WorldWideScience

Sample records for microalgae rotifer artemia

  1. Real-time PCR detection and quantification of fish probiotic Phaeobacter strain 27-4 and fish pathogenic Vibrio in microalgae, rotifer, Artemia and first feeding turbot (Psetta maxima) larvae

    Prol, M.J.; Bruhn, Jesper Bartholin; Pintado, J.

    2009-01-01

    and in presence of microalgae (Isochrysis galbana), rotifers (Brachionus plicatilis), Artemia nauplii or turbot (Psetta maxima) larvae by real-time PCR based on primers directed at genetic loci coding for antagonistic and virulence-related functions respectively. The optimized protocol was used to study...

  2. Use of Probiotic Bacillus spp. in Rotifer (Brachionus plicatilis) and Artemia (Artemia urmiana) Enrichment: Effects on Growth and Survival of Pacific White Shrimp, Litopenaeus vannamei, Larvae.

    Jamali, Hadi; Imani, Ahmad; Abdollahi, Daruosh; Roozbehfar, Reza; Isari, Amin

    2015-06-01

    This study was to evaluate the effect of a preparation of Bacillus probiotic (Bacillus licheniformis and B. subtilis, 1:1) on growth and survival rate of Pacific white shrimp, Litopenaeus vannamei larvae. The larvae were fed on Artemia urmiana nauplii and Brachionus plicatilis enriched with the probiotic preparation at 1 × 10(6) CFU mL(-1) rate. The experimental setup was completely randomized design comprised of six treatments, namely solo Artemia nauplii (A) or rotifer (R), Artemia nauplii and rotifer without any enrichment (A + R), Artemia nauplii enrichment with probiotic bacilli (Bacillus licheniformis and B. subtilis) (A + B), rotifer enrichment with probiotic bacilli (R + B) and enriched Artemia nauplii and rotifer (A + R + B). All treatments were performed in triplicate. Chemical parameters of rearing water viz. pH, salinity and temperature were 7.5-8, 30-31 ppt and 31-32 °C, respectively. Photoperiod was 16L:8D. Shrimp larvae were fed Artemia nauplii and rotifers at 5-20 and 10-40 individuals per shrimp larvae four times a day, respectively. Growth and survival rate of larvae were determined at MII, MIII, PL1, PL4, PL7 and PL10 stages. Larvae in A + R + B treatment showed the highest total length (10.89 ± 0.51 mm), weight (674 ± 73 μg) and survival rate (65% ± 3.5). Lowest total length, weight and survival rate (7.96 ± 0.63 mm, 493 ± 52 μg and 24.5 ± 2.4%, respectively) were recorded in treatment B larvae. We concluded that Bacillus probiotic can improve growth and survival rate of Pacific white shrimp larvae without conceivably undesirable effects.

  3. Successful Replacement of Artemia salina nauplii with Marine Rotifers (Brachionus plicatilis) in the Diet of Preadult Zebrafish (Danio rerio).

    Lawrence, Christian; James, Althea; Mobley, Scottie

    2015-10-01

    Previously established rearing protocols for zebrafish begin feeding with marine rotifers (Brachionus plicatilis), followed by Artemia nauplii until the fish reach subadult stage, the developmental time point at which they can be most easily transitioned onto a processed diet. However, the inclusion of Artemia is less than ideal, given its fluctuating availability and high costs. We tested whether or not we could replace Artemia with rotifers during our normal rearing sequence and still meet published performance standards for (i) weaning fish onto a processed diet by 25 days postfertilization (dpf) and (ii) successful breeding by 60 dpf. Here, we present the results of trials where wild-type and casper zebrafish were fed exclusively with rotifers (R) or rotifers followed by Artemia (RA) for the first 25 dpf after which point all fish were transitioned to a processed diet (Gemma Micro 300). We measured growth and survival at days 25 and 60, and tested for reproductive capability at 60 dpf. While growth performance was significantly better in the RA groups, we were still able to meet goals for both weaning and generation time in the R groups without compromising survival or sex ratios.

  4. The changes in the biochemical compositions and enzymatic activities of rotifer (Brachionus plicatilis, Müller) and Artemia during the enrichment and starvation periods.

    Naz, Mehmet

    2008-12-01

    The changes in the biochemical compositions and enzymatic activities of rotifer (Brachionus plicatilis) and Artemia, enriched and stored at 4 degrees C temperature, were determined. The total starvation period was 16 h and samples were taken at the end of the 8th and 16th hours. In present study, the rotifer and nauplii catabolized a large proportion of the protein during the enrichment period. Lipid contents of both live preys increased during the enrichment period and decreased in nauplii and metanauplii throughout the starvation period but lipid content of the rotifer remained relatively constant during the starvation period. The changes observed in the amino acid compositions of Artemia and the rotifer were statistically significant (P < 0.05). The conspicuous decline the essential amino acid (EAA) and nonessential amino acid (NEAA) content of the rotifer was observed during the enrichment period. However, the essential amino acid (EAA) and nonessential amino acid (NEAA) contents of Artemia nauplii increased during the enrichment period. The unenriched and enriched rotifers contained more monounsaturated fatty acid (MUFAs) than polyunsaturated fatty acid (PUFAs) and saturated fatty acids (SFA). However, Artemia contained more PUFAs than MUFAs and SFA during the experimental period. A sharp increase in the amounts of docosahexaenoic acid (DHA) during the enrichment of the rotifer and Artemia nauplii was observed. However, the amount of DHA throughout the starvation period decreased in Artemia metanauplii but not in Artemia nauplii. Significant differences in tryptic, leucine aminopeptidase N (LAP), and alkaline phosphatase (AP) enzyme activities of Artemia and rotifer were observed during the enrichment and starvation period (P < 0.05). The digestive enzymes derived from live food to fish larvae provided the highest contribution at the end of the enrichment period. In conclusion, the results of the study provide important contributions to determine the most

  5. Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

    D'Alvise, Paul; Lillebø, Siril; Prol García, María Jesús

    2012-01-01

    -antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7) cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio...

  6. Effect of temperature and viscosity on swimming velocity of the copepod Acartia tonsa, brine shrimp Artemia salina and rotifer Brachionus plicatilis

    Larsen, Poul Scheel; Madsen, C.V.; Riisgard, H.U.

    2008-01-01

    Beating cilia are important organelles for swimming in many zooplanktonic aquatic organisms, including many invertebrate larvae, rotifers and ciliates, but other planktonic organisms, such as copepods and brine shrimps, use muscle-powered swimming appendages. In recent studies we found...... of swimming velocity for a 10 degrees C temperature reduction) that is found to be largest for the brine shrimp Artemia salina nauplius (37 %) and the rotifer Brachionus plicatilis (26%), but negligible for the copepod Acartia tonsa (4%). We suggest that experimental data on change in swimming velocity (V......) due to change in kinematic viscosity (v) be correlated in terms of a power law, V proportional to v(-m). The present data on swimming velocity of copepods, brine shrimps and rotifers show values of exponent m approximate to 1.5 to 3, with a trend of decreasing values for increasing size of species...

  7. The Effects of Microalgae as Live Food for Brachionus plicatilis (Rotifer) in Intensive Culture System.

    Rahman, Abdull Razak Abd; Cob, Zaidi Che; Jamari, Zainoddin; Mohamed, Abdul Majid; Toda, Tatsuki; Ross, Othman Haji

    2018-03-01

    Brachionus plicatilis is used to feed fish and crustacean larvae in the aquaculture industry. It is well established that the type of microalgae may influence rotifer production. This experiment was conducted to determine the effect of five different locally available microalgae species at Fisheries Research Institute (FRI), Kampung Pulau Sayak, Kedah, Malaysia on the instantaneous growth rate (μ) of rotifer. Nannochloris sp., Tetraselmis sp., Isochrysis sp., Chlorella sp., and Nannochloropsis sp. were used as feed at different algae densities (0.1, 0.3, 0.7 and 1.5 × 10 6 cells/ml) and culture volumes (20, 70 and 210 ml). At algae densities ranging from 0.3 to 1.5 × 10 6 cells/ml, an average μ value of more than 0.90 per day were recorded for all algae species. However, at density of 0.1 × 10 6 cells/ml, only Tetraselmis sp. resulted in the significantly highest μ value compared with others ( p < 0.05). In terms of volume, smaller culture volume of Tetraselmis sp. (20 ml) showed significantly higher μ compared with higher volume (70 and 210 ml cultures).

  8. In vitro populations of rotifer Brachionus plicatilis Müller demonstrate inhibition when fed with copper-preaccumulating microalgae.

    Moreno-Garrido, I; Lubián, L M; Soares, A M

    1999-10-01

    Four marine microalgal species (Chlorella autotrophyca, Nannochloropsis gaditana, Tetraiselmis chuii, and Isochrysis aff. galbana) were exposed for 24 h to 1 mg L(-1) dissolved copper and then transferred to fresh medium. After that, a group of 10 neonate rotifers were fed with these four microalgal species. The levels of accumulated copper in cellular concentrations of the microalgae were checked, with the result of around 40% of original concentration, with the exception of I. aff. galbana (25% of original concentration). In all cases, cells with preaccumulated metal caused a delay of 1 or 2 days in populational development of rotifers (increase in "lag phase"). The microalgae that were not fed to rotifers (disposed in parallel series) did not significantly transfer metal to the medium after the first day.

  9. Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

    D’Alvise, Paul W.; Lillebø, Siril; Prol-Garcia, Maria J.; Wergeland, Heidrun I.; Nielsen, Kristian F.; Bergh, Øivind; Gram, Lone

    2012-01-01

    Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 107 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA) did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua) to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect. PMID:22928051

  10. Phaeobacter gallaeciensis reduces Vibrio anguillarum in cultures of microalgae and rotifers, and prevents vibriosis in cod larvae.

    Paul W D'Alvise

    Full Text Available Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect.

  11. Assessment of endemic microalgae as potential food for Artemia franciscana culture

    Juan M Pacheco-Vega

    2015-03-01

    Full Text Available In this study, five microalgal strains were isolated from Bahía de La Paz, Baja California Sur, Mexico and identified as Grammatophora sp., Navícula sp., Rhabdonema sp., Schizochytrium sp., and Nitzschia sp., and their evaluation as potential food for Artemia franciscana. The isolated strains were cultured outdoors and harvested after four days. Chaetoceros muelleri was cultured under laboratory conditions and used as control. The protein, lipid, and carbohydrate composition and the fatty acid profiles of the strains were determined by gas chromatography. To assess the effect of microalgal strains on A. franciscana, decapsulated cysts were cultured at outdoor conditions in 15 L containers. The experiment was conducted for twelve days. Samples from the five different feeding treatments were taken at the beginning and end of the experiment to assess number, size, and weight of Artemia larvae. Treatment with Rhabdonema sp. showed larvae with a lower percentage of polyunsaturated fatty acids (PUFAs while Grammatophora sp. showed those with the greatest PUFA proportion, even more than those fed Chaetoceros muelleri (control. Larvae consuming Schizochytrium sp. had no docosahexanoic (DHA nor eicosapentaenoic (EPA fatty acid content. Growth and survival of A. franciscana did not show significant differences among feed treatments, except when it was fed Nitzschia sp., showing lower survival and dry weight. Treatment based on Schizochytrium sp. and Rhabdonema sp. had a greater A. franciscana size but reduced dry weight; additional tests including two or more algal species for every treatment should be carried out to determine the best yield.

  12. [Effects of red tide microalgae Alexandrium tamarense on the life history of rotifer Brachionus plicatilis].

    Xie, Zhi-Hao; Xiao, Huh; Cai, Heng-Jiang; Wang, Ren-Jun; Tang, Xue-Xi

    2007-12-01

    In this paper, life-table method was used to study the effects of different concentration Alexandrium tamarense on the durations of different development stages of Brachionus plicatilis and the characters of its population growth. The results showed that A. tamarense had significant effects on the growth and development of B. plicatilis via prolonging the durations of the rotifer' s pre-reproduction and generation succession, shortening the durations of its reproduction and post-reproduction and its mean lifespan, and reducing its laying eggs and fecundity. The net reproduction rate and intrinsic increasing rate of B. plicatilis decreased significantly, in comparison with those of the control. B. plicatilis could maintain definite population increase at the presence of different concentration A. tamarense.

  13. Growth and survival of Octopus vulgaris (Cuvier 1797 paralarvae fed on three Artemia-based diets complemented with frozen fish flakes, crushed zooplankton and marine microalgae

    Lidia Fuentes

    2011-07-01

    Full Text Available During one month, paralarvae of common octopus (Octopus vulgaris were fed 3 different diets: (1 Artemia sp. enriched with Isochrysis galbana (AI complemented with sand eel (Hyperoplus lanceolatus flakes (AH; (2 Artemia sp. enriched with crushed marine zooplankton (AZ; and (3 Artemia sp. cultured with Isochrysis galbana and further enriched with the microalga Nannochloropsis sp. (AN. The highest dry weight (1.6179±0.3861 mg was registered with the AN diet and the best average survival (67.0% with the AZ diet. Considering the highest dry weight obtained, the moderate high survival and the fact that with this diet it was possible to attain the adult stage, the AN diet was the most appropriate. The reasons for the best result in growth observed with AN are discussed as: (1 the combination of docosahexaenoic acid (DHA provided by Isochrysis galbana and the high eicosapentaenoic acid (EPA content present in Nannochloropsis sp.; (2 the fact that the higher protein/lipid ratio of this diet improves the final dry weight of the paralarvae; and (3 the fact that Nannochloropsis sp. could inhibit the harmful microflora growth in the rearing tank. Regarding nutritional aspects, DHA content per se is not the only determinant factor for growth and survival of O. vulgaris paralarvae, but the presence of a high protein/lipid ratio and a high phospholipid content in the diet could possibly explain the better quality and strength of the paralarvae.

