolet et al., 2010). Depolarization of linearly polarized incident laser light is used to determine the ratio of frozen droplets to all droplets. Frozen fractions of the three particle types with different residence times from CLINCH will be presented in this study. The number of collisions between a single droplet and several aerosol particles can be calculated by accounting for the theoretical collision efficiency at the experimental conditions in order to obtain the freezing efficiency (frozen fraction/number of collisions). Nucleation efficiency is compared with other contact freezing studies and with immersion freezing

  3. Ultrastructure of the echinoderm cuticle after fast-freezing/freeze substitution and conventional chemical fixations.

    Science.gov (United States)

    Ameye, L; Hermann, R; DuBois, P; Flammang, P

    2000-03-15

    The cuticles of the pedicellaria primordia in the sea urchin Paracentrotus lividus and of the tube foot disk in the sea star Asterias rubens were preserved by different methods, viz., glutaraldehyde fixation followed by osmium tetroxide postfixation, glutaraldehyde-ruthenium red fixation followed by osmium tetroxide-ruthenium red postfixation, and two fast freezing / freeze substitution methods (FF/FS). The gross ultrastructure of the cuticle as well as the influence of the preservation method on this ultrastructure were identical for the two tissues studied. The cuticle ultrastructure was poorly preserved after glutaraldehyde fixation / osmium tetroxide postfixation. Its preservation was improved after ruthenium red was added in the fixative and postfixative, but the best preservation was consistently achieved using FF/FS. Both low-pressure freezing (plunge freezing) and high-pressure freezing were tested, the latter giving seemingly better results. With these methods, the cuticle appeared to be composed of a proximal lower cuticle, an intermediate upper cuticle, and a distal fuzzy coat. In particular, cryoimmobilization methods emphasized or revealed the occurrence of a well-developed fibrillar lower cuticle in the pedicellaria, the complexity of the upper cuticle which consisted of several zones, and the importance of the usually poorly preserved fuzzy coat that is actually the thickest layer of the cuticle. These observations bring new insights on the functions of the cuticle, and particularly of the fuzzy coat. According to its preservation characteristics, the fuzzy coat presumably consists mostly of proteoglycans. This composition could give it shock absorption and antifouling properties. Furthermore, its important thickness also implies that molecules detected by the short sensory cilia must diffuse through and could be selected by the fuzzy coat. PMID:10738319

  4. Survival strategies of freshwater insects in cold environments

    Directory of Open Access Journals (Sweden)

    Valeria LENCIONI

    2004-09-01

    Full Text Available At high latitudes and altitudes, ice formation is a major variable affecting survival of freshwater fauna and hence the abundance and composition of invertebrate communities. Freezing, but also desiccation and anoxia, are lethal threats to all life stages of aquatic insects, from the eggs to the adults. During cold periods, the aquatic stages commonly remain in or move to a portion of the water body that will not freeze or dry (e.g., deep waters of lakes, springs and hyporheic zone where they can remain active. Less frequently they migrate to habitats that will freeze at the onset of winter. Insects have developed a complex of strategies to survive at their physiological temperature minimum, comprising (a morphological (melanism, reduction in size, hairiness/pubescence, brachyptery and aptery, (b behavioural (basking in the sun, changes in feeding and mating habit, parthenogenesis, polyploidy, ovoviviparity, habitat selection and cocoon building, (c ecological (extension of development to several years by quiescence or diapause and reduction of the number of generations per year, (d physiological and biochemical (freezing tolerance and freezing avoidance adaptations. Most species develop a combination of these survival strategies that can be different in the aquatic and terrestrial phase. Freezing avoidance and freezing tolerance may be accompanied by diapause. Both cold hardiness and diapause manifest during the unfavourable season and: (i involve storage of food resources (commonly glycogen and lipids; (ii are under hormonal control (ecdysone and juvenile hormone; (iii involve a depression or suppression of the oxidative metabolism with mitochondrial degradation. However, where the growing season is reduced to a few weeks, insects may develop cold hardiness without entering diapause, maintaining in the haemolymph a high concentration of Thermal Hysteris Proteins (THPs for the entire year and a slow but continuous growth. A synthesis of literature regarding adaptation strategies in aquatic insects is presented, highlighting the scarcity of information on freshwater insects from Alpine regions. Most references are on Diptera Chironomidae from North America and North Europe. Some recent findings on aquatic insects from Italian Alpine streams are also presented.

