Kniesz, Katharina; Brandt, Angelika; Riehl, Torben
Macrostylis marionae n. sp. is described by means of integrative taxonomy. It is the second isopod species (Crustacea) described from the hadal Puerto Rico Trench. It differs from other Macrostylidae (Janiroidea) predominantly by the lack of the tergal borders between the fossosome segments. Adult males of M. marionae n. sp. differed from females and juveniles of both sexes in a higher number of peritrich ciliate epibionts. In total, 64.3% of adult males and only 10.5% of adult females were infested. Because macrostylids are generally considered infaunal, with a digging lifestyle, while peritrichs require aquatic medium for filter feeding, this observed pattern led to the hypothesis of a behavioural sexual dimorphism in this species of Macrostylidae. Accordingly, the epibionts may prefer adult male macrostylids as basibionts because of a rather epifaunal and roaming lifestyle. In contrast they may avoid females due to a stationary and infaunal behaviour. Additionally, the stage progression of the M. marionae male ontogeny was reconstructed.
Røy, Hans; Vopel, Kay; Huettel, Marcus
with flow adjusted to in situ velocity. The water motion around the colonies was then characterized by particle tracking velocimetry. This shows that the feather-shaped colony of Z. niveum generates a unidirectional flow of seawater through the colony with no recirculation. The source of the feeding current......We investigated the constraints on sulfide uptake by bacterial ectosymbionts on the marine peritrich ciliate Zoothamnium niveum by a combination of experimental and numerical methods. Protists with symbionts were collected on large blocks of mangrove-peat. The blocks were placed in a flow cell...... bacteria due to Z. niveum's habitat preference and due to the feeding current. Z. niveum is capable of exploiting low concentrations of sulfide in near norm-oxic seawater. This links its otherwise dissimilar habitats and makes it functionally similar to invertebrates with thiotrophic symbionts in filtering...
Three new and four known species of sessile peritrichs were identified from the crustacean ectoparasites, Lernaea barnimiana (Hartman, 1870), L. cyprinacea Linnaeus, 1758 and Dolops ranarum(Stuhimann, 1891) from various fish hosts in South Africa The new species described are: Epistylis cyprinaceae sp. n., ...
Sedlacek, Linda; Thistle, David; Fernandez-Leborans, Gregorio; Carman, Kevin R.; Barry, James P.
We report the first observations of ciliate epibionts on deep-sea, benthic harpacticoid copepods. One ciliate epibiont species belonged to class Karyorelictea, one to subclass Suctoria, and one to subclass Peritrichia. Our samples came from the continental rise off central California (36.709°N, 123.523°W, 3607 m depth). We found that adult harpacticoids carried ciliate epibionts significantly more frequently than did subadult copepodids. The reason for the pattern is unknown, but it may involve differences between adults and subadult copepodids in size or in time spent swimming. We also found that the ciliate epibiont species occurred unusually frequently on the adults of two species of harpacticoid copepod; a third harpacticoid species just failed the significance test. When we ranked the 57 harpacticoid species in our samples in order of abundance, three species identified were, as a group, significantly more abundant than expected by chance if one assumes that the abundance of the group and the presence of ciliate epibionts on them were uncorrelated. High abundance may be among the reasons a harpacticoid species carries a ciliate epibiont species disproportionately frequently. For the combinations of harpacticoid species and ciliate epibiont species identified, we found one in which males and females differed significantly in the proportion that carried epibionts. Such a sex bias has also been reported for shallow-water, calanoid copepods.
Sun, Ping; Clamp, John C; Xu, Dapeng
Despite extensive previous morphological work, little agreement has been reached about phylogenetic relationships among peritrich ciliates, making it difficult to study the evolution of the group in a phylogenetic framework. In this study, the nucleotide characteristics and secondary structures of internal transcribed spacers 1 and 2 (ITS1 and ITS2) of 26 peritrich ciliates in 12 genera were analyzed. Information from secondary structures of ITS1 and ITS2 then was used to perform the first systematic study of ITS regions in peritrich ciliates, including one species of Rhabdostyla for which no sequence has been reported previously. Lengths of ITS1 and ITS2 sequences varied relatively little among taxa studied, but their G+C content was highly variable. General secondary structure models of ITS1 and ITS2 were proposed for peritrich ciliates and their reliability was assessed by compensatory base changes. The secondary structure of ITS1 contains three major helices in peritrich ciliates and deviations from this basic structure were found in all taxa examined. The core structure of peritrich ITS2 includes four helices, with helix III as the longest and containing a motif 5'-MAC versus GUK-3' at its apex as well as a YU-UY mismatch in helix II. In addition, the structural motifs of both ITS secondary structures were identified. Phylogenetic analyses using ITS data were performed by means of Bayesian inference, maximum likelihood and neighbor joining methods. Trees had a consistent branching pattern that included the following features: (1) Rhabdostyla always clustered with members of the family Vorticellidae, instead of members of the family Epistylididae, in which it is now classified on the basis of morphology. (2) The systematically questionable genus Ophrydium closely associated with Carchesium, forming a clearly defined, monophyletic group within the Vorticellidae. This supported the hypothesis derived from previous study based on small subunit rRNA gene sequences
Mahasri, G.; Kusdarwati, R.; Kismiyati; Rozi; Gustrifandi, H.
The purpose of this research was to analys immunogenic membrane protein as immunostimulant development material to control the mortality of white shrimp in traditional plus pond. This research was designed to use explorative experiment and experimental laboratory methods which used completed random sampling design. Collected data was analyzed with analysis of variance for examination of survival rate (SR), total haemocyte count (THC) and differensial haemocyte Count (DHC). The research divided into 2 part of riset: (1) Identification, cultivation Zoothamnium penaei, analysed of membrane protein by SDS-PAGE, (2) Field test protein membran on Survival Rate level, immune response (THC and/or DHC level) and infestation of Zoothamnium penaei in traditional plus pond. The result showed that there were seven bands membrane protein of Zoothamnium penaei with molecular weight 38 kDa, 48 kDa, 67 kDa, 71 kDa, 77 kDa, 98 kDa dan 104 kDa by using SDS-PAGE. Immunogenicity tested decrease by using ELISA and western blotting there are only found three bands with molecular weight 38 kDa, 48 kDa dan 67 kDa. The membrane protein could increase the immun respons and decrease the mortality, by subsequenly, it could increase the survival rate from 17% until 68% and pressured the parasite infestation of white shrimp.
Su, Lei; Zhang, Qianqian; Gong, Jun
Peritrich ciliates are highly diverse and can be important bacterial grazers in aquatic ecosystems. Morphological identifications of peritrich species and assemblages in the environment are time-consuming and expertise-demanding. In this study, two peritrich-specific PCR primers were newly designed to amplify a fragment including the internal transcribed spacer (ITS) region of ribosomal rDNA from environmental samples. The primers showed high specificity in silico, and in tests with peritrich isolates and environmental DNA. Application of these primers in clone library construction and sequencing yielded exclusively sequences of peritrichs for water and sediment samples. We also found the ITS1, ITS2, ITS, D1 region of 28S rDNA, and ITS+D1 region co-varied with, and generally more variable than, the V9 region of 18S rDNA in peritrichs. The newly designed specific primers thus provide additional tools to study the molecular diversity, community composition, and phylogeography of these ecologically important protists in different systems.
CUPUL-MAGAÑA FABIO GERMÁN
Full Text Available Se registra por vez primera la presencia de cuatro géneros de diatomeas (Amphora, Cymbella, Navicula y Nitzschia, un alga azul-verde del género Trichodesmium y colonias de protozoarios ciliados del género Epistylis, como epibiontes de cocodrilos de río juveniles (Crocodylus acutus. Los epibiontes se encontraron en la región ventral del cuerpo de cocodrilos juveniles, menores de 75 cm de largo, capturados en el estero Boca Negra, Jalisco, México.
Ji, Daode; Kusuoka, Yasushi
This paper includes the proposal of a new genus for a new species of peritrichous ciliate, Apocarchesium rosettum n. gen., n. sp., as well as the first description by modern techniques of another peritrich, Ophrydium eichornii Ehrenberg, 1838. The genus Apocarchesium is separated from the related genus Carchesium by the appearance of the stalk and the arrangement of zooids, and diagnosed as follows: colonial vorticellid, with all zooids attached in rosette fashion to the tip of their common stalk, which is unbranched and contracts spirally; pellicle with parallel silverlines. The morphology, infraciliature, and silverline system of both species were investigated by observation in vivo and silver-staining methods.
Petkeviciute, Egle; Kania, Per Walter; Skovgaard, Alf
Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heat shock at two different salinities (10 and 32‰), and it was furthermore investigated whether experimentally induced epibiont infestation led to elevated expression of stress-related genes...
Dovgal, I.; Chatterjee, T.; Ingole, B.S.
. 2008. An overview of suctorian ciliates (Ciliophora, Suctorea) as epibionts of halacarid mites (Acari, Halacaridae). Zootaxa. 1810, 60-68. Fisher R. 2003. Ciliate hitch-hikers-nematode ecto-commensals from tropical Australian sea-grass meadows...
Full Text Available Effects of ocean acidification (OA on the colonization/settlement pattern of the epibiont community of the leaves and rhizomesof the Mediterranean seagrass,Posidoniaoceanica, have been studied at volcanic CO2vents off Ischia (Italy, using “mimics”as artificial substrates. The experiments were conducted in shallowPosidoniastands (2-3 m depth, in three stations on the northand three on the south sides of the study area, distributed along a pH gradient. At each station, 4 rhizome mimics and 6 artificialleaves were collected every three months (Sept 2009-Sept 2010. The epibionts on both leaf and rhizome mimics showed clearchanges along the pH gradient; coralline algae and calcareous invertebrates (bryozoans, serpulid polychaetes and barnacles weredominant at control stations but progressively disappeared at the most acidified stations. In these extremely low pH sites theassemblage was dominated by filamentous algae and non calcareous taxa such as hydroids and tunicates. Settlement pattern onthe artificial leaves and rhizome mimics over time showed a consistent distribution pattern along the pH gradient and highlightedthe peak of recruitment of the various organisms in different periods according to their life history.Posidoniamimics at theacidified station showed a poor and very simplified assemblage where calcifying epibionts seemed less competitive for space. Thisprofound difference in epiphyte communities in low pH conditions suggests cascading effects on the food web of the meadow and,consequently, on the functioning of the system
Full Text Available The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5, which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to
Guilini, Katja; Weber, Miriam; de Beer, Dirk; Schneider, Matthias; Molari, Massimiliano; Lott, Christian; Bodnar, Wanda; Mascart, Thibaud; De Troch, Marleen; Vanreusel, Ann
The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA) threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy) and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5), which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to assure that the
Kravchuk, O I; Lavrov, A I; Finoshin, A D; Gornostaev, N G; Georgiev, A A; Abaturova, S B; Mikhailov, V S; Lyupina, Yu V
It was found that cells of different color morphs of the cold-water marine sponges Halichondria panicea (Pallas, 1766) of the class Demospongiae differ in the content of epibionts of bacteria of the genus Pseudoalteromonas. The sponge cells with elevated levels of epibionts of bacteria of the genus Pseudoalteromonas showed an increased expression of Hsp70 proteins but had a reduced level of the proteasomal catalytic beta 5 subunit, which was accompanied by a change in their activity. Probably, epibionts of bacteria of the genus Pseudoalteromonas may affect the ubiquitin-proteasome system in the cells of cold-water marine sponges and, thereby, ensure their adaptive plasticity.
Durand, Lucile; Roumagnac, Marie; Cueff-Gauchard, Valérie; Jan, Cyrielle; Guri, Mathieu; Tessier, Claire; Haond, Marine; Crassous, Philippe; Zbinden, Magali; Arnaud-Haond, Sophie; Cambon-Bonavita, Marie-Anne
Rimicaris exoculata is a deep-sea hydrothermal vent shrimp whose enlarged gill chamber houses a complex trophic epibiotic community. Its gut harbours an autochthonous and distinct microbial community. This species dominates hydrothermal ecosystem megafauna along the Mid-Atlantic Ridge, regardless of contrasting geochemical conditions prevailing in them. Here, the resident gut epibiont community at four contrasted hydrothermal vent sites (Rainbow, TAG, Logatchev and Ashadze) was analysed and compiled with previous data to evaluate the possible influence of site location, using 16S rRNA surveys and microscopic observations (transmission electron microscopy, scanning electron microscopy and fluorescence in situ hybridization analyses). Filamentous epibionts inserted between the epithelial cell microvilli were observed on all examined samples. Results confirmed resident gut community affiliation to Deferribacteres, Mollicutes, Epsilonproteobacteria and to a lesser extent Gammaproteobacteria lineages. Still a single Deferribacteres phylotype was retrieved at all sites. Four Mollicutes-related operational taxonomic units were distinguished, one being only identified on Rainbow specimens. The topology of ribotype median-joining networks illustrated a community diversification possibly following demographic expansions, suggesting a more ancient evolutionary history and/or a larger effective population size at Rainbow. Finally, the gill chamber community distribution was also analysed through ribotype networks based on sequences from R. exoculata collected at the Rainbow, Snake Pit, TAG, Logatchev and Ashadze sites. Results allow the refining of hypotheses on the epibiont role and transmission pathways. © FEMS 2015. All rights reserved. For permissions, please e-mail: firstname.lastname@example.org.
Graham, Linda E; Knack, Jennifer J; Graham, Melissa E; Graham, James M; Zulkifly, Shahrizim
Periphyton dominated by the cellulose-rich filamentous green alga Cladophora forms conspicuous growths along rocky marine and freshwater shorelines worldwide, providing habitat for diverse epibionts. Bacterial epibionts have been inferred to display diverse functions of biogeochemical significance: N-fixation and other redox reactions, phosphorus accumulation, and organic degradation. Here, we report taxonomic diversity of eukaryotic and prokaryotic epibionts and diversity of genes associated with materials cycling in a Cladophora metagenome sampled from Lake Mendota, Dane Co., WI, USA, during the growing season of 2012. A total of 1,060 distinct 16S, 173 18S, and 351 28S rRNA operational taxonomic units, from which >220 genera or species of bacteria (~60), protists (~80), fungi (6), and microscopic metazoa (~80), were distinguished with the use of reference databases. We inferred the presence of several algal taxa generally associated with marine systems and detected Jaoa, a freshwater periphytic ulvophyte previously thought endemic to China. We identified six distinct nifH gene sequences marking nitrogen fixation, >25 bacterial and eukaryotic cellulases relevant to sedimentary C-cycling and technological applications, and genes encoding enzymes in aerobic and anaerobic pathways for vitamin B12 biosynthesis. These results emphasize the importance of Cladophora in providing habitat for microscopic metazoa, fungi, protists, and bacteria that are often inconspicuous, yet play important roles in ecosystem biogeochemistry. © 2015 Phycological Society of America.
Silvio Felipe Barbosa Lima
Full Text Available This paper describes the epibiosis of Ostrea cf. puelchana on Callinectes exasperatus (Gerstaecker, 1856, both collected from the estuary of the Paraíba River, in the state of Paraíba, northeastern Brazil. The basibiont crab was captured using a trap installed in mangrove area at a depth of about 2 meters. The oyster was closely attached to the left side of dorsal carapace covering most of the epibranchial, mesobranchial and metabranchial regions. Possible advantages and disadvantages for both the epibiont and the basibiont are discussed. We believe that young O. cf. puelchana may avoid a variety of potential predators due to the considerable movement capacity of C. exasperatus and may also serve as a small protective shield for the basibiont. However, the oyster, which is a bivalve with an epifaunal lifestyle, is likely to be negatively affected, mainly due to burrowing activity of the crab. This is the first record of epibiosis between bivalves of the genus Ostrea Linnaeus, 1758 and crabs of the genus Callinectes Stimpson, 1860.
Full Text Available Epibionts on the surface of the skin and shell of a specimen of Chelonia mydas and three Lepidochelys olivacea found floating on the coast of Concepción, Chile, between June 2010 and December 2012, were analyzed. These epibionts were analyzed during the clinical inspection and the tissue changes related to its settlement, with filamentous algae around, were observed. Subsequently, the epibionts were identified by morphological observation. The knowledge about theses epibionts in Chile is reviewed and the potential occurrence of Debilitated Turtle Syndrome (DTS in these turtles is discussed. The presence of sea turtles in the Chilean coast is considered a casual event, so there is little information on this issue. We propose it is necessary to carry out more studies on the association between turtles and epibionts because their identification, colonizing reptiles’ surface may give relevant information to a better understanding of different diseases, including DTS, that affect these marine reptiles and facilitates the development of strategies intended to recover their populations.
Sprechmann, P.; Verde, M.; Martinez, S.; Gaucher, C.
A special lithofacies of the Camacho formation (Middle-Upper Miocene, Uruguay), exposed at Puerto Arazati, is studied from a sedimentologic and paleontologic point of view. Ostreid biostromes and patch reefs show different kinds of growings patterns. Two kinds of ostreid concentration s, biogenic and sedimentologic were distinguished in Puerto Arazati based on taphonomic evidence. Endolith association and epibionts from biostrome and patch reef hardgrounds were also analysed in Puerto Arazati. Both sedimentologic and paleontologic evidence indicates a free of sediment, shallow water depositional environment, in the photic zone. Complementary data about endoliths from other outcrops of the Camacho Formation are included (author)
Full Text Available In the present study we record several instances of reef fish species foraging on epibionts of sea turtles (cleaning symbiosis at the oceanic islands of Fernando de Noronha Archipelago and near a shipwreck, both off the coast of Pernambuco State, northeast Brazil. Nine reef fish species and three turtle species involved in cleaning are herein recorded. Besides our records, a summary of the literature on this association type is presented. Postures adopted by turtles during the interaction are related to the habits of associated fishes. Feeding associations between fishes and turtles seem a localized, albeit common, phenomenon.
Full Text Available Seaweeds are key species of the Baltic Sea benthic ecosystems. They are the substratum of numerous fouling epibionts like bryozoans and tubeworms. Several of these epibionts bear calcified structures and could be impacted by the high pCO2 events of the late summer upwellings in the Baltic nearshores. Those events are expected to increase in strength and duration with global change and ocean acidification. If calcifying epibionts are impacted by transient acidification as driven by upwelling events, their increasing prevalence could cause a shift of the fouling communities toward fleshy species. The aim of the present study was to test the sensitivity of selected seaweed macrofoulers to transient elevation of pCO2 in their natural microenvironment, i.e. the boundary layer covering the thallus surface of brown seaweeds. Fragments of the macroalga Fucus serratus bearing an epibiotic community composed of the calcifiers Spirorbis spirorbis (Annelida and Electra pilosa (Bryozoa and the non-calcifier Alcyonidium hirsutum (Bryozoa were maintained for 30 days under three pCO2 conditions: natural 460 ± 59 µatm, present-day upwelling1193 ± 166 µatm and future upwelling 3150 ± 446 µatm. Only the highest pCO2 caused a significant reduction of growth rates and settlement of S. spirorbis individuals. Additionally, S. spirorbis settled juveniles exhibited enhanced calcification of 40% during daylight hours compared to dark hours, possibly reflecting a day-night alternation of an acidification-modulating effect by algal photosynthesis as opposed to an acidification-enhancing effect of algal respiration. E. pilosa colonies showed significantly increased growth rates at intermediate pCO2 (1193 µatm but no response to higher pCO2. No effect of acidification on A. hirsutum colonies growth rates was observed. The results suggest a remarkable resistance of the algal macro-epibionts to levels of acidification occurring at present day upwellings in the Baltic
Full Text Available In the present study we record several instances of reef fish species foraging on epibionts of sea turtles (cleaning symbiosis at the oceanic islands of Fernando de Noronha Archipelago and near a shipwreck, both off the coast of Pernambuco State, northeast Brazil. Nine reef fish species and three turtle species involved in cleaning are herein recorded. Besides our records, a summary of the literature on this association type is presented. Postures adopted by turtles during the interaction are related to the habits of associated fishes. Feeding associations between fishes and turtles seem a localized, albeit common, phenomenon.No presente estudo registramos diversos episódios de peixes recifais alimentando-se de epibiontes sobre o corpo de tartarugas marinhas (simbiose de limpeza nas ilhas oceânicas do arquipélago de Fernando de Noronha e próximo a um naufrágio na costa de Pernambuco, nordeste do Brasil. Nove espécies de peixes recifais e três espécies de tartarugas envolvidas nas associações são aqui registradas. Além de nossos registros, apresentamos também um resumo da literatura sobre o tema. As posturas adotadas pelas tartarugas durante as interações estão relacionadas com os hábitos dos peixes associados. Associações alimentares entre peixes e tartarugas podem ser consideradas como um fenômeno local, embora comum.