  14. Substituição de Artemia sp. pelo rotífero Brachionus plicatilis na larvicultura do camarão-d'água-doce (Macrobrachium rosenbergii De Man, 1879 Replacement of the Artemia sp. for the rotifer Brachionus plicatilis in the hatchering of the freshwater prawn (Macrobrachium rosenbergii De Man, 1879

    Luciana Almada Thomaz

    2004-12-01

    sp. for the enriched and frozen rotifer (Brachionus plicatilis O.F. Müller, 1786 on the larval development and survival of the freshwater prawn M. rosenbergii. The experiment was developed according to the following treatments: 100% B. plicatilis (30 rots/ mL (T1; 100% Artemia sp. (5 nas/ mL (T2, 60% Artemia sp. (3 nas/ mL + 40% B. plicatilis (12 rots/ mL (T3 e 40% Artemia sp. (2 nas/ mL + 60% B. plicatilis (18 rots/ mL (T4. Humid ration was added to all treatments. The results of the final survival in post-larvae were analyzed by the X² test and demonstrated no significant differences from treatment T2 (68.36% to T3 and T4: 68.76% and 64.60%, respectively. T1 treatment (100% B. plicatilis presented total mortality at 14th day of the experiment. Average dry weight of the pos-larvae was analyzed statistically by ANOVA and showed no significant differences in values: 3.29 mg (T2, 3.08 mg (T3 and 3.38 mg (T4. No significant differences among treatments T2, T3 and T4 were observed. The best mortality rate was observed from 1 to 15 day of hatchery based on the number of dead larval stored in the daily material siphoned. Therefore, these results suggest that the total substitution of the enriched and frozen rotifer is not recommended due to a total mortality of larvae, whereas the partial replacement of 40% and 60% of the Artemia sp nauplii by the enriched and frozen rotifer is possible, with no significant damages to survival and post-larval growth.

  15. Laboratory scale photobioreactor for high production of microalgae Rhodomonas salina used as food for intensive copepod cultures

    Thuy, Minh Vu Thi; Jepsen, Per Meyer; Hansen, Benni Winding

    Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems (photobio......Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems...... for copepods (Støttrup and Jensen, 1990; Zhang et al., 2013). Despite the benefit of using R. salina in cultivation of copepods, to our knowledge, there is no report on the production of this microalga at industrial scale to supply sufficient food for mass production of copepods. We intend to conduct the basic...... was cultivated continuously at temperature of 20ºC and salinity of 30ppt in two tubular PBRs with addition of CO2. The experiment was run two times and each PBR in 18 - 30 days. Periodically, the algae were sampled for analyzing the growth, biochemical composition and production. An exponential light model...

  16. Effect of enriched Brachionus plicatilis and Artemia salina nauplii by ...

    The growth, developmental stages and survival rates of Sparus aurata larvae fed with Brachionus plicatilis and Artemia salina nauplii enriched by microalga Tetraselmis chuii were studied. Two experiments were carried out; the first concerning with culturing the microalga (T. chuii) in four different media, then using these ...

  17. The Complete and Updated "Rotifer Polyculture Method" for Rearing First Feeding Zebrafish

    Lawrence, Christian; Best, Jason; Cockington, Jason; Henry, Eric C.; Hurley, Shane; James, Althea; Lapointe, Christopher; Maloney, Kara; Sanders, Erik

    2016-01-01

    The zebrafish (Danio rerio) is a model organism of increasing importance in many fields of science. One of the most demanding technical aspects of culture of this species in the laboratory is rearing first-feeding larvae to the juvenile stage with high rates of growth and survival. The central management challenge of this developmental period revolves around delivering highly nutritious feed items to the fish on a nearly continuous basis without compromising water quality. Because larval zebrafish are well-adapted to feed on small zooplankton in the water column, live prey items such as brachionid rotifers, Artemia, and Paramecium are widely recognized as the feeds of choice, at least until the fish reach the juvenile stage and are able to efficiently feed on processed diets. This protocol describes a method whereby newly hatched zebrafish larvae are cultured together with live saltwater rotifers (Brachionus plicatilis) in the same system. This polyculture approach provides fish with an "on-demand", nutrient-rich live food source without producing chemical waste at levels that would otherwise limit performance. Importantly, because the system harnesses both the natural high productivity of the rotifers and the behavioral preferences of the fish, the labor involved with maintenance is low. The following protocol details an updated, step-by-step procedure that incorporates rotifer production (scalable to any desired level) for use in a polyculture of zebrafish larvae and rotifers that promotes maximal performance during the first 5 days of exogenous feeding. PMID:26863035

  18. Optimised selenium enrichment of Artemia sp. feed to improve red drum (Sciaenops ocellatus) larvae rearing.

    Juhász, Péter; Lengyel, Szvetlana; Udvari, Zsolt; Sándor, Alex Nagy; Stündl, László

    2017-09-01

    Selenium is an essential microelement for the normal functioning of life processes. Moreover, it is a component of enzymes with antioxidant effects. However, it has the smallest window of any micronutrient between requirement and toxicity. Selenium is a regularly used element in fish feeds; moreover, enriching zooplankton with selenium to rear larvae is also a well-known technology. It is accepted that the most common starter foods of fish larvae, natural rotifers contain the smallest dosage of selenium, but providing selenium enriched Artemia sp. instead could increase survival and growth rate of fish. However, no such references are available for the red drum (Sciaenops ocellatus) larvae. Therefore, in this study, Artemia sp. was enriched with nano-selenium of verified low toxicity and easy availability in 5 treatments (1, 5, 10, 50, 100 mg/l Se), and then, fish larvae were fed with four of these enriched Artemia stocks (1, 5, 10, 50 mg/l Se) and a control group. At the end of the 9-day-long experiment, survival rate (S) and growth parameters (SL, W, K-factor, SGR) of fish larvae were calculated as well as their selenium retention and glutathione peroxidase enzyme activity were analysed. It was revealed that a moderate level of selenium enrichment (~4 mg/kg dry matter) of Artemia sp. positively influences the rearing efficiency (i.e. survival and growth) of fish larvae, but higher dosages of selenium could cause adverse effects.

  19. Complexity in a population of Artemia

    Ali, A.A., E-mail: abduladem1@yahoo.co [Electrical Engineering Department, University of Basrah (Iraq); Fortuna, L., E-mail: lfortuna@diees.unict.i [DIEEI, Faculty of Engineering, University of Catania (Italy); Frasca, M., E-mail: mfrasca@diees.unict.i [DIEEI, Faculty of Engineering, University of Catania (Italy); Rashid, M.T., E-mail: mofid76@yahoo.co [Electrical Engineering Department, University of Basrah (Iraq); Xibilia, M.G., E-mail: mxibilia@ingegneria.unime.i [DiSIA, Faculty of Engineering, University of Messina (Italy)

    2011-04-15

    Highlights: Experiments on collective motion of populations of animals (Artemia salina). Design of low-cost experimental setup for complex systems. Control of collective motion of populations of Artemia. Models of collective motion of populations of Artemia. - Abstract: Artemia salina belongs to a genus of very primordial crustaceans, whose behavior is not widely investigated in literature. Their collective behavior is studied in this paper both experimentally and theoretically. Different experiments have been designed to control the direction of motion of an Artemia population by exploiting their sensitivity to light and to measure the response of the population to light at different wavelengths. Mathematical models have been also derived, explaining the mechanisms underlying Artemia flocking formation when a light spot is applied to the system. The results obtained allow to develop new strategies for distributed control of agents and to test them in a simple and low cost experimental setup.

  20. Complexity in a population of Artemia

    Ali, A.A.; Fortuna, L.; Frasca, M.; Rashid, M.T.; Xibilia, M.G.

    2011-01-01

    Highlights: → Experiments on collective motion of populations of animals (Artemia salina). → Design of low-cost experimental setup for complex systems. → Control of collective motion of populations of Artemia. → Models of collective motion of populations of Artemia. - Abstract: Artemia salina belongs to a genus of very primordial crustaceans, whose behavior is not widely investigated in literature. Their collective behavior is studied in this paper both experimentally and theoretically. Different experiments have been designed to control the direction of motion of an Artemia population by exploiting their sensitivity to light and to measure the response of the population to light at different wavelengths. Mathematical models have been also derived, explaining the mechanisms underlying Artemia flocking formation when a light spot is applied to the system. The results obtained allow to develop new strategies for distributed control of agents and to test them in a simple and low cost experimental setup.

  1. Factors affecting egg ratios in planktonic rotifers

    Sarma, S.S.S.; Gulati, R.D.; Nandini, S.

    2005-01-01

    Edmondson’s egg ratio (number of amictic eggs per female) is an important life history variable, which has been in wide use to understand and predict patterns of population growth in planktonic rotifers under field conditions. It is also useful as an indicator of the health of rotifers under culture

  2. The Brine Shrimp Artemia Survives in Diluted Water of Lake Bunyampaka, an Inland Saline Lake in Uganda

    Martin Sserwadda

    2018-02-01

    Full Text Available Ugandan aquaculture is in the process of development; however, it requires access to an affordable live food source, such as brine shrimp Artemia. This study fits within a broader feasibility study of domestic Artemia production in salt lakes. Since Uganda is a landlocked country, the only opportunity for live water food sources lies in the salt lakes in the west of the country. This study used saline water from one of these lakes, Lake Bunyampaka (salinity 72 mg L−1. Two Artemia strains, i.e., the Great Salt Lake strain, which is the dominant strain on the market, and the Vinh Chau strain, which is by far the most inoculated strain in the world, were assayed for their survival, growth, and reproduction in diluted Lake Bunyampaka water, using natural seawater as control. The organisms were fed live freshly cultured microalgae Tetraselmis suecica ad libitum. Our study revealed that the Vinh Chau strain performed especially well in Lake Bunyampaka water diluted to 50 g L−1. The data presented in this study generate the first useful information for the future inoculation of Artemia in Lake Bunyampaka in Uganda, and hence domestic Artemia production in the country; however, further larger-scale laboratory work, followed by field trials, is still needed.

  3. Manual on the production and use of live food for aquaculture

    Lavens, P; Sorgeloos, Patrick

    1996-01-01

    .... The manual is divided into different sections according to the major groups of live food organisms used in aquaculture, namely micro-algae, rotifers, Artemia, natural zooplankton, and copepods...

  4. Adult Artemia as food for juvenile prawns

    Royan, J.P.; Sumitra-Vijayaraghavan; Krishnakumari, L.

    Feeding experiments on three commercially important shrimps Penaues indicus, Metapenaeus dobsoni and M. monoceros were carried out using adult Artemia as feed. Good growth and food conversion efficiencies were recorded at 15% feeding level in all...

  5. MANAJEMEN KULTUR ROTIFER DENGAN TANGKI VOLUME KECIL

    Philip Teguh Imanto

    2009-04-01

    Full Text Available Keberhasilan pembenihan ikan sangat dipengaruhi keberhasilan produksi jasad pakan rotifer secara tepat dan efisien. Penelitian kultur rotifer dengan tangki volume kecil bertujuan untuk mendapatkan efisiensi produksi yang paling optimal dan memenuhi prinsip dasar akuakultur low volume high density. Penelitian menggunakan tangki polyethylene dengan volume 500 L dan volume media awal 100 L, padat tebar awal 200 ind. rotifer per mL dengan sediaan pakan dasar fitoplankton Nannocloropsis occulata, ragi roti (0,05 g/mio.rot./feeding dan suplemen Scott emulsion (0,005 g/mio.rot./feeding. Penelitian dilakukan secara bertahap; tahap pertama (I tanpa penambahan air laut, peningkatan volume hanya dari penambahan 15 L Nannochloropsis tiap hari sampai hari kelima, tahap kedua (II dengan penambahan alga 40 L dan air laut 40 L; serta tahap ketiga (III dengan menggandakan pemberian ragi roti. Hasil penelitian menunjukkan bahwa pada percobaan tahap I: total produksi rata-rata 122,37 x 106 ind. rotifer, pada tahap II: 97,67 x 106 ind. rotifer, dan pada tahap III: dicapai rata-rata total produksi tertinggi dengan 187,17 x 106 ind. rotifer per tanki kultur 500 L. Pengelolaan kultur pada tahap III memberikan hasil terbaik dengan simpangan terkecil antar tangki kultur ulangan, dan membuktikan sebagai pengelolaan terbaik untuk kultur rotifer dengan tangki volume kecil.  Success of marine seed production is highly influenced by effective and efficient production performance of life food rotifer. Observation on rotifer culture using small volume tank was aimed to get the optimum production and efficiency, to fulfill the basic principle of aquaculture “low volume high density”. Polyethylene tanks of 500 L. were used as culture container, with initial 100 liter sea water as culture medium and initial density of 200 ind. rotifer per mL. N. occulata, baker yeast (0.05 g/mio.rotifer/feeding and Scott emulsion (0.005 g/mio.rotifer/feeding were used as basic feed, and

  6. Preface: evolving rotifers, evolving science: Proceedings of the XIV International Rotifer Symposium

    Devetter, Miloslav; Fontaneto, D.; Jersabek, Ch.D.; Welch, D.B.M.; May, L.; Walsh, E.J.

    2017-01-01

    Roč. 796, č. 1 (2017), s. 1-6 ISSN 0018-8158 Institutional support: RVO:60077344 Keywords : evolving rotifers * 14th International Rotifer Symposium * evolving science Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.056, year: 2016

  7. Ingestion of Brachionus plicatilis under different microalgae conditions

    Zhou, Wenli; Tang, Xuexi; Qiao, Xiuting; Wang, You; Wang, Renjun; Feng, Lei

    2009-09-01

    The effects of four microalgae, Chlorella vulgaris, Platymonas helgolandicavar, Isochrysis galbana, and Nitzschia closterium on the grazing and filtering rates of the marine rotifer, Brachionus plicatilis, were evaluated under laboratory conditions. The grazing rates in separate cultures of the four microalga were as follows: C. vulgaris > P. helgolandicavar > I. galbana > N. closterium. However, the filtering rates occurred in the following order: P. helgolandicavar > N. closterium > C. vulgaris > I. galbana. A mixed diets experiment revealed that P. helgolandicavar was the preferred diet of B. plicatilis. In addition, the grazing rate of B. plicatilis increased gradually as the density of the microalgae increased, until concentrations of 2.5×106 cells mL-1 for C. vulgaris and 1.5×106 cells mL-1 for I. galbana were obtained. Furthermore, the filtering rate increased slightly when the density of the microalgae was low, after which it declined as the microalgal density increased. The grazing rates of B. plicatilis were as follows during the different growth phases: stationary phase > exponential phase > lag phase > decline phase. Additionally, the filtering rates during the growth phases were: exponential phase > lag phase > stationary phase > decline phase. The results of this study provide foundational information that can be used to explore the optimal culture conditions for rotifers and to promote the development of aquaculture.