  5. BIOCONVERSION OFWATER HYACINTH (EICHHORNIA CRASSIPES TO VERMICOMPOST BY THE EARTHWORM EUDRILUS EUGENIAE: AN IDEAL METHOD FOR SOLID WASTE MANAGEMENT

    Directory of Open Access Journals (Sweden)

    RAO,K.R

    2013-02-01

    Full Text Available Vermicomposting is a process in which organic waste can be converted to an energy rich byproduct by the action of microbial population present in the gut flora of earthworms. Earthworms are considered as bioengineers as they enrich the soil by adding micronutrient and macronutrients through their cast. This enriched soil will be useful for getting higher yield in the agricultural crops. The vermibiotechnology facilitates the recycling of industrial, agricultural, domestic and aquatic weeds by reducing environmental pollution and directly in solid waste management. In the present investigation an attempt has been made to recycle the water hyacinth to vermicompost by using the earthworm species Eudrilus eugeniae .The investigations for the directed to understand mobilization of microbial populations from different treatment groups. Variations in bacteria, fungi and actinomycetes were studied from four different experimental groups for a duration of 120 days. Results are discussed in the light of available literature.

  6. DNA damage and repair process in earthworm after in-vivo and in vitro exposure to soils irrigated by wastewaters

    International Nuclear Information System (INIS)

    In this study, DNA damage to earthworms (Eisenia fetida) after in vivo exposure to contaminated soils was measured by detecting DNA strand breakages (DSBs) and causality was analyzed through fractionation based bioassays. A non-linear dose-response relationship existed between DNA damage and total soil PAHs levels. DNA damage, measured with the comet assay, and its repair process, were observed. To identify the chemical causality, an in vitro comet assay using coelomocytes was subsequently performed on the fractionated organic extracts from soils. The results showed that the PAHs in the soils were responsible for the exerting genotoxic effects on earthworms. When normalized to benzo(a)pyrene toxic equivalent (TEQBaP), the saturation dose in the dose-response curve was about 10 ng TEQBaP g-1 soil (dw). - A non-linear dose-response relationship exists between earthworm DNA damage, measured with comet assay, and total PAHs levels in soils irrigated by wastewaters

  7. Time-dependent freezing rate parcel model

    Science.gov (United States)

    Vali, G.; Snider, J. R.

    2015-02-01

    The time-dependent freezing rate (TDFR) model here described represents the formation of ice particles by immersion freezing within an air parcel. The air parcel trajectory follows an adiabatic ascent and includes a period in time when the parcel remains stationary at the top of its ascent. The description of the ice nucleating particles (INPs) in the air parcel is taken from laboratory experiments with cloud and precipitation samples and is assumed to represent the INP content of the cloud droplets in the parcel. Time dependence is included to account for variations in updraft velocity and for the continued formation of ice particles under isothermal conditions. The magnitudes of these factors are assessed on the basis of laboratory measurements. Results show that both factors give rise to three-fold variations in ice concentration for a realistic range of the input parameters. Refinements of the parameters specifying time dependence and INP concentrations are needed to make the results more specific to different atmospheric aerosol types. The simple model framework described in this paper can be adapted to more elaborate cloud models. The results here presented can help guide decisions on whether to include a time-dependent ice nucleation scheme or a simpler singular description in models.

  8. Time-dependent freezing rate parcel model

    Science.gov (United States)

    Vali, G.; Snider, J. R.

    2014-11-01

    The Time-Dependent Freezing Rate (TDFR) model here described represents the formation of ice particles by immersion freezing within an air parcel. The air parcel trajectory follows an adiabatic ascent and includes a period at time with the parcel remaining stationary at the top of its ascent. The description of the ice nucleating particles (INPs) in the air parcel is taken from laboratory experiments with cloud and precipitation samples and is assumed to represent the INP content of the cloud droplets in the parcel. Time-dependence is included to account for variations in updraft velocity and for the continued formation of ice particles at isothermal conditions. The magnitudes of these factors are assessed on the basis of laboratory measurements. Results show that both factors give rise to factors of about 3 variations in ice concentration for a realistic range of the input parameters. Refinements of the parameters specifying time-dependence and INP concentrations are needed to make the results more specific to different atmospheric aerosol types. The simple model framework described in this paper can be adapted to more elaborate cloud models. The results here presented can help guide decisions on whether to include a time-dependent ice nucleation scheme or a simpler singular description in models.