Full Text Available La laguna de La Mancha está conectada al Golfo de México a través de una boca estuarina efímera, una barra arenosa, la cual se abre durante la época de lluvias y se cierra durante el otoño y la temporada de vientos invernales. Cuando la laguna se llena con la entrada de agua proveniente de un arroyo permanente, ubicado en la parte sur, el nivel del agua se incrementa y la barra arenosa se abre, descargando grandes volúmenes de agua hacia el océano y dejando expuesta a la desecación la zona intermareal previamente inundada. En este estudio, se describen las variaciones espacio-temporales de la estructura y composición de la comunidad de epibiontes que vive en la superficie de las raíces del mangle rojo,y su relación con la dinámica hidrológica de la boca estuarina. Se recolectaron cuatro raíces trimestralmente, durante un año, en diez estaciones de muestreo. También se midió la temperatura del agua, salinidad, oxígeno disuelto, profundidad y transparencia en cada muestreo. Se determinó la abundancia, la biomasa y la riqueza específica, a lo largo de las raíces en segmentos verticales de 10cm llamados horizontes. Se registraron un total de 59 632 especímenes y una biomasa total de 172g/cm2, y un máximo de once horizontes presentaron al menos una especie de epibionte. Se identificaron dos especies de poliquetos, 12 de moluscos y 14 de crustáceos, siendo Mytilopsis leucophaeata la más abundante, Ficopomatus miamiensis la más común y Crassostrea rhizophorae la de mayor contribución a la biomasa. Se evaluó la eficiencia del muestreo mediante curvas de acumulación de especies, resultando que la eficiencia fue, en general, >90% de la riqueza estimada por modelos asintóticos. La hidrodinámica de la boca estuarina tuvo gran influencia en las condiciones ambientales de la laguna y en las variaciones espacio-temporales de la comunidad de epibiontes: (a cuando la boca estuarina está cerrada son más claros los gradientes
Density, size structure, shell orientation and epibiontic colonization of the fan mussel Pinna nobilis L. 1758 (Mollusca: Bivalvia in three contrasting habitats in an estuarine area of Sardinia (W Mediterranean
Full Text Available We investigated the spatial distribution, size structure, shell orientation and valve colonization by epibionts of the endangered Mediterranean bivalve Pinna nobilis in three continuous but different habitats in the Gulf of Oristano (Sardinia, western Mediterranean. The sampling stations chosen were: an estuarine area (E of coastal salt-marshes characterized by unvegetated sea-bottoms; and two areas in a seagrass meadow characterized by an extensive Posidonia oceanica meadow (Mw and patched mixed meadows of P. oceanica and Cymodocea nodosa (Me. We found significant differences in mean densities among stations and the highest value was found in the estuarine area. Shell orientation showed that there was uniform circular distribution of specimens in the Mw station and a unimodal distribution in the Me and E stations, where specimens were set at 0°N and 10°NNE, which is a pattern related to sea drift. Shell epibiosis displayed differences between habitats. The highest valve colonization was in the estuary, with filamentous dark algae and Ostrea edulis reaching almost 90 percent of shell coverage. This study provides new information on habitat preferences and data for assessing local populations of P. nobilis that is useful for its conservation and improving the knowledge of its ecology.
Jagadeesan, L; Jyothibabu, R
Globally, tumour-like anomalies (TLA) in copepods and the critical assessment of their possible causes are rare. The exact causative factor and ecological consequences of TLA in copepods are still unclear and there is no quantitative data available so far to prove conclusively the mechanism involved in developing TLA in copepods. TLA in copepods are considered as a potential threat to the well-being of the aquatic food web, which prompted us to assess these abnormalities in Indian marine waters and assess the possible etiological agents. We carried out a focused study on copepods collected from 10 estuarine inlets and five coastal waters of India using a FlowCAM, advanced microscopes and laboratory-incubated observations. The analysis confirmed the presence of TLA in copepods with varying percentage of incidence in different environments. TLA was recorded in 24 species of copepods, which constituted ~1-15 % of the community in different environments. TLA was encountered more frequently in dominant copepods and exhibited diverse morphology; ~60 % was round, dark and granular, whereas ~20 % was round/oval, transparent and non-granular. TLA was mostly found in the dorsal and lateral regions of the prosome of copepods. The three suggested reasons/assumptions about the causes of TLA such as ecto-parasitism (Ellobiopsis infection), endo-parasitism (Blastodinium infection) and epibiont infections (Zoothamnium and Acineta) were assessed in the present study. We did find infections of endo-parasite Blastodinium, ecto-parasite Ellobiopsis and epibiont Zoothamnium and Acineta in copepods, but these infectious percentages were found <1.5 % to the total density and most of them are species specific. Detailed microscopical observations of the samples collected and the results of the incubation experiments of infected copepods revealed that ecto-parasitism, endo-parasitism and epibiont infections have less relevance to the formation of TLA in copepods. On the other hand
Full Text Available The Pacific oyster, Crassostrea gigas (Thunberg, is the main bivalve species cultivated in the world. With global warming enabling its reproduction and larval survival at higher latitudes, this species is now recognized as invasive and creates wild oyster reefs globally. In this study, the spatial distribution of photosynthetic assemblages colonizing the shells of wild C. gigas was investigated on both a large scale (two contrasting types of reefs found in mudflats and rocky areas and a small scale (within individual shells using a hyperspectral imager. The microspatial distribution of all phototrophs was obtained by mapping the Normalized Difference Vegetation Index (NDVI. Second derivative (δδ analyses of hyperspectral images at 462, 524, 571 and 647 nm were subsequently applied to map diatoms, cyanobacteria, rhodophytes and chlorophytes, respectively. A concomitant pigment analysis was carried out by high performance liquid chromatography and completed by taxonomic observations. This study showed that there was high microalgal diversity associated with wild oyster shells and that there were differences in the structure of the phototropic assemblages depending on the type of reef. Namely, vertically-growing oysters in mudflat areas had a higher biomass of epizoic diatoms (hyperspectral proxy at δδ462 nm and were mainly colonized by species of the genera Navicula, Nitzschia and Hippodonta, which are epipelic or motile epipsammic. The assemblages on the horizontal oysters contained more tychoplanktonic diatoms (e.g. Thalassiosira pseudonana, T. proschkinae and Plagiogrammopsis vanheurckii. Three species of boring cyanobacteria were observed for both types of reef: Mastigocoleus testarum, Leptolyngbya terrebrans, and Hyella caespistosa, but the second derivative analysis at 524 nm showed a significantly higher biomass for the horizontally-growing oysters. There was no biomass difference for the boring chlorophyte assemblages (δδ647 nm, with two species: Eugomontia testarum and Ostreobium quekettii observed for both types of reef. This study shows that oyster shells are an idiosyncratic but ubiquitous habitat for phototrophic assemblages. The contribution of these assemblages in terms of biomass and production to the functioning of coastal areas, and particularly to shellfish ecosystems, remains to be evaluated.
Galle, Arnošt; Plusquellec, Y.
Roč. 7, - (2002), s. 53-64+2 pl. ISSN 0945-7275 R&D Projects: GA AV ČR IAA3013807; GA ČR GA205/98/1347 Institutional research plan: CEZ:AV0Z3013912 Keywords : Hyostragulidae fam. nov. Subject RIV: DB - Geology ; Mineralogy
Chatterjee, T.; Fernandez-Leborans, G.; Ramteke, D.; Ingole, B.S.
patzcuarensis Villalobos, 1943, lake Pátzcuaro (Michoacán, Mexico) (Mayen-Estrada & Aladro-Lubel, 1998). On Liocarcinus depurator (Linnaeus, 1758), L. vernalis (Risso, 1827), Goneplax rhomboids( Linnaeus, 1758), Dardanus arrosor (Herbst, 1796), Paguristes... oculatus (Fabricius, 1775), Pagurus excavates (Herbst, 1791), and Pagurus prideaux Leach, 1815 from N.W. Mediterranean Sea (Fernandez-Leborans, 2003). Acknowledgement Thanks are due to Dr Marleen De Troch, Marine Biology Section, University of Ghent...
Dovgal, I.; Chatterjee, T.; Ingole, B.S.
Subclass Exogenia Collin Order Metacinetida Jankowski Family Paracinetidae Jankowski Limnoricus ceter Jankowski, 1981 (Fig. 1–3) Diagnosis: Marine commensal, loricate, suctorian ciliate with stalk delimited from posterior margin of lorica. Both lorica...–11) =Thecacineta halacari Schulz, 1933 DOVGAL ET AL.62 · Zootaxa 1810 © 2008 Magnolia Press =Lissacineta allgeni Jankowski, 1981, syn. n. =Thecacineta allgeni (Jankowski, 1981), syn. n. Diagnosis: Marine suctorians with stylotheca. Cell body, slightly...
Robin, N.; Bakel, van B.W.M.; Hondt, d' J.-L.; Charbonnier, S.
The earliest known crabs are of Early and Middle Jurassic age; in general, they are rare. Here we describe a new species of homolodromioid from the late Bathonian of Sarthe (France), based on a single dorsal carapace, Tanidromites raboeufi n. sp. This specimen has mostly well-preserved cuticle, and
Ingole, B.S.; Singh, R.; Sautya, S.; Dovgal, I.; Chatterjee, T.
samples taken from the upper slope of the Northern Seamount located off Nicobar Island, 9859 0 31.52 00 N93857 0 15.48 00 E, from a water depth of 1301 m. Upon collection, the sponges were carefully separated from the sediment and immediately preserved... with absolute alcohol. In the laboratory, the sponge samples were washed carefully and the entire faunal community associated with sponge spicules were sorted out carefully and identified to the lowest possible taxa. All the nematodes were separated and fixed...
The bromotyrosine derivative ianthelline was isolated recently from the Atlantic boreo-arctic deep-sea sponge Stryphnus fortis, and shown to have clear antitumor and antifouling effects. However, chemosystematics, field observations, and targeted metabolic analyses (using UPLC-MS) suggest that ianthelline is not produced by S. fortis but by Hexadella dedritifera, a sponge that commonly grows on S. fortis. This case highlights the importance of combining taxonomic and ecological knowledge to the field of sponge natural products research.
Dovgal, I.; Chatterjee, T.; Ingole, B.S.; Nanajkar, M.
of individuals from type copepoda host: body length (individuals from Kinorhyncha) 14-24 µm (47-49 µm under colonization of the type copepod host); width in the middle of body 12-17 µm (22-30 µm); macronucleus diameter 6-8 µm (13-16 µm); length of the lorica 44...
Santhakumari, V.; Nair, N.B.
Seven ectocommensalic ciliates, namely, Vorticella companula, Zoothamnium rigidum, Cothurnia gammari, Legenophrys cochinensis sp. nov., Epistylis gammari, Folliculina producta and Foliculina boltoni, all first-time recorded from the wood...
Arellano, Shawn M.; Lee, Onon; Lafi, Feras Fawzi; Yang, Jiangke; Wang, Yong; Young, Craig; Qian, Peiyuan
The encrusting sponge Myxilla (Ectyomyxilla) methanophila (Poecilosclerida: Myxillidae) is an epibiont on vestimentiferan tubeworms at hydrocarbon seeps on the upper Louisiana slope of the Gulf of Mexico. It has long been suggested that this sponge
Fosca P. P. Leite
Full Text Available ABSTRACT Sponges are biogenic substrates that increase the available space on rocky shores and provide shelter for many groups of the benthic fauna, which can live both inside and on these sessile invertebrates. In order to assess the differences in temporal variation of endobiont and epibiont groups, samples of the red sponge Tedania ignis (Duchassaing & Michelotti, 1864 were obtained each month for one year. The density, richness and diversity of endobiont and epibiont groups were analyzed in relation to abiotic factors. The dry mass of the sponge was negatively correlated with the density of individuals in both groups and positively with the diversity of endobionts, while organic matter was positively correlated with the diversity of epibionts. Endobiont diversity was more highly correlated with intrinsic factors of the sponge, whereas the diversity of epibionts was more highly correlated with factors related to the surrounding environment.
Full Text Available Several microorganisms – epibionts – can adhere to living supports taking advantage for their survival, feeding and movement. Epibiosis occurs particularly in aquatic environments, on both benthic and planktonic organisms, among which copepods and cladocerans represent an important living support. The harpacticoid copepod Tigriopus fulvus, living in the splashpools of rocky coasts, was studied to recognize the occurrence of epibionts on the exoskeleton surface using scanning electon microscopy techniques. The first evidence of ciliate Scyphidia sp. on Tigriopus fulvus has been described and the occurrence of algae Cocconeis sp. has been observed as well. Epibionts were found to adhere to antennae, a site linked to the exploitation of water currents carrying food particles to mouthparts and to swimming legs. The reason of the occurrence on swimming legs is less clear and needs further observations. Pertinent results are described and discussed and the influence of epibionts on life cycle and behavior of Tigriopus fulvus is considered.
Full Text Available Colacium vesiculosum (Euglenophyceae is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton Colacium vesiculosum Ehrenberg (Euglenophyceae es un epibionte común en microcrustáceos del plancton de aguas continentales. La interacción epibiontes y organismo substrato es poco conocida, particularmente en ambientes subtropicales de América del Sur. Se analiza la prevalencia, densidad, biomasa y sitios de adhesión de C. vesiculosum en microcrustáceos planctónicos de un lago subtropical de Argentina. Con el fin de evaluar si los epibiontes afectan la tasa de filtración de Notodiaptomus spiniger Brian, crustáceo dominante del zooplancton, se realizaron bioensayos utilizando el fitoplancton <53µm. Los crustáceos fueron muestreados con un tubo de PVC (1m de largo, 10cm de diámetro filtrándose 50L de agua a través de una red de 53µm de abertura de malla. El recuento de los microcrustáceos se realizó en cámaras de Bogorov bajo microscopio estereoscópico. Los organismos infectados fueron separados y observados al microscopio fotónico para determinaciones de densidad y biovolumen de los epibiontes, y su distribución en el exoesqueleto. La prevalencia de C. vesiculosum fue mayor en crustáceos adultos que en estadíos larvales y juveniles. El grupo más infestado fue el de los copépodos calanoideos en relación con su alta densidad. Los sitios de adhesión sobre el exoesqueleto fueron las regiones del cuerpo que durante la
Kandhai, M.C.; Reij, M.W.; Puyvelde, van K.; Guillaume-Gentil, O.; Beumer, R.R.; Schothorst, van M.
Enterobacter sakazakii is a motile, peritrichous, gram-negative rod that was previously known as a yellow pigmented Enterobacter cloacae. It is documented as a rare cause of outbreaks and sporadic cases of life-threatening neonatal meningitis, necrotizing enterocolitis, and sepsis. E. sakazakii has
Sep 7, 1988 ... During parasitological surveys in Gazankulu, an infection of a trichodinid peritrich was found in the urinary bladder and ureters of the three-spot barb, Barbus trimaculatus Peters, 1852, collected from Hudson-. Ntsanwisi Dam in the Olifants River system. A taxonomic description of this new species, ...
Full Text Available Colacium vesiculosum (Euglenophyceae is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton <53µm. Crustaceans were sampled using a PVC tube (1.2m long and 10cm in diameter, filtering 50L of water through a 53µm-mesh. Microcrustaceans were counted in Bogorov chambers under a stereoscopic microscope. The infested organisms were separated and observed with a photonic microscope to determine density and biovolume of epibionts, by analyzing their distribution on the exoskeleton. The prevalence of C. vesiculosum was higher in adult crustaceans than in their larvae and juveniles. The most infested group was that of calanoid copepods, related to their high density. The attachment sites on the exoskeleton were found to be the portions of the body which have a higher probability of encounter with epibionts during locomotion and feeding, i.e., antennae and thoracic legs in copepods, and thoracic legs and postabdomen in cladocerans. The similar values found in the filtering rate of infested and uninfested individuals of N. spiniger and the constant prevalence (<40% of epibiont algae, suggest that C. vesiculosum does not condition the life of planktonic crustaceans of Paiva Lake. Rev. Biol. Trop. 59 (3: 1295-1306. Epub 2011 September 01.
Neves, Ricardo C.; Cunha, Maria R.; Funch, Peter
The metazoan phylum Cycliophora includes small cryptic epibionts that live attached to the mouthparts of clawed lobsters. The life cycle is complex, with alternating sexual and asexual generations, and involves several sessile and free-living stages. So far, the morphological and genetic characte......The metazoan phylum Cycliophora includes small cryptic epibionts that live attached to the mouthparts of clawed lobsters. The life cycle is complex, with alternating sexual and asexual generations, and involves several sessile and free-living stages. So far, the morphological and genetic...
Bentall, Gena B.; Rosen, Barry H.; Kunz, Jessica M.; Miller, Melissa A.; Saunders, Gary W.; LaRoche, Nicole L.
Ecological associations between epibionts (organisms that live on the surface of another living organism) and vertebrates have been documented in both marine and terrestrial environments, and may be opportunistic, commensal, or symbiotic (Lewin et al. 1981, Holmes 1985, Allen et al. 1993, Bledsoe et al. 2006, Pfaller et al. 2008, Suutari et al. 2010). Although epibiont proliferation is frequently reported on slow-moving, sparsely haired organisms such as manatees and sloths, reports from densely furred, highly mobile mammals are much less common. There are reports of epizoic algae for several species of pinnipeds (Kenyon and Rice 1959, Scheffer 1962, Baldridge 1977, Allen et al. 1993), which rely to varying degrees on both pelage and blubber for thermoregulation, but the phenomenon has not been widely described. Scheffer (1962) noted that red algae was fairly common on the pelage of northern fur seals (Callorhinus ursinus), pinnipeds for which fur likely makes a comparatively high contribution to thermoregulation (Donohue et al. 2000). For species with pelage that plays a critical role of thermal insulation, it seems implausible that an epibiont would persist on healthy individuals that devote significant energy resources toward grooming and actively maintaining their coat. Biological characteristics of epibiont settlement and attachment, and physiological requirements of epizoic species play key roles in their successful colonization and potential host impacts. To investigate this relationship, we explore a novel discovery of an epizoic alga from southern sea otters, including describing algal development on sea otter hair and molecular identification of the algae.
Udoh James Philip
Full Text Available The distribution and occurrence of epibionts on the dorsal carapace, ventral carapace and chela of 325 specimens of Callinectes amnicola (De Rocheburne, 1883 (103.4 - 138.7 mm carapace width from the Qua Iboe (QIRE and Imo River (IRE estuaries in southeast Nigeria was determined. The only ectosymbiont observed was cirriped barnacle, Chelonibia patula, mostly of smaller sizes (2.25 mm, infesting only 25-29% of intermoult crabs, more on females and in the Imo River estuary, with an average of four barnacles per crab, presupposing low level of epibiont-host interaction. There was no significant difference (P>0.05 in spatial distribution but epibionts were highest in the dry season in low salinity IRE (0.53‰ and in wet season in the medium-salinity QIRE (17.4‰. No public health risk has been reported among crab consumers in the study area. This study highlights epibiont-host interaction in the study area largely unknown for proper management of the fishery.
Hunting, E.R.; van Soest, R.W.M.; van der Geest, H.G.; Vos, A.; Debrot, A.O.
Sponges are major epibionts of mangrove roots in the Caribbean. Mangrove sponge communities in the Caribbean mainly consist of species that are typical to this habitat and community compositions often differ from those found on coral reefs nearby. Heterogeneity in species distributions between
Utz, Laura R P; Farias, Ana Carolina Silva Rodrigues; Freitas, Eduarda Correa; de Araújo, Gabriella Oliveira
Epistylis riograndensis n. sp., a freshwater peritrich hosting symbiotic algae in its cytoplasm, was collected from an artificial lake, in a Botanical garden in Southern Brazil. Its detailed morphology was investigated using live and silver-stained specimens. The colonial sessile E. riograndensis has elongate zooids measuring, on average, 162 μm in length and 45 μm in width. A single contractile vacuole located near the infundibulum and a C-shaped macronucleus located transversely in the adoral half of the cell were also observed. The oral infraciliature revealed in silver-stained specimens was typical of peritrich ciliates. Three infundibular polykineties consisting of 3 rows of kinetosomes were observed. Molecular analyses of 18s rDNA placed E. riograndensis among other Epistylis species in the Order Vorticellida.
Mary R. Gradoville
Full Text Available Filamentous diazotrophic Cyanobacteria of the genus Trichodesmium, often found in colonial form, provide an important source of new nitrogen to tropical and subtropical marine ecosystems. Colonies are composed of several clades of Trichodesmium in association with a diverse community of bacterial and eukaryotic epibionts. We used high-throughput 16S rRNA and nifH gene sequencing, carbon (C and dinitrogen (N2 fixation assays, and metagenomics to describe the diversity and functional potential of the microbiome associated with Trichodesmium colonies collected from the North Pacific Subtropical Gyre (NPSG. The 16S rRNA and nifH gene sequences from hand-picked colonies were predominantly (>99% from Trichodesmium Clade I (i.e., T. thiebautii, which is phylogenetically and ecologically distinct from the Clade III IMS101 isolate used in most laboratory studies. The bacterial epibiont communities were dominated by Bacteroidetes, Alphaproteobacteria, and Gammaproteobacteria, including several taxa with a known preference for surface attachment, and were relatively depleted in the unicellular Cyanobacteria and small photoheterotrophic bacteria that dominate NPSG surface waters. Sequencing the nifH gene (encoding a subcomponent of the nitrogenase enzyme identified non-Trichodesmium diazotrophs that clustered predominantly among the Cluster III nifH sequence-types that includes putative anaerobic diazotrophs. Trichodesmium colonies may represent an important habitat for these Cluster III diazotrophs, which were relatively rare in the surrounding seawater. Sequence analyses of nifH gene transcripts revealed several cyanobacterial groups, including heterocystous Richelia, associated with the colonies. Both the 16S rRNA and nifH datasets indicated strong differences between Trichodesmium epibionts and picoplankton in the surrounding seawater, and also between the epibionts inhabiting Trichodesmium puff and tuft colony morphologies. Metagenomic and 16S r
Rimondino, Clara; Torre, Luciana; Sahade, Ricardo Jose; Tatian, Marcos
The muddy bottoms of inner Potter Cove, King George Island (Isla 25 de Mayo), South Shetlands, Antarctica, show a high density and richness of macrobenthic species, particularly ascidians. In other areas, ascidians have been reported to play the role of ecosystem engineers, as they support a significant number of epibionts, increasing benthic diversity. In this study, a total of 21 sessile macro-epibiotic taxa present on the ascidian species Corella antarctica Sluiter, 1905, Cnemidocarpa verr...