  8. Microalgae Nutraceuticals

    Marcello Nicoletti

    2016-08-01

    Full Text Available Among the new entries in the food supplements sector, an important place must be assigned to nutraceuticals containing microalgae, nowadays accounting for a large and rapidly expanding market. The marketed products are mainly based on three production strains, i.e., Spirulina and Chlorella, followed at a distance by Klamath. It is a composite situation, since two of them are cyanobacteria and the second one is eukaryotic. The reality is that each presents similarities in shape and appearance concerning the marketed form and several utilizations, and peculiarities that need special attention and adequate studies. First, general information is reported about the current scientific knowledge on each microalga, in particular the nutritional value and properties in prevention and wellbeing. Second, original studies are presented concerning the quality control of marketed products. Quality control is a key argument in nutraceuticals validation. Microalgae are particular organisms that need specific approaches to confirm identity and validate properties. The proposed control of quality is based on microscopic analysis of the morphologic characteristics. The final parts of this paper are dedicated to the need for specificity in uses and claims and to considerations about the future of microalgae in food supplements.

  9. Swimming speed alteration of Artemia sp. and Brachionus plicatilis as a sub-lethal behavioural end-point for ecotoxicological surveys.

    Garaventa, Francesca; Gambardella, Chiara; Di Fino, Alessio; Pittore, Massimiliano; Faimali, Marco

    2010-03-01

    In this study, we investigated the possibility to improve a new behavioural bioassay (Swimming Speed Alteration test-SSA test) using larvae of marine cyst-forming organisms: e.g. the brine shrimp Artemia sp. and the rotifer Brachionus plicatilis. Swimming speed was investigated as a behavioural end-point for application in ecotoxicology studies. A first experiment to analyse the linear swimming speed of the two organisms was performed to verify the applicability of the video-camera tracking system, here referred to as Swimming Behavioural Recorder (SBR). A second experiment was performed, exposing organisms to different toxic compounds (zinc pyrithione, Macrotrol MT-200, and Eserine). Swimming speed alteration was analyzed together with mortality. The results of the first experiment indicate that SBR is a suitable tool to detect linear swimming speed of the two organisms, since the values have been obtained in accordance with other studies using the same organisms (3.05 mm s(-1) for Artemia sp. and 0.62 mm s(-1) for B. plicatilis). Toxicity test results clearly indicate that swimming speed of Artemia sp. and B. plicatilis is a valid behavioural end-point to detect stress at sub-lethal toxic substance concentrations. Indeed, alterations in swimming speed have been detected at toxic compound concentrations as low as less then 0.1-5% of their LC(50) values. In conclusion, the SSA test with B. plicatilis and Artemia sp. can be a good behavioural integrated output for application in marine ecotoxicology and environmental monitoring programs.

  10. Effect of concentrations of Artemia salina on zootechnical ...

    The best performances of survival, growth and metamorphosis were produced by 3 AN/ml concentrations of Artemia. The cost of food has increased with the concentration level of Artemia. Then, the production of viable shrimp post larvae and cheaper may be done at 3 AN/ml optimal concentrations of Artemia. Keywords: ...

  11. Factors influencing Artemia populations in Antillean salines

    Kristensen, Ingvar; Hulscher-Emeis, T. Marian

    1972-01-01

    In the Netherlands Antilles two extreme “forms” of Artemia salina, f. arietina and f. milhauseni, show all intermediate gradations. They hybridize constantly. When forma arietina is moved from lower concentrations into highly concentrated brine it will produce offspring that exhibit characteristics

  12. Selective feeding of bdelloid rotifers in river biofilms.

    Benoit Mialet

    Full Text Available In situ pigment contents of biofilm-dwelling bdelloid rotifers of the Garonne River (France were measured by high performance liquid chromatography (HPLC and compared with pigment composition of surrounding biofilm microphytobenthic communities. Among pigments that were detected in rotifers, the presence of carotenoids fucoxanthin and myxoxanthophyll showed that the rotifers fed on diatoms and cyanobacteria. Unexpectedly, while diatoms strongly dominated microphytobenthic communities in terms of biomass, HPLC results hinted that rotifers selectively ingested benthic filamentous cyanobacteria. In doing so, rotifers could daily remove a substantial fraction (up to 28% of this cyanobacterial biomass. The possibility that the rotifers hosted symbiotic myxoxanthophyll-containing cyanobacteria was examined by localisation of chlorophyll fluorescence within rotifers using confocal laser scanning microscopy (CLSM. CLSM results showed an even distribution of quasi-circular fluorescent objects (FO throughout rotifer bodies, whereas myxoxanthophyll is a biomarker pigment of filamentous cyanobacteria, so the hypothesis was rejected. Our results also suggest that rotifers converted β-carotene (provided by ingested algae into echinenone, a photoprotective pigment. This study, which is the first one to detail in situ pigment contents of rotifers, clearly shows that the role of cyanobacteria as a food source for meiobenthic invertebrates has been underestimated so far, and deserves urgent consideration.

  13. Prospects of Artemia culture in the coastal zone

    Royan, J.P.

    The importance of the brine shrimp Artemia as live feed in shrimp hatcheries has been pointed out. The paper deals with the resource potential and status of cyst production in India. There is a need for setting up a Pilot Project for Artemia cyst...

  14. Use of the genus Artemia in ecotoxicity testing

    Nunes, Bruno S.; Carvalho, Felix D.; Guilhermino, Lucia M.; Van Stappen, Gilbert

    2006-01-01

    Information related to varied uses of several species of the genus Artemia (commonly known as brine shrimp), is dispersed among literature from several scientific areas, such as Ecology, Physiology, Ecotoxicology, Aquaculture and Genetics. The present paper reviews information related to Artemia that may be considered relevant for ecotoxicity testing. Integration of different areas of scientific knowledge concerning biology, life cycle and environmental needs of Artemia is of crucial importance when considering the interpretation of results drawn from tests involving this genus. Furthermore, this paper provides suggestions to overcome problems related to toxicity assessment with the use of Artemia as test organism in bioassays, under the scope of estuarine, marine and hypersaline environments. Aspects related to variability in results, adoptable toxicity end-points, culture conditions, characteristics of species and strains, influence of geographical origins over physiological features and responses to exposure to chemical agents are considered. - The physiology, reproductive processes and general use of Artemia in modern ecotoxicological testing are reviewed

  15. Use of the genus Artemia in ecotoxicity testing

    Nunes, Bruno S. [Instituto de Ciencias Biomedicas de Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Largo Prof. Abel Salazar 2, 4099-003 Porto (Portugal) and Centro Interdisciplinar de Investigacao Marinha e Ambiental, Rua dos Bragas 289, 4150-123 Porto (Portugal)]. E-mail: bruno@ufp.pt; Carvalho, Felix D. [REQUIMTE, Departamento de Toxicologia da Faculdade de Farmacia da Universidade do Porto, Rua Anibal Cunha, 164, 4050-047 Porto (Portugal); Guilhermino, Lucia M. [Instituto de Ciencias Biomedicas de Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Largo Prof. Abel Salazar 2, 4099-003 Porto (Portugal); Centro Interdisciplinar de Investigacao Marinha e Ambiental, Rua dos Bragas 289, 4150-123 Porto (Portugal); Van Stappen, Gilbert [Laboratory of Aquaculture and Artemia Reference Centre, Ghent University, Rozier 44, B-9000 Ghent (Belgium)

    2006-11-15

    Information related to varied uses of several species of the genus Artemia (commonly known as brine shrimp), is dispersed among literature from several scientific areas, such as Ecology, Physiology, Ecotoxicology, Aquaculture and Genetics. The present paper reviews information related to Artemia that may be considered relevant for ecotoxicity testing. Integration of different areas of scientific knowledge concerning biology, life cycle and environmental needs of Artemia is of crucial importance when considering the interpretation of results drawn from tests involving this genus. Furthermore, this paper provides suggestions to overcome problems related to toxicity assessment with the use of Artemia as test organism in bioassays, under the scope of estuarine, marine and hypersaline environments. Aspects related to variability in results, adoptable toxicity end-points, culture conditions, characteristics of species and strains, influence of geographical origins over physiological features and responses to exposure to chemical agents are considered. - The physiology, reproductive processes and general use of Artemia in modern ecotoxicological testing are reviewed.

  16. Effects of population outcrossing on rotifer fitness

    2010-01-01

    Background Outcrossing between populations can exert either positive or negative effects on offspring fitness. Cyclically parthenogenetic rotifers, like other continental zooplankters, show high genetic differentiation despite their high potential for passive dispersal. Within this context, the effects of outcrossing may be relevant in modulating gene flow between populations through selection for or against interpopulation hybrids. Nevertheless, these effects remain practically unexplored in rotifers. Here, the consequences of outcrossing on the rotifer Brachionus plicatilis were investigated. Cross-mating experiments were performed between a reference population and three alternative populations that differed in their genetic distance with regard to the former. Two offspring generations were obtained: F1 and BC ('backcross'). Fitness of the outcrossed offspring was compared with fitness of the offspring of the reference population for both generations and for three different between-population combinations. Four fitness components were measured throughout the rotifer life cycle: the diapausing egg-hatching proportion, clone viability (for the clones originating from diapausing eggs), initial net growth rate R for each viable clone, and the proportion of male-producing clones. Additionally, both the parental fertilisation proportion and a compound fitness measure, integrating the complete life cycle, were estimated. Results In the F1 generation, hybrid vigour was detected for the diapausing egg-hatching proportion, while R was lower in the outcrossed offspring than in the offspring of the reference population. Despite these contrasting results, hybrid vigour was globally observed for the compound measure of fitness. Moreover, there was evidence that this vigour could increase with the genetic differentiation of the outcrossed populations. In the BC generation, the hybrid vigour detected for the egg-hatching proportion in the F1 generation reverted to outbreeding

  17. Effects of population outcrossing on rotifer fitness

    Serra Manuel

    2010-10-01

    Full Text Available Abstract Background Outcrossing between populations can exert either positive or negative effects on offspring fitness. Cyclically parthenogenetic rotifers, like other continental zooplankters, show high genetic differentiation despite their high potential for passive dispersal. Within this context, the effects of outcrossing may be relevant in modulating gene flow between populations through selection for or against interpopulation hybrids. Nevertheless, these effects remain practically unexplored in rotifers. Here, the consequences of outcrossing on the rotifer Brachionus plicatilis were investigated. Cross-mating experiments were performed between a reference population and three alternative populations that differed in their genetic distance with regard to the former. Two offspring generations were obtained: F1 and BC ('backcross'. Fitness of the outcrossed offspring was compared with fitness of the offspring of the reference population for both generations and for three different between-population combinations. Four fitness components were measured throughout the rotifer life cycle: the diapausing egg-hatching proportion, clone viability (for the clones originating from diapausing eggs, initial net growth rate R for each viable clone, and the proportion of male-producing clones. Additionally, both the parental fertilisation proportion and a compound fitness measure, integrating the complete life cycle, were estimated. Results In the F1 generation, hybrid vigour was detected for the diapausing egg-hatching proportion, while R was lower in the outcrossed offspring than in the offspring of the reference population. Despite these contrasting results, hybrid vigour was globally observed for the compound measure of fitness. Moreover, there was evidence that this vigour could increase with the genetic differentiation of the outcrossed populations. In the BC generation, the hybrid vigour detected for the egg-hatching proportion in the F1

  18. Feeding and larval growth of an exotic freshwater prawn Macrobrachium equidens (Decapoda: Palaemonidae, from Northeastern Pará, Amazon Region

    JEAN N. GOMES

    2014-09-01

    Full Text Available In the present study, we carried out experiments on the diet of the freshwater prawn Macrobrachium equidens. We tested which type of food and which density of food is suitable for larval development. For the experiment on the type of food, eight treatments were carried out: (I starvation, (AL microalgae, (RO rotifers, (AN Artemia, (RO + AN rotifers + Artemia, (AL + RO microalgae + rotifers, (AL + AN microalgae + Artemia, (AL + RO + AN microalgae + rotifers + Artemia. For the experiment on the density of food, we used the type of food, which had resulted in a high survival rate in the previous experiment. Three treatments were carried out: 4, 8 and 16 Artemia nauplii /mL. The rate of feeding during larval development was observed. The survival, weight and percentage of juveniles of each feeding experiment were determined. We found that larvae are carnivores; however, they have requirements with respect to the type of food, because larvae completed their cycle from the zoeal to the juvenile stage only when Artemia nauplii were available. We also verified that the larvae feed mainly during the day-time, and are opportunistic with respect to the density of food offered.

  19. Larvicidal activity of some marine macrophytes against Artemia salina

    PrabhaDevi; Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

    and Microdictyon pseudohapteron, seagrasses (Halophila ovalis and Syringodium isoetifolium and lichens (Umbilicaria arpina) were tested for larvicidal activity using Artemia salina nauplii. The LC50 values for the PE-fraction of M. pseudohapteron and A. muscoides...

  20. Microalgae: biofuel production

    Babita Kumari

    2013-04-01

    Full Text Available In the present day, microalgae feedstocks are gaining interest in energy scenario due to their fast growth potential coupled with relatively high lipid, carbohydrate and nutrients contents. All of these properties render them an excellent source for biofuels such as biodiesel, bioethanol and biomethane; as well as a number of other valuable pharmaceutical and nutraceutical products. The present review is a critical appraisal of the commercialization potential of microalgae biofuels. The available literature on various aspects of microalgae for e.g. its cultivation, life cycle assessment, and conceptualization of an algal biorefinery, has been done. The evaluation of available information suggests the operational and maintenance cost along with maximization of oil-rich microalgae production is the key factor for successful commercialization of microalgae-based fuels.

  1. Does haplodiploidy purge inbreeding depression in rotifer populations?

    Ana M Tortajada

    2009-12-01

    Full Text Available Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression.We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed and interclonal (outcrossed crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured.Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation.

  2. Biotechnological applications of microalgae

    Wan-Loy Chu

    2012-01-01

    Microalgae are important biologicalresources that have a wide range of biotechnologicalapplications. Due to their high nutritional value,microalgae such as Spirulina and Chlorella are beingmass cultured for health food. A variety of high-valueproducts including polyunsaturated fatty acids (PUFA),pigments such as carotenoids and phycobiliproteins, andbioactive compounds are useful as nutraceuticals andpharmaceuticals, as well as for industrial applications. Interms of environmental biotechnolo...