  9. Time-dependent freezing rate parcel model

    Directory of Open Access Journals (Sweden)

    G. Vali

    2014-11-01

    Full Text Available The Time-Dependent Freezing Rate (TDFR model here described represents the formation of ice particles by immersion freezing within an air parcel. The air parcel trajectory follows an adiabatic ascent and includes a period at time with the parcel remaining stationary at the top of its ascent. The description of the ice nucleating particles (INPs in the air parcel is taken from laboratory experiments with cloud and precipitation samples and is assumed to represent the INP content of the cloud droplets in the parcel. Time-dependence is included to account for variations in updraft velocity and for the continued formation of ice particles at isothermal conditions. The magnitudes of these factors are assessed on the basis of laboratory measurements. Results show that both factors give rise to factors of about 3 variations in ice concentration for a realistic range of the input parameters. Refinements of the parameters specifying time-dependence and INP concentrations are needed to make the results more specific to different atmospheric aerosol types. The simple model framework described in this paper can be adapted to more elaborate cloud models. The results here presented can help guide decisions on whether to include a time-dependent ice nucleation scheme or a simpler singular description in models.

  10. Asset Freezing: Smart Sanction or Criminal Charge?

    Directory of Open Access Journals (Sweden)

    Wouter de Zanger

    2011-02-01

    Full Text Available In this article the question is asked whether asset freezing can be qualified as a criminal charge within the meaning of Article6 ECHR and if yes, what effects this qualification may have on the legislative framework on so called smart sanctions. Byanalysing Community and EU law and case law of the European Court of Human Rights, General Court of Instance andCourt of Justice of the European Communities the authors give an overview of the notion and possible qualification of assetfreezing as a criminal charge. The article further focusses on the consequenses of qualifying asset freezing as a criminal chargeunder ECHR and EC/EU law and concludes by answering the aforementioned question.This article is a rewrite of a research paper written under supervision of prof. dr. J.A.E. Vervaele and prof. dr. C.H. Brants(Willem Pompe Institute for Criminal Law and Criminology, Utrecht University School of Law, whom the authors wouldlike to thank for their useful comments and supervision.

  11. Effect of Long-Term Freezing and Freeze–Thaw Cycles on Indigenous and Inoculated Microorganisms in Dewatered Blackwater

    DEFF Research Database (Denmark)

    Gunnarsdottir, Ragnhildur; Müller, Karoline

    2012-01-01

    Wastewater treatment in many Arctic regions is inadequate, even nonexisting. Natural freezing of wastewater in those areas may be beneficial for reduction of microorganisms. The aim of this study was to investigate the effect of long-term freezing, and repeated freezing and thawing, on indigenous coliforms, fecal streptococci, and antibiotic-resistant (AR) bacteria, and inoculated Salmonella Enteriditis and E. coli bacteriophage ?X174 in dewatered blackwater. At the end of the long-term freezing experiment (10 months), an MPN recovery study was done, including the microbial groups that had shown the largest reduction, using tryptone soy broth at incubation temperatures of 10 and 20 °C overnight for the coliforms and AR bacteria, and buffered peptone water at incubation temperature of 37 °C for 18–20 h for Salmonella. Fecal streptococci were more resistant to long-term freezing than the coliform group. Total number of AR bacteria decreased slowly but constantly over the 10-month freezing period. Salmonella rapidly decreased and were nondetectable within a week but exhibited some recovery after 10 months of freezing, whereas limited or no recovery of coliforms and AR-bacteria was detected. Bacteriophages showed limited reduction during the long-term freezing. Repeated freezing and thawing increased the reduction of all tested microbial groups markedly.