Erler, Dirk V.; Welsh, David T.; Bennet, William W.; Meziane, Tarik; Hubas, Cédric; Nizzoli, Daniele; Ferguson, Angus J. P.
In this study we quantified nitrate (NO3-) reduction (denitrification, anammox and DNRA) and N2O production in sediments and epibiont communities associated with Sydney Rock Oyster (Saccostrea glomerata) farming. In sediments beneath an active suspended oyster farm, DNRA accounted for 98% of NO3- reduction with rates of up to 169 ± 45 μmol N m-2 h-1. Much of this DNRA was fuelled by NO3- derived from nitrification. Reference sediments had significantly lower DNRA rates of 83.8 ± 28.2 μmol N m-2 h-1, however this constituted 96% of the sites total NO3- reduction. Fatty acid analysis showed that sediment organic matter was more labile in the oyster impacted sediments, facilitating subtle shifts in sediment oxygen demand which increased the Fe2+ availability with respect to the reference sediments. The difference in DNRA rate between the sites was attributed to autotrophic oxidation of soluble Fe2+ in sediments underlying the oyster cultures. DNRA was absent in the oyster shell epibiont communities and rates of anammox and denitrification were lower than in the sediments. Production of NH4+ from the oysters and their associated epibionts was larger than DNRA and reached a rate of 206.2 μmol N m-2 h-1. Nitrous oxide production rates were generally low compared to other aquaculture systems and the net flux of N2O for the combined oyster cultivation system (i.e. sediments plus epibionts) was negative, i.e. there was N2O consumption in the sediments beneath the oysters. Overall, subtropical suspended oyster farming systems favour inorganic N retention over N loss.
Hunting, E.R.; van Soest, R.W.M.; van der Geest, H.G.; Vos, A.; Debrot, A.O.
Sponges are major epibionts of mangrove roots in the Caribbean. Mangrove sponge communities in the Caribbean mainly consist of species that are typical to this habitat and community compositions often differ from those found on coral reefs nearby. Heterogeneity in species distributions between locations and within locations between roots is often reported. This study quantifi es the diversity and abundance of mangrove associated sponges in the inner bays of Curaçao and Aruba and correlates va...
Robinson, Nathan J.; Majewska, Roksana; Lazo-Wasem, Eric A.; Nel, Ronel; Paladino, Frank V.; Rojas, Lourdes; Zardus, John D.; Pinou, Theodora
The macro-epibiotic communities of sea turtles have been subject to growing interest in recent years, yet their micro-epibiotic counterparts are almost entirely unknown. Here, we provide the first evidence that diatoms are epibionts for all seven extant species of sea turtle. Using Scanning Electron Microscopy, we inspected superficial carapace or skin samples from a single representative of each turtle species. We distinguished 18 diatom taxa from these seven individuals, with each sea turtl...
Andrew R Thurber
Full Text Available Vent and seep animals harness chemosynthetic energy to thrive far from the sun's energy. While symbiont-derived energy fuels many taxa, vent crustaceans have remained an enigma; these shrimps, crabs, and barnacles possess a phylogenetically distinct group of chemosynthetic bacterial epibionts, yet the role of these bacteria has remained unclear. We test whether a new species of Yeti crab, which we describe as Kiwa puravida n. sp, farms the epibiotic bacteria that it grows on its chelipeds (claws, chelipeds that the crab waves in fluid escaping from a deep-sea methane seep. Lipid and isotope analyses provide evidence that epibiotic bacteria are the crab's main food source and K. puravida n. sp. has highly-modified setae (hairs on its 3(rd maxilliped (a mouth appendage which it uses to harvest these bacteria. The ε- and γ- proteobacteria that this methane-seep species farms are closely related to hydrothermal-vent decapod epibionts. We hypothesize that this species waves its arm in reducing fluid to increase the productivity of its epibionts by removing boundary layers which may otherwise limit carbon fixation. The discovery of this new species, only the second within a family described in 2005, stresses how much remains undiscovered on our continental margins.
Thurber, Andrew R; Jones, William J; Schnabel, Kareen
Vent and seep animals harness chemosynthetic energy to thrive far from the sun's energy. While symbiont-derived energy fuels many taxa, vent crustaceans have remained an enigma; these shrimps, crabs, and barnacles possess a phylogenetically distinct group of chemosynthetic bacterial epibionts, yet the role of these bacteria has remained unclear. We test whether a new species of Yeti crab, which we describe as Kiwa puravida n. sp, farms the epibiotic bacteria that it grows on its chelipeds (claws), chelipeds that the crab waves in fluid escaping from a deep-sea methane seep. Lipid and isotope analyses provide evidence that epibiotic bacteria are the crab's main food source and K. puravida n. sp. has highly-modified setae (hairs) on its 3(rd) maxilliped (a mouth appendage) which it uses to harvest these bacteria. The ε- and γ- proteobacteria that this methane-seep species farms are closely related to hydrothermal-vent decapod epibionts. We hypothesize that this species waves its arm in reducing fluid to increase the productivity of its epibionts by removing boundary layers which may otherwise limit carbon fixation. The discovery of this new species, only the second within a family described in 2005, stresses how much remains undiscovered on our continental margins.
Full Text Available The muddy bottoms of inner Potter Cove, King George Island (Isla 25 de Mayo, South Shetlands, Antarctica, show a high density and richness of macrobenthic species, particularly ascidians. In other areas, ascidians have been reported to play the role of ecosystem engineers, as they support a significant number of epibionts, increasing benthic diversity. In this study, a total of 21 sessile macro-epibiotic taxa present on the ascidian species Corella antarctica Sluiter, 1905, Cnemidocarpa verrucosa (Lesson, 1830 and Molgula pedunculata Herdman, 1881 were identified, with Bryozoa being the most diverse. There were differences between the three ascidian species in terms of richness, percent cover and diversity of sessile macro-epibionts. The morphological characteristics of the tunic surface, the available area for colonization (and its relation with the age of the basibiont individuals and the pH of the ascidian tunic seem to explain the observed differences. Recent environmental changes in the study area (increase of suspended particulate matter caused by glaciers retreat have been related to observed shifts in the benthic community structure, negatively affecting the abundance and distribution of the studied ascidian species. Considering the diversity of sessile macro-epibionts found on these species, the impact of environmental shifts may be greater than that estimated so far.
Simon Le Bloa
Full Text Available Rimicaris exoculata is a caridean shrimp that dominates the fauna at several hydrothermal vent sites of the Mid-Atlantic Ridge. It has two distinct and stable microbial communities. One of these epibiontic bacterial communities is located in the shrimp gut and has a distribution and role that are poorly understood. The second colonizes its enlarged gill chamber and is involved in host nutrition. It is eliminated after each molt, and has colonization processes reminiscent of those of a biofilm. The presence and expression of genes usually involved in quorum sensing (QS were then studied. At four sites, Rainbow, TAG, Snake Pit and Logatchev, two lux genes were identified in the R. exoculata epibiontic community at different shrimp molt stages and life stages. RT-PCR experiments highlighted lux gene expression activity at TAG, Snake Pit and Rainbow vent sites. Their potential QS activity and their possible roles in epibiont colonization processes are discussed. Moreover, phylogenetic analysis has shown the presence of three clades for luxS (Epsilonproteobacteria and four clades for luxR (Gammaproteobacteria genes, each clade being restricted to a single site. These genes are more divergent than the 16S rRNA one. They could therefore be used as biogeographical genetic markers.
Leonard, Kaeden; Hewitt, Chad L; Campbell, Marnie L; Primo, Carmen; Miller, Steven D
Reduced competition is a frequent explanation for the success of many introduced species. In benthic marine biofouling communities, space limitation leads to high rates of overgrowth competition. Some species can utilise other living organisms as substrate (epibiosis), proffering a competitive advantage for the epibiont. Additionally, some species can prevent or reduce epibiotic settlement on their surfaces and avoid being basibionts. To test whether epibiotic pressure differs between native and introduced species, we undertook ex situ experiments comparing bryozoan larval settlement to determine if introduced species demonstrate a greater propensity to settle as epibionts, and a reduced propensity to be basibionts, than native species. Here we report that introduced species opportunistically settle on any space (bare, native, or introduced), whereas native species exhibit a strong tendency to settle on and near other natives, but avoid settling on or near introduced basibionts. In addition, larvae of native species experience greater larval wastage (mortality) than introduced species, both in the presence and absence of living substrates. Introduced species' ability to settle on natives as epibionts, and in turn avoid epibiosis as basibionts, combined with significantly enhanced native larval wastage, provides a comprehensive suite of competitive advantages contributing to the invasion success of these biofouling species.
Mia M. Bengtsson
Full Text Available Eelgrass (Zostera marina is a marine foundation species essential for coastal ecosystem services around the northern hemisphere. Like all macroscopic organisms, it possesses a microbiome (here defined as an associated prokaryotic community which may play critical roles in modulating the interaction of eelgrass with its environment. For example, its leaf surface microbiome could inhibit or attract eukaryotic epibionts which may overgrow the eelgrass leading to reduced primary productivity and subsequent eelgrass meadow decline. We used amplicon sequencing of the 16S and 18S rRNA genes of prokaryotes and eukaryotes to assess the leaf surface microbiome (prokaryotes as well as eukaryotic epibionts in- and outside lagoons on the German Baltic Sea coast. Prokaryote microbiomes varied substantially both between sites inside lagoons and between open coastal and lagoon sites. Water depth, leaf area and biofilm chlorophyll a concentration explained a large amount of variation in both prokaryotic and eukaryotic community composition. The prokaryotic microbiome and eukaryotic epibiont communities were highly correlated, and network analysis revealed disproportionate co-occurrence between a limited number of eukaryotic taxa and several bacterial taxa. This suggests that eelgrass leaf surfaces are home to a mosaic of microbiomes of several epibiotic eukaryotes, in addition to the microbiome of the eelgrass itself. Our findings thereby underline that eukaryotic diversity should be taken into account in order to explain prokaryotic microbiome assembly and dynamics in aquatic environments.
Cristiane Maria Rocha Farrapeira
Full Text Available This study aimed to describe the epibiosis of barnacles Amphibalanus improvisus on eight adult Macrobrachium acanthurus males from the Mundaú Lagoon, state of Alagoas, Brazil. The number of epibiont barnacles varied from 247 to 1,544 specimens per prawn; these were distributed predominantly on the cephalothorax and pereiopods, but also on the abdomen and other appendices. Although some were already reproducing, most barnacles had been recruited recently or were still sexually immature; this suggests recent host arrival in that estuarine environment. Despite the fact that other barnacles occur in this region, A. improvisus is the only species reported as an epibiont on Macrobrachium acanthurus; this was also the first record of epibiosis on this host. The occurrence of innumerable specimens in the pereiopods' articulations and the almost complete covering of the carapace of some prawns (which also increased their weight suggest that A. improvisus is adapted to fixate this kind of biogenic substrate and that the relationship between the two species biologically damages the basibiont.O objetivo deste trabalho foi relatar a epibiose de cirrípedes Amphibalanus improvisus em oito camarões machos adultos da espécie Macrobrachium acanthurus provenientes da Laguna Mundaú, Alagoas, Brasil. O número de cirrípedes epibiontes variou desde 247 até 1.544 espécimes por camarão, distribuídos predominantemente no cefalotórax e pereiópodos, mas presentes também no abdome e demais apêndices. A grande maioria dos cirrípedes era recém-recrutada ou ainda estava sexualmente imatura, embora de alguns estivessem já em reprodução, sugerindo a chegada recente de seu hospedeiro no ambiente estuarino. Apesar de ocorrem outros cirrípedes na região, A. improvisus foi à única espécie relatada como epibionte em Macrobrachium acanthurus e isto se constituiu o primeiro registro de epibiose de Amphibalanus improvisus A ocorrência de inúmeros esp
Ross, A.J.; Rucker, R.R.; Ewing, W.H.
A description was given of a gram-negative, peritrichously flagellated, fermentative bacterium that was isolated on numerous occasions from kidney tissues of rainbow trout (Salmo gairdneri) afflicted with redmouth disease. Although the bacteria apparently were members of the family Enterobacteriaceae, it was impossible to determine their taxonomic position within the family with certainty. Hence it was recommended that their taxonomic position remain sub judice for the present. As a temporary designation RM bacterium was used. Redmouth disease was transmitted from infected to normal fish through the medium of water.
Macek, Miroslav; Callieri, C.; Šimek, Karel; Vázquez, A.L.
Roč. 166, č. 2 (2006), s. 261-287 ISSN 0003-9136 R&D Projects: GA ČR(CZ) GA206/97/0072; GA MŠk(CZ) ME 296; GA MŠk(CZ) OK 118 Grant - others:UNAM DGAPA/PAPIIT(MX) IN208502; EC(XE) ENV4-CT95-0007; EC(XE) EVK1-CT-1999-00032; FES UNAM(MX) PAPCA Institutional research plan: CEZ:AV0Z6017912 Keywords : mountain lakes * timberline * acidified lakes * tropical high altitude lake * mixotrophy * oligotrichs * prostomes * gymnosotmes * peritrichs * scuticociliates Subject RIV: EH - Ecology, Behaviour Impact factor: 1.362, year: 2006
Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.
. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic...... ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic "conservation traps" comparable to amber....
Full Text Available Invasive species can alter coastal ecosystems both directly, e.g. through competition for substratum and nutrients, and indirectly. Indirect effects may be mediated by creation of dissimilar or inimical habitats, changes in predator and/or prey assemblages, alterations in associated biota, and perturbations of water movement and thermal regimes. Previous studies have shown that invasive algae can modify native habitat architecture, disrupt intricately linked food webs and alter epibiotic assemblages. In the UK, the seagrass Zostera marina supports a diverse epibiotic assemblage, influencing key factors such as sediment dynamics, depositional regime and trophic linkages. Increasing encroachment of the invasive alga Sargassum muticum into seagrass meadows changes the physical and chemical characteristics of the local environment and creates the potential for changes in the epibionts associated with the seagrass blades, threatening the integrity of the seagrass ecosystem. We investigated the effects of S. muticum invasion upon the epibiota of Z. marina in a drowned river valley in SW England seasonally from spring to autumn over four years in an in-situ manipulative experiment, comparing permanent quadrats with and without artificially introduced S. muticum. Epibiota were weighed, identified to the most detailed operational taxonomic unit (OTU possible, and unitary organisms were enumerated. Multivariate PERMANOVA+ analysis revealed significant differences in epibiont assemblages between Sargassum treatments. Linear mixed effects models indicated that differences in epibiota assemblage composition were not reflected as significant differences in mean biomass per sample, or number of epibiont OTUs per sample. We conclude that S. muticum invasion into Z. marina meadows may significantly alter the species composition and abundance distribution of epibiotic assemblages found on the blades of the seagrass. Thus S. muticum invasion could have more wide
Udoh James Philip; Otoh Aniekan Johnny
The distribution and occurrence of epibionts on the dorsal carapace, ventral carapace and chela of 325 specimens of Callinectes amnicola (De Rocheburne, 1883) (103.4 - 138.7 mm carapace width) from the Qua Iboe (QIRE) and Imo River (IRE) estuaries in southeast Nigeria was determined. The only ectosymbiont observed was cirriped barnacle, Chelonibia patula, mostly of smaller sizes (2.25 mm), infesting only 25-29% of intermoult crabs, more on females and in the Imo River estuary, with an average...
-specific in occurrence rather than free-living in the water column. This substrate-specific nature helps these protists to grow on Sargassum as epibionts (Raghukumar, 2002). Though the brown alga produces tannins on distal growing tips that have an inhibitory effect... on living surfaces. Hydrobiologia 461, 37–40. Badrinathan S., Shiju T.M., Sharon C.A.S., Arya R. and Pragasam V. (2012) Purification and structural characterization of sulfated polysaccharide from Sargassum myriocystum and its efficacy in scavenging free...
Majewska, Roksana; Lazo-Wasem, Eric A.; Nel, Ronel; Paladino, Frank V.; Rojas, Lourdes; Zardus, John D.; Pinou, Theodora
The macro-epibiotic communities of sea turtles have been subject to growing interest in recent years, yet their micro-epibiotic counterparts are almost entirely unknown. Here, we provide the first evidence that diatoms are epibionts for all seven extant species of sea turtle. Using Scanning Electron Microscopy, we inspected superficial carapace or skin samples from a single representative of each turtle species. We distinguished 18 diatom taxa from these seven individuals, with each sea turtle species hosting at least two diatom taxa. We recommend that future research is undertaken to confirm whether diatom communities vary between sea turtle species and whether these diatom taxa are facultative or obligate commensals. PMID:27257972
Mahasri, G.; Sari, P. D. W.; Prayogo
The main causes of death of pacific white shrimp in aquaculture are diseases. One effort to control deseases by improving the defense ability of shrimp body against disesases and optimizing water quality during farming through the application of a new aquaculture technology called Immuno-Probiocirculation System (SI-PBR). This research aimed to analyze immune response on Total Haemocyte Count (THC) and Differential Haemocyte Count (DHC), parasitic infestation on pacific white shrimp in many ages, survival rate of pacific white shrimp during farming period for 90 days in SI-PBR. The results of this research showed that the lowest parasitic infestation (Zoothamnium penaei) is 12.46 % that happened on 90-days-old shrimp in SI-PBR pond, while the highest infestasion is on the shrimp not given SI-PBR, reaching 54.65 %. In addition, the immune response (THC and DHC) also increased. The highest survival rate discovered in 90 days shrimp farming is 80% using SI-PBR. This is higher than the pond without SI-PBR, which is 22 %. Therefore, SI-PBR in shrimp farming in tradisional ponds is able to increase immune response, survival rate, and is also able to decrease parasitic infestation during 90 days of farming.
Laurent, Mélina C Z; Gros, Olivier; Brulport, Jean-Pierre; Gaill, Françoise; Bris, Nadine Le
Large organic falls to the benthic environment, such as dead wood or whale bones, harbour organisms relying on sulfide-oxidizing symbionts. Nothing is known however, concerning sulfide enrichment at the wood surface and its relation to wood colonization by sulfide-oxidizing symbiotic organisms. In this study we combined in situ hydrogen sulfide and pH measurements on sunken wood, with associated fauna microscopy analyses in a tropical mangrove swamp. This shallow environment is known to harbour thiotrophic symbioses and is also abundantly supplied with sunken wood. A significant sulfide enrichment at the wood surface was revealed. A 72h sequence of measurements emphasized the wide fluctuation of sulfide levels (0.1->100muM) over time with both a tidal influence and rapid fluctuations. Protozoans observed on the wood surface were similar to Zoothamnium niveum and to vorticellids. Our SEM observations revealed their association with ectosymbiotic bacteria, which are likely to be sulfide-oxidizers. These results support the idea that sunken wood surfaces constitute an environment suitable for sulfide-oxidizing symbioses.
Guri, Mathieu; Durand, Lucile; Cueff-Gauchard, Valérie; Zbinden, Magali; Crassous, Philippe; Shillito, Bruce; Cambon-Bonavita, Marie-Anne
The caridean shrimp Rimicaris exoculata dominates the fauna at several Mid-Atlantic Ridge hydrothermal vent sites. This shrimp has an enlarged gill chamber, harboring a dense ectosymbiotic community of chemoautotrophic bacteria associated with mineral oxide deposits. Until now, their acquisition is not fully understood. At three hydrothermal vent sites, we analyzed the epibionts diversity at different moult stages and also in the first stages of the shrimp life (eggs, hatched eggs (with larvae) and juveniles). Hatched eggs associated with young larvae were collected for the first time directly from gravid females at the Logachev vent site during the Serpentine cruise. An approach using 16S rRNA clone libraries, scanning and transmission electron microscopy, and fluorescent in situ hybridization was used. Molecular results and microscope observations indicated a switch in the composition of the bacterial community between early R. exoculata life cycle stage (egg libraries dominated by the Gammaproteobacteria) and later stages (juvenile/adult libraries dominated by the Epsilonproteobacteria). We hypothesized that the epibiotic phylotype composition could vary according to the life stage of the shrimp. Our results confirmed the occurrence of a symbiosis with Gammaproteobacteria and Epsilonproteobacteria, but more complex than previously assumed. We revealed the presence of active type-I methanotrophic bacteria colonizing the cephalothorax of shrimps from the Rainbow site. They were also present on the eggs from the Logachev site. This could be the first 'epibiotic' association between methanotrophic bacteria and hydrothermal vent crustacean. We discuss possible transmission pathways for epibionts linked to the shrimp life cycle.
Dove, Alistair D M; LoBue, Carl; Bowser, Paul; Powell, Mark
A significant number of moribund and dead lobsters Homarus americanus were reported to New York state authorities by lobster fishers in Long Island Sound (LIS) during the summer of 2002. Morbid lobsters were characterised by an orange discolouration of the abdomen, lethargy, an excess of epibionts and poor post-capture survival. On necropsy, severe extensive multifocal or diffuse mineralised granulomatous inflammation of the gills and antennal glands was the most striking pathology. In the gills, granulomas often occluded the lumen of filaments, resulting in congestion, ischemia and coagulative necrosis of gill tissues. In the antennal glands, granulomas were concentrated along the border between the coelomosac and labyrinth. No significant pathogens were recovered from diseased individuals. In prechronic individuals, however, it was evident that granulomas were focused around calcium carbonate (aragonite) crystals. This disease may result from anomalously high sea-bottom temperatures in LIS (approximately 23 degrees C) during the summer of 2002 and associated disruptions of the calcium chemistry of lobsters in favour of deposition of minerals in soft tissues. The ultimate cause of death of affected lobsters is probably respiratory failure due to reduced effective surface area of the gills, exacerbated by hypermetabolic temperatures and an abundance of epibionts.