  3. Rotifer digestive enzymes: direct detection using the ELF technique

    Štrojsová, M.; Vrba, Jaroslav

    2007-01-01

    Roč. 593, č. 1 (2007), s. 159-165 ISSN 0018-8158. [International Symposium on Rotifers /11./. Mexiko City, 08.03.2006-13.03.2006] R&D Projects: GA AV ČR(CZ) IAA6017202; GA AV ČR(CZ) IAA600170602; GA AV ČR(CZ) 1QS600170504 Institutional research plan: CEZ:AV0Z60170517 Keywords : rotifers * enzyme localization * phosphatase * lipase * .beta.-N-acetylhexosaminidase Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.201, year: 2007

  4. Brine shrimp bioassay: importance of correct taxonomic identification of Artemia (Anostraca) species.

    Ruebhart, David R; Cock, Ian E; Shaw, Glen R

    2008-08-01

    Despite the common use of the brine shrimp bioassay in toxicology, there is confusion in the literature regarding citation of the correct taxonomic identity of the Artemia species used. The genus Artemia, once thought to be represented by a single species Artemia salina, is now known to be composed of several bisexual species as well as parthenogenetic populations. Artemia franciscana is the best studied of the Artemia species and is considered to represent the vast majority of studies in which Artemia is used as an experimental test organism. We found that in studies referring to the use of A. salina, the zoogeography of the cyst harvest site indicated that the species used was actually A. franciscana. Those performing bioassays with Artemia need to exercise diligence in assigning correct species identification, as the identity of the test organism is an important parameter in assuring the validity of the results of the assay.

  5. Seasonal development of planktonic rotifers in Slapy Reservoir (Czech Republic)

    Devetter, Miloslav

    2011-01-01

    Roč. 66, č. 4 (2011), s. 662-668 ISSN 0006-3088 Institutional research plan: CEZ:AV0Z60660521 Keywords : rotifer community * seasonal development * downstream reservoir Subject RIV: EH - Ecology, Behaviour Impact factor: 0.557, year: 2011

  6. A method for efficient extraction of rotifers (Rotifera) from soils

    Devetter, Miloslav

    2010-01-01

    Roč. 53, č. 2 (2010), s. 115-118 ISSN 0031-4056 R&D Projects: GA ČR(CZ) GP206/06/P405 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil rotifers * Bdelloids * quantitative extraction Subject RIV: EH - Ecology, Behaviour Impact factor: 1.474, year: 2010

  7. A multiplex PCR method for rapid identification of Brachionus rotifers.

    Vasileiadou, Kalliopi; Papakostas, Spiros; Triantafyllidis, Alexander; Kappas, Ilias; Abatzopoulos, Theodore J

    2009-01-01

    Cryptic species are increasingly being recognized in many organisms. In Brachionus rotifers, many morphologically similar yet genetically distinct species/biotypes have been described. A number of Brachionus cryptic species have been recognized among hatchery strains. In this study, we present a simple, one-step genetic method to detect the presence of those Brachionus sp. rotifers that have been found in hatcheries. With the proposed technique, each of the B. plicatilis sensu stricto, B. ibericus, Brachionus sp. Nevada, Brachionus sp. Austria, Brachionus sp. Manjavacas, and Brachionus sp. Cayman species and/or biotypes can be identified with polymerase chain reaction (PCR) analysis. Based on 233 cytochrome c oxidase subunit I sequences, we reviewed all the available cryptic Brachionus sp. genetic polymorphisms, and we designed six nested primers. With these primers, a specific amplicon of distinct size is produced for every one of the involved species/biotypes. Two highly sensitive protocols were developed for using the primers. Many of the primers can be combined in the same PCR. The proposed method has been found to be an effective and practical tool to investigate the presence of the above six cryptic species/biotypes in both individual and communal (bulk) rotifer deoxyribonucleic acid extractions from hatcheries. With this technique, hatchery managers could easily determine their rotifer composition at the level of cryptic species and monitor their cultures more efficiently.

  8. Carotenoids in Microalgae.

    Henríquez, Vitalia; Escobar, Carolina; Galarza, Janeth; Gimpel, Javier

    Carotenoids are a class of isoprenoids synthesized by all photosynthetic organisms as well as by some non-photosynthetic bacteria and fungi with broad applications in food, feed and cosmetics, and also in the nutraceutical and pharmaceutical industries. Microalgae represent an important source of high-value products, which include carotenoids, among others. Carotenoids play key roles in light harvesting and energy transfer during photosynthesis and in the protection of the photosynthetic apparatus against photooxidative damage. Carotenoids are generally divided into carotenes and xanthophyls, but accumulation in microalgae can also be classified as primary (essential for survival) and secondary (by exposure to specific stimuli).In this chapter, we outline the high value carotenoids produced by commercially important microalgae, their production pathways, the improved production rates that can be achieved by genetic engineering as well as their biotechnological applications.

  9. Tolerance of Artemia to static and shock pressure loading

    Fitzmaurice, B. C.; Appleby-Thomas, G. J.; Painter, J. D.; Ono, F.; McMillan, P. F.; Hazael, R.; Meersman, F.

    2017-10-01

    Hydrostatic and hydrodynamic pressure loading has been applied to unicellular organisms for a number of years due to interest from food technology and extremophile communities. There is also an emerging interest in the response of multicellular organisms to high pressure conditions. Artemia salina is one such organism. Previous experiments have shown a marked difference in the hatching rate of these organisms after exposure to different magnitudes of pressure, with hydrostatic tests showing hatching rates at pressures up to several GPa, compared to dynamic loading that resulted in comparatively low survival rates at lower pressure magnitudes. In order to begin to investigate the origin of this difference, the work presented here has focussed on the response of Artemia salina to (quasi) one-dimensional shock loading. Such experiments were carried out using the plate-impact technique in order to create a planar shock front. Artemia cysts were investigated in this manner along with freshly hatched larvae (nauplii). The nauplii and cysts were observed post-shock using optical microscopy to detect motility or hatching, respectively. Hatching rates of 18% were recorded at pressures reaching 1.5 GPa, as determined with the aid of numerical models. Subjecting Artemia to quasi-one-dimensional shock loading offers a way to more thoroughly explore the shock pressure ranges these organisms can survive.

  10. Field culture of American strain of Artemia in India

    Royan, J.P.; Sumitra-Vijayaraghavan; Krishnakumari, L.

    Pilot scale culture of Artemia was carried out in a 0.22 ha condenser unit of salt pans. Pond was fertilized with inorganic salts. The nauplii of San Francisco Bay, USA strain were inoculated. Within a period of 5 months a production of 20.6 kg dry...

  11. Does Haplodiploidy Purge Inbreeding Depression in Rotifer Populations?

    Tortajada, Ana M.; Carmona, María José; Serra, Manuel

    2009-01-01

    Background Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression. Methodology/Principal Findings We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed) and interclonal (outcrossed) crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured. Conclusions/Significance Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation. PMID:19997616

  12. Trade-off between reproduction and lifespan of the rotifer Brachionus plicatilis under different food conditions.

    Sun, Yunfei; Hou, Xinying; Xue, Xiaofeng; Zhang, Lu; Zhu, Xuexia; Huang, Yuan; Chen, Yafen; Yang, Zhou

    2017-11-13

    Phaeocystis globosa, one of the most typical red tide-forming species, is usually mixed in the food composition of rotifers. To explore how rotifers respond by adjusting life history strategy when feeding on different quality foods, we exposed the rotifer Brachionus plicatilis to cultures with 100% Chlorella, a mixture of 50% P. globosa and 50% Chlorella, or 100% P. globosa. Results showed that rotifers exposed to 100% Chlorella or to mixed diets produced more total offspring and had higher age-specific fecundity than those exposed to 100% P. globosa. Food combination significantly affected the net reproduction rates of rotifers. By contrast, rotifers that fed on 100% P. globosa or on mixed diets had a longer lifespan than those fed on 100% Chlorella. The overall performances (combining reproduction and lifespan together) of rotifers cultured in 100% Chlorella or mixed diets were significantly higher than those cultured in 100% P. globosa. In general, Chlorella favors rotifers reproduction at the cost of shorter lifespan, whereas P. globosa tends to extend the lifespan of rotifers with lower fecundity, indicating that trade-off exists between reproduction and lifespan under different food conditions. The present study also suggests that rotifers may have the potential to control harmful P. globosa.

  13. Production of biodiesel from microalgae

    Danilović Bojana R.

    2014-01-01

    Full Text Available In recent years, more attention has been paid to the use of third generation feedstocs for the production of biodiesel. One of the most promising sources of oil for biodiesel production are microalgae. They are unicellular or colonial photosynthetic organisms, with permanently increasing industrial application in the production of not only chemicals and nutritional supplements but also biodiesel. Biodiesel productivity per hectare of cultivation area can be up to 100 times higher for microalgae than for oil crops. Also, microalgae can grow in a variety of environments that are often unsuitable for agricultural purposes. Microalgae oil content varies in different species and can reach up to 77% of dry biomass, while the oil productivity by the phototrophic cultivation of microalgae is up to 122 mg/l/d. Variations of the growth conditions and the implementation of the genetic engineering can induce the changes in the composition and productivity of microalgal oil. Biodiesel from microalgae can be produced in two ways: by transesterification of oil extracted from biomass or by direct transesterification of algal biomass (so called in situ transesterification. This paper reviews the curent status of microalgae used for the production of biodiesel including their isolation, cultivation, harvesting and conversion to biodiesel. Because of high oil productivity, microalgae will play a significant role in future biodiesel production. The advantages of using microalgae as a source for biofuel production are increased efficiency and reduced cost of production. Also, microalgae do not require a lot of space for growing and do not have a negative impact on the global food and water supplies. Disadvantages of using microalgae are more difficult separation of biomass and the need for further research to develop standardized methods for microalgae cultivation and biodiesel production. Currently, microalgae are not yet sustainable option for the commercial

  14. Continuous Exposure Of Vibrio Anguillarum To Tropodithietic Acid: Genetic Changes And Influence On Virulence

    Rasmussen, Bastian Barker; D'Alvise, Paul; Grotkjær, Torben

    2015-01-01

    Introduction: The fish pathogen Vibrio anguillarum is a major problem in aquaculture causing Vibriosis. Bacteria of the Roseobacter clade can antagonize pathogenic vibrios in cultures in live feed such as microalgae, rotifers and Artemia, as well as in fish larvae. Therefore, roseobacters could...

  15. Biofuels from Microalgae

    Barbosa, M.J.; Wijffels, R.H.

    2013-01-01

    Microalgae are a promising feedstock for sustaineble production of biofuela due to their unique capacity to reach high lipid productivities. Although the promises are there, production costs and energy requirements are high and the technology is still ammature for the production of bulk products. It

  16. Economics of microalgae production

    Acién, F.G.; Molina, E.; Fernández-Sevilla, J.M.; Barbosa, M.; Gouveia, L.; Sepúlveda, C.; Bazaes, J.; Arbib, Z.

    2017-01-01

    The economic analysis of biomass production is a critical step in ensuring the success of any microalgae-based industry. Until recently, only small-scale facilities of less than 10. ha have been in operation, but now large-scale facilities of more than 200. ha are being built and operated.

  17. Food commodities from microalgae

    Draaisma, R.B.; Wijffels, R.H.; Slegers, P.M.; Brentner, L.B.; Roy, A.; Barbosa, M.J.

    2013-01-01

    The prospect of sustainable production of food ingredients from photoautotrophic microalgae was reviewed. Clearly, there is scope for microalgal oils to replace functions of major vegetable oils, and in addition to deliver health benefits to food products. Furthermore, with a limited production

  18. Functional ingredients from microalgae

    Buono, S.; Langellotti, A.L.; Martello, A.; Rinna, F.; Fogliano, V.

    2014-01-01

    A wide variety of natural sources are under investigation to evaluate their possible use for new functional ingredient formulation. Some records attested the traditional and ancient use of wild harvested microalgae as human food but their cultivation for different purposes started about 40 years

  19. Study of inter species diversity and population structure by molecular genetic method in Iranian Artemia

    Hajirostamloo, Mahbobeh

    2005-01-01

    Artemia is a small crustacean that adapted to live in brine water and has been seen in different brine water sources in Iran. Considering the importance of genetic studies manifest inter population differences in species, to estimate genetic structure, detect difference at molecular level and separate different Artemia populations of Iran, also study of phylogenic relationships among them, samples of Artemia were collected from nine region: Urmia lake in West Azerbaijan, Sh...

  20. Freshwater copepods and rotifers: predators and their prey

    Brandl, Zdeněk

    2005-01-01

    Roč. 546, č. 1 (2005), s. 475-489 ISSN 0018-8158. [Rotifera /10./. Illmitz, 07.06.2003-13.06.2003] R&D Projects: GA AV ČR(CZ) KSK6005114 Institutional research plan: CEZ:AV0Z60170517 Keywords : rotifers * cyclopoid copepod s * calanoid copepod s * feeding * predation Subject RIV: EG - Zoology Impact factor: 0.978, year: 2005

  1. Advances in editing microalgae genomes

    Daboussi, Fayza

    2017-01-01

    There have been significant advances in microalgal genomics over the last decade. Nevertheless, there are still insufficient tools for the manipulation of microalgae genomes and the development of microalgae as industrial biofactories. Several research groups have recently contributed to progress by demonstrating that particular nucleases can be used for targeted and stable modifications of the genomes of some microalgae species. The nucleases include Meganucleases, Zinc Finger nucleases, TAL...

  2. Use of the Crustacean Artemia franciscana for Alternative Biotests

    Petr Dvořák

    2010-01-01

    Full Text Available Use of the crustacean Artemia franciscana for alternative biotests of the second generation was studied, and possible experimental design and applications of such tests outlined. In addition to the classical use in ecotoxicology, the test can be used in pharmacology as well, or to monitor the effects of ionizing radiation in co-exposure with some chemical compounds. The synergistic effect of co-exposure of PCB (DELOR 103, cadmium chloride and potassium dichromate with beta 89Sr irradiation was shown. We also demonstrated the anti-oxidative and pro-oxidative effects of the ascorbic acid in dependence on its concentration. Use of the pharmaco-toxicological screening in search for the novel inhibitors of cyclin-dependent kinases was demonstrated as well, showing that Artemia franciscana may be used as a suitable biosensor instead of the expensive tests on higher vertebrates.