  12. Bioaccumulation of polycyclic aromatic hydrocarbons by earthworms: Assessment of equilibrium partitioning theory in in situ studies and water experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ma, W.; Kleunen, A. van; Immerzeel, J. [Inst. for Forestry and Nature Research, Wageningen (Netherlands). Dept. of Ecotoxicology; Maagd, P.G.J. de [Inst. for Inland Water Management and Waste Water Treatment, Lelystad (Netherlands). Dept. of Industrial Pollution Control

    1998-09-01

    The purpose of this study was to assess the suitability of applying equilibrium partitioning (EqP) theory to predict the bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) by earthworms when these are exposed to contaminated soils in the field. Studies carried out in situ in various contaminated floodplain sites showed the presence of linear relationships with intercept zero between the lipid-normalized concentration of different PAHs in the earthworm, Lumbricus rubellus and the organic-matter-normalized concentration of the compounds in soil. The demonstration of such an isometric relationship is in agreement with the prediction of EqP theory that the biota-soil accumulation factor (BSAF) should be independent of the octanol/water partition coefficient, log K{sub ow}. The average BSAF of PAH compounds in the sampled 20-cm top layer of soil was 0.10. The present study also investigated the route of uptake of PAHs for earthworms in soil. The bioconcentration factor of low-molecular-weight PAHs, such as phenanthrene, fluoranthene, and pyrene, was derived from bioconcentration kinetic modeling of water-only experiments and found to be of the same order of magnitude as the bioaccumulation factor in the field when the latter was normalized to calculated concentrations in soil pore water. The results indicated that the exposure of earthworms to PAHs in soil is mediated through direct contact of the worms with the dissolved interstitial soil-water phase, further supporting the applicability of EqP theory to PAHs. The experimental data on the biotransformation of PAHs suggest that earthworms possess some capacity of metabolization, although this does not seem to be a major factor in the total elimination of these compounds. Even though the EqP approach was found to be applicable to low-molecular-weight PAHs with respect to the prediction of bioaccumulation by earthworms in the field, the results were less conclusive for high-molecular-weight compounds, such as benzo[a]pyrene.

  13. Determining the influence of rainfall patterns and carbendazim on the surface activity of the earthworm Lumbricus terrestris.

    Science.gov (United States)

    Ellis, Sian R; Hodson, Mark E; Wege, Phil

    2010-08-01

    Carbendazim is highly toxic to earthworms and is used as a standard control substance when running field-based trials of pesticides, but results using carbendazim are highly variable. In the present study, impacts of timing of rainfall events following carbendazim application on earthworms were investigated. Lumbricus terrestris were maintained in soil columns to which carbendazim and then deionized water (a rainfall substitute) were applied. Carbendazim was applied at 4 kg/ha, the rate recommended in pesticide field trials. Three rainfall regimes were investigated: initial and delayed heavy rainfall 24 h and 6 d after carbendazim application, and frequent rainfall every 48 h. Earthworm mortality and movement of carbendazim through the soil was assessed 14 d after carbendazim application. No detectable movement of carbendazim occurred through the soil in any of the treatments or controls. Mortality in the initial heavy and frequent rainfall was significantly higher (approximately 55%) than in the delayed rainfall treatment (approximately 25%). This was due to reduced bioavailability of carbendazim in the latter treatment due to a prolonged period of sorption of carbendazim to soil particles before rainfall events. The impact of carbendazim application on earthworm surface activity was assessed using video cameras. Carbendazim applications significantly reduced surface activity due to avoidance behavior of the earthworms. Surface activity reductions were least in the delayed rainfall treatment due to the reduced bioavailability of the carbendazim. The nature of rainfall events' impacts on the response of earthworms to carbendazim applications, and details of rainfall events preceding and following applications during field trials should be made at a higher level of resolution than is currently practiced according to standard International Organization for Standardization protocols. PMID:20821637

  14. Slow dehydration promotes desiccation and freeze tolerance in the Antarctic midge Belgica antarctica.

    Science.gov (United States)

    Hayward, Scott A L; Rinehart, Joseph P; Sandro, Luke H; Lee, Richard E; Denlinger, David L