Pereira, Renato Crespo; Costa, Erica da Silva; Sudatti, Daniela Bueno; da Gama, Bernardo Antonio Perez
Secondary metabolites play an important ecological role as a defense mechanism in seaweeds. Chemical defenses are well known to change in response to herbivory, but other driving factors, either biotic or abiotic, are often neglected. Epibiosis may not only reduce seaweed fitness, but also increase attractiveness to consumers, and thus defense production should also be triggered by epibionts. In this study, three Southwestern Atlantic seaweeds, Gracilaria cearensis, Pterocladiella capillacea (Rhodophyceae) and Codium decorticatum (Chlorophyceae) were investigated in laboratory bioassays designed to test whether the action of herbivory or simulated epibiosis influences chemical defenses. Crossed induction experiments were also performed in order to assess whether herbivore induction influences antifouling chemical defense, as well as whether epibiont induction would affect defense against herbivores. The effect of laboratory conditions on seaweeds in the absence of field stimuli was also investigated by comparing consumption of artificial food with extracts from acclimatized and non-acclimatized seaweeds (i.e., natural defense levels). Only the green seaweed C. decorticatum exhibited inducible antifouling defenses triggered by simulated epibiosis, but not by herbivores. In the other seaweeds there was no induction either by herbivory or simulated epibiosis. Acclimatization did not affect C. decorticatum defenses. However, non-acclimatized G. cearensis artificial foods were preferred over acclimatized ones, while extracts from acclimatized P. capillacea increased herbivore consumption, highlighting the need to acclimatize seaweeds before the main induction experiments. This is the first report of inducible defenses due to simulated fouling in seaweeds.
Bertucci, Frédéric; Legraverant, Yohann; Berthe, Cécile; Brooker, Rohan M.; Lo, Cédrik; Lecchini, David
Biofouling increases the operational and economic costs associated with pearl production. As current procedures for reducing oyster biofouling can be detrimental to survival and growth and may pollute the surrounding environment developing alternative, biologically-mediated, methods could potentially increase both production and ecological sustainability. With this in mind, the present study investigated natural cleaning of black-lipped pearl oysters, Pinctada margaritifera, by butterflyfishes (Chaetodon). The feeding behaviour of six butterflyfish species was examined at Rangiroa Atoll, French Polynesia: Chaetodon auriga, Chaetodon citrinellus, Chaetodon ephippium, Chaetodon lunulatus, Chaetodon trifascialis and Chaetodon ulietensis. All species cleaned the surface of pearl oysters by removing epibionts (from 16% to 40% of total biomass), although dietary variation may explain different cleaning efficiencies. Generalist omnivores (C. auriga, C. citrinellus, C. ephippium and C. ulietensis) were the most efficient cleaners (% cleaning range: 26-40% of total biomass). Within this group, C. ephippium removed the most biomass (average of 41%) targeting algae and anemones. However, C. auriga targeted the most diverse range of epibionts, removing significant amounts of algae, sponges, tunicates, and anemones. These results suggest that foraging by butterflyfishes can substantially reduce biofouling on economically-important tropical bivalves.
N. M. Korniichuk
Full Text Available Freshwater molluscs serve as test objects in the ecological monitoring of the environment, because they are able to extract in indicator quantity from the environment and accumulate in their bodies radionuclides, various macro- and micronutrients, toxic substances of inorganic and organic origin, and so on. The gastropods are a taxonomically diverse, ecologically plastic and rather widespread group of aquatic organisms, whose role in the life of freshwater ecosystems is very important. Molluscs often have various interactions in biogeocenoses that determines their trophic net. As a rule, these interactions occur in the form of ectocommensalism, endocommensalism, supercrescence, predation or parasitism. The latter type of interaction is the subject of many studies, but the epibionts of gastropods and bivalves have practically not been studied and this research is an effort towards filling this gap. Species composition of algal epibionts identifies specific sensitivity to the effects of certain environmental factors and reflects the processes occurring in their ecosystem water bodies. This determines their efficient use for analyzing changes of water bodies as aquatic habitat, particularly in terms of complex anthropogenic pressure on aquatic ecosystems. The aim of the research was to determine the ecological characteristics of algal communities on gastropod shells: Lymnaea stagnalis, L. auricularia and Viviparus viviparus (the Uzh river, Korosten district, Zhytomyr region. Identified microalgae communities were grouped and studied according to such indices as: confinedness to the habitat (substrate, temperature, fluidity and water oxygenating, saprobiological characteristics according to the Pantle-Buck system in the modification of Sladecek and Watanabe, salinity according to Kolbe’s system, pH at Hustedt scale in the interpretation of M. M. Davydova and geographical limitations of the objects of study. Algal fouling on the shells L. stagnalis
Li, Ye; Zhai, He; Sanchez, Sandra; Kearns, Daniel B; Wu, Yilin
Bacterial swimming in confined two-dimensional environments is ubiquitous in nature and in clinical settings. Characterizing individual interactions between swimming bacteria in 2D confinement will help to understand diverse microbial processes, such as bacterial swarming and biofilm formation. Here we report a novel motion pattern displayed by flagellated bacteria in 2D confinement: When two nearby cells align their moving directions, they tend to engage in cohesive swimming without direct cell body contact, as a result of hydrodynamic interaction but not flagellar intertwining. We further found that cells in cohesive swimming move with higher directional persistence, which can increase the effective diffusivity of cells by ∼3 times as predicted by computational modeling. As a conserved behavior for peritrichously flagellated bacteria, cohesive swimming in 2D confinement may be key to collective motion and self-organization in bacterial swarms; it may also promote bacterial dispersal in unsaturated soils and in interstitial space during infections.
Okamoto, T.; Taguchi, H.; Nakamura, K. (Kirin Brewery Co. Ltd., Tokyo (Japan))
Bacteria such as Zymomonas atracts attention in production of ethanol from carbohydrates in addition to yeast used for a long time, however, Zymomonas ferments only glucose, fructose and sucrose. After searching microbes in the nature with excellent properties in fermentation ability and salt resistance, a new Gram-negative bacterium has been isolated from a certain tree sap which is suitable for production of ethanol from maltose and starch hydrolyzate. The features of cell morphology of the new bacterium are: bacillus, peritrichous, no sport forming, Q-9 in quinone system, and an anaerobic Gram-negative bacterium. It utilizes maltose, sorbitol and maltose and produces [alpha]-glucosidas but no [beta]-galactosidase nor arginine dihydrase. The strain T109 is deposited as FERM BP-3292 to the Industrial Research Institute of Microbiology. 2 figs., 2 tabs.
Cillie, G.C.; Hart, O.O.; Davies, T.R.; Hassett, A.J.
Deterioration of the performance of biological wastewater treatment plants at Daspoort Sewage Works, Pretoria, South Africa, during 1975 was attributed to toxic material in the sewage. Unusually high concentrations of mercury, phenol, chromium, and an organophosphorus compound were detected. These substances singly or in combination could have been responsible for the deterioration. Data from the biological plants and research units at Daspoort are collected and reviewed to evaluate the water quality effects of the period of low performance. Encystation by peritrichous ciliates caused high bacteria counts in biofilter effluents. Nitrification declined rapidly and recovery was delayed, while carbon oxidation was affected to a limited extent. The water product was of the same quality throughout, even when the influent was little better than settled sewage. (12 graphs, 4 references, 3 tables)
Duval, B.; Margulis, L.
Ophrydium versatile is a sessile peritrichous ciliate (Kingdom Protoctista, class Oligohymenophora, order Peritrichida, suborder Sessilina) that forms green, gelatinous colonies. Chlorophyll a and b impart a green color to Ophrydium masses due to 400-500 Chlorella-like endosymbionts in each peritrich. Ophrydium colonies, collected from two bog wetlands (Hawley and Leverett, Massachusetts) were analyzed for their gel inhabitants. Other protists include ciliates, mastigotes, euglenids, chlorophytes, and heliozoa. Routine constituents include from 50-100,000 Nitzschia per ml of gel and at least four other diatom genera (Navicula, Pinnularia, Gyrosigma, Cymbella) that may participate in synthesis of the gel matrix. Among the prokaryotes are filamentous and coccoid cyanobacteria, large rod-shaped bacteria, at least three types of spirochetes and one unidentified Saprospira-like organism. Endosymbiotic methanogenic bacteria, observed using fluorescence microscopy, were present in unidentified hypotrichous ciliates. Animals found inside the gel include rotifers, nematodes, and occasional copepods. The latter were observed in the water reservoir of larger Ophrydium masses. From 30-46% of incident visible radiation could be attenuated by Ophrydium green jelly masses in laboratory observations. Protargol staining was used to visualize the elongate macronuclei and small micronucleus of O. versatile zooids and symbiotic algal nuclei. Electron microscopic analysis of the wall of the Chlorella-like symbiont suggests that although the Ophrydium zooids from British Columbia harbor Chlorella vulgaris, those from Hawley Bog contain Graesiella sp. The growth habit in the photic zone and loose level of individuation of macroscopic Ophrydium masses are interpretable as extant analogs of certain Ediacaran biota: colonial protists in the Vendian fossil record.
Afifi Khattab, Rafat
The intensity of infestation of the epizoic stalked barnacle Octolasmis on the blue crab was calculated for a total of 180 individuals collected around Jeddah, the western Red Sea Saudi coast. More than 90% of the crabs were found bearing the Octolasmis at a prevalence rate of 92% and mean intensity of 18.5±18.6 (0-127 epibiont per host). The intensity of infestation increased with host size in the range 90-135 mm. Generally, females were more infested (69%) than the males (31%). Octolasmis angulata occurred mostly on the gills, and the lower side of the gill chambers was more infested (84%) than the upper side (16%) and the left side of gills was also more infested than the right side in both males and females. Further studies are still needed to examine the commensal relationship and its impact on the fishery market of the Red Sea blue crab populations.
Nathan J Robinson
Full Text Available The macro-epibiotic communities of sea turtles have been subject to growing interest in recent years, yet their micro-epibiotic counterparts are almost entirely unknown. Here, we provide the first evidence that diatoms are epibionts for all seven extant species of sea turtle. Using Scanning Electron Microscopy, we inspected superficial carapace or skin samples from a single representative of each turtle species. We distinguished 18 diatom taxa from these seven individuals, with each sea turtle species hosting at least two diatom taxa. We recommend that future research is undertaken to confirm whether diatom communities vary between sea turtle species and whether these diatom taxa are facultative or obligate commensals.
Hügler, Michael; Petersen, Jillian M; Dubilier, Nicole; Imhoff, Johannes F; Sievert, Stefan M
The shrimp Rimicaris exoculata dominates the faunal biomass at many deep-sea hydrothermal vent sites at the Mid-Atlantic Ridge. In its enlarged gill chamber it harbors a specialized epibiotic bacterial community for which a nutritional role has been proposed. We analyzed specimens from the Snake Pit hydrothermal vent field on the Mid-Atlantic Ridge by complementing a 16S rRNA gene survey with the analysis of genes involved in carbon, sulfur and hydrogen metabolism. In addition to Epsilon- and Gammaproteobacteria, the epibiotic community unexpectedly also consists of Deltaproteobacteria of a single phylotype, closely related to the genus Desulfocapsa. The association of these phylogenetic groups with the shrimp was confirmed by fluorescence in situ hybridization. Based on functional gene analyses, we hypothesize that the Gamma- and Epsilonproteobacteria are capable of autotrophic growth by oxidizing reduced sulfur compounds, and that the Deltaproteobacteria are also involved in sulfur metabolism. In addition, the detection of proteobacterial hydrogenases indicates the potential for hydrogen oxidation in these communities. Interestingly, the frequency of these phylotypes in 16S rRNA gene clone libraries from the mouthparts differ from that of the inner lining of the gill chamber, indicating potential functional compartmentalization. Our data show the specific association of autotrophic bacteria with Rimicaris exoculata from the Snake Pit hydrothermal vent field, and suggest that autotrophic carbon fixation is contributing to the productivity of the epibiotic community with the reductive tricarboxylic acid cycle as one important carbon fixation pathway. This has not been considered in previous studies of carbon fixation and stable carbon isotope composition of the shrimp and its epibionts. Furthermore, the co-occurrence of sulfur-oxidizing and sulfur-reducing epibionts raises the possibility that both may be involved in the syntrophic exchange of sulfur compounds
Buschbaum, Christian; Cornelius, Annika; Goedknegt, M. Anouk
In sedimentary coastal ecosystems shells of epibenthic organisms such as blue mussels (Mytilus edulis) provide the only major attachment surface for barnacle epibionts, which may cause detrimental effects on their mussel basibionts by e.g. reducing growth rate. In the European Wadden Sea, beds of native blue mussels have been invaded by Pacific oysters Crassostrea gigas, which transformed these beds into mixed reefs of oysters with mussels. In this study, we determined the spatial distribution of M. edulis and their barnacle epibionts (Semibalanus balanoides) within the reef matrix. Mean mussel density near the bottom was about twice as high compared to the mussel density near the top of an oyster reef, whereas barnacles on mussels showed a reversed pattern. Barnacle dry weight per mussel was on average 14 times higher near the top than at the bottom. This pattern was confirmed by experimentally placing clean M. edulis at the top and on the bottom of oyster reefs at two sites in the Wadden Sea (island of Texel, The Netherlands; island of Sylt, Germany). After an experimental period of five weeks (April and May 2015, the main settlement period of S. balanoides), the number of barnacles per mussel was at both sites significantly higher on mussels near the top compared to near the bottom. We conclude that the oyster reef matrix offers a refuge for M. edulis: inside reefs they are not only better protected against predators but also against detrimental barnacle overgrowth. This study shows that alien species can cause beneficial effects for native organisms and should not be generally considered as a risk for the recipient marine ecosystems.
Crespo-Picazo, J L; García-Parraga, D; Domènech, F; Tomás, J; Aznar, F J; Ortega, J; Corpa, J M
Diseases associated to external parasitosis are scarcely reported in sea turtles. During the last decades several organism have been documented as a part of normal epibiont community connected to sea turtles. The copepod Balaenophilus manatorum has been cited as a part of epibiont fauna with some concern about its parasitic capacity. This study serves three purposes, i.e. (i) it sheds light on the type of life style that B. manatorum has developed with its hosts, particularly turtles; (ii) it makes a cautionary note of the potential health risks associated with B. manatorum in sea turtles under captivity conditions and in the wild, and (iii) it provides data on effective treatments against B. manatorum. We report for the first time a massive infestation of the copepod B. manatorum and subsequent acute mortality in a group of loggerhead sea turtle hatchlings. Four-month-old turtles from a head-starting program started exhibiting excitatory and fin rubbing behavior preceding an acute onset of lethargy, skin ulceration and death in some animals. All the individuals (n = 57) were affected by severe copepod load and presented different degrees of external macroscopic skin lesions. The ventral area of front flippers, axillar and pericloacal skin were mostly affected, and were the main parasite distribution regions. Copepods were also detected on plastron and carapace sutures. The gut contents of B. manatorum reacted positively for cytokeratin, indicating consumption of turtle skin. Severe ulcerative necrotic dermatitis and large amount of bacteria presence were the major histopathological findings. Individual fresh water immersion for 10 min and lufenuron administration (0.1 ppm) to the water system every 2 weeks proved effective for removing turtle parasites and to control re-infestation, respectively. The results from our study clearly indicated that B. manatorum individuals consume turtle skin. The pathological effects of this agent and the potential implications
The present study aimed to explicitly quantify the link between the attributes of shallow-water gorgonian colonies (Octocorallia: Alcyonacea) and the ecological patterns of associated non-colonial epifaunal invertebrates. Based on multiple regression analysis, we tested the contribution of several attributes (colony height, width, and area, fractal dimension as a measure of colony complexity, lacunarity as a measure of the heterogeneity, and “colonial” epibiont cover) to abundance and taxonomic richness of associated assemblages. The results highlight the variation in the response of epifaunal assemblages to the gorgonian colony characteristics. The nature and intensity of the relationships were gorgonian species-dependent and varied from one taxonomic group to another. For both gorgonian species analyzed, the strongest predictor of species richness and abundance of the epifaunal assemblages was “colonial” epibiont cover, possibly due to a trophic effect (direct or indirect enhancement of food availability) combined with the surface available for colonization (species–area effect). Although structural complexity is usually indicated as the main driver for rich and abundant coral-associated assemblages, no significant relationship was observed between fractal dimension and the community descriptors; lacunarity, which reflects the sizes of the inter-branch spaces, was only linked to taxonomic richness in the assemblages associated with Leptogorgia lusitanica. The validity of the paradigm that structural complexity enhances biodiversity may be scale-dependent. In the case of gorgonians, the effect of complexity at the “garden” level may be more relevant than at the individual colony level. This reinforces the need for the conservation of gorgonian aggregation areas as a whole in order to preserve host diversity and size structure. © 2015 Springer-Verlag Berlin Heidelberg
Full Text Available This study provides data to define an efficient biocide-free strategy based on zosteric acid to counteract biofilm formation on the membranes of submerged bioreactor system plants. 16S rRNA gene phylogenetic analysis showed that gammaproteobacteria was the prevalent taxa on fouled membranes of an Italian wastewater plant. Pseudomonas was the prevalent genus among the cultivable membrane-fouler bacteria and Pseudomonas putida was selected as the target microorganism to test the efficacy of the antifoulant. Zosteric acid was not a source of carbon and energy for P. putida cells and, at 200 mg/L, it caused a reduction of bacterial coverage by 80%. Biofilm experiments confirmed the compound caused a significant decrease in biomass (−97% and thickness (−50%, and it induced a migration activity of the peritrichous flagellated P. putida over the polycarbonate surface not amenable to a biofilm phenotype. The low octanol-water partitioning coefficient and the high water solubility suggested a low bioaccumulation potential and the water compartment as its main environmental recipient and capacitor. Preliminary ecotoxicological tests did not highlight direct toxicity effects toward Daphnia magna. For green algae Pseudokirchneriella subcapitata an effect was observed at concentrations above 100 mg/L with a significant growth of protozoa that may be connected to a concurrent algal growth inhibition.
Zhu, Bo; Lou, Miao-Miao; Xie, Guan-Lin; Wang, Guo-Fen; Zhou, Qin; Wang, Fang; Fang, Yuan; Su, Ting; Li, Bin; Duan, Yong-Pin
Two isolates of mulberry-pathogenic bacteria isolated from diseased mulberry roots were investigated in a polyphasic taxonomic study. Comparative 16S rRNA gene sequence analysis combined with rpoB gene sequence analysis allocated strains R18-2(T) and R3-3 to the genus Enterobacter, with Enterobacter asburiae, E. amnigenus, E. cancerogenus, E. cloacae subsp. cloacae, E. cloacae subsp. dissolvens and E. nimipressuralis as their closest relatives. Cells of the isolates were Gram-negative, facultatively anaerobic rods, 0.3-1.0 µm wide and 0.8-2.0 µm long, with peritrichous flagella, showing a DNA G+C content of 55.1 ± 0.5 mol%. Calculation of a similarity index based on phenotypic features and fatty acid methyl ester (FAME) analysis suggested that these isolates are members of E. cancerogenus or E. asburiae or a closely related species. Biochemical data revealed that the isolates could be differentiated from their nearest neighbours by the presence of lysine decarboxylase activity and their ability to utilize d-arabitol. DNA-DNA relatedness also distinguished the two isolates from phylogenetically closely related Enterobacter strains. Based on these data, it is proposed that the isolates represent a novel species of the genus Enterobacter, named Enterobacter mori sp. nov. The type strain is R18-2(T) ( = CGMCC 1.10322(T) = LMG 25706(T)).
Full Text Available Pectobacterium is one of the major destructive causal agent in most crop plants throughout the world. During a survey in spring of 2005 in the rangeland of Kermanshah and Isfahan, provinces of Iran, samples of bulbs and stems of crown imperial with brown spot and soft rot were collected. Eight strains of pectolytic Erwinia were isolated and purified from these samples. Phenotypic tests indicated that the strains were gram-negative, facultative anaerobic, rod shaped, motile with peritrichous flagella. They were oxidase negative, catalase positive and also able to macerate potato slices. Pathogenicity of all the strains were confirmed on corn, philodendron and crown imperial by inoculation of these crops with a bacterial suspension and reisolation of the strain from symptomatic tissues. A pair of specific PCR primers was used to detect these bacterial strains. The primer set (EXPCCF/EXPCCR amplified a single fragment of the expected size (0.55 kb from genomic DNA of all strains used in this study. In nested PCR, the primer set (INPCCR/INPCCF amplified the expected single fragment (0.4 kb from the PCR product of first PCR amplification. On the basis of the biochemical and phenotypic characteristics and PCR amplification by the specific PCR primers, these strains were identified as Pectobacterium carotovorum subsp. carotovorum. This is the first report of occurrence of crown imperial bacterial soft-rot in Iran.