  3. Virulence of luminous vibrios to Artemia franciscana nauplii.

    Soto-Rodriguez, S A; Roque, A; Lizarraga-Partida, M L; Guerra-Flores, A L; Gomez-Gill, B

    2003-02-27

    From healthy and diseased penaeid shrimp from Asia and the Americas, 25 luminous and 2 non-luminous bacterial strains were isolated, and 14 were phenotypically identified as Vibrio harveyi; 9 isolates produced significant mortalities (45 to 80%) in Artemia franciscana nauplii at inoculation densities of 10(5) to 10(6) CFU ml(-1) compared to the controls (unchallenged nauplii). The maximum number of bacteria ingested (bioencapsulated) by the Artemia nauplii varied from less than 10 to 10(3) CFU nauplius(-1) and no significant relationship was observed between the density of bacteria inoculated, the amount of bacteria ingested, and naupliar mortality. Significant correlations were obtained between naupliar mortality and production of proteases, phospholipases or siderophores, but not between mortality and lipase production, gelatinase production, hydrophobicity or hemolytic activity. The results suggest that virulence of the strains tested was more related to the production of particular exoenzymes than to the measured colonization factors.

  4. Soil Bdelloid Rotifers in Aksaray (Central Anatolia, Türkiye

    Göksal Sezen

    2014-07-01

    Full Text Available Abstract: Twelve bdelloid rotifer taxa were recorded as a result of the examination of 20 soil samples collected from different regions of Aksaray. Of these, Ceratotrocha cornigera (Bryce, 1893 and C. veleta Donner, 1949 are secondly recorded from Turkey. While the highest species richness was found in Eşmekaya and Ortaköy localities, no species was found in the samples collected from the localities; Şerefli Koçhisar, Topakkaya, Toki, State Hospital and Aksaray University Campus. Key words: bdelloid, soil rotifer, species diversity, Turkish Fauna Aksaray'ın Toprakta Yaşayan Bdelloid Rotiferleri (Orta Anadolu, Türkiye Özet: Aksaray ilinin farklı bölgelerinden toplanan yirmi toprak örneğinin incelenmesi sonucunda on iki bdelloid rotifer taksonu kaydedildi. Bunlardan Ceratotrocha cornigera (Bryce, 1893 ve C. veleta Donner, 1949 Türkiye'den ikinci kez rapor edildi. En yüksek tür zenginliği Eşmekaya ve Ortaköy lokalitelerinde bulunurken, Şerefli Koçhisar, Topakkaya, Toki, Devlet Hastanesi ve Aksaray Universitesi Kampüsü lokalitelerinden toplanan örneklerde hiç bir tür bulunamadı. Anahtar Kelimeler: bdelloid, toprak rotiferleri, Türkiye Faunası

  5. The brine shrimp Artemia: adapted to critical life conditions

    Gonzalo M Gajardo

    2012-06-01

    Full Text Available The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological to the population level. Such conditions are experienced by very few equivalent macro-planktonic organisms; thus, Artemia can be considered a model animal extremophile offering a unique suite of adaptations that are the focus of this review. The most obvious is a highly efficient osmoregulation system to withstand up to 10 times the salt concentration of ordinary seawater. Under extremely critical environmental conditions, for example when seasonal lakes dry out, Artemia takes refuge by producing a highly resistant encysted gastrula embryo (cyst capable of severe dehydration enabling an escape from population extinction. Cysts can be viewed as gene banks that store a genetic memory of historical population conditions. Their occurrence is due to the evolved ability of females to perceive forthcoming unstable environmental conditions expressed by their ability to switch reproductive mode, producing either cysts (oviparity when environmental conditions become deleterious or free-swimming nauplii (ovoviviparity that are able to maintain the population under suitable conditions.At the population level the trend is for conspecific populations to be fragmented into locally adapted populations, whereas species are restricted to salty lakes in particular regions (regional endemism. The Artemia model depicts adaptation as a complex response to critical life conditions, integrating and refining past and present experiences at all levels of organization. Although we consider an invertebrate restricted to a unique environment, the processes to be discussed are of general biological interest. Finally, we highlight the benefits of understanding the stress

  6. Fuels from microalgae

    1989-06-01

    Many species of aquatic plants can provide a source of renewable energy. Some species of microalgae, in particular, produce lipids -- oils that can be extracted and converted to a diesel fuel substitute or to gasoline. Since 1979 the Aquatic Species Program element of the Biofuels Program, has supported fundamental and applied research to develop the technology for using this renewable energy resource. This document, produced by the Solar Technical Information Program, provides an overview of the DOE/SERI Aquatic Species Program element. Chapter 1 is an introduction to the program and to the microalgae. Chapter 2 is an overview of the general principles involved in making fuels from microalgae. It also outlines the technical challenges to producing economic, high-energy transportation fuels. Chapter 3 provides an overview of the Algal Production and Economic Model (APEM). This model was developed by researchers within the program to identify aspects of the process critical to performance with the greatest potential to reduce costs. The analysis using this model has helped direct research sponsored by the program. Finally, Chapter 4 provides an overview of the Aquatic Species Program and describes current research. 28 refs., 17 figs.

  7. Application of rotifer Brachionus plicatilis in detecting the toxicity of harmful algae

    Yan, Tian; Wang, Yunfeng; Wang, Liping; Chen, Yang; Han, Gang; Zhou, Mingjiang

    2009-05-01

    The toxicity of seven major HAB (harmful algal bloom) species/strains, Prorocentrum donghaiense, Phaeocystis globosa, Prorocentrum micans, Alexandrium tamarense (AT-6, non-PSP producer), Alexandrium lusitanicum, Alexandrum tamarense (ATHK) and Heterosigma akashiwo were studied against rotifer Brachionus plicatilis under laboratory conditions. The results show that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6), or A. lusitanicum could maintain the individual survival and reproduction, as well as the population increase of the rotifer, but the individual reproduction would decrease when exposed to these five algae at higher densities for nine days; H. akashiwo could decrease the individual survival and reproduction, as well as population increase of the rotifer, which is similar to that of the starvation group, indicating that starvation might be its one lethal factor except for the algal toxins; A. tamarense (ATHK) has strong lethal effect on the rotifer with 48h LC50 at 800 cells/mL. The experiment on ingestion ability indicated by gut pigment change shows that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6) and A. lusitanicum can be taken by the rotifers as food, but A. tamarense (ATHK) or H. akashiwo can be ingested by the rotifers. The results indicate that all the indexes of individual survival and reproduction, population increase, gut pigment change of the rotifers are good and convenient to be used to reflect the toxicities of HAB species. Therefore, rotifer is suggested as one of the toxicity testing organisms in detecting the toxicity of harmful algae.

  8. Phototrophic pigment production with microalgae

    Mulders, K.J.M.

    2014-01-01

    Abstract

    Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main focus on secondary

  9. Multi-Product Microalgae Biorefineries

    Lam, 't G.P.; Vermuë, M.H.; Eppink, M.H.M.; Wijffels, R.H.; Berg, van den C.

    2018-01-01

    Although microalgae are a promising biobased feedstock, industrial scale production is still far off. To enhance the economic viability of large-scale microalgae processes, all biomass components need to be valorized, requiring a multi-product biorefinery. However, this concept is still too

  10. Temperature-dependent elimination efficiency on Phaeocystis globosa by different initial population sizes of rotifer Brachionus plicatilis.

    Sun, Yunfei; Wang, Yuanyuan; Lei, Jin; Qian, Chenchen; Zhu, Xuexia; Akbar, Siddiq; Huang, Yuan; Yang, Zhou

    2018-07-01

    Due to sea water eutrophication and global warming, the harmful Phaeocystis blooms outbreak frequently in coastal waters, which cause a serious threat to marine ecosystem. The application of rotifer to control the harmful alga is a promising way. To investigate the influence of initial rotifer density and temperature on the ability of rotifer Brachionus plicatilis to eliminate Phaeocystis globosa population, we cultured P. globosa with different initial rotifer densities (1, 3, 5 inds mL -1 ) at 19, 22, 25, 28, and 31 °C for 9-16 d. Results showed that the population of rotifer feeding on Phaeocystis increased rapidly and higher temperatures favored the growth of P. globosa and B. plicatilis. With increased initial rotifer density and temperature, both the clearance rate of rotifer and the reduction rate of P. globosa increased, and thus P. globosa were eliminated earlier. Both temperature and initial rotifer density had significant effects on clearance rate of rotifer and the time to Phaeocystis extinction, and there was a significant interaction between the two factors on the two parameters, i.e., the effect of initial rotifer density on eliminating Phaeocystis decreased with increasing temperature. The rotifer in 5 inds mL -1 at 28 °C eliminated P. globosa in 4 d, whereas the rotifer in 1 ind mL -1 at 19 °C spent about 16 d on eliminating P. globosa. In conclusion, higher temperature and bigger initial rotifer density promote rotifer to eliminate the harmful P. globosa, and the optimal temperature for rotifer to clear P. globosa is 28 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Comparison live adult Artemia and squid meat on the growth of Penaeid shrimp Metapenaeus dobsoni (Miers)

    Nair, S.R.S.; Achuthankutty, C.T.; Royan, J.P.

    An experiment lasting 14 weeks was conducted to compare the efficiency of live adult Artemia with fresh squid meat on growth of penaeid shrimp Metapenaeus dobsoni. The shrimps were found actively feeding on live Artemia and grew 84% more than those...

  12. Stimulating effect of space flight factors on Artemia cysts: comparison with irradiation by gamma rays

    Gaubin, Y.; Pianezzi, B.; Gasset, G.; Plannel, H.; Kovalev, E.E.

    1986-01-01

    The Artemia cyst, a gastrula in dormant state, is a very suitable material to investigate the individual effects of HZE cosmic particles. Monolayers of Artemia cysts, sandwiched with nuclear emulsions, flew aboard the Soviet biosatellite Cosmos 1129. The space flight stimulated the developmental capacity expressed by higher percentages of emergence, hatching, and alive nauplii at day 4-5. A greater mean life span was reported in Artemias developed from Artemia cysts hit by the cosmic heavy ions. On Earth, Artemia cysts were exposed to 1, 10, 100, 200 and 400 Gy of gamma (gamma) rays. A stimulating effect on developmental capacity was observed for 10 Gy; the mean life span was significantly increased for this dose. These results are discussed in comparison with previous investigations performed on Earth and in space

  13. Distribution and abundance of Artemia salina in the Salt Lake Basin (Central Anatolia, Turkey

    Alaş Ali

    2017-06-01

    Full Text Available In this study, the distribution and abundance of Artemia salina in 10 different stations of the Salt Lake basin were investigated. In addition, its relationship to pH, dissolved oxygen, temperature, electrical conductivity and water levels were analyzed. Field studies were carried out from July to August of 2010. Artemia salina was observed in five of these stations. Artemia salina was not seen in some stations that have high electrical conductivity. It is determined that, in the station named Tersakan Lake where electrical conductivity was 154 mS/cm, Artemia salina is more abundant when compared to the other stations. But as underground water pumps that are built for the irrigation of agricultural lands decrease water levels, Artemia salina’s life is under threat.

  14. Primary Screening of the Bioactivity of Brackishwater Cyanobacteria: Toxicity of Crude Extracts to Artemia salina Larvae and Paracentrotus lividus Embryos

    Viviana R. Lopes

    2010-03-01

    Full Text Available Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. The aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuarine environments, towards the nauplii of the brine shrimp Artemia salina and embryos of the sea urchin Paracentrotus lividus. The A. salina lethality test was used as a frontline screen and then complemented by the more specific sea urchin embryo-larval assay. Eighteen cyanobacterial isolates, belonging to the genera Cyanobium, Leptolyngbya, Microcoleus, Phormidium, Nodularia, Nostoc and Synechocystis, were tested. Aqueous extracts of cyanobacteria strains showed potent toxicity against A. salina, whereas in P. lividus, methanolic and aqueous extracts showed embryo toxicity, with clear effects on development during early stages. The results suggest that the brackishwater cyanobacteria are producers of bioactive compounds with toxicological effects that may interfere with the dynamics of invertebrate populations.

  15. Survival and growth of catfish Pangasionodon sp. larvae fed on vitamin C-enriched Artemia

    Mia Setiawati

    2015-05-01

    Full Text Available ABSTRACT The research was conducted to evaluate effect of the administration of Artemia enriched with vitamin C on the survival, total body length, and average body weight of Pangasionodon sp. larvae. Artemia were enriched with either 0, 50, 100, or 150 mg/L vitamin C immersed in the culture medium for 13 hours. Two days old larvae were fed on enriched Artemia 12 times/day for seven days. At the end of feeding experiment, it was found that fish fed on Artemia enriched with 100 mg/L culture medium had the highest survival, total length and body weight, respectively 76.17±12.78%, 1.63±0.34 cm, and 20.6±3.8 mg. Keywords: survival, growth, Artemia, vitamin C, catfish, Pangasionodon sp.  ABSTRAK Penelitian ini dilakukan untuk mengetahui pengaruh Artemia yang diperkaya dengan vitamin C dosis berbeda terhadap kelangsungan hidup, panjang total, dan bobot tubuh larva ikan patin Pangasionodon sp. Pada penelitian ini, Artemia diperkaya dengan vitamin C dosis 0, 50, 100, atau 150 mg/L media pengayaan. Larva yang berumur dua hari diberi pakan Artemia hasil pengayaan sebanyak 12 kali sehari selama tujuh hari masa pemeliharaan. Pada akhir percobaan, didapatkan bahwa larva ikan yang diberi Artemia diperkaya vitamin C dosis 100 mg/L media pengayaan memberikan kelangsungan hidup 76,17±12,78%, panjang total 1,63±0,34 cm, dan bobot tubuh paling tinggi 20,6±3,8 mg. Kata kunci: kelangsungan hidup, pertumbuhan, Artemia, vitamin C, ikan patin, Pangasionodon sp. 

  16. SALT EFFECTS ON EGGS AND NAUPLII OF ARTEMIA SALINA L

    Boone, Eleanor; Baas-Becking, L. G. M.