    2007-03-01

    Adaptations to low moisture availability are arguably as important as cold resistance for polar terrestrial invertebrates, especially because water, in the form of ice, is biologically inaccessible for much of the year. Desiccation responses under ecologically realistic soil humidity conditions--those close to the wilting points of plants [98.9% relative humidity (RH)]--have not previously been examined in polar insect species. In the current study we show that, when desiccated at 98.2% RH, larvae of the Antarctic midge Belgica antarctica are more tolerant of dehydration than larvae desiccated at lower humidities (75% RH), and develop an increased tolerance to freezing. The slow rate of desiccation at this high RH enabled more than 50% of larvae to survive the loss of >75% of their osmotically active water (OAW). Survival rates were further increased when rehydration was performed at 100% RH, rather than by direct contact with water. Two days at 98.2% RH resulted in a approximately 30% loss of OAW, and dramatically increased the freeze tolerance of larvae to -10 and -15 degrees C. The supercooling point of animals was not significantly altered by this desiccation treatment, and all larvae were frozen at -10 degrees C. This is the first evidence of desiccation increasing the freeze tolerance of a polar terrestrial arthropod. Maximum water loss and body fluid osmolality were recorded after 5 days at 98.2% RH, but osmolality values returned to predesiccated levels following just 1 h of rehydration in water, well before all the water lost through desiccation had been replenished. This suggests active removal of osmolytes from the extracellular fluids during the desiccation process, presumably to intracellular compartments. Heat-shock proteins appear not to contribute to the desiccation tolerance we observed in B. antarctica. Instead, we suggest that metabolite synthesis and membrane phospholipid adaptation are likely to be the underpinning physiological mechanisms enhancing desiccation and cold tolerance in this species. PMID:17297143

  15. Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

    OpenAIRE

    Sizmur, Tom; Palumbo-roe, Barbara; Watts, Michael J.; Hodson, Mark E.

    2011-01-01

    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm cas...

  16. Freezing and Thawing Durability of Very High Strength Concrete

    Directory of Open Access Journals (Sweden)

    Sameer Hamoush

    2011-01-01

    Full Text Available Problem statement: The newly developed Very High Strength Concrete (VHSC, having compressive strengths of 29 ksi and flexural strengths of 6 ksi, represents a breakthrough in concrete technology. Study to further enhance the properties of this new concrete is continuing. Approach: The objective of this study is to investigate the effect of exposing Very High Strength Concrete (VHSC specimens to rapid freeze/thaw cycles. Twenty one specimens were tested according to the Standards of the American Society for Testing and Materials ASTM C215, ASTM C666 and ASTM C78. Results: One hundred freeze/thaw cycles were performed on the VHSC specimens. Change in specimen?s dimensions and material?s properties were recorded at zero, forty, seventy and one hundred cycles. Dimensions and properties considered were: dimension of cross section, length, weight, Dynamic Moduli, Poisson?s Ratio, durability factor and Modulus of Rupture. Conclusion/Recommendations: The test results indicated that VHSC is good freeze-thaw resistance (durability factor > 85% and can avoid freeze/thaw damage. Freeze- thaw cycling did not significantly affect VHSC specimens? cross sectional dimensions, length, or Poisson?s Ratio. However, there was a decrease in the specimens? weight with the increase in number of freeze/thaw cycles, but the decrease was very slim indicating little or no deterioration has occur. Moreover, the fine voids exist in VHSC greatly lower the freezing point of any trapped water, making the material less susceptible to Freeze- Thaw damage.

  17. Using infrared thermography to study freezing in plants

    Science.gov (United States)

    Factors that determine when and to what extent a plant will freeze are complex. While thermocouples have served as the main method of monitoring the freezing process in plants, infrared thermography offers distinct advantages, and the use of this latter technology has provided new insights on the p...

  18. Increasing Freezing Tolerance: Kinase Regulation of ICE1.

    Science.gov (United States)

    Zhan, Xiangqiang; Zhu, Jian-Kang; Lang, Zhaobo

    2015-02-01

    Cold temperatures trigger the ICE1-CBF-COR transcriptional cascade in plants, which reprograms gene expression to increase freezing tolerance. In this issue of Developmental Cell, Ding et al. (2015) report that cold stress activates the protein kinase OST1 to phosphorylate and thereby stabilize and stimulate ICE1. This enhances plant tolerance to freezing temperatures. PMID:25669879

  19. Research Progress of Porous Ceramics Produced by Freeze Casting Technique

    Directory of Open Access Journals (Sweden)

    LIU Gang, YAN Yan

    2014-06-01

    Full Text Available Freeze casting, a novel technique for ceramics achieving unique porous microstructures with excellent mechanical properties, progressed very quickly in the past decade and has become a very hot research field. The present review summarizes the freeze casting history and introduces the basic principles, characteristics, processing affecting factors, and potential applications. Furthermore, several perspectives are given in the end.