Sabaneyeva, E; Castelli, M; Szokoli, F; Benken, K; Lebedeva, N; Salvetti, A; Schweikert, M; Fokin, S; Petroni, G
Newly isolated strains of the ciliate Paramecium calkinsi and their cytoplasmic bacterial endosymbionts were characterized by a multidisciplinary approach, including live observation, ultrastructural investigation, and molecular analysis. Despite morphological resemblance, the characterized P. calkinsi strains showed a significant molecular divergence compared to conspecifics, possibly hinting for a cryptic speciation. The endosymbionts were clearly found to be affiliated to the species "Candidatus Trichorickettsia mobilis" (Rickettsiales, Rickettsiaceae), currently encompassing only bacteria retrieved in an obligate intracellular association with other ciliates. However, a relatively high degree of intraspecific divergence was observed as well, thus it was possible to split "Candidatus Trichorickettsia" into three subspecies, one of which represented so far only by the newly characterized endosymbionts of P. calkinsi. Other features distinguished the members of each different subspecies. In particular, the endosymbionts of P. calkinsi resided in the cytoplasm and possessed numerous peritrichous flagella, although no motility was evidenced, whereas their conspecifics in other hosts were either cytoplasmic and devoid of flagella, or macronuclear, displaying flagellar-driven motility. Moreover, contrarily to previously analyzed "Candidatus Trichorickettsia" hosts, infected P. calkinsi cells frequently became amicronucleate and demonstrated abnormal cell division, eventually leading to decline of the laboratory culture. Copyright © 2017 Elsevier GmbH. All rights reserved.
Kim, Dong-Uk; Lee, Hyosun; Lee, Suyeon; Park, Sooyeon; Yoon, Jung-Hoon; Zhao, Lei; Kim, Min-Kyu; Ahn, Jae-Hyung; Ka, Jong-Ok
A gamma radiation-resistant and pink-to-red pigmented bacterial strain, designated ID1504 T , was isolated from a car air-conditioning system sampled in Korea. The cells were observed to be Gram-stain negative, aerobic, motile with peritrichous flagella and short rod-shaped. Phylogenetically, the strain groups with the members of the genus Deinococcus and exhibits high 16S rRNA gene sequence similarities with Deinococcus arenae SA1 T (94.0%), Deinococcus actinosclerus BM2 T (93.9%) and Deinococcus soli N5 T (93.5%). The predominant fatty acids were identified as C 17:0 , C 16:0 , summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c) and iso-C 17:0 . The major respiratory quinone was identified as MK-8. The polar lipids were found to be comprised of unidentified phospholipids, unidentified glycolipids, an unidentified aminophospholipid and an unidentified lipid. The DNA G+C content of the strain was determined to be 68.3 mol%. On the basis of the phenotypic, genotypic and chemotaxonomic characteristics, strain ID1504 T should be classified in a novel species in the genus Deinococcus, for which the name Deinococcus multiflagellatus sp. nov. (= KACC 19287 T = NBRC 112888 T ) is proposed.
SIGAL, N; SENEZ, J C; LEGALL, J; SEBALD, M
Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315-1318. 1963-The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c(3) and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin ("nigrificans" and "orientis") are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively.
Shamim, Saba; Rehman, Abdul; Qazi, Mahmood Hussain
To use of microorganisms for bioremediation purposes, the study of their motility behavior toward metals is essential. In the present study, Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 were used as cadmium (Cd)-resistant and -sensitive bacteria, respectively, to evaluate the effects of Cd on their motility behaviors. Potassium morpholinopropane sulfonate (MOPS) buffer was used to observe the motility behavior of both isolates. Movement of mt2 was less in MOPS buffer compared with CH34, likely reflecting the mono-flagellated nature of mt2 and the peritrichous nature of CH34. The swimming, swarming, twitching, and chemotaxis behaviors of mt2 were greater in the presence of glucose than that of Cd. mt2 exhibited negative motility behaviors when exposed to Cd, but the opposite effect was seen in CH34. Cd was found to be a chemorepellent for mt2 but a chemoattractant for CH34, suggesting that CH34 is a potential candidate for metal (Cd) bioremediation.
Amano, Nanako; Yamamuro, Ayaka; Miyahara, Morio; Kouzuma, Atsushi; Abe, Takashi; Watanabe, Kazuya
Abacterial strain, designated MMFC1 T , was isolated from a methanol-fed microbial fuel cell that had been inoculated with sludge obtained from a wastewater-treatmentfacility in a chemical plant. The strain grows by fermenting methanol to produce acetate under anaerobic conditions, while homoacetogenic growth is not observed. MMFC1 T also grows on pyruvate and lactate but not on sugars and other organic acids. Cells are curved rods and motile, have peritrichous flagella, and form endospores. The genome sequence of strain MMFC1 T supports the physiological data. Phylogenetic analysis based on the 16S rRNA gene sequence shows that strain MMFC1 T is affiliated with the family Sporomusaceae, while the closest relative is Sporomusa ovata with nucleotide-sequencesimilarity of 93.5 %. Major fatty acids are iso-C13 : 0 3-OH, C16 : 1ω9 and iso-C17 : 0. On the basis of its physiological, genomic and phylogenetic features, a novel genus and species are proposed to accommodate strain MMFC1 T , with the name Methylomusa anaerophila gen. nov., sp. nov. The type strain of Methylomusa anaerophila is MMFC1 T (=JCM 31821 T = KCTC 15592 T ).
She, Yue-Hui; Zhang, Fan; Xia, Jing-Jing; Kong, Shu-Qiong; Wang, Zheng-Liang; Shu, Fu-Chang; Hu, Ji-Ming
Three biosurfactant-producing indigenous microorganisms (XDS1, XDS2, XDS3) were isolated from a petroleum reservoir in the Daqing Oilfield (China) after polymer flooding. Their metabolic, biochemical, and oil-degradation characteristics, as well as their oil displacement in the core were studied. These indigenous microorganisms were identified as short rod bacillus bacteria with white color, round shape, a protruding structure, and a rough surface. Strains have peritrichous flagella, are able to produce endospores, are sporangia, and are clearly swollen and terminal. Bacterial cultures show that the oil-spreading values of the fermentation fluid containing all three strains are more than 4.5 cm (diameter) with an approximate 25 mN/m surface tension. The hydrocarbon degradation rates of each of the three strains exceeded 50%, with the highest achieving 84%. Several oil recovery agents were produced following degradation. At the same time, the heavy components of crude oil were degraded into light components, and their flow characteristics were also improved. The surface tension and viscosity of the crude oil decreased after being treated by the three strains of microorganisms. The core-flooding tests showed that the incremental oil recoveries were 4.89-6.96%. Thus, XDS123 treatment may represent a viable method for microbial-enhanced oil recovery.
Hervé, Vincent; Leroy, Boris; Da Silva Pires, Albert; Lopez, Pascal Jean
In most cities, streets are designed for collecting and transporting dirt, litter, debris, storm water and other wastes as a municipal sanitation system. Microbial mats can develop on street surfaces and form microbial communities that have never been described. Here, we performed the first molecular inventory of the street gutter-associated eukaryotes across the entire French capital of Paris and the non-potable waters sources. We found that the 5782 OTUs (operational taxonomic units) present in the street gutters which are dominated by diatoms (photoautotrophs), fungi (heterotrophs), Alveolata and Rhizaria, includes parasites, consumers of phototrophs and epibionts that may regulate the dynamics of gutter mat microbial communities. Network analyses demonstrated that street microbiome present many species restricted to gutters, and an overlapping composition between the water sources used for street cleaning (for example, intra-urban aquatic networks and the associated rivers) and the gutters. We propose that street gutters, which can cover a significant surface area of cities worldwide, potentially have important ecological roles in the remediation of pollutants or downstream wastewater treatments, might also be a niche for growth and dissemination of putative parasite and pathogens.
Full Text Available The emblematic hydrothermal worm Alvinella pompejana is one of the most thermo tolerant animal known on Earth. It relies on a symbiotic association offering a unique opportunity to discover biochemical adaptations that allow animals to thrive in such a hostile habitat. Here, by studying the Pompeii worm, we report on the discovery of the first antibiotic peptide from a deep-sea organism, namely alvinellacin. After purification and peptide sequencing, both the gene and the peptide tertiary structures were elucidated. As epibionts are not cultivated so far and because of lethal decompression effects upon Alvinella sampling, we developed shipboard biological assays to demonstrate that in addition to act in the first line of defense against microbial invasion, alvinellacin shapes and controls the worm's epibiotic microflora. Our results provide insights into the nature of an abyssal antimicrobial peptide (AMP and into the manner in which an extremophile eukaryote uses it to interact with the particular microbial community of the hydrothermal vent ecosystem. Unlike earlier studies done on hydrothermal vents that all focused on the microbial side of the symbiosis, our work gives a view of this interaction from the host side.
Pascual Jiménez, Cristina; Huchin-Mian, Juan Pablo; Simões, Nuno; Briones-Fourzán, Patricia; Lozano-Álvarez, Enrique; Sánchez Arteaga, Ariadna; Pérez-Vega, Juan Antonio; Simá-Álvarez, Raúl; Rosas Vazquez, Carlos; Rodríguez-Canul, Rossanna
The present study compares 13 physiological and immunological variables between a group of healthy Panulirus argus lobsters and a group of lobsters naturally infected with Panulirus argus Virus 1 (PaV1). Viral infection was determined through histopathology and PCR. Ten of the 13 variables differed significantly between the 2 groups. Using these variables, a principal component analysis yielded 2 separate clusters: one corresponding to the healthy group and the other corresponding to the infected group. In particular, infected lobsters exhibited significantly lower levels of osmotic pressure, total hemocyte counts, plasmatic proteins, and total phenoloxidase (PO) activity in plasma, as well as significantly higher levels of cholesterol and acylglycerides. These features are consistent with metabolic wasting, hyperlipidemia, and presumed immune suppression. Infection with PaV1 appears to increase the susceptibility of lobsters to some other opportunistic pathogens, as 61.1% of infected lobsters presented infestations of ciliate epibionts (Epystilis and Zoothamniun) in the gill chamber compared with 11.5% lobsters in the healthy group. Infected lobsters also showed significantly higher levels of total PO activity in degranulated hemocytes and trypsin inhibitor activity, potentially indicating activation of immune response by the PO system during the systemic infection with PaV1.
Shelly C Wu
Full Text Available Filamentous algae are often visible on the carapaces of freshwater turtles and these algae are dominated by a few species with varying geographic distributions. Compared to filamentous algae, little is known about the much more speciose microalgae on turtles. Our objectives were to compare the diatom flora on a single turtle species (the common snapping turtle, Chelydra serpentina across part of its range to examine spatial patterns and determine whether specific diatom taxa were consistently associated with turtles (as occurs in the filamentous alga Basicladia spp.. Using preserved turtle specimens from museums, we systematically sampled diatoms on the carapaces of 25 snapping turtles across five states. The diverse diatom assemblages formed two groups-the southern Oklahoma group and the northern Illinois/Wisconsin/New York group, with Arkansas not differing from either group. Of the six diatom species found in all five states, four species are widespread, whereas Luticola cf. goeppertiana and L. cf. mutica are undescribed species, known only from turtles in our study. L. cf. goeppertiana comprised 83% of the diatom abundance on Oklahoma turtles and was relatively more abundant on southern turtles (Oklahoma and Arkansas than on northern turtles (where mean abundance/state was > 10%. L. cf. mutica was the most abundant species (40% on New York turtles. Some Luticola species are apparently turtle associates and results support a pattern of spatial variation in Luticola species, similar to that in Basicladia. Using museum specimens is an efficient and effective method to study the distribution of micro-epibionts.
Wu, Shelly C.; Bergey, Elizabeth A.
Filamentous algae are often visible on the carapaces of freshwater turtles and these algae are dominated by a few species with varying geographic distributions. Compared to filamentous algae, little is known about the much more speciose microalgae on turtles. Our objectives were to compare the diatom flora on a single turtle species (the common snapping turtle, Chelydra serpentina) across part of its range to examine spatial patterns and determine whether specific diatom taxa were consistently associated with turtles (as occurs in the filamentous alga Basicladia spp.). Using preserved turtle specimens from museums, we systematically sampled diatoms on the carapaces of 25 snapping turtles across five states. The diverse diatom assemblages formed two groups–the southern Oklahoma group and the northern Illinois/Wisconsin/New York group, with Arkansas not differing from either group. Of the six diatom species found in all five states, four species are widespread, whereas Luticola cf. goeppertiana and L. cf. mutica are undescribed species, known only from turtles in our study. L. cf. goeppertiana comprised 83% of the diatom abundance on Oklahoma turtles and was relatively more abundant on southern turtles (Oklahoma and Arkansas) than on northern turtles (where mean abundance/state was > 10%). L. cf. mutica was the most abundant species (40%) on New York turtles. Some Luticola species are apparently turtle associates and results support a pattern of spatial variation in Luticola species, similar to that in Basicladia. Using museum specimens is an efficient and effective method to study the distribution of micro-epibionts. PMID:28192469
Chi Chiu Cheang
Full Text Available Turtle barnacles are common epibionts on marine organisms. Chelonibia testudinaria is specific on marine turtles whereas C. patula is a host generalist, but rarely found on turtles. It has been questioned why C. patula, being abundant on a variety of live substrata, is almost absent from turtles. We evaluated the genetic (mitochondrial COI, 16S and 12S rRNA, and amplified fragment length polymorphism (AFLP and morphological differentiation of C. testudinaia and C. patula from different hosts, to determine the mode of adaptation exhibited by Chelonibia species on different hosts. The two taxa demonstrate clear differences in shell morphology and length of 4-6(th cirri, but very similar in arthropodal characters. Moreover, we detected no genetic differentiation in mitochondrial DNA and AFLP analyses. Outlier detection infers insignificant selection across loci investigated. Based on combined morphological and molecular evidence, we proposed that C. testudinaria and C. patula are conspecific, and the two morphs with contrasting shell morphologies and cirral length found on different host are predominantly shaped by developmental plasticity in response to environmental setting on different hosts. Chelonibia testudinaria is, thus, a successful general epibiotic fouler and the phenotypic responses postulated can increase the fitness of the animals when they attach on hosts with contrasting life-styles.
Arellano, Shawn M.
The encrusting sponge Myxilla (Ectyomyxilla) methanophila (Poecilosclerida: Myxillidae) is an epibiont on vestimentiferan tubeworms at hydrocarbon seeps on the upper Louisiana slope of the Gulf of Mexico. It has long been suggested that this sponge harbors methylotrophic bacteria due to its low δ13C value and high methanol dehydrogenase activity, yet the full community of microbial associations in M. methanophila remained uncharacterized. In this study, we sequenced 16S rRNA genes representing the microbial community in M. methanophila collected from two hydrocarbon-seep sites (GC234 and Bush Hill) using both Sanger sequencing and next-generation 454 pyrosequencing technologies. Additionally, we compared the microbial community in M. methanophila to that of the biofilm collected from the associated tubeworm. Our results revealed that the microbial diversity in the sponges from both sites was low but the community structure was largely similar, showing a high proportion of methylotrophic bacteria of the genus Methylohalomonas and polycyclic aromatic hydrocarbon (PAH)-degrading bacteria of the genera Cycloclasticus and Neptunomonas. Furthermore, the sponge microbial clone library revealed the dominance of thioautotrophic gammaproteobacterial symbionts in M. methanophila. In contrast, the biofilm communities on the tubeworms were more diverse and dominated by the chemoorganotrophic Moritella at GC234 and methylotrophic Methylomonas and Methylohalomonas at Bush Hill. Overall, our study provides evidence to support previous suggestion that M. methanophila harbors methylotrophic symbionts and also reveals the association of PAH-degrading and thioautotrophic microbes in the sponge. © 2012 Springer Science+Business Media New York.
Isa, Hasmidah Md; Kamal, Abu Hena Mustafa; Idris, Mohd Hanafi; Rosli, Zamri; Ismail, Johan
Mangroves support diverse macroalgal assemblages as epibionts on their roots and tree trunks. These algae provide nutrients to the primary consumers in the aquatic food web and have been reported to be substantial contributors to marine ecosystems. The species diversity, biomass, and habitat characteristics of mangrove macroalgae were investigated at three stations in the Sibuti mangrove estuary, Sarawak, Malaysia, from November 2012 to October 2013. Three groups of macroalgae were recorded and were found to be growing on mangrove prop roots, namely Rhodophyta ( Caloglossa ogasawaraensis , Caloglossa adhaerens , Caloglossa stipitata , Bostrychia anomala, and Hypnea sp.), Chlorophyta ( Chaetomorpha minima and Chaetomorpha sp.), and Phaeophyta ( Dictyota sp.). The biomass of macroalgae was not influenced ( p >0.05) by the season in this mangrove forest habitat. The macroalgal species Hypnea sp. contributed the highest biomass at both Station 1 (210.56 mg/cm 2 ) and Station 2 (141.72 mg/cm 2 ), while the highest biomass was contributed by B. anomala (185.89 mg/cm 2 ) at Station 3. This study shows that the species distribution and assemblages of mangrove macroalgae were influenced by environmental parameters such as water nutrients, dissolved solids, and salinity in the estuarine mangrove habitats of Sibuti, Sarawak.
Arellano, Shawn M; Lee, On On; Lafi, Feras F; Yang, Jiangke; Wang, Yong; Young, Craig M; Qian, Pei-Yuan
The encrusting sponge Myxilla (Ectyomyxilla) methanophila (Poecilosclerida: Myxillidae) is an epibiont on vestimentiferan tubeworms at hydrocarbon seeps on the upper Louisiana slope of the Gulf of Mexico. It has long been suggested that this sponge harbors methylotrophic bacteria due to its low δ(13)C value and high methanol dehydrogenase activity, yet the full community of microbial associations in M. methanophila remained uncharacterized. In this study, we sequenced 16S rRNA genes representing the microbial community in M. methanophila collected from two hydrocarbon-seep sites (GC234 and Bush Hill) using both Sanger sequencing and next-generation 454 pyrosequencing technologies. Additionally, we compared the microbial community in M. methanophila to that of the biofilm collected from the associated tubeworm. Our results revealed that the microbial diversity in the sponges from both sites was low but the community structure was largely similar, showing a high proportion of methylotrophic bacteria of the genus Methylohalomonas and polycyclic aromatic hydrocarbon (PAH)-degrading bacteria of the genera Cycloclasticus and Neptunomonas. Furthermore, the sponge microbial clone library revealed the dominance of thioautotrophic gammaproteobacterial symbionts in M. methanophila. In contrast, the biofilm communities on the tubeworms were more diverse and dominated by the chemoorganotrophic Moritella at GC234 and methylotrophic Methylomonas and Methylohalomonas at Bush Hill. Overall, our study provides evidence to support previous suggestion that M. methanophila harbors methylotrophic symbionts and also reveals the association of PAH-degrading and thioautotrophic microbes in the sponge.
Full Text Available Abstract Background The sulfide-rich Frasassi caves in central Italy contain a rare example of a freshwater ecosystem supported entirely by chemoautotrophy. Niphargus ictus, the sole amphipod species previously reported from this locality, was recently shown to host the first known case of a freshwater chemoautotrophic symbiosis. Since the habitat of N. ictus is highly fragmented and is comprised of streams and lakes with various sulfide concentrations, we conducted a detailed study to examine the potential genetic diversity of this species within Frasassi. Results By sequencing one nuclear (ITS and two mitochondrial (COI and 12S regions, we show that four partially sympatric Niphargus clades are present in Frasassi. Morphological and behavioral data obtained for three of these clades are perfectly congruent with this molecular delineation and make it possible to distinguish them in the field. Phylogenetic analyses of 28S ribosomal DNA sequences reveal that, among the four clades, only two are closely related to each other. Moreover, these four clades occupy distinct niches that seem to be related to the chemical properties and flow regimes of the various water bodies within Frasassi. Conclusions Our results suggest that four distinct Niphargus species are present in Frasassi and that they originated from three or four independent invasions of the cave system. At least two among the four species harbor Thiothrix epibionts, which paves the way for further studies of the specificity and evolutionary history of this symbiosis.
Meyer, K S
Most marine hard-bottom habitats are isolated, separated from other similar habitats by sand or mud flats, and can be considered analogous to terrestrial islands. The extensive scientific literature on terrestrial islands provides a theoretical framework for the analysis of isolated marine habitats. More individuals and higher species richness occur on larger marine substrata, a pattern that resembles terrestrial islands. However, while larger terrestrial islands have greater habitat diversity and productivity, the higher species richness on larger marine hard substrata can be explained by simple surface area and hydrodynamic phenomena: larger substrata extend further into the benthic boundary, exposing fauna to faster current and higher food supply. Marine island-like communities are also influenced by their distance to similar habitats, but investigations into the reproductive biology and dispersal ability of individual species are required for a more complete understanding of population connectivity. On terrestrial islands, nonrandom co-occurrence patterns have been attributed to interspecific competition, but while nonrandom co-occurrence patterns have been found for marine fauna, different mechanisms are responsible, including epibiontism. Major knowledge gaps for community assembly in isolated marine habitats include the degree of connectivity between isolated habitats, mechanisms of succession, and the extent of competition on hard substrata, particularly in the deep sea. Anthropogenic hard substrata of known age can be used opportunistically as "natural" laboratories to begin answering these questions. © 2017 Elsevier Ltd. All rights reserved.