    1931-01-01

    Eggs of Artemia salina L., the brine shrimp, are easily obtainable in large quantities. Ecdysis takes place in two stages: (a) extrusion of the inner membrane, and (b) ecdysis of the nauplius from that membrane. The conditions which allow for the former are much more varied than those for the latter. Nauplii form in only solutions of a few sodium salts; and, in Mg, Ca, and Sr salts, potassium is very toxic. The possible environment for the nauplii (1 M total molarity) has been ascertained for chlorides of Na, K, Mg, and Ca. The facts observed account for the peculiar distribution of the organism. PMID:19872620

  17. Solar Pond devices: free energy or bioreactors for Artemia biomass production?

    Gouveia, Luisa; Sousa, João; Marques, Ana; Tavares, Célia; Giestas, Margarida

    2009-08-01

    The recent exponential growth in industrial aquaculture has led to a huge increase in Artemia biomass production in order to meet increased fish production needs. The present study explores the potential use of salt gradient solar ponds (SGSPs) for production of Artemia nauplii. An SGSP is a basin of water where solar energy is trapped and collected via an artificially imposed gradient. Three zones can be identified in an SGSP: upper and lower zones, which are both convective, and a middle zone, which is intended to be non-convective. The latter acts as a transparent insulation layer and allows for storage of solar energy at the bottom, where it is available for use. The combination of salt, temperature and high transparency could make SGSPs promising bioreactors for the production of Artemia nauplii. Using particle image velocymetry (PIV) and Shadowgraph visualisation techniques, the behaviour of Artemia nauplii under critical cultivation parameters (namely, salinity, temperature and light) was monitored to determine movement velocity, and how movement of Artemia affects the salt gradient. It was observed that Artemia nauplii constantly follow light, irrespective of adverse salinity and/or temperature conditions. However, despite the substantial displacement of Artemia following the light source, the salt gradient is not disrupted. The suitability of SGSPs as bioreactors for Artemia biomass production was then tested. The results were disappointing, probably due to the lack of sufficient O(2) for Artemia survival and growth. Follow-up trials were conducted aimed at using the SGSP as a green and economically attractive energy source to induce faster hatching of cysts and improved Artemia nauplii growth. The results of these trials, and a case study of Artemia nauplii production using an SGSP, are presented. The authors constructed a Solar Pond device, which they suggest as a novel way of supplying thermal energy for Artemia biomass production in an aquaculture

  18. Sobrevivencia, metamorfosis y crecimiento de larvas del camarón Penaeus californiensis (Decapoda: Peneidae alimentadas con diferentes microalgas

    José Naranjo

    1999-12-01

    Full Text Available Se realizó una prueba experimental en un Centro de Producción Ostrícola en Bahía de Kino, Sonora, con el fin de evaluar el efecto de diferentes microalgas en el desarrollo de larvas de camarón café Penaeus californiensis. Las microalgas evaluadas fueron la diatomea Chaetoceros gracilis y los fitoflagelados Isochrysis galbana y Dunalliella sp., solas o en combinación y adición de nauplios de Artemia sp. a partir del estadio de zoea III, excepto en un tratamiento donde no se adicionó Artemia sp. Se utilizaron 24 unidades experimentales (tres por tratamiento, consistentes en garrafones plásticos de 16 l de capacidad, una densidad de siembra de 50 nauplios/l, una temperatura de 25°C controlada mediante calentadores sumergibles de 50 watts y una salinidad de 35 ppmil. C. gracilis produjo la mejor sobrevivencia (55%, siguiendole la combinación de C. gracilis con Dunaliella sp. (48%, la más baja sobrevivencia fue para el tratamiento donde se utilizó Dunaliella sp. fueron evidentes un retraso en la velocidad de metamorfosis para los tratamientos donde C. gracilis no fue utilizada y diferencias significativas (pThe effect of three microalgae, Chaetoceros gracilis, Isochrysis galbana, and Dunalliella sp. on the larval development of yellowleg shrimp Penaeus californiensis, was evaluated in the Oyster Production Center of Bahia Kino, Sonora, México. The effects of each microalgae (1 individually, (2 combined and (3 mixed with Artemia nauplii (from zoea III stage, were considered. Twenty four experimental units (three 16.0 l plastic bottles per treatment were used. During the experiment temperature was maintained around 25°C, and salinity around 35 ppt. The stocking density of nauplii was 50/l. The best survival was obtained with C. gracilis (55%, followed by the combination of C. gracilis and Dunalliella sp (48%. The worst survival was obtained in the treatment with Dunalliella sp. An evident delay in the metamorphosis times was observed in

  19. Cell disruption for microalgae biorefineries.

    Günerken, E; D'Hondt, E; Eppink, M H M; Garcia-Gonzalez, L; Elst, K; Wijffels, R H

    2015-01-01

    Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave treatment, pulsed electric field treatment, non-mechanical cell disruption and some emerging technologies. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Pilot cultivation of the chlorophyte microalga Scenedesmus obliquus as a promising feedstock for biofuel

    Abomohra, Abd El-Fatah; El-Sheekh, Mostafa; Hanelt, Dieter

    2014-01-01

    Scenedesmus obliquus was discussed by phycologists as a promising microalga for biofuel production based on its biomass and fatty acid productivity. In the present study, S. obliquus was pilot cultivated for large scale production in a semicontinuous culture for 3 months using polyethylene transparent bags. Cultivation of S. obliquus resulted in a maximum biomass productivity of 0.14 g L −1  d −1 and maximum esterified fatty acid productivity of 17.37 mg L −1  d −1 at light intensity of 130 μmol m −2  s −1 . Using of different flocculants for biomass harvest showed maximum flocculation efficiency of 82% using 250 mg L −1 of NaOH for 2 h. Drying of the harvested biomass showed significant increase of esterified fatty acid content by 5 and 7% with respect to control at 75 and 100 °C, respectively. In addition, fatty acid profile and iodine number of S. obliquus oil meet biodiesel standard specifications which make the fatty acid of S. obliquus eligible for further research to be used as a feedstock for biofuel production. Furthermore, the present investigation showed that after oil extraction, the residual algal biomass increased survival and fresh weight of Artemia (brine shrimp) which confirms that the residual algal biomass can be significantly used as food additives for animal feeding. - Highlights: • Scenedesmus obliquus was cultivated in plastic bags in a semicontinuous culture for high biomass production. • Different flocculants were used for harvesting of S. obliquus and the oil was chemically extracted. • The residual algal biomass was used for feeding of Artemia. • The annual productivity of EFA from S. obliquus would be nearly 5 times higher than Jatropha. • The residual algal biomass increased survival and fresh weight of Artemia

  1. Growth and survival of Hippocampus erectus (Perry, 1810 juveniles fed on Artemia with different HUFA levels

    Nicolás Vite-Garcia

    2014-03-01

    Full Text Available Survival during first months after birth is one of the bottlenecks for consolidating the seahorse farming industry. In this work, Artemia metanauplii enriched with two highly unsaturated fatty acids (HUFA rich commercial emulsions with different docosahexaenoic acid (DHA levels (63% and 14% of total lipids, a vegetable oil with no DHA, and non-enriched Artemia as control, were used to feed 5-day-old juvenile Hippocampus erectus for 60 days. Enriched Artemia had similar levels of DHA (13% and 9%, despite great differences of DHA in the emulsions, with traces of DHA in non-enriched and vegetable oil enriched Artemia. More than 20% of DHA was found in 24 h starved juveniles fed both DHA-enriched treatments, similar to values in newly born juveniles, but those fed vegetable oil enriched Artemia or non-enriched Artemia had 5% of DHA. Total lipid and protein levels were similar in juveniles from the four treatments. The n-3/n-6 ratio was almost four-fold higher in seahorses fed DHA-enriched treatments compared to juveniles fed the non-enriched treatments. Survival of seahorses only partially reflected the DHA levels: it was lower in the vegetable oil treatment, similar in the seahorses fed Artemia with higher DHA and in the control treatment, and higher in seahorses fed the HUFA-enriched Artemia with lower DHA levels, although growth was similar in the two DHA-enriched Artemia treatments. Juvenile H. erectus seahorses perform better when they have at least 20% of DHA in their tissues, and these levels can be attained with no more than 14% of DHA in emulsions, eliminating the need for more expensive emulsions with higher DHA levels.

  2. Improvement of the nutritional value and growth of rotifer (Brachionus plicatilis by different enrichment period with Bacillus sp.

    Sutia Budi

    2011-01-01

    Full Text Available Brachionus plicatilis is a widely used as natural feed in hatchery. Characteristics of rotifers as biocapsule can improve the quality of rotifers in a practical way. Bacillus sp. is capable of improving the nutrition rotifers to produce vitamins, food detoxication or through enzymatic activity such as protease, lipase, and amylase. This research aimed at observing the influence of the enrichment length of Bacillus sp. on the quality of nutrition and growth of rotifers. The research container was a polyearbonate vessel of one ton volume which contained Nannochloropsis sp. with the density of 105 cell/mL, it was then scattered with rotifer with the density of 1,000 ind./mL. The types of bacteria used were Bacillus subtilis, B. pumilus and B. licheformis with the density of 2x1010 cfu/g. The experiments tried with different enrichment length were A = 0 hour, B = 5 hours, C = 10 hours and D = 10 hours with triplicate. As the comparing data, rotifer culture experiment was carried out with Nannochlorophsis sp.as the control. The number of containers were 24 which consists of 12 for threatment and 12 pieces as control. Variables measured were proximate to each treatment and the growth of rotifers. The result of the research revealed the enrichment length of rotifers with Bacillus sp. has significantly (P Key words: rotifers, Bacillus, enrichment period, proximate   ABSTRAK Brachionus plicatilis merupakan pakan alami yang banyak digunakan dalam pembenihan. Karakteristik rotifer sebagai biokapsul secara praktis dapat meningkatkan kualitas rotifer. Bacillus sp. mampu memperbaiki nutrisi rotifer dengan memproduksi vitamin, detoksikasi pangan maupun melalui aktivitas enzimatis seperti protease, lipase, dan amilase. Penelitian ini bertujuan untuk melihat pengaruh pengkayaan Bacillus sp. terhadap kualitas nutrisi dan pertumbuhan rotifer. Wadah penelitian menggunakan bak fiber volume 1 ton yang berisikan Nannochloropsis sp. dengan kepadatan 105 cell

  3. Microalgae biofuel potentials (review).

    Ghasemi, Y; Rasoul-Amini, S; Naseri, A T; Montazeri-Najafabady, N; Mobasher, M A; Dabbagh, F

    2012-01-01

    With the decrease of fossil based fuels and the environmental impact of them over the planet, it seems necessary to seek the sustainable sources of clean energy. Biofuels, is becoming a worldwide leader in the development of renewable energy resources. It is worthwhile to say that algal biofuel production is thought to help stabilize the concentration of carbon dioxide in the atmosphere and decrease global warming impacts. Also, among algal fuels' attractive characteristics, algal biodiesel is non toxic, with no sulfur, highly biodegradable and relatively harmless to the environment if spilled. Algae are capable of producing in excess of 30 times more oil per acre than corn and soybean crops. Currently, algal biofuel production has not been commercialized due to high costs associated with production, harvesting and oil extraction but the technology is progressing. Extensive research was conducted to determine the utilization of microalgae as an energy source and make algae oil production commercially viable.

  4. MORFOMETRI ROTIFER Brachionus rotundiformis STRAIN SS ASAL TAMBAK MINANGA DAN TAMBAK WATULINEY SULAWESI UTARA YANG DIKULTUR PADA SALINITAS YANG BERBEDA

    Inneke Fenny Melke Rumengan

    2016-11-01

    The rotifers Brachionus rotundiformis were found predominantly in Minanga and Watuliney brackishwater ponds in North Sulawesi. The two ponds are located 7 km apart at south-eastern coast of North Sulawesi facing to Maluku Sea. Morphometry of the two groups may associate with the original salinities of the ponds, 25—33 and 0—3 ppt in Minanga and Watuliney ponds, respectively. The rotifers were cultured at different salinities in laboratory in order to observe the plasticity of their size. Rotifers from Minanga ponds were gradually adapted by lowering salinities from 30 ppt to 25, 20 until 5 ppt. In contrast, Rotifers from Watuliney ponds were adapted gradually by increasing salinities from 5 ppt to 10, 15, 20, 25, and 30 ppt. In each treatment, 5 first laid eggs were put into each test tube containing Nannochloropsi oculata (3x106 cells/mL at 25°C, and after 7 days, the rotifer population remarkably increased due to parthenogenetic reproduction, and then body size of 30 egg-carrying rotifers of each treatment were measured under microscope. Body size of rotifers from Minanga ponds in all treatment was lower than that of rotifers from Watuliney ponds. Statistically, morphometry of the two groups was significantly different. However, there was a tendency for that lorica length of rotifers from Watuliney ponds to increase as the salinity increase, while rotifers from Minanga  ponds did not significantly changed in their sizes as the salinity changed.

  5. Free Amino Acid Enriched Rotifer for Larval Grouper Cromileptes altivelis (Pengkayaan Rotifer dengan Asam Amino Bebas Untuk Larva Kerapu Bebek Cromileptes altivelis

    Dedi Jusadi

    2015-12-01

    Full Text Available Pembenihan ikan kerapu dihadapkan pada rendahnya sintasan, terutama fase awal hidupnya. Rendahnya sintasan diduga berhubungan dengan belum berkembangnya organ pencernaan larva dan tidak tersedianya pakan yang siap diserap tubuh. Pemberian asam amino bebas seperti taurin dan glutamin melalui rotifer diharapkan dapat meningkatan ketersediaan nutrien yang dapat diserap dengan cepat oleh larva, sehingga sintasan larva tinggi dan dapat tumbuh lebih cepat. Penelitian bertujuan mengukur pengaruh glutamin atau taurin terhadap sintasan dan pertumbuhan larva kerapu bebek Cromileptes altivelis. Larva umur 1 hari (10 ekor.L-1 dipelihara dalam bak fiberglass volume 500 L yang diisi air laut sampai 330 L. Larva diberi pakan rotifer diperkaya 0,5 g glutamin, 0,5 g taurin, atau tanpa glutamin dan taurin. Larva dipelihara selama 16 hari dengan pemberian pakan 2 kali  per hari. Satu jam setelah pemberian pakan dilakukan pengamatan terhadap jumlah rotifer dalam saluran pencernaan larva ikan. Hasil penelitian menunjukkan jumlah rotifer dalam saluran pencernaan larva meningkat seiring dengan bertambahnya umur. Namun, jumlah rata-rata rotifer yang dikonsumsi larva pada perlakuan 0,5 g glutamin atau 0,5 g taurin lebih banyak dibanding perlakuan tanpa taurin dan glutamin. Larva yang diberi rotifer hasil pengkayaan dengan 0,5 g glutamin atau 0,5 g taurin memiliki sintasan yang tidak berbeda (P>0,05, masing-masing 19,2±2,25%, dan 24,5±1,20%, dan secara signifikan lebih banyak dibanding larva di perlakuan tanpa glutamin dan taurin yang nilainya 13,0±1,70%. Larva yang diberi rotifer hasil pengkayaan dengan 0,5 g taurin secara signifikan lebih panjang (5,5±0,18 mm dari ikan di perlakuan 0,5 g glutamin (5,3±0,12 mm. Demikian juga, larva di perlakuan glutamin lebih panjang dari pelakuan tanpa glutamin dan taurin (5,0±0,16 mm. Pengkayaan rotifer menggunakan asam amino bebas taurin atau glutamin dapat meningkatkan sintasan dan pertumbuhan larva kerapu bebek. Namun

  6. Cost of reproduction in selected species of zooplankton (rotifers and cladocerans)

    Sarma, S.S.S.; Nandini, S.; Gulati, R.D.