  20. PENGGUNAAN BERBAGAI JENIS BAHAN PELINDUNG UNTUK MEMPERTAHANKAN VIABILITAS BAKTERI ASAM LAKTAT YANG DI ISOLASI DARI AIR SUSU IBU PADA PROSES PENGERINGAN BEKU [Utilization of various cryogenic agents during freeze drying to Maintain the viability of Lactic Acid Bacteria Isolated from breast milk

    Directory of Open Access Journals (Sweden)

    Ni Nyoman Puspawati1*

    2010-06-01

    Full Text Available Lactic acid bacteria are the most important bacteria having potential as probiotic. The objectives of the present study were to examine the growth of Lactic Acid Bacteria, identify the Lactic Acid Bacteria capable of surviving and evaluate the best cryogenic agents that protect the viability of Lactic Acid Bacteria during freeze drying. Four cryogenic agents, i.e. sucrose, lactose, skim milk and maltodextrin, were used in freeze drying of three species of Lactic Acid Bacteria, i.e. Pediococcus pentosaceus A16, Lactobacillus brevis A17 and Lactobacillus rhamnosus R21 isolated from breast milk. Evaluation included viability before and after freeze drying, survival of freeze dried culture in 0.5 % bile salt and low pH for 5 hours. The result showed that three of cryogenics, i.e. sucrose, lactose and skim milk improved the viability of freeze dried of all lactobacilli, except maltodextrin that did not give protection to L. rhamnosus R21. Evaluation on the survival of LAB in 0.5 % bile salt showed that cryogenic agents improved the survival rate of all Lactic Acid Bacteria during freeze drying. The cryogenic also improved the survival rate of LAB at low pH, with the best protection given by skim milk on L. rhamnosus R21.

  1. Effects of gamma radiation on reproductive ability of earthworm-Eisenia fetida

    International Nuclear Information System (INIS)

    Earthworms are the most suitable biological indicators of radioactive pollution because they are parts of nutritional chains and webs, occur in relatively high numbers and can be collected during most parts of the year. They are among the best bio-indicators of polluted soils. Eisenia fetida is selected for the radiation studies as it is recommended as important test species by FASSET (Framework for Assessment of Environmental impacT), International Environment Agency, England. In view of this an attempt has been made to expose the earthworms (E. fetida) to various doses of gamma radiation to see the effect of radiation on its reproductive parameters. Three to four months old E. fetida were exposed to different doses of gamma radiation including 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 Gy to study the effects of radiation on different reproductive parameters. The number of cocoon laid and the hatchings were recorded for all the above doses. There was no reduction found in the cocoon production for all the doses including in the present study. However, significant reductions in the percentage of hatchings were observed when the earthworms were exposed to 3, 5, 10, 15, 20, 25, 40, 45, 50, 55 and 60 Gy of gamma radiation doses. Dose response curve for percentage reduction in hatchings were constructed and the same will be presented. Reduction in size and weight of the cocoons were observed from the samples exposed to the doses of 20, 25, 30, 35, 40, 45,ed to the doses of 20, 25, 30, 35, 40, 45, 50, 55 and 60 Gy. Delayed hatchability was also recorded for the above said doses. (author)

  2. Biological significance of metals partitioned to subcellular fractions within earthworms (Aporrectodea caliginosa).

    Science.gov (United States)

    Vijver, Martina G; van Gestel, Cornelis A M; van Straalen, Nico M; Lanno, Roman P; Peijnenburg, Willie J G M

    2006-03-01

    Metal ions in excess of metabolic requirements are potentially toxic and must be removed from the vicinity of important biological molecules to protect organisms from adverse effects. Correspondingly, metals are sequestrated in various forms, defining the accumulation pattern and the magnitude of steady-state levels reached. To investigate the subcellular fractions over which Ca, Mg, Fe, Cu, Zn, Cd, Pb, Ni, and As are distributed, earthworms (Aporrectodea caliginosa) collected from the field were analyzed by isolating metal-rich granules and tissue fragments from intracellular microsomal and cytosolic fractions (i.e., heat-stable proteins and heat-denatured proteins). The fractions showed metal-specific binding capacity. Cadmium was mainly retrieved from the protein fractions. Copper was equally distributed over the protein fraction and the fraction comprising tissue fragments, cell membranes, and intact cells. Zinc, Ca, Mg, and As were mainly found in this fraction as well. Lead, Fe, and Ni were mainly isolated from the granular fraction. To study accumulation kinetics in the different fractions, three experiments were conducted in which earthworms were exposed to metal-spiked soil and a soil contaminated by anthropogenic inputs and, indigenous earthworms were exposed to field soils. Although kinetics showed variation, linear uptake and steady-state types of accumulation patterns could be understood according to subcellular compartmentalization. For risk assessment purposes, subcellular distribution of metals might allow for a more precise estimate of effects than total body burden. Identification of subcellular partitioning appears useful in determining the biological significance of steady-state levels reached in animals. PMID:16566166

  3. Screening of actinomycetes from earthworm castings for their antimicrobial activity and industrial enzymes

    Scientific Electronic Library Online (English)

    Vijay, Kumar; Alpana, Bharti; Yogesh Kumar, Negi; Omprakash, Gusain; Piyush, Pandey; Gajraj Singh, Bisht.