Domínguez-Machín, Magda E; Hernández-Vergara, Martha P; Jiménez-García, Isabel; Simá-Alvarez, Raúl; Rodríguez-Canul, Rossanna
We surveyed protozoan and metazoan parasites as well as white spot syndrome virus (WSSV) and infectious hypodermal hematopoietic necrosis virus (IHHNV) in white shrimp Litopenaeus setiferus and the palaemonid prawn Macrobrachium acanthurus native to the lower Jamapa River region of Veracruz, Mexico. The presence of parasites and the infection parameters were evaluated in 113 palaemonid prawns collected during the northwind (n = 45), rainy (n = 38) and dry seasons (n = 30) between October 2007 and July 2008, and in 91 shrimp collected in the rainy season between May and June 2008. In L. setiferus, ciliates of the subclass Apostomatia (Ascophrys sp.) were evident in gills, and third-stage larvae of the nematode Physocephalus sexalatus were evident in the stomach. Cestodes of the genus Prochristianella were evident in the hepatopancreas, while some gregarines of the genus Nematopsis, as well as unidentified larval cestodes, were observed in the intestine. Histology identified Ascophrys sp. in association with gill necrosis and tissue melanization. Slight inflammation was observed in intestinal epithelium near cestode larvae. In M. acanthurus, epibionts of the protozoans Epistylis sp., Acineta sp. and Lagenophrys sp. were observed under uropods, periopods and pleopods. An unidentified ciliate of the Apostomatia was also found in the gills, and Nematopsis was identified in the intestine. No histopathology was observed in association with these parasites. Moreover, neither WSSV nor IHHNV were detected by the polymerase chain reaction (PCR) in any of the L. setiferus or M. acanthurus analysed.
Tobon Lopez, Alexander; Amorocho Llanos, Diego Fernando
The objective of this research was to determine biological and ecological population characteristics of the hawksbill turtle (Eretmochelys imbricata) found in the southern Colombian Pacific Department of Cauca. Morphometric measurements were recorded, the health status of individuals was reviewed, and blood samples were taken for a biochemistry assessment. During the seven months of the investigation, 25 hawksbill turtles were caught (16 different individuals) on the reefs of Gorgona Natural National Park. Forty-six percent of the total numbers of turtles assessed were recaptured during the study period. While no obvious health problems were noted, most animals possessed epibionts and filamentous algae covering the carapace, some parts of the limbs, as well as on their neck. Curved carapace length (CCL) showed the highest proportion of individuals were between 37 and 45 cm. Sixteen individuals captured in Gorgona Natural National Park were compared with 11 individuals captured in the coastal zone of the Department of Cauca. Using the Mann-Whitney U test, a significant difference in CCL was found between these two groups; the animals from Gorgona National Park were larger than those present on the coast of the mainland (Z = -2.59, p = 0.007). Uric acid concentrations were found to be higher than previously referenced values.
Population study of the Hawksbill Turtle eretmochelys imbricata (Cheloniidae) in the southern pacific region of Colombia; Estudio poblacional de la Tortuga Carey Eretmochelys imbricata (Cheloniidae) en el pacifico sur de Colombia
Tobon Lopez, Alexander; Amorocho Llanos, Diego Fernando
The objective of this research was to determine biological and ecological population characteristics of the hawksbill turtle (Eretmochelys imbricata) found in the southern Colombian Pacific Department of Cauca. Morphometric measurements were recorded, the health status of individuals was reviewed, and blood samples were taken for a biochemistry assessment. During the seven months of the investigation, 25 hawksbill turtles were caught (16 different individuals) on the reefs of Gorgona Natural National Park. Forty-six percent of the total numbers of turtles assessed were recaptured during the study period. While no obvious health problems were noted, most animals possessed epibionts and filamentous algae covering the carapace, some parts of the limbs, as well as on their neck. Curved carapace length (CCL) showed the highest proportion of individuals were between 37 and 45 cm. Sixteen individuals captured in Gorgona Natural National Park were compared with 11 individuals captured in the coastal zone of the Department of Cauca. Using the Mann-Whitney U test, a significant difference in CCL was found between these two groups; the animals from Gorgona National Park were larger than those present on the coast of the mainland (Z = -2.59, p = 0.007). Uric acid concentrations were found to be higher than previously referenced values.
Patterns of biodiversity (alpha- and beta-diversity), abundance and community structure of the epifaunal assemblages associated with two gorgonians, Eunicella gazella and Leptogorgia lusitanica, were analysed in relation to host, colony size, location and time. Colony size and time were the major factors shaping attendant assemblages. Patterns of alpha-diversity and beta-diversity were host-dependent. Assemblages associated with E. gazella showed a significant inter-annual variability for most of the metrics analysed, while in those associated with L. lusitanica only Shannon-Wiener varied significantly between years. In L lusitanica Hurlbert\\'s expected number of taxa was significantly lower in small-sized than in medium- to large-sized colonies, but an opposite pattern was detected for beta-diversity, reflecting the higher heterogeneity among small-sized colonies. The dbRDA analysis segregated the assemblages associated with each of the two hosts; the faunal patterns were mainly explained by colony size related attributes (area, number of branches and, to a lesser extent, width) and the "colonial" epibiont cover. However, we suggest that altogether they may act as a metacommunity, with high temporal and spatial fluidity in their composition and structure related to multiple factors including not only a component of stochasticity but also life history events, biotic interactions and response to habitat heterogeneity and environmental variability. (C) 2013 Elsevier B.V. All rights reserved.
Carvalho, Susana; Cú rdia, Joã o; Pereira, Fá bio; Guerra-Garcí a, José Manuel; Santos, Miguel N.; Cunha, Marina R.
Patterns of biodiversity (alpha- and beta-diversity), abundance and community structure of the epifaunal assemblages associated with two gorgonians, Eunicella gazella and Leptogorgia lusitanica, were analysed in relation to host, colony size, location and time. Colony size and time were the major factors shaping attendant assemblages. Patterns of alpha-diversity and beta-diversity were host-dependent. Assemblages associated with E. gazella showed a significant inter-annual variability for most of the metrics analysed, while in those associated with L. lusitanica only Shannon-Wiener varied significantly between years. In L lusitanica Hurlbert's expected number of taxa was significantly lower in small-sized than in medium- to large-sized colonies, but an opposite pattern was detected for beta-diversity, reflecting the higher heterogeneity among small-sized colonies. The dbRDA analysis segregated the assemblages associated with each of the two hosts; the faunal patterns were mainly explained by colony size related attributes (area, number of branches and, to a lesser extent, width) and the "colonial" epibiont cover. However, we suggest that altogether they may act as a metacommunity, with high temporal and spatial fluidity in their composition and structure related to multiple factors including not only a component of stochasticity but also life history events, biotic interactions and response to habitat heterogeneity and environmental variability. (C) 2013 Elsevier B.V. All rights reserved.
El-Hedeny, Magdy; El-Sabbagh, Ahmed; Al Farraj, Saleh
The Middle ‒ Upper Jurassic hard substrates of central Saudi Arabia displayed considerable signs of bioerosion and encrustations. They include organic (oysters, other bivalves, gastropods, corals and brachiopods) and an inorganic carbonate hardground that marks the boundary between the Middle Jurassic Tuwaiq Mountain Limestone and the Upper Jurassic Hanifa Formation. Traces of bioerosion in organic substrates include seven ichnotaxa produced by bivalves (Gastrochaenolites Leymerie, 1842), polychaete annelids (Trypanites Mägdefrau, 1932; MaeandropolydoraVoigt, 1965 and CaulostrepsisClarke, 1908), sponges (Entobia Bronn, 1837), acrothoracican cirripedes (Rogerella Saint-Seine, 1951), gastropods (Oichnus Bromley, 1981) and probable ?Centrichnus cf. eccentricus. The encrusting epifauna on these substrates consist of several organisms, including oysters, serpulid worms, corals and foraminifera. In contrast, the carbonate hardground was only bioeroded by Gastrochaenolite, Trypanites and Entobia. Epibionts on this hardground include ;Liostrea Douvillé, 1904-type; oysters, Nanogyra nana Sowerby, 1822 and serpulids. In general, bioerosion and encrustation are less diversified in hardground than in organic substrates, indicating a long time of exposition of organic substrates with slow to moderate rate of deposition in a restricted marine environment. Both organic and inorganic commuinities are correlated with those of other equatorial, subtropical and temperate equivalents.
Full Text Available We describe and name Loxolenichnus stellatocinctus Breton and Wisshak igen. et isp. nov., a bioerosion trace fossil on an Upper Cenomanian oyster from Le Mans (France. This trace is attributed here to a parasitic gastropod. The characteristics of this ichnospecies are a combination of one or several, vertical or oblique, complete penetrations, and an asymmetrical attachment etching (fixichnion with a diagnostic set of stellate grooves increasingly distinct towards the margin of the trace. By including two former Oichnus ichnospecies, Loxolenichnus halo comb. nov. and Loxolenichnus taddei comb. nov., Oichnus, is now constrained to pure predation traces (praedichnia. The numerous oysters collected from the Marnes à Pycnodonte biauriculata Formation show associated epibionts and encrusters as well as borers and scrapers. Encrusters comprise 24 taxa while bioerosion trace fossils comprise 17 ichnotaxa ranging from very rare (< 0.1% to quite abundant (81%. The taphonomic history leading to an ex-situ condensation of these oysters is complex. Both the Gnathichnus and Entobia ichnofacies are represented on the shellgrounds, presumably alternatingly.
Cachet, Nadja; Genta-Jouve, Grégory; Ivanisevic, Julijana; Chevaldonné, Pierre; Sinniger, Frédéric; Culioli, Gérald; Pérez, Thierry; Thomas, Olivier P.
Metabolomics has recently proven its usefulness as complementary tool to traditional morphological and genetic analyses for the classification of marine invertebrates. Among the metabolite-rich cnidarian order Zoantharia, Parazoanthus is a polyphyletic genus whose systematics and phylogeny remain controversial. Within this genus, one of the most studied species, Parazoanthus axinellae is prominent in rocky shallow waters of the Mediterranean Sea and the NE Atlantic Ocean. Although different morphotypes can easily be distinguished, only one species is recognized to date. Here, a metabolomic profiling approach has been used to assess the chemical diversity of two main Mediterranean morphotypes, the “slender” and “stocky” forms of P. axinellae. Targeted profiling of their major secondary metabolites revealed a significant chemical divergence between the morphotypes. While zoanthoxanthin alkaloids and ecdysteroids are abundant in both morphs, the “slender” morphotype is characterized by the presence of additional and bioactive 3,5-disubstituted hydantoin derivatives named parazoanthines. The absence of these specific compounds in the “stocky” morphotype was confirmed by spatial and temporal monitoring over an annual cycle. Moreover, specimens of the “slender” morphotype are also the only ones found as epibionts of several sponge species, particularly Cymbaxinella damicornis thus suggesting a putative ecological link. PMID:25655432
Man, Yi; Page, William; Poole, Robert J.; Lauga, Eric
Peritrichous bacteria swim in viscous fluids by rotating multiple helical flagellar filaments. As the bacterium swims forward, all its flagella rotate in synchrony behind the cell in a tight helical bundle. When the bacterium changes its direction, the flagellar filaments unbundle and randomly reorient the cell for a short period of time before returning to their bundled state and resuming swimming. This rapid bundling and unbundling is, at its heart, a mechanical process whereby hydrodynamic interactions balance with elasticity to determine the time-varying deformation of the filaments. Inspired by this biophysical problem, we present in this paper what is perhaps the simplest model of bundling whereby two or more straight elastic filaments immersed in a viscous fluid rotate about their centerline, inducing rotational flows which tend to bend the filaments around each other. We derive an integrodifferential equation governing the shape of the filaments resulting from mechanical balance in a viscous fluid at low Reynolds number. We show that such equation may be evaluated asymptotically analytically in the long-wavelength limit, leading to a local partial differential equation governed by a single dimensionless bundling number. A numerical study of the dynamics predicted by the model reveals the presence of two configuration instabilities with increasing bundling numbers: first to a crossing state where filaments touch at one point and then to a bundled state where filaments wrap along each other in a helical fashion. We also consider the case of multiple filaments and the unbundling dynamics. We next provide an intuitive physical model for the crossing instability and show that it may be used to predict analytically its threshold and adapted to address the transition to a bundling state. We then use a macroscale experimental implementation of the two-filament configuration in order to validate our theoretical predictions and obtain excellent agreement. This long
Li, Ts D; Doronina, N V; Ivanova, E G; Trotsenko, Iu A
Two strains (KM3 and KM5) of halophilic methylobacteria isolated from Red Sea algae do not require vitamin B12 for growth and can use methanol, methylamine, dimethylamine, trimethylamine, dimethyl sulfide, and fructose as sources of carbon and energy. The cells of these strains are gram-negative motile monotrichous (strain KM3) or peritrichous (strain KM5) rods. The strains are strictly aerobic and require Na+ ions but not growth factors for growth. They are oxidase- and catalase-positive and reduce nitrates to nitrites. Both strains can grow in a temperature range of 4 to 37 degrees C (with optimal growth at 29-34 degrees C), at pH between 5.5 and 8.5 (with optimal growth at pH 7.5-8.0), and in a range of salt concentrations between 0.5 and 15% NaCl (with optimal growth at 5-9% NaCl). The phospholipids of these strains are dominated by phosphatidylethanolamine and phosphatidylglycerol and also include phosphatidylcholine, phosphatidylserine, and cardiolipin. The dominant fatty acids are C(16:1omega7c) and C(16:0). The major ubiquinone is Q8. The cells accumulate ectoin, glutamate, and sucrose as intracellular osmoprotectants. The strains implement the 2-keto-3-deoxy-6-phosphogluconate-dependent variant of the ribulose monophosphate pathway. The G+C content of the DNA is 44.4-44.7 mol %. Analysis of the 16S rRNA genes showed that both strains belong to Gammaproteobacteria and have a high degree of homology (99.4%) to Methylophaga marina ATCC 35842T . Based on the data of polyphasic taxonomy, strains KM3 and KM5 are identified as new strains M. marina KM3 (VKM B-2386) and M. marina KM5 (VKM B-2387). The ability of these strains to produce auxins (indole-3-acetic acid) suggests their metabolic association with marine algae.
Zhang, Yong-Guang; Zhou, Xing-Kui; Guo, Jian-Wei; Xiao, Min; Wang, Hong-Fei; Wang, Yun; Bobodzhanova, Khursheda; Li, Wen-Jun
A Gram-stain-positive, alkaliphilic bacterium, designated EGI 80668 T , was isolated from a Tamarix cone soil in Xinjiang, north-west China. Cells were facultatively anaerobic, terminal endospore-forming and motile by means of peritrichous flagella. Colonies were yellowish and the cells showed oxidase-negative and catalase-positive reactions. Strain EGI 80668 T grew at pH 8.0-10.0 and with 0-10 % (w/v) NaCl (optimally at pH 9.0 and with 1-2 % NaCl) on marine agar 2216. The predominant menaquinone was MK-7. The major fatty acids were anteiso-C17 : 0 and anteiso-C15 : 0. The cellular polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unknown phospholipids and one unknown aminophospholipid. The G+C content of the genomic DNA was 38.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain EGI 80668 T was affiliated to the genus Bacillus. The highest 16S rRNA gene sequence similarity between strain EGI 80668 T and a member of the genus Bacillus was 96.83 % with Bacillus cellulosilyticus JCM 9156 T . A polyphasic taxonomic study based on morphological, physiological, biochemical and phylogenetic data indicated that strain EGI 80668 T represents a novel species of the genus Bacillus, for which the name Bacillus tamaricis sp. nov. (type strain EGI 80668 T =KCTC 33703 T =CGMCC 1.15917 T ) is proposed.
Hernández-Eugenio, Guadalupe; Fardeau, Marie-Laure; Cayol, Jean-Luc; Patel, Bharat K C; Thomas, Pierre; Macarie, Hervé; Garcia, Jean-Louis; Ollivier, Bernard
A strictly anaerobic, gram-positive, sporulating rod (0.5-0.6 x 2.0-4.0 microm), designated strain Lup 21T, was isolated from an upflow anaerobic sludge blanket (UASB) reactor treating cheese-factory wastewater. Strain Lup 21T was motile by means of peritrichous flagella, had a G+C content of 31.4 mol% and grew optimally at 37 degrees C, pH 7.4, in the absence of NaCl. It is a heterotrophic micro-organism, utilizing proteinaceous compounds (gelatin, peptides, Casamino acids and various single amino acids) but unable to use any of the carbohydrates tested as a carbon and energy source. It reduced thiosulfate and elemental sulfur to sulfide in the presence of Casamino acids as carbon and energy sources. Acetate, butyrate, isobutyrate, isovalerate, CO2 and sulfide were end products from oxidation of gelatin and Casamino acids in the presence of thiosulfate as an electron acceptor. In the absence of thiosulfate, serine, lysine, methionine and histidine were fermented. On the basis of 16S rRNA similarity, strain Lup 21T was related to members of the low-G+C Clostridiales group, Clostridium subterminale DSM 6970T being the closest relative (with a sequence similarity of 99.4%). DNA-DNA hybridization was 56% with this species. On the basis of phenotypic, genotypic and phylogenetic characteristics, the isolate was designated as a novel species of the genus Clostridium, Clostridium thiosulfatireducens sp. nov. The type strain is strain Lup 21T (= DSM 13105T = CIP 106908T).
Cho, Hayoung; Heo, Jun; Ahn, Jae-Hyung; Weon, Hang-Yeon; Kim, Jeong-Seon; Kwon, Soon-Wo; Kim, Soo-Jin
The taxonomic position of a bacterial strain designated T16R-228 T , isolated from a rhizosphere soil sample of a tomato plant collected from a farm in Buyeo, Chungcheongnam-do, Republic of Korea, was determined using a polyphasic approach. On the basis of morphological, genetic and chemotaxonomic characteristics, it was determined to belong to the genus Paenibacillus. It was an aerobic, Gram-stain-positive, non-motile, catalase-negative, oxidase-negative rod with peritrichous flagella. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, hydroxyl- phosphatidylethanolamine and one unidentified polar lipid. Menaquiones were MK-7. Predominant cellular fatty acids were anteiso-C15 : 0, C16 : 0 and iso-C16 : 0. DNA G+C content was 56.8 mol%. The phylogenetic tree constructed based on the 16S rRNA gene sequences showed the strain formed a clade with P. mucilaginosus VKPM B-7519 T , P. edaphicus T7 T , P. ehimensis KCTC 3748 T , P. koreensis YC300 T , P. tianmuensis B27 T and P. elgii SD17 T , showing the highest sequence similarity with P. mucilaginosus VKPM B-7519 T (96.5 %). The polyphasic data supported that strain T16R-228 T was clearly distinguished from its closely related species and represents a novel species of the genus Paenibacillus for which the name Paenibacillus solanacearum is proposed. The type strain is T16R-228 T (=KACC 18654 T =NBRC 111896 T ).
Full Text Available The northern coast of Rio de Janeiro State lacks natural consolidate substrates, making it a proper environment to the development of researches using artificial structures. After studies about the type of substrate, concrete seems to be the most appropriate for studying fouling community development. This research was carried out to investigate the functional role of biofouling in the development of the ichthyic community in the north of Rio de Janeiro State. Percentage data of the epibenthic organisms' coverage and samples of the fish community with gillnet and visual census showed that biofouling in artificial reefs might have more than one functional role, acting as a facilitator in the recruitment of fish species and as a link in the trophic marine chain. Through the increase of localized structural complexity provided by the reef itself and by the fouling organisms which act as "engineering species", additional protection options are offered to the ichthyic community, especially recruits. Also, the epibiont biomass represents an important link in the food web, acting either as a direct source or in the transference of energy to higher trophic levels. Through the relationship between the ichthyic and fouling communities we concluded that the functional role of the latter in artificial reef habitats could be characterized mainly as shelter and feeding grounds for few fish species.O litoral norte do Estado do Rio de Janeiro possui uma escassez de substrato consolidado natural tornando o ambiente propício para o desenvolvimento de pesquisas com estruturas artificiais. Após estudos conclusivos sobre o tipo de substrato, o concreto parece ser o mais apropriado para o desenvolvimento da comunidade incrustante. Novas pesquisas foram realizadas para investigar o papel funcional da bioincrustação no desenvolvimento da comunidade íctica no norte do Estado do Rio de Janeiro. Dados de porcentagem de cobertura dos organismos epibênticos e
Full Text Available El objetivo de esta investigación fue conocer aspectos poblacionales, biológicos y ecológicos de las tortugas carey (Eretmochelys imbricata presentes en el Pacífico sur de Colombia (Departamento del Cauca, para esto se tomó información de morfometría, se revisó el estado de salud de los individuos y se tomaron muestras de sangre para valoración de química sanguínea. Durante siete meses de muestreo se capturaron 25 tortugas carey (16 individuos diferentes en los arrecifes del Parque Nacional Natural Gorgona, con un porcentaje de recaptura del 46 %. Aunque no se notaron problemas evidentes de salud, la mayoría de animales presentaron gran parte del caparazón cubierto de algas filamentosas y algunos epibiontes sobre el plastrón y el caparazón. La Longitud Curva Caparazón (LCC mostró una mayor proporción de individuos con tallas entre 37 y 45 cm de longitud (prom. 42,3 cm; min. 37,5 cm; max. 58 cm. Por medio de la prueba de Mann Whitney U, se comparó la LCC de los 16 individuos diferentes capturados en el PNN Gorgona, con 11 individuos capturados en la zona del litoral del Departamento del Cauca, encontrándose diferencias significativas entre estos dos grupos, donde los animales presentes en el PNN Gorgona fueron de mayor talla que los presentes en el continente (Z = -2,59; p = 0,007. Los valores de ácido úrico se encontraron por encima de los valores de referencia.