    2002-01-01

    Reproduction is an energetically costly biological process. Among the freshwater zooplankton, rotifers and cladocerans reproduce parthenogenetically and the cost of reproduction can be estimated using the life table data from demographic studies. Reduced probability of future survival or future

  7. Methods for culturing saltwater rotifers (Brachionus plicatilis) for rearing larval zebrafish.

    Lawrence, Christian; Sanders, Erik; Henry, Eric

    2012-09-01

    The saltwater rotifer, Brachionus plicatilis, is widely used in the aquaculture industry as a prey item for first-feeding fishes due to its ease of culture, small size, rapid reproductive rate, and amenability to enrichment with nutrients. Despite the distinct advantages of this approach, rotifers have only been sporadically utilized for rearing larval zebrafish, primarily because of the common misconception that maintaining cultures of rotifers is difficult and excessively time-consuming. Here we present simple methods for maintaining continuous cultures of rotifers capable of supporting even the very largest zebrafish aquaculture facility, with minimal investments in materials, time, labor, and space. Examples of the methods' application in one large, existing facility is provided, and troubleshooting of common problems is discussed.

  8. Specific toxic effect of dinoflagellate Heterocapsa circularisquama on the rotifer Brachionus plicatilis.

    Kim, D; Sato, Y; Oda, T; Muramatsu, T; Matsuyama, Y; Honjo, T

    2000-12-01

    Heterocapsa circularisquama (Dinophyceae), a noxious red tide dinoflagellate, is known to have a specifically lethal effect on shellfish, especially bivalves such as pearl oyster (Pinctada fucata), but no detrimental effects of this alga on fishes have not been observed so far. In this study, we found that H. circularisquama was toxic to a microzooplankton, a rotifer (Brachionus plicatilis) in a cell concentration-dependent manner, while the cultured supernatant or ultrasonic ruptured H. circularisquama had no significant toxic effect on the rotifer. Since no such toxic effects on the rotifer were observed in Chattonella marina, Heterosigma akashiwo, or Cochlodinium polykrikoides, other species of harmful red tide plankton, H. circularisquama may have a strictly specific toxic mechanism against the rotifer as well as bivalves.

  9. Physicochemical analysis of cellulose from microalgae ...

    African Journal of Biotechnology ... Nannochloropsis gaditana is a microalgae belonging to the class of Eustigmatophyceae. This particular microalga is the most studied species. For its richness in lipids, it is used for the biodiesel production.

  10. Mongolian Rotifers on Micr oscope Slides: Instructions to Permanent Specimen Mounts from Expedition Material

    Christian D. Jersabek; Erdene Bolortsetseg; Howard L. Taylor

    2010-01-01

    We here describe a method for permanently mounting specimens on microscope slides, as we applied it in the newly established rotifer collection in Ulaanbaatar, Mongolia. The liquid photopolymer NOA 61 was used as a primary sealant for pure glycerine mounts. We furthermore outline simple methods of rotifer narcotization and fi xation in the fi eld that yield, for the majority of species, adequately preserved specimen mat...

  11. Null models for study Rotifers and Crustaceans Zooplankton species richness in Chilean Patagonian lakes

    Escalante, Patricio de los Ríos

    2016-01-01

    Abstract Aims The Patagonian lakes are characterized by their oligotrophy that is the cause of low species number in their zooplankton assemblage. The aim of the present study is to analyze the crustacean and rotifers species number pattern in Patagonian lakes among a latitudinal gradient (40-51 °S). Results The results revealed that there are direct significant correlations between total species with rotifer species, and chlorophyll concentration with crustacean species number, and an inve...

  12. Microalgae harvesting techniques: A review.

    Singh, Gulab; Patidar, S K

    2018-07-01

    Microalgae with wide range of commercial applications have attracted a lot of attention of the researchers in the last few decades. However, microalgae utilization is not economically sustainable due to high cost of harvesting. A wide range of solid - liquid separation techniques are available for microalgae harvesting. The techniques include coagulation and flocculation, flotation, centrifugation and filtration or a combination of various techniques. Despite the importance of harvesting to the economics and energy balance, there is no universal harvesting technique for microalgae. Therefore, this review focuses on assessing technical, economical and application potential of various harvesting techniques so as to allow selection of an appropriate technology for cost effectively harvesting of microalgae from their culture medium. Various harvesting and concentrating techniques of microalgae were reviewed to suggest order of suitability of the techniques for four main microalgae applications i.e biofuel, human and animal food, high valued products, and water quality restoration. For deciding the order of suitability, a comparative analysis of various harvesting techniques based on the six common criterions (i.e biomass quality, cost, biomass quantity, processing time, species specific and toxicity) has been done. Based on the order of various techniques vis-a-vis various criteria and preferred order of criteria for various applications, order of suitability of harvesting techniques for various applications has been decided. Among various harvesting techniques, coagulation and flocculation, centrifugation and filtration were found to be most suitable for considered applications. These techniques may be used alone or in combination for increasing the harvesting efficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Laboratory and field studies on an Indian strain of the brine shrimp Artemia

    Royan, J.P.

    The Tuticorin strain of the brine shrimp @iArtemia@@ was studied under both laboratory and field conditions. Studies on the survival of the nauplii at different temperatures and salinities revealed that the nauplii preferred a salinity of 35 ppt...

  14. Morphological similarity and ecological overlap in two rotifer species.

    Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José

    2013-01-01

    Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on

  15. Morphological similarity and ecological overlap in two rotifer species.

    Carmen Gabaldón

    Full Text Available Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention, these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1 functional response, expressed by clearance rates; (2 tolerance to starvation, measured by growth and reproduction; and (3 vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not

  16. Biochemical diversification through foreign gene expression in bdelloid rotifers.

    Chiara Boschetti

    Full Text Available Bdelloid rotifers are microinvertebrates with unique characteristics: they have survived tens of millions of years without sexual reproduction; they withstand extreme desiccation by undergoing anhydrobiosis; and they tolerate very high levels of ionizing radiation. Recent evidence suggests that subtelomeric regions of the bdelloid genome contain sequences originating from other organisms by horizontal gene transfer (HGT, of which some are known to be transcribed. However, the extent to which foreign gene expression plays a role in bdelloid physiology is unknown. We address this in the first large scale analysis of the transcriptome of the bdelloid Adineta ricciae: cDNA libraries from hydrated and desiccated bdelloids were subjected to massively parallel sequencing and assembled transcripts compared against the UniProtKB database by blastx to identify their putative products. Of ~29,000 matched transcripts, ~10% were inferred from blastx matches to be horizontally acquired, mainly from eubacteria but also from fungi, protists, and algae. After allowing for possible sources of error, the rate of HGT is at least 8%-9%, a level significantly higher than other invertebrates. We verified their foreign nature by phylogenetic analysis and by demonstrating linkage of foreign genes with metazoan genes in the bdelloid genome. Approximately 80% of horizontally acquired genes expressed in bdelloids code for enzymes, and these represent 39% of enzymes in identified pathways. Many enzymes encoded by foreign genes enhance biochemistry in bdelloids compared to other metazoans, for example, by potentiating toxin degradation or generation of antioxidants and key metabolites. They also supplement, and occasionally potentially replace, existing metazoan functions. Bdelloid rotifers therefore express horizontally acquired genes on a scale unprecedented in animals, and foreign genes make a profound contribution to their metabolism. This represents a potential

  17. Flashing light in microalgae biotechnology.

    Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

    2016-03-01

    Flashing light can enhance photosynthesis and improve the quality and quantity of microalgal biomass, as it can increase the products of interest by magnitudes. Therefore, the integration of flashing light effect into microalgal cultivation systems should be considered. However, microalgae require a balanced mix of the light/dark cycle for higher growth rates, and respond to light intensity differently according to the pigments acquired or lost during the growth. This review highlights recently published results on flashing light effect on microalgae and its applications in biotechnology, as well as the recently developed bioreactors designed to fulfill this effect. It also discusses how this knowledge can be applied in selecting the optimal light frequencies and intensities with specific technical properties for increasing biomass production and/or the yield of the chemicals of interest by microalgae belonging to different genera. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Heavy metal sorption by microalgae

    Sandau, E.; Sandau, P.; Pulz, O.

    1996-01-01

    Viable microalgae are known to be able to accumulate heavy metals (bioaccumulation). Against a background of the increasing environmental risks caused by heavy metals, the microalgae Chlorella vulgaris and Spirulina platensis and their potential for the biological removal of heavy metals from aqueous solutions were taken as an example for investigation. Small-scale cultivation tests (50 l) with Cd-resistant cells of Chlorella vulgaris have shown that approx. 40% of the added 10 mg Cd/l was removed from the solution within seven days. At this heavy metal concentration sensitive cells died. Non-viable microalgae are able to eliminate heavy metal ions in a short time by biosorption in uncomplicated systems, without any toxicity problems. Compared with original biomasses, the sorption capacity of microalgal by-products changes only insignificantly. Their low price makes them economical. (orig.)

  19. Marine microalgae flocculation using plant: the case of Nannochloropsis oculata and Moringa oleifera

    Baharuddin, N.; Aziz, N. S.; Sohif, H. N.; Basiran, M. N.

    2016-01-01

    Marine microalgae have been commercially used as live feed for aquaculture and nutritional supplements. However, harvesting of marine microalgae is a major obstacle for industrial scale and one of the promising harvesting techniques is bio-flocculation. Nannochloropsis oculata from the culture broth was investigated. The potential of Moringa oleifera as a flocculant has been evaluated using jar test experiments. Moringa oleifera after oil extraction (MOAE) and with non-extracted Moringa oleifera (MOWE) have been studied and compared to chemical flocculant, aluminium sulphate. Three parameters involved: pH, settling time and flocculant dosage. When MOAE and MOWE were used as flocculants, the highest flocculation efficiency of Nannochloropsis oculata was observed at 93.77 percent (pH 7, 150 minutes, 5000 mg/L) and 70.56 percent (pH 7, 90 minutes, 4000 mg/L) respectively. Harvesting efficiency of 99.98 percent with short settling time, 30 minutes and 2000 mg/L of flocculant dosage at pH 6 was achieved using aluminium sulphate. The concentrated of Nannochloropsis oculata was then fed to the Brachionus plicatilis (rotifers) to observe the growth characteristics in 12 days period. Concentrates of MOWE gave better growth of Brachionus plicatilis than growth in concentrates of MOAE and live Nannochloropsis oculata. In contrast, growth of Brachionus plicatilis in aluminium sulphate was tremendously decline. In Conclusion, bio-flocculation using Moringa oleifera was rapid, inexpensive and eco-friendly technology as no addition of chemical flocculants was required. (author)

  20. Phosphopantetheinylation in the green microalgae Chlamydomonas reinhardtii

    Sonnenschein, Eva; Pu, Yuan; Beld, Joris

    2016-01-01

    available microalgal genome data revealed that most green microalgae appear to carry two PPTases forming clusters with each C. reinhardtii PPTase, while microalgae of other divisions carry one or two PPTases and do not cluster in the pattern of the green algal data. This new understanding on the PPTases...... in microalgae shows that microalgae are already primed for biotechnological applications in contrast to other organisms. Thus, microalgae have great potential for metabolic engineering efforts in the realm of biofuel and high-value products including direct engineering of the fatty acid or secondary metabolism...

  1. Airborne Microalgae: Insights, Opportunities, and Challenges

    Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

    2016-01-01

    Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

  2. Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis.

    Koushirou Suga

    Full Text Available BACKGROUND: Rotifers are among the most common non-arthropod animals and are the most experimentally tractable members of the basal assemblage of metazoan phyla known as Gnathifera. The monogonont rotifer Brachionus plicatilis is a developing model system for ecotoxicology, aquatic ecology, cryptic speciation, and the evolution of sex, and is an important food source for finfish aquaculture. However, basic knowledge of the genome and transcriptome of any rotifer species has been lacking. METHODOLOGY/PRINCIPAL FINDINGS: We generated and partially sequenced a cDNA library from B. plicatilis and constructed a database of over 2300 expressed sequence tags corresponding to more than 450 transcripts. About 20% of the transcripts had no significant similarity to database sequences by BLAST; most of these contained open reading frames of significant length but few had recognized Pfam motifs. Sixteen transcripts accounted for 25% of the ESTs; four of these had no significant similarity to BLAST or Pfam databases. Putative up- and downstream untranslated regions are relatively short and AT rich. In contrast to bdelloid rotifers, there was no evidence of a conserved trans-spliced leader sequence among the transcripts and most genes were single-copy. CONCLUSIONS/SIGNIFICANCE: Despite the small size of this EST project it revealed several important features of the rotifer transcriptome and of individual monogonont genes. Because there is little genomic data for Gnathifera, the transcripts we found with no known function may represent genes that are species-, class-, phylum- or even superphylum-specific; the fact that some are among the most highly expressed indicates their importance. The absence of trans-spliced leader exons in this monogonont species contrasts with their abundance in bdelloid rotifers and indicates that the presence of this phenomenon can vary at the subphylum level. Our EST database provides a relatively large quantity of transcript

  3. Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis.