    2012-03-01

    Full Text Available Actinomycetes from earthworm castings were isolated and screened for their antimicrobial activity and industrial enzymes. A total of 48 isolates were obtained from 12 samples of earthworm castings. Highest numbers of isolates were recovered from forest site (58.33 %) as compared to grassland (25%) a [...] nd agricultural land (16.66%). The growth patterns, mycelial coloration of abundance actinomycetes were documented. The dominant genera Identified by cultural, morphological and physiological characteristics were Streptomyces (60.41%) followed by Streptosporangium (10.41%), Saccharopolyspora (6.25%) and Nocardia (6.25%). Besides these, other genera like Micromonospora, Actinomadura, Microbispora, Planobispora and Nocardiopsis were also recovered but in low frequency. Among the 48 isolates, 52.08% were found active against one or more test organisms. Out of 25 active isolates 16% showed activity against bacterial, human fungal as well as phytopathogens. Among 48 isolates 38, 32, 21, 20, 16 and 14 produced enzyme amylase, caseinase, cellulase, gelatinase, xylanase and lipase respectively while 10 isolates produced all the enzymes. More interestingly 2, 3, and 1 isolates produced amylase, xylanase and lipase at 45°C respectively. In the view of its antimicrobial activity as well as enzyme production capability the genus Streptomyces was dominant. The isolate EWC 7(2) was most promising on the basis of its interesting antimicrobial activity and was identified as Streptomyces rochei. The results of these findings have increased the scope of finding industrially important actinomycetes from earthworm castings and these organisms could be promising sources for industrially important molecules or enzymes.

  4. Screening of actinomycetes from earthworm castings for their antimicrobial activity and industrial enzymes

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2012-03-01

    Full Text Available Actinomycetes from earthworm castings were isolated and screened for their antimicrobial activity and industrial enzymes. A total of 48 isolates were obtained from 12 samples of earthworm castings. Highest numbers of isolates were recovered from forest site (58.33 % as compared to grassland (25% and agricultural land (16.66%. The growth patterns, mycelial coloration of abundance actinomycetes were documented. The dominant genera Identified by cultural, morphological and physiological characteristics were Streptomyces (60.41% followed by Streptosporangium (10.41%, Saccharopolyspora (6.25% and Nocardia (6.25%. Besides these, other genera like Micromonospora, Actinomadura, Microbispora, Planobispora and Nocardiopsis were also recovered but in low frequency. Among the 48 isolates, 52.08% were found active against one or more test organisms. Out of 25 active isolates 16% showed activity against bacterial, human fungal as well as phytopathogens. Among 48 isolates 38, 32, 21, 20, 16 and 14 produced enzyme amylase, caseinase, cellulase, gelatinase, xylanase and lipase respectively while 10 isolates produced all the enzymes. More interestingly 2, 3, and 1 isolates produced amylase, xylanase and lipase at 45°C respectively. In the view of its antimicrobial activity as well as enzyme production capability the genus Streptomyces was dominant. The isolate EWC 7(2 was most promising on the basis of its interesting antimicrobial activity and was identified as Streptomyces rochei. The results of these findings have increased the scope of finding industrially important actinomycetes from earthworm castings and these organisms could be promising sources for industrially important molecules or enzymes.

  5. The role of macrosymbiont genotypes and earthworms in the enrichment of soil with biological nitrogen

    Science.gov (United States)

    Nazaryuk, V. M.; Kalimullina, F. R.; Klenova, M. I.