Zbinden, M.; Le Bris, N.; Compere, P.; Gaill, F.
The shrimp Rimicaris exoculata dominates the megafauna of some mid-Atlantic Ridge hydrothermal vent fields. This species harbors a rich bacterial epibiosis inside its gill chamber. At the Rainbow vent field, the epibionts are associated with iron oxide deposits. Investigation of both bacteria and minerals by scanning electron microscopy (SEM) and X-ray microanalysis (EDX) shows the occurrence of three distinct compartments in the gill chamber: (1) the lower pre-branchial chamber, housing bacteria, but devoid of minerals, (2) the "true" branchial chamber that contains the gills and remains free of both bacteria and minerals, and (3) the upper pre-branchial chamber housing the main ectosymbiotic bacterial community and associated iron oxides. According to our chemical and temperature data, abiotic iron oxidation appears to be kinetically inhibited in the environment of the shrimps and this would explain the lack of iron oxide deposits in the first two areas. We propose that, in the third area, iron oxidation is microbially promoted. The discrepancy between the spatial distribution of bacteria and minerals suggests that different bacterial metabolisms are involved in the two compartments. A possible explanation lies in the modification of physico-chemical conditions downstream of the gills, that would reduce the oxygen content and favor the development of bacterial iron-oxidizers in this Fe II-rich environment. A potential role of such iron-oxidizing symbionts in the shrimp diet is suggested. This would be unusual for hydrothermal ecosystems, where most previously described symbioses rely on sulphide or methane as an energy source.
Full Text Available The reactive oxygen species (ROS superoxide has been implicated in both beneficial and detrimental processes in coral biology, ranging from pathogenic disease resistance to coral bleaching. Despite the critical role of ROS in coral health, there is a distinct lack of ROS measurements and thus an incomplete understanding of underpinning ROS sources and production mechanisms within coral systems. Here, we quantified in situ extracellular superoxide concentrations at the surfaces of aquaria-hosted Porites astreoides during a diel cycle. High concentrations of superoxide (~10’s of nM were present at coral surfaces, and these levels did not change significantly as a function of time of day. These results indicate that the coral holobiont produces extracellular superoxide in the dark, independent of photosynthesis. As a short-lived anion at physiological pH, superoxide has a limited ability to cross intact biological membranes. Further, removing surface mucus layers from the P. astreoides colonies did not impact external superoxide concentrations. We therefore attribute external superoxide derived from the coral holobiont under these conditions to the activity of the coral host epithelium, rather than mucus-derived epibionts or internal sources such as endosymbionts (e.g., Symbiodinium. However, endosymbionts likely contribute to internal ROS levels via extracellular superoxide production. Indeed, common coral symbionts, including multiple strains of Symbiodinium (clades A to D and the bacterium Endozoicomonas montiporae LMG 24815, produced extracellular superoxide in the dark and at low light levels. Further, representative P. astreoides symbionts, Symbiodinium CCMP2456 (clade A and E. montiporae, produced similar concentrations of superoxide alone and in combination with each other, in the dark and low light, and regardless of time of day. Overall, these results indicate that healthy, non-stressed P. astreoides and representative symbionts produce
Dominique A Cowart
Full Text Available Prokaryotic communities forming symbiotic relationships with the vent shrimp, Rimicaris exoculata, are well studied components of hydrothermal ecosystems at the Mid-Atlantic Ridge (MAR. Despite the tight link between host and symbiont, the observed lack of spatial genetic structure seen in R. exoculata contrasts with the geographic differentiation detected in specific bacterial ectosymbionts. The geographic clustering of bacterial lineages within a seemingly panmictic host suggests either the presence of finer scale restriction to gene flow not yet detected in the host, horizontal transmission (environmental selection of its endosymbionts as a consequence of unique vent geochemistry, or vertically transmitted endosymbionts that exhibit genetic differentiation. To identify which hypothesis best fits, we tested whether bacterial assemblages exhibit differentiation across sites or host populations by performing a 16S rRNA metabarcoding survey on R. exoculata digestive prokaryote samples (n = 31 taken from three geochemically distinct vents across MAR: Rainbow, Trans-Atlantic Geotraverse (TAG and Logatchev. Analysis of communities across two organs (digestive tract, stomach, three molt colors (white, red, black and three life stages (eggs, juveniles, adults also provided insights into symbiont transmission mode. Examining both whole communities and operational taxonomic units (OTUs confirmed the presence of three main epibionts: Epsilonproteobacteria, Mollicutes and Deferribacteres. With these findings, we identified a clear pattern of geographic segregation by vent in OTUs assigned to Epsilonproteobacteria. Additionally, we detected evidence for differentiation among all communities associated to vents and life stages. Overall, results suggest a combination of environmental selection and vertical inheritance of some of the symbiotic lineages.
Domènech, Francesc; Tomás, Jesús; Crespo-Picazo, José Luis; García-Párraga, Daniel; Raga, Juan Antonio; Aznar, Francisco Javier
Species of Balaenophilus are the only harpacticoid copepods that exhibit a widespread, obligate association with vertebrates, i.e., B. unisetus with whales and B. manatorum with marine turtles and manatees. In the western Mediterranean, juveniles of the loggerhead sea turtle, Caretta caretta are the only available hosts for B. manatorum, which has been found occurring at high prevalence (>80%) on them. A key question is how these epibionts are transmitted from host to host. We investigated this issue based on experiments with live specimens of B. manatorum that were cultured with turtle skin. Specimens were obtained from head-started hatchlings of C. caretta from the western Mediterranean. Hatched nauplii crawled only on rough substrates and lacked the ability to swim. Only copepodites IV and V, and adults, were able to perform directional swimming. Legs 2, 3 and 4 played a major role in swimming and were only well-developed in these stages. Nauplii reared in wells with turtle skin readily fed on this item. Late copepodites and adults also fed on turtle skin but did not consume other potential food items such as fish skin, baleen plates or planktonic algae. Evidences suggest that the transmission of B. manatorum should rely on hosts' bodily contacts and/or swimming of late developmental stages between spatially close hosts. The possibility of long-ranged dispersal is unlikely for two reasons. First, all developmental stages seem to depend on turtle skin as a food resource. Second, the average clutch size of ovigerous females was small (turtles that occur at very low densities (turtles·km-2) in the western Mediterranean. The high prevalence of B. manatorum in loggerhead turtles in this area raises the question whether these turtles have contacts, or tend to closely aggregate, more than is currently believed.
Cristina Gioia Di Camillo
Full Text Available The surface of many marine organisms is colonized by complex communities of microbes, yet our understanding of the diversity and role of host-associated microbes is still limited. We investigated the association between Ectopleura crocea (a colonial hydroid distributed worldwide in temperate waters and prokaryotic assemblages colonizing the hydranth surface. We used, for the first time on a marine hydroid, a combination of electron and epifluorescence microscopy and 16S rDNA tag pyrosequencing to investigate the associated prokaryotic diversity. Dense assemblages of prokaryotes were associated with the hydrant surface. Two microbial morphotypes were observed: one horseshoe-shaped and one fusiform, worm-like. These prokaryotes were observed on the hydrozoan epidermis, but not in the portions covered by the perisarcal exoskeleton, and their abundance was higher in March while decreased in late spring. Molecular analyses showed that assemblages were dominated by Bacteria rather than Archaea. Bacterial assemblages were highly diversified, with up to 113 genera and 570 Operational Taxonomic Units (OTUs, many of which were rare and contributed to <0.4%. The two most abundant OTUs, likely corresponding to the two morphotypes present on the epidermis, were distantly related to Comamonadaceae (genus Delftia and to Flavobacteriaceae (genus Polaribacter. Epibiontic bacteria were found on E. crocea from different geographic areas but not in other hydroid species in the same areas, suggesting that the host-microbe association is species-specific. This is the first detailed report of bacteria living on the hydrozoan epidermis, and indeed the first study reporting bacteria associated with the epithelium of E. crocea. Our results provide a starting point for future studies aiming at clarifying the role of this peculiar hydrozoan-bacterial association.
1. The distribution of egg masses of the freshwater snails Lymnaea stagnalis and Planorbarius corneus on the undersides of water lily leaves (e.g. Nuphar lutea) is related to the prevalence of the leaf-mining beetle Galerucella nymphaeae. 2. When given the choice, Planorbarius significantly avoids leaves that were infested by the mining beetle. Conversely, Lymnaea did not discriminate against mined leaves. 3. Intact Nuphar leaves block over 95% of incident ultraviolet radiation. Yet, ultraviolet transmission reaches almost 100% under beetle mining scars. These are several times wider than snail embryos. 4. When exposed to natural sunlight, Lymnaea embryos proved to be resistant to ambient ultraviolet, while Planorbarius embryos were rapidly killed. Thus, one selective advantage of Planorbarius discrimination against mined leaves when depositing its eggs could be the avoidance of ultraviolet radiation passing through mining scars. 5. Other mining-related modifications of the leaves, reduced area, decreased longevity, altered aufwuchs (i.e. biofilm and epibionts) are discussed but seem less relevant for the oviposition preference of Planorbarius. 6. The discriminatory behaviour of this snail species was triggered by water-borne cues emitted by the damaged leaf, not by the eggs or larvae of the beetle. 7. This study illustrates how environmental stress on a given species, ultraviolet radiation in this case, can be ecologically buffered (shading by Nuphar) or enhanced (reduction of Nuphar shading through beetle mining) by associated species. It highlights how the impact of a given stress depends on the identity of the target species as well as on the identity and role of other species in the community.
Full Text Available Species of Balaenophilus are the only harpacticoid copepods that exhibit a widespread, obligate association with vertebrates, i.e., B. unisetus with whales and B. manatorum with marine turtles and manatees. In the western Mediterranean, juveniles of the loggerhead sea turtle, Caretta caretta are the only available hosts for B. manatorum, which has been found occurring at high prevalence (>80% on them. A key question is how these epibionts are transmitted from host to host. We investigated this issue based on experiments with live specimens of B. manatorum that were cultured with turtle skin. Specimens were obtained from head-started hatchlings of C. caretta from the western Mediterranean. Hatched nauplii crawled only on rough substrates and lacked the ability to swim. Only copepodites IV and V, and adults, were able to perform directional swimming. Legs 2, 3 and 4 played a major role in swimming and were only well-developed in these stages. Nauplii reared in wells with turtle skin readily fed on this item. Late copepodites and adults also fed on turtle skin but did not consume other potential food items such as fish skin, baleen plates or planktonic algae. Evidences suggest that the transmission of B. manatorum should rely on hosts' bodily contacts and/or swimming of late developmental stages between spatially close hosts. The possibility of long-ranged dispersal is unlikely for two reasons. First, all developmental stages seem to depend on turtle skin as a food resource. Second, the average clutch size of ovigerous females was small (< 70 eggs for free-living phases to successfully contact turtles that occur at very low densities (< 0.6 turtles·km-2 in the western Mediterranean. The high prevalence of B. manatorum in loggerhead turtles in this area raises the question whether these turtles have contacts, or tend to closely aggregate, more than is currently believed.
López, Boris A; Macaya, Erasmo C; Tala, Fadia; Tellier, Florence; Thiel, Martin
Dispersal on floating seaweeds depends on availability, viability, and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°-42°S). We determined the biomass and demography of stranded individuals on 33 beaches for three subsequent years (2013, 2014, 2015) to examine whether rafting is restricted to certain districts and seasons (winter or summer). Stranded kelps were found on all beaches. Most kelps had only one stipe (one individual), although we also frequently found coalesced holdfasts with mature males and females, which would facilitate successful rafting dispersal, gamete release, and reproduction upon arrival. High biomasses of stranded kelps occurred in the northern-central (30°S-33°S) and southernmost districts (37°S-42°S), and lower biomasses in the northernmost (28°S-30°S) and southern-central districts (33°S-37°S). The highest percentages and sizes of epibionts (Lepas spp.), indicative of prolonged floating periods, were found on stranded kelps in the northernmost and southernmost districts. Based on these results, we conclude that rafting dispersal can vary regionally, being more common in the northernmost and southernmost districts, depending on intrinsic (seaweed biology) and extrinsic factors (shore morphology and oceanography) that affect local supply of kelps and regional hydrodynamics. © 2016 Phycological Society of America.
S. Valeria Teso
Full Text Available The invasive kelp Undaria pinnatifida (Phaeophyceae, Laminariales was first reported in Golfo Nuevo in 1992 and since then it has spread widely over more than 170 km, all along the northern Patagonian coast, Argentina. Field observations in the region have indicated the potential role of invertebrate grazers, like the sea urchins Arbacia dufresnii and Pseudechinus magellanicus and the gastropod Tegula patagonica, in controlling algal density. Laboratory experiments were conducted to ascertain whether, and if so, to what extent these grazers actually feed on the algae. The studied sea urchins fed on the alga, whereas the snail scraped off biofouling adhered to its surface. Higher densities of grazers were observed on the kelp during summer and might be attributed to increasing in metabolism with increasing temperature, and degradation of blades and sporophylls, which possibly increase their palatability.El alga invasora Undaria pinnatifida (Phaeophyceae, Laminariales fue reportada por primera vez en Golfo Nuevo en 1992, dispersándose ampliamente a lo largo de 170 km de costa en el norte de la Patagonia, Argentina. Observaciones de campo hechas en los erizos de mar Arbacia dufresnii y Pseudechinus magellanicus y en el gasterópodo Tegula patagonica evidenciaron que son posibles consumidores de Undaria pinnatifida en la población local. Se realizaron experimentos de laboratorio con el objetivo de probar si estos pastoreadores eran capaces de consumir el alga. Los erizos de mar estudiados consumen el alga, mientras que el gasterópodo ramonea los epibiontes presentes sobre su superficie. Altas densidades de ramoneadores fueron encontradas sobre el alga durante el verano y podrían ser atribuidas a un aumento del su metabolismo con el aumento de la temperatura y a la degradación de las láminas y esporofilos, lo cual posiblemente aumente la palatabilidad del alga.
Moenne, Alejandra; González, Alberto; Sáez, Claudio A
Green and red macroalgae are closely related organisms, and with terrestrial plants, and constitute the base of marine food webs in coastal ecosystems. Green and red seaweeds, as all living organisms, require essential metals, such as copper, iron, zinc, which can act as co-factors for several proteins and enzymes; however, these metals in excess can induce stress and impair cell viability. Most important negative effects of metal excess are related to the induction of an oxidative stress condition, characterized by the over-accumulation of Reactive Oxygen Species (ROS). In this respect, copper, abundant in wastewaters disposed to coastal environments from domestic and industrial activities, has been one of the most studied metals. Different investigations have provided evidence that green and red macroalgae display several defenses against copper excess to prevent, or at least reduce, stress and damage, among which are cellular exclusion mechanisms, synthesis of metal-chelating compounds, and the activation of the antioxidant system. Most important defense mechanisms identified in green and red seaweed involve: metal-binding to cell wall and epibionts; syntheses of metallothioneins and phytochelatins that accumulate in the cytoplasm; and the increase in the activity of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, glutathione peroxidase and catalase, and greater production of antioxidant metabolites as glutathione and ascorbate in organelles and the cytoplasm. In this review, we go through historical records, latest advances, and pending tasks aiming to expand our current knowledge on defense mechanisms to copper excess in green and red macroalgae, with emphasis on biochemical and molecular aspects. Copyright © 2016 Elsevier B.V. All rights reserved.
Bailey, J.; Flood, B.; Ricci, E.
The colorless sulfur bacteria are non-photosynthetic chemolithotrophs that live at interfaces between nitrate, or oxygen, and hydrogen sulfide. In sulfidic settings such as cold seeps and oxygen minimum zones, these bacteria are thought to constitute a critical node in the geochemical cycling of carbon, sulfur, nitrogen, and phosphorous. Many of these bacteria remain uncultivated and their metabolisms and physiologies are incompletely understood. Thiomargarita namibiensis is the largest of these sulfur bacteria, with individual cells reaching millimetric diameters. Despite the current inability to maintain a Thiomargarita culture in the lab, their large size allows for individual cells to be followed in time course experiments. Here we report on the novel use of a tetrazolium-based dye that measures the flux of NADH production from catabolic pathways via a colorimetric response. Staining with this dye allows for metabolism to be detected, even in the absence of observable cell division. When coupled to microscopy, this approach also allows for metabolism in Thiomargaritato be differentiated from that of epibionts or contaminants in xenic samples. The results of our tetrazolium dye-based assay suggests that Thiomargarita is the most metabolically versatile under anoxic conditions where it appears capable of using acetate, succinate, formate, thiosulfate, citrate, thiotaurine, hydrogen sulfide, and perhaps hydrogen as electron donors. Under hypoxic conditions, staining results suggest the utilization of acetate, citrate, and hydrogen sulfide. Cells incubated under oxic conditions showed the weakest tetrazolium staining response, and then only to hydrogen sulfide and questionably succinate. These initial results using a redox sensitive dye suggest that Thiomargarita is most metabolically versatile under anaerobic and hypoxic conditions. The results of this assay can be further evaluated using molecular approaches such as transcriptomics, as well as provide cultivation
Ni, Sha; Taubner, Isabelle; Böhm, Florian; Winde, Vera; Böttcher, Michael E.
The calcareous tubeworm Spirorbis spirorbis is a widespread serpulid species in the Baltic Sea, where it commonly grows as an epibiont on brown macroalgae (genus Fucus). It lives within a Mg-calcite shell and could be affected by ocean acidification and temperature rise induced by the predicted future atmospheric CO2 increase. However, Spirorbis tubes grow in a chemically modified boundary layer around the algae, which may mitigate acidification. In order to investigate how increasing temperature and rising pCO2 may influence S. spirorbis shell growth we carried out four seasonal experiments in the Kiel Outdoor Benthocosms at elevated pCO2 and temperature conditions. Compared to laboratory batch culture experiments the benthocosm approach provides a better representation of natural conditions for physical and biological ecosystem parameters, including seasonal variations. We find that growth rates of S. spirorbis are significantly controlled by ontogenetic and seasonal effects. The length of the newly grown tube is inversely related to the initial diameter of the shell. Our study showed no significant difference of the growth rates between ambient atmospheric and elevated (1100 ppm) pCO2 conditions. No influence of daily average CaCO3 saturation state on the growth rates of S. spirorbis was observed. We found, however, net growth of the shells even in temporarily undersaturated bulk solutions, under conditions that concurrently favoured selective shell surface dissolution. The results suggest an overall resistance of S. spirorbis growth to acidification levels predicted for the year 2100 in the Baltic Sea. In contrast, S. spirorbis did not survive at mean seasonal temperatures exceeding 24 °C during the summer experiments. In the autumn experiments at ambient pCO2, the growth rates of juvenile S. spirorbis were higher under elevated temperature conditions. The results reveal that S. spirorbis may prefer moderately warmer conditions during their early life stages
Braus, Michael J; Graham, Linda E; Whitman, Thea L
The branched periphytic green alga Cladophora glomerata, often abundant in nearshore waters of lakes and rivers worldwide, plays important ecosystem roles, some mediated by epibiotic microbiota that benefit from host-provided surface, organic C, and O 2 . Previous microscopy and high-throughput sequencing studies have indicated surprising epibiont taxonomic and functional diversity, but have not included adequate consideration of sample replication or the potential for spatial and temporal variation. Here, we report the results of 16S rRNA amplicon-based phylum-to-genus taxonomic analysis of Cladophora-associated bacterial epibiota sampled in replicate from three microsites and at six times during the open-water season of 2014, from the same lake locale (Picnic Point, Lake Mendota, Dane Co., WI, USA) explored by high-throughput sequencing studies in two previous years. Statistical methods were used to test null hypotheses that the bacterial community: (i) is homogeneous across microsites tested, and (ii) does not change over the course of a growth season or among successive years. Results indicated a dynamic microbial community that is more strongly influenced by sampling day during the growth season than by microsite variation. A surprising diversity of bacterial genera known to be associated with the key function of methane-oxidation (methanotrophy), including relatively high-abundance of Crenothrix, Methylomonas, Methylovulum, and Methylocaldum-showed intraseasonal and interannual variability possibly related to temperature differences, and microsite preferences possibly related to variation in methane abundance. By contrast, a core assemblage of bacterial genera seems to persist over a growth season and from year to year, possibly transmitted by a persistent attached host resting stage. © 2017 Phycological Society of America.
Full Text Available Seasonal variation in the relative contributions of littoral and pelagic food sources to the diets of open-water zooplankton and subsequent changes in their trophic positions were investigated with carbon and nitrogen Stable Isotope Analysis (SIA. We selected three open water stations as truly pelagic, but also influenced by littoral and riverine carbon sources. During each of the four seasons, integrated pelagic zooplankton samples were collected over 0-50 m depth intervals at each site along with seston in the size range 1.2-76 μm. In addition, vertical temperature profiles were measured. Littoral benthos from three sites along the main longitudinal axis of the lake was sampled to serve as a reference for tracing Lago Maggiore's littoral carbon isotopic signature. Among stations differences in δ13C and δ15N signatures of the different components of the pelagic food web, from seston to predatory zooplankton, were statistically non significant, thus confirming that allochthonous input may become important only after exceptional rainfall events. Changes in the δ13C pelagic baseline mirrored mean water temperature (0-50 m seasonal changes. Similarly to Lake Geneva, they were likely driven by changes in carbon sources for phytoplankton growth during stratification and vertical water mixing. Differently from what observed for the other taxa, the role of littoral food sources was far from negligible (>50% for diaptomids during winter and spring. We do not know however, whether such a result could be at least partially attributed to the heavy infestation by algal epibionts, or was consequent to the fact that these zooplankters may carry littoral carbon to the pelagial via horizontal migration. In winter, Bythotrephes longimanus was able to prey on Cyclops, thus occupying a trophic position comparable to that of planktivorous fish. Such a result confirms an ability of this visual, invertebrate predator to compete with young zooplanktivorous fish
Wortham, Jennifer L; Vanmaurik, Lauren N; Wayne Price, W
Setae are vital in grooming activities and aiding in the removal of epibionts and sedimentary fouling from the body surfaces of decapod crustaceans. Thus, the setal structures and their arrangement on the grooming appendages and sensory structures of the commercially important shrimp, Macrobrachium rosenbergii, were examined using scanning electron microscopy. Macrobrachium rosenbergii is extensively grown in aquaculture and exhibits unique male morphological forms, termed morphotypes. The three male morphotypes are termed blue-clawed males, orange-clawed males, and small-clawed or undifferentiated males and all three differ in their dominance, behavior, body morphology, and reproductive success. Seven setal types, two of which have never been described in the literature, are identified on the grooming appendages (third maxillipeds, first, second, and fifth pereopods) and antennae: simple, serrate, serrulate, spiniform, pappose, crinoid, and spinulate. The latter two setae are newly identified. Certain setal types, such as serrate and serrulate setae were located and associated with specific grooming appendages such as the first pereopods. The types of setae on the grooming appendages varied among females and male morphotypes and the novel setal types (crinoid and spinulate) were found only on two of the male morphotypes. A literature review of terminology related to the structure of setae and setal types in decapod crustaceans is offered as the usage of various terms is ambiguous and conflicting in the literature. The intention of this review is to provide future authors with a comprehensive collection of terms and images that can be used to describe various aspects of setal morphology in decapods. Copyright © 2014 Wiley Periodicals, Inc.
Moya, Gabriela; Yan, Zheng-Fei; Won, KyungHwa; Yang, Jung-Eun; Wang, Qi-Jun; Kook, MooChang; Yi, Tae-Hoo
A Gram-stain-negative, smooth, bright yellow-pigmented, aerobic, catalase- and oxidase-positive and rod-shaped bacterial strain was isolated from rhizosphere of Hibiscus syriacus L. (Mugunghwa flower) located in Kyung Hee University, Yongin, Gyeonggi, South Korea. Cells were dimorphic, non-motile or non-stalked, and motile by means of peritrichous flagellum. The strain, named THG-AG3.4T, grew at 15-35 °C, at pH 6.5-9.0 and in the presence of 0-1.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain THG-AG3.4T was most closely related to Caulobacter segnis ATCC 21756T (98.64 % similarity), Caulobacter vibrioides CB51T (98.57 %) and Caulobacter henricii ATCC 15253T (97.41 %). The DNA G+C content of strain THG-AG3.4T was 64.0 mol%. In DNA-DNA hybridization, the DNA-DNA relatedness between strain THG-AG3.4T and its closest phylogenetic neighbour was below 55.0 %. The predominant isoprenoid quinone detected in strain THG-AG3.4T was ubiquinone-10 (Q-10). The major polar lipids were found to be an unidentified lipid, two unidentified phosphoglycolipids, five unidentified glycolipids, eight unidentified aminolipids and phosphatidylglycerol. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). Thus, based on the report of the phenotypic, genotypic and phylogenetic characterization of strain THG-AG3.4T, it has been concluded that the isolate represents a novel species of the genus Caulobacter, for which the name Caulobacter hibisci sp. nov. is proposed. The type strain is THG-AG3.4T (=KACC 18849T=CCTCC AB 2016077T).
Sánchez-Porro, Cristina; Kaur, Bhavleen; Mann, Henrietta; Ventosa, Antonio
A Gram-negative, heterotrophic, aerobic, non-endospore-forming, peritrichously flagellated and motile bacterial strain, designated BH1(T), was isolated from samples of rusticles, which are formed in part by a consortium of micro-organisms, collected from the RMS Titanic wreck site. The strain grew optimally at 30-37°C, pH 7.0-7.5 and in the presence of 2-8 % (w/v) NaCl. We carried out a polyphasic taxonomic study in order to characterize the strain in detail. Phylogenetic analyses based on 16S rRNA gene sequence comparison indicated that strain BH1(T) clustered within the branch consisting of species of Halomonas. The most closely related type strains were Halomonas neptunia (98.6 % 16S rRNA sequence similarity), Halomonas variabilis (98.4 %), Halomonas boliviensis (98.3 %) and Halomonas sulfidaeris (97.5 %). Other closely related species were Halomonas alkaliphila (96.5 % sequence similarity), Halomonas hydrothermalis (96.3 %), Halomonas gomseomensis (96.3 %), Halomonas venusta (96.3 %) and Halomonas meridiana (96.2 %). The major fatty acids of strain BH1(T) were C(18 : 1)ω7c (36.3 %), C(16 : 0) (18.4 %) and C(19 : 0) cyclo ω8c (17.9 %). The DNA G+C content was 60.0 mol% (T(m)). Ubiquinone 9 (Q-9) was the major lipoquinone. The phenotypic features, fatty acid profile and DNA G+C content further supported the placement of strain BH1(T) in the genus Halomonas. DNA-DNA hybridization values between strain BH1(T) and H. neptunia CECT 5815(T), H. variabilis DSM 3051(T), H. boliviensis DSM 15516(T) and H. sulfidaeris CECT 5817(T) were 19, 17, 30 and 29 %, respectively, supporting the differential taxonomic status of BH1(T). On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain BH1(T) is considered to represent a novel species, for which the name Halomonas titanicae sp. nov. is proposed. The type strain is BH1(T) (=ATCC BAA-1257(T) =CECT 7585(T) =JCM 16411(T) =LMG 25388(T)).
Full Text Available Abstract Background Swarming motility allows microorganisms to move rapidly over surfaces. The Gram-positive bacterium Paenibacillus vortex exhibits advanced cooperative motility on agar plates resulting in intricate colonial patterns with geometries that are highly sensitive to the environment. The cellular mechanisms that underpin the complex multicellular organization of such a simple organism are not well understood. Results Swarming by P. vortex was studied by real-time light microscopy, by in situ scanning electron microscopy and by tracking the spread of antibiotic-resistant cells within antibiotic-sensitive colonies. When swarming, P. vortex was found to be peritrichously flagellated. Swarming by the curved cells of P. vortex occurred on an extremely wide range of media and agar concentrations (0.3 to 2.2% w/v. At high agar concentrations (> 1% w/v rotating colonies formed that could be detached from the main mass of cells by withdrawal of cells into the latter. On lower percentage agars, cells moved in an extended network composed of interconnected "snakes" with short-term collision avoidance and sensitivity to extracts from swarming cells. P. vortex formed single Petri dish-wide "supercolonies" with a colony-wide exchange of motile cells. Swarming cells were coupled by rapidly forming, reversible and non-rigid connections to form a loose raft, apparently connected via flagella. Inhibitors of swarming (p-Nitrophenylglycerol and Congo Red were identified. Mitomycin C was used to trigger filamentation without inhibiting growth or swarming; this facilitated dissection of the detail of swarming. Mitomycin C treatment resulted in malcoordinated swarming and abortive side branch formation and a strong tendency by a subpopulation of the cells to form minimal rotating aggregates of only a few cells. Conclusion P. vortex creates complex macroscopic colonies within which there is considerable reflux and movement and interaction of cells. Cell
Li, Ma; Hong, Cao Yong; Yan, Wang Xiao; Chao, Zheng Shuai; Gang, Yang Cheng; Ling, Duo Jin; Kui, Zhou Xing; Qin, Xi Jia; Liang, Zhu Ming; He, Mo Ming
A novel strain, 1433 T , was isolated from leaves of Chinese red pepper (Huajiao, Zanthoxylum bungeanum Maxim) collected from Gansu province in northwestern China, and was characterised by a polyphasic approach. Cells of strain 1433 T were observed to be Gram-stain positive, aerobic, asporogenous, rod shaped, motile and to have peritrichous flagella. The strain was observed to grow at a range of temperatures and pH, 4-45 °C (optimum 28-32 °C) and 6.0-10.0 (optimum pH 6.0-7.0), respectively. Growth was found to occur in the presence of 0-7% (w/v) NaCl [optimum 0-3% (w/v)]. The G+C content of the genomic DNA was determined to be 41.9 mol% and the cell wall peptidoglycan found to contain meso-diaminopimelic acid. The predominant menaquinone was identified as MK-7 and the major polar lipids as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified polar lipid and three unidentified phospholipids. The major cellular fatty acids were identified as iso-C 15:0 (31.6%), anteiso-C 15:0 (26.9%) and iso-C 14:0 (17.1%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 1433 T is a member of the genus Bacillus and is closely related to Bacillus aryabhattai DSM 21047 T (99.4% sequence similarity) and Bacillus megaterium DSM 32 T (99.2%). DNA-DNA relatedness of the novel strain 1433 T with B. aryabhattai DSM 21047 T and B. megaterium DSM 32 T was 33.8 ± 2.8% and 28.9 ± 3.4%, respectively. On the basis of the polyphasic evidence presented, strain 1433 T is considered to represent a novel species of the genus Bacillus, for which we propose the name Bacillus zanthoxyli sp. nov. The type strain is 1433 T (= CCTCC AB 2016326 T = KCTC33730 T ).
Siddiqi, Muhammad Zubair; Siddiqi, Muhammad Hanif; Im, Wan Taek; Kim, Yeon-Ju; Yang, Deok-Chun
A Gram-staining-positive, catalase-positive, oxidase-negative, facultatively anaerobic, rod-shaped bacterium designated strain DCY88T, was isolated from flowers of magnolia. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Paenibacillus that was closely related to Paenibacillus hordei RH-N24T (97.8 %). The other most closely related species were Paenibacillus illinoisensis NRRL NRS-1356T (94.3 %), Paenibacillus hunanensis DSM 22170T (94.2 %), Paenibacillus peoriae DSM 8320T (93.9 %), Paenibacillus kribbensis Am49T (93.8 %) and the type species of the genus, Paenibacillus polymyxa ATCC 842T (93.3 %). Cells of the strain were endospore-forming and motile by peritrichous flagella. Strain DCY88T formed pink-pigmented colonies on trypticase soy agar and R2A agar medium. Growth of strain DCY88T occurs at temperatures 5-37 °C, at pH 4-9 and 0.5-5.5 % NaCl (w/v). The menaquinone was MK-7.The cell wall peptidoglycan of strain DCY88T contained meso-diaminopimelic acid. The major fatty acids were anteiso-C15 : 0 (61.0 %) and C16 : 0 (11.0 %). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified polar lipid. The strain DCY88T contained spermidine as the major polyamine. The DNA G+C content was 51.6 mol%. The DNA-DNA hybridization relatedness between strain DCY88T and P. hordei RH-N24T was 48 ± 2 %. The phenotypic, phylogenetic and chemotaxonomic results indicate that the strain DCY88T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus kyungheensis sp. nov. is proposed. The type strain is DCY88T ( = JCM 19886T = KCTC 33429T).
Lee, Michael D; Webb, Eric A; Walworth, Nathan G; Fu, Fei-Xue; Held, Noelle A; Saito, Mak A; Hutchins, David A
form large macroscopic colonies that appear to perpetually host an association of diverse interacting microbes distinct from the surrounding seawater, potentially making the entire assemblage a unique miniature ecosystem. Since its first successful cultivation in the early 1990s, there have been questions about the potential interdependencies between Trichodesmium and its associated microbial community and whether the host's seemingly enigmatic nitrogen fixation schema somehow involved or benefited from its epibionts. Here, we revisit these old questions with new technology and investigate gene expression activities of microbial communities living in association with Trichodesmium . Copyright © 2017 American Society for Microbiology.
Vicente, Jan; Zea, Sven; Hill, Russell T
The new discovery by Vicente et al. (2014) of specialized epizoic symbioses between sponges of the genera Plakortis and Xestospongia revealed the obligate interaction of two new Plakortis spp. associating with Xestospongia deweerdtae and a new Xestospongia sp. In this study we formally describe the two new Plakortis spp. as Plakortis deweerdtaephila sp. nov. (previously reported as Plakortis sp. 1), Plakortis symbiotica sp. nov. (previously reported as Plakortis sp. 2) and describe the new Xestospongia sp. epibiont as Haliclona (Halichoclona) plakophila sp. nov. Plakortis deweerdtaephila associates only with X. deweerdtae, and has very small to large straight diods (24.2-233.7 μm long) and triods (26.4-102.6 μm long) that form large ectosomal circular meshes (114-329 μm diameter). P. symbiotica associates with both X. deweerdtae and H. plakophila, has larger curved diods (71.9-141.8 μm long) and triods (20.4-70.6 μm long) that form smaller ectosomal circular meshes (43-121 μm diameter) than P. deweerdtaephila. Phylogenetic analysis of cox1 and cob gene fragments revealed a strongly supported clade that grouped both Plakortis spp. nov. distantly from any other known Plakortis spp. H. plakophila is described as a thin encrusting veneer of tissue with occasional papillae, so far only found associated with P. symbiotica in La Parguera, Puerto Rico. Phylogenetic analysis of 18S rRNA and cox1 gene fragments place it distantly from any known clade of Haplosclerida. We found a new associated morphotype of X. deweerdtae from Bocas del Toro Panama, which completely overgrew P. deweerdtaephila. In addition, free-living morphotypes from Panama produce larger S-shaped and round bracket shaped strongyles never before observed for this species, leading us to redescribe X. deweerdtae. All X. deweerdtae morphotypes shared >99% sequence homology of cox1, 18S rRNA and 28S rRNA genes with the holotype of X. deweerdtae. This study highlights the highly variable morphological
Pett-Ridge, J.; Finzi, J. A.; Capone, D. G.; Popa, R.; Nealson, K. H.; Ng, W.; Spormann, A. M.; Hutcheon, I. D.; Weber, P. K.
, inter-species transfers (with Rhizobium epibionts), and within-cell depth profiles. Spatial enrichment patterns were correlated with morphological features evidenced in TEM images of microtomed filaments. These features indicate how 15N and 13C "hotspots" are dispersed throughout individual cells in different species, and may indicate isolated locations of increased N2 fixation, sites of amino acid/protein synthesis, or cyanophycin storage granules. This combination of Nano-Secondary Ion Mass Spectrometry (NanoSIMS) analysis and high resolution microscopy allows isotopic analysis to be linked to morphological features and holds great promise for fine-scale studies of bacteria metabolism.
Best, Mairi; Purser, Autun
from the mound. On retrieval, the specimens are being further studied for net material loss, surface alteration, microbial recruitment, endo- and epibionts, and microstructural and chemical modification. Understanding the production and cycling of carbon across the sediment/water interface in this environment will help elucidate the formation and evolution of these hydrate deposits, their distribution through time, and the ecological and taphonomic feedbacks they generate.
Full Text Available Many crustacean species show extended parental care (XPC for fully developed juvenile offspring. Herein, the present state of knowledge of the major patterns and consequences of XPC is reviewed, and furthermore important future research topics are identified. Crustaceans with XPC are found in marine, freshwater and terrestrial environments, but care for late juvenile stages appears to be more common in terrestrial environments. In all species, females participate or even take the main share of XPC activities. Crustaceans that carry their offspring during XPC commonly release early juvenile stages, while species inhabiting particular microhabitats may host offspring until these have reached subadult or adult stages. Apart from providing a suitable and safe microhabitat to small offspring, parents share food with, groom or actively defend their juveniles. Some of the most important benefits of XPC include improved juvenile growth and survival. XPC may also lead to conflicts among developing offspring or between parents and offspring, especially during later phases of XPC when resources (food and space become increasingly limiting. Similarly, during long-lasting cohabitation, epibionts (e.g., parasites may be transferred from parents to offspring, as is indicated by observational evidence. For several species, local recruitment, where juveniles recruit in the immediate vicinity of their parents, has been observed. Under these conditions, local populations may rapidly increase, potentially leading to intra-specific competition for space, thereby possibly causing a decrease in reproductive activity or a reduction in length of XPC. Another consequence of XPC and local recruitment could be limited dispersal potential, but some marine crustaceans with XPC and local recruitment nevertheless have a wide geographic distribution. It is hypothesized that the existence of suitable dispersal vectors such as floating macroalgae or wood can lead to a substantial
Halolactibacillus halophilus gen. nov., sp. nov. and Halolactibacillus miurensis sp. nov., halophilic and alkaliphilic marine lactic acid bacteria constituting a phylogenetic lineage in Bacillus rRNA group 1.
Ishikawa, Morio; Nakajima, Kazuyuki; Itamiya, Yuko; Furukawa, Sayumi; Yamamoto, Yasushi; Yamasato, Kazuhide
Eleven novel strains of marine-inhabiting lactic acid bacteria that were isolated from living and decaying marine organisms collected from a temperate area of Japan are described. The isolates were motile with peritrichous flagella and non-sporulating. They lacked catalase, quinones and cytochromes. Fermentation products from glucose were lactate, formate, acetate and ethanol. Lactate yield as percentage conversion from glucose was affected by the pH of the fermentation medium: approximately 55 % at the optimal growth pH of 8.0, greater than approximately 70 % at pH 7.0 and less than approximately 30 % at pH 9.0. The molar ratio of the other three products was the same at each cultivation pH, approximately 2 : 1 : 1. Carbohydrates and related compounds were aerobically metabolized to acetate and pyruvate as well as lactate. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. The optimum NaCl concentration for growth was 2.0-3.0 % (w/v), with a range of 0-25.5 %. The optimum pH for growth was 8.0-9.5, with a range of 6.0-10.0. The G+C content of the DNA was 38.5-40.7 mol%. The isolates constituted two genomic species (DNA-DNA relatedness of less than 41 %) each characterized by sugar fermentation profiles. The cell-wall peptidoglycan of both phenotypes contained meso-diaminopimelic acid. The major cellular fatty acids were C(16 : 0) and a-C(13 : 0). Comparative sequence analysis of the 16S rRNA genes revealed that these isolates represent novel species constituting a phylogenetic unit outside the radiation of typical lactic acid bacteria and an independent line of descent within the group composed of the halophilic/halotolerant/alkaliphilic and/or alkalitolerant species in Bacillus rRNA group 1, with 94.8-95.1 % similarity to the genus Paraliobacillus, 93.7-94.1 % to the genus Gracilibacillus and 93.8-94.2 % to Virgibacillus marismortui. On the basis of possession of physiological and biochemical characteristics common to typical lactic acid
Tambalo Dinah D
Full Text Available Abstract Background Rhizobium leguminosarum bv. viciae establishes symbiotic nitrogen fixing partnerships with plant species belonging to the Tribe Vicieae, which includes the genera Vicia, Lathyrus, Pisum and Lens. Motility and chemotaxis are important in the ecology of R. leguminosarum to provide a competitive advantage during the early steps of nodulation, but the mechanisms of motility and flagellar assembly remain poorly studied. This paper addresses the role of the seven flagellin genes in producing a functional flagellum. Results R. leguminosarum strains 3841 and VF39SM have seven flagellin genes (flaA, flaB, flaC, flaD, flaE, flaH, and flaG, which are transcribed separately. The predicted flagellins of 3841 are highly similar or identical to the corresponding flagellins in VF39SM. flaA, flaB, flaC, and flaD are in tandem array and are located in the main flagellar gene cluster. flaH and flaG are located outside of the flagellar/motility region while flaE is plasmid-borne. Five flagellin subunits (FlaA, FlaB, FlaC, FlaE, and FlaG are highly similar to each other, whereas FlaD and FlaH are more distantly related. All flagellins exhibit conserved amino acid residues at the N- and C-terminal ends and are variable in the central regions. Strain 3841 has 1-3 plain subpolar flagella while strain VF39SM exhibits 4-7 plain peritrichous flagella. Three flagellins (FlaA/B/C and five flagellins (FlaA/B/C/E/G were detected by mass spectrometry in the flagellar filaments of strains 3841 and VF39SM, respectively. Mutation of flaA resulted in non-motile VF39SM and extremely reduced motility in 3841. Individual mutations of flaB and flaC resulted in shorter flagellar filaments and consequently reduced swimming and swarming motility for both strains. Mutant VF39SM strains carrying individual mutations in flaD, flaE, flaH, and flaG were not significantly affected in motility and filament morphology. The flagellar filament and the motility of 3841 strains
Lukeneder, A.; Halásová, E.; Rehákova, D.; Józsa, Š.; Soták, J.; Kroh, A.; Jovane, L.; Florindo, F.; Sprovieri, M.; Giorgioni, M.; Lukeneder, S.
of Earth Sciences, 103/1, 138-158. Lukeneder A. 2008. The ecological significance of solitary coral and bivalve epibionts on Lower Cretaceous (Valanginian-Aptian) ammonoids from the Italian Dolomites. Acta Geologica Polonica, 58/4, 425-436. Lukeneder, A., Aspmair, C. 2006. Startigraphic implication of a new Lower Cretaceous ammonoid fauna from the Puez area (Valanginaian - Aptian, Dolomites, Southern Alps, Italy). Geo.Alp, 3, 55-91.