    2010-06-01

    The specific features of the symbiotic apparatus and the accumulation of the plant biomass under the influence of different genotypes of peas ( Pisum sativum L.) on gray forest soils were studied in field conditions. With the alternation of legume and grass cultures, the genotypes of plants with supernodulation were found to affect the microbial nitrogen content in the soil to a greater extent than the concentration of ammonium and nitrate nitrogen. For the growing period, the N content in the microbial biomass increased, on the average, by 1.3 to 1.5 times. The consumption of nitrogen by the plants of the supernodular mutant K-301a was found to be 2.6 and 3.0 times greater than that by the pea plants of the Ramonskii-77 variety and of the K-562a line, respectively. During the after effect of the symbiotically bound air nitrogen, a significant uptake of this element was observed only by the oat plants grown after the K-56 2a. The nitrogen fixation by these plants was 1.3 times more active than that by the peas of the Ramonskii-77 variety. The importance of earthworms (Lumbricidae) and plant residues of different genotypes for the processes of mineralization of organic compounds and accumulation of ammonium, nitrate, and microbial nitrogen in the soils under optimal hydrothermal conditions was revealed. In the experiment, two maximums of the CO2 emission were recorded; they may be related to the periodic production of organic mass by the earthworms and the creation of favorable conditions for microbial activity by them. The accumulation of nitrate nitrogen (up to 150 mg/kg) in the soil was the greatest owing to the interaction between the earthworms and the residues of the supernodular K-301a mutant.

  6. Effects of Bio solids at Varying Rates on Earthworms (Eisenia fetida) and Springtails (Folsomia candida)

    International Nuclear Information System (INIS)

    Land spreading is a major option internationally for the disposal/use of treated sewage sludge (bio solids), but effects of this practice on soil organisms are largely unknown. This study investigated the effects of bio solids on two soil invertebrate species, earthworms (Eisenia fetida) and Collembola (Folsomia candida), in laboratory tests. Five bio solids from different sewage works were assessed at rates equivalent to 0, 2, 5, 10, and 20tha-1. Bio solids applied at 2 and 5tha-1 did not cause mortality of adult earthworms but did at 10 and 20tha-1. At 5, 10 and 20tha-1, all bio solids had significantly fewer juvenile worms relative to controls. Increasing the rates from 2 to 10tha-1 did not impact on the number of adult Collembola, but at 20tha-1 there were significantly fewer adults. There were significantly fewer juvenile Collembola recorded for bio solids applied at the 2tha-1 when compared with controls, and also when bio solids were applied at 5, 10, and 20tha-1 relative to 2tha-1. Some significant difference between bio solids were observed, but generally, negative effects were not related to heavy metal concentrations in bio solids. It is recommended that possible detrimental mechanisms (e.g., ammonia production, lack of oxygen) be investigated in future work. It is concluded that bio solids, applied at legal, low rates (about 2tha-1) are unlikely to (about 2tha-1) are unlikely to be detrimental to earthworms or adult Collembola but can be detrimental to Collembola reproduction.

  7. Ecotoxicological effects on the earthworm Eisenia fetida following exposure to soil contaminated with imidacloprid.

    Science.gov (United States)

    Zhang, Qingming; Zhang, Baohua; Wang, Caixia

    2014-11-01

    Imidacloprid, a neonicotinoid insecticide, has been used widely in agriculture worldwide. The adverse effects of imidacloprid on exposed biota have brought it increasing attention. However, knowledge about the effects of imidacloprid on antioxidant defense systems and digestive systems in the earthworm is vague and not comprehensive. In the present study, the changes in the activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), cellulase, reactive oxygen species (ROS), and malondialdehyde (MDA) in the earthworm Eisenia fetida exposed to artificial soil treated with imidacloprid were examined systematically. The results showed that the activity of these biomarkers was closely related to the dose and duration of the exposure to imidacloprid. The activity of SOD was stimulated significantly at doses of 0.66 and 2 mg kg(-1) imidacloprid but markedly inhibited at a dose of 4 mg kg(-1) imidacloprid with prolonged exposure. The activities of CAT and POD increased irregularly at 0.2-4 mg kg(-1) imidacloprid over different exposure times. The level of ROS at a dose of 2 or 4 mg kg(-1) imidacloprid was significantly increased over the entire exposure period. When the concentration of imidacloprid was above 0.66 mg kg(-1), the balance of the activity of the antioxidant enzymes and ROS level was interrupted. The activity of cellulase decreased significantly with prolonged exposure. At the stress of 4 mg kg(-1) imidacloprid, the content of MDA was significantly increased with increasing exposur