    Suga, Koushirou; Welch, David Mark; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

    2007-08-01

    Rotifers are among the most common non-arthropod animals and are the most experimentally tractable members of the basal assemblage of metazoan phyla known as Gnathifera. The monogonont rotifer Brachionus plicatilis is a developing model system for ecotoxicology, aquatic ecology, cryptic speciation, and the evolution of sex, and is an important food source for finfish aquaculture. However, basic knowledge of the genome and transcriptome of any rotifer species has been lacking. We generated and partially sequenced a cDNA library from B. plicatilis and constructed a database of over 2300 expressed sequence tags corresponding to more than 450 transcripts. About 20% of the transcripts had no significant similarity to database sequences by BLAST; most of these contained open reading frames of significant length but few had recognized Pfam motifs. Sixteen transcripts accounted for 25% of the ESTs; four of these had no significant similarity to BLAST or Pfam databases. Putative up- and downstream untranslated regions are relatively short and AT rich. In contrast to bdelloid rotifers, there was no evidence of a conserved trans-spliced leader sequence among the transcripts and most genes were single-copy. Despite the small size of this EST project it revealed several important features of the rotifer transcriptome and of individual monogonont genes. Because there is little genomic data for Gnathifera, the transcripts we found with no known function may represent genes that are species-, class-, phylum- or even superphylum-specific; the fact that some are among the most highly expressed indicates their importance. The absence of trans-spliced leader exons in this monogonont species contrasts with their abundance in bdelloid rotifers and indicates that the presence of this phenomenon can vary at the subphylum level. Our EST database provides a relatively large quantity of transcript-level data for B. plicatilis, and more generally of rotifers and other gnathiferan phyla, and

  4. Cell disruption for microalgae biorefineries

    Günerken, E.; Hondt, d' E.; Eppink, M.H.M.; Garcia-Gonzalez, L.; Elst, K.; Wijffels, R.H.

    2015-01-01

    Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of

  5. Species-specific separation of lake plankton reveals divergent food assimilation patterns in rotifers.

    Burian, Alfred; Kainz, Martin J; Schagerl, Michael; Yasindi, Andrew

    2014-06-01

    1. The analysis of functional groups with a resolution to the individual species level is a basic requirement to better understand complex interactions in aquatic food webs. Species-specific stable isotope analyses are currently applied to analyse the trophic role of large zooplankton or fish species, but technical constraints complicate their application to smaller-sized plankton. 2. We investigated rotifer food assimilation during a short-term microzooplankton bloom in the East African soda lake Nakuru by developing a method for species-specific sampling of rotifers. 3. The two dominant rotifers, Brachionus plicatilis and Brachionus dimidiatus , were separated to single-species samples (purity >95%) and significantly differed in their isotopic values (4.1‰ in δ 13 C and 1.5‰ in δ 15 N). Bayesian mixing models indicated that isotopic differences were caused by different assimilation of filamentous cyanobacteria and particles plicatilis (48%), whereas it was hardly ingested by B. dimidiatus . Overall, A . fusiformis was, relative to its biomass, assimilated to small extents, demonstrating a high grazing resistance of this species. 5. In combination with high population densities, these results demonstrate a strong potential of rotifer blooms to shape phytoplankton communities and are the first in situ demonstration of a quantitatively important direct trophic link between rotifers and filamentous cyanobacteria.

  6. Identification of genes differentially expressed by calorie restriction in the rotifer (Brachionus plicatilis).

    Oo, Aung Kyaw Swar; Kaneko, Gen; Hirayama, Makoto; Kinoshita, Shigeharu; Watabe, Shugo

    2010-01-01

    A monogonont rotifer Brachionus plicatilis has been widely used as a model organism for physiological, ecological studies and for ecotoxicology. Because of the availability of parthenogenetic mode of reproduction as well as its versatility to be used as live food in aquaculture, the population dynamic studies using the rotifer have become more important and acquired the priority over those using other species. Although many studies have been conducted to identify environmental factors that influence rotifer populations, the molecular mechanisms involved still remain to be elucidated. In this study, gene(s) differentially expressed by calorie restriction in the rotifer was analyzed, where a calorie-restricted group was fed 3 h day(-1) and a well-fed group fed ad libitum. A subtracted cDNA library from the calorie-restricted rotifer was constructed using suppression subtractive hybridization (SSH). One hundred sixty-three expressed sequence tags (ESTs) were identified, which included 109 putative genes with a high identity to known genes in the publicly available database as well as 54 unknown ESTs. After assembling, a total of 38 different genes were obtained among 109 ESTs. Further validation of expression by semi-quantitative reverse transcription-PCR showed that 29 out of the 38 genes obtained by SSH were up regulated by calorie restriction.

  7. [Immunocytochemical studies on the phase of differentiation of hatching gland cells in brine shrimp, Artemia salina].

    Li, Ling; Fan, Ting Jun; Wang, Xiao Feng; Cong, Ri Shan; Yu, Qiu Tao; Zhong, Qi Wang

    2004-04-01

    Hatching enzyme (HE), synthesized in hatching gland cells (HGCs), plays vital roles in animal hatching. Immunocytochemical techniques employing anti-GST-UVS.2 antiserum, prepared from Xenopus HE and with specificity to brine shrimp HE, were first used to investigate the differentiation and variability of hatching gland cells (HGCs) in the hatching process of embryos of brine shrimp, Artemia salina, in this study. HGCs with immunoreactivity to anti-GST-UVS.2 antiserum were identified, for the first time, in brine shrimp embryos during hatching process. Immunocytochemical staining results showed that, (1) HE-positive immunoreactivity is really specific to Artemia HE, and its appearance and disappearance are closely correlated with the hatching process of Artemia salina. (2) Artemia HGCs, first appeared in embryos 5 hours before hatching and disappeared 4 hours after hatching, were also a transient type of cells, with an existence period of 9 hours. (3) The head portion of Artemia embryo is probably the initial position of HE secretion, and likely to be the main position of HE secretion as well. The detailed process and mechanism need to be studied. (4) The appearance of HGCs is in a synchronous mode from places all over the embryos, and their disappearance is also in a synchronous mode. (5) The number of HGCs increased gradually along with embryo development process and reached a maximum number at hatching. Contrarily, the number of HGCs decreased gradually after hatching, and HGCs disappeared 5 hours after hatching. However, the intensity of HE-positive reaction was almost at the same level at the period of HGCs'presence. (6) Artemia HGCs were distributed throughout the body of embryos at all time during their presence. Therefore, it can concluded that Artemia HGCs, as a transient type of cells, first appeared in embryos 4 hours before hatching and disappeared in embryos 5 hours after hatching, and with distinguished patterns of appearance, disappearance and

  8. Observations on development of artemia eggs irradiated on earth

    He Jian; Zhou Qiling; Xing Guoren; Zheng Decun; Su Ruizhen; Chen Qu'e

    1990-01-01

    For accompanying with space radiobiological studies, dry eggs of native Artemia were irradiated in the laboratory by 14 MeV fast neutrons and 60 Co γ-rays, and their development was then followed. Doses of the fast neutrons used were 10, 50, 100, 200, 400, 600, 800 and 1000 Gy, and those of γ-rays were 50, 100, 500, 1000 and 2000 Gy respectively. The irradiated eggs, together with the control, were stored at 4 deg C before incubation and observations. The results are as follows: (1) A significant delay of early development was seen in eggs irradiated by both radiatoins. (2) The rates of emergence and hatching decreased with the increase of the doses, and went down further after the prolongation of egg-storage at 4 deg C. (3) The mortality peak of the larvae hatched from irradiated eggs appeared within 2-5 days after hatching, and the RBE's of the fast neutrons, for LD 50 , comparing with the γ-rays were found to be: 1.80 on the 3rd day, 2.44 on the 4th day, and 2.27 on the 5th day

  9. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

    Alvarado-Flores, Jesus, E-mail: jalvaflo@hotmail.com [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rico-Martinez, Roberto, E-mail: rrico@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Ventura-Juarez, Javier, E-mail: jventur@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Morfologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Silva-Briano, Marcelo, E-mail: msilva@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Biologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rubio-Franchini, Isidoro, E-mail: rubio_reyes@hotmail.com [Instituto de Servicios de Salud del Estado de Aguascalientes, Laboratorio Estatal de Salud Publica, Av. Siglo XXI 105, Ciudad Satelite Morelos, C.P. 20270, Aguascalientes, Ags. (Mexico)

    2012-03-15

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green{sup Registered-Sign} analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  10. Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions.

    Kaneko, Gen; Yoshinaga, Tatsuki; Gribble, Kristin E; Welch, David M; Ushio, Hideki

    2016-07-22

    Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

  11. Effect of nutritional state on Hsp60 levels in the rotifer Brachionus plicatilis following toxicant exposure.

    Wheelock, C E; Baumgartner, T A; Newman, J W; Wolfe, M F; Tjeerdema, R S

    2002-11-13

    The nutritional state of an organism can affect the results of toxicity testing. Here we exemplified this fact by examining the effect of nutritional deprivation on heat shock protein 60 (hsp60) production in the rotifer Brachionus plicatilis following exposure to two proven inducers of hsp60, a water-accommodated fraction of crude oil (WAF) and a dispersed oil preparation (DO). Both DO and WAF exposures of unfed rotifers resulted in significantly greater hsp60 levels than that of fed DO and WAF exposed rotifers at 8 h: 870 and 3100% of control, respectively. Results clearly demonstrate that a poor nutritional state potentiates stress protein induction upon exposure to water-soluble petroleum products. It is therefore critical to define the organismal nutritional status when reporting toxic responses. Copyright 2002 Elsevier Science B.V.

  12. Purification and characterization of an endoglucanase from the marine rotifer, Brachionus plicatilis.

    Chun, C Z; Hur, S B; Kim, Y T

    1997-10-01

    The marine rotifer, Brachionus plicatilis, is able to digest Chlorella efficiently, suggesting that the rotifer contains a powerful cellulolytic enzyme system. A multi-component cellulolytic complex, including endoglucanase (CM-cellulase), cellobiohydrolase and beta-glucosidase, was found in Brachionus plicatilis. Endoglucanase (endo-beta-1,4 glucanase) was purified to homogeneity from rotifer homogenates using a sequential chromatographic method. The purified enzyme exhibits a strong hydrolytic activity with carboxymethyl(CM)-cellulose. The optimum temperature and pH for the endoglucanase activity were 37 degrees C and 7.0, respectively. 80% of the CM-cellulase activity was retained in salt mixture that ranged from 150 to 500 mM NaCl equivalent. The purified protein was isolated with a molecular weight of approximately 62 kDa estimated by SDS-polyacrylamide gel electrophoresis.

  13. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

    Alvarado-Flores, Jesús; Rico-Martínez, Roberto; Ventura-Juárez, Javier; Silva-Briano, Marcelo; Rubio-Franchini, Isidoro

    2012-01-01

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green ® analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  14. Efficient recovery of uranium using genetically improved microalgae; Recuperacion eficaz de uranio utilizando microalgas geneticamente mejoradas

    Lopez-Rodas, V.; Gonzalez Conde, E.; Garcia-Balboa, C.

    2014-07-01

    Although bioaccumulation is an enzymatic process that requires live microalgae bio sorption is based on physicochemical interactions, and it is not necessary that microalgae are alive, whereby dried microalgae biomass achieves the same results. This alternative could represent a new safe and inexpensive way to recover U. (Author)

  15. Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.

    Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi

    2016-08-01

    The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.

  16. Microalgae Culture Collection: 1984-1985

    1984-09-01

    The Microalgae Culture Collection at the Solar Energy Research Institute has been established for the maintenance and distribution of strains that have been characterized for biomass fuel applications.

  17. Reproductive performance of the guppy fish Poecilia reticulata [Peters, 1859] fed with live Artemia franciscana [Kellog, 1906] cultured with inert and live diets

    M. García-Ulloa

    2004-01-01

    Full Text Available El comportamiento reproductivo del guppy Poecilia reticulata —evaluado como número de crías, longitud estándar, peso húmedo y seco de las crías y su proporción sexual— fue estudiado usando varias dietas para los reproductores. Los tratamientos consistieron en adultos vivos de Artemia franciscana cultivada con microalgas vivas (Tetraselmis suecica y Chaetoceros calcitrans, harina de Spirulina, harina de soya, harina de trigo, una mezcla 50%/50% de dichas harinas y una dieta comercial como grupo control. Después de 45 días bajo condiciones experimentales de laboratorio, no se encontraron diferencias significativas (P > 0.05 en el número de crías producidas por hembra y en la longitud estándar individual de las crías entre los tratamientos. Las crías producidas por el grupo control fueron más pesadas que las del resto de los tratamientos (4.14 y 1.06 mg de peso húmedo y seco, respectivamente. En promedio, el grupo de reproductores alimentado con Spirulina produjo mayor cantidad de machos. Los resultados destacan el uso de la dieta comercial para cubrir con los requerimientos reproductivos de P. reticulata.

  18. Cestodes change the isotopic signature of brine shrimp, Artemia, hosts: implications for aquatic food webs.

    Sánchez, Marta I; Varo, Nico; Matesanz, Cristina; Ramo, Cristina; Amat, Juan A; Green, Andy J

    2013-01-01

    To reach the final host (greater flamingos), the cestode Flamingolepis liguloides alters the behaviour of its intermediate host, the brine shrimp, Artemia parthenogenetica, causing it to spend more time close to the water surface. During summer 2010, we showed that the prevalence of this cestode was consistently higher at the top of the water column in the Odiel salt pans in south-western Spain. We used stable nitrogen (N) and carbon (C) isotopic analysis to test the hypothesis that cestodes also alter resource use by Artemia. In early summer, we compared stable isotopes in infected hosts at the surface with those from uninfected hosts at the bottom of the water column. In late summer, we compared infected and uninfected Artemia from the bottom. δ(15)N was consistently enriched in infected individuals compared with uninfected hosts, especially in Artemia with multiple infections of F. liguloides (family Hymenolepididae) and those with mixed infections of F. liguloides and cestodes of the family Dilepididae. Infected individuals from the surface were enriched in δ(13)C compared with uninfected ones from the bottom, but the opposite was found when comparing uninfected and infected Artemia from the same depth. This may be caused by the increase in lipid concentration in infected Artemia. Isolated cysticercoids of F. liguloides were significantly enriched in δ(13)C compared with cysticercoids in infected hosts, but surprisingly were not enriched in N. Our findings illustrate the way cestodes can alter food webs and highlight the importance of considering the parasitic status of prey in studies of trophic ecology in saline wetlands. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  19. Microalgae as embedded environmental monitors

    Ogburn, Zachary L.; Vogt, Frank

    2017-01-01

    In marine ecosystems, microalgae are an important component as they transform large quantities of inorganic compounds into biomass and thereby impact environmental chemistry. Of particular relevance is phytoplankton's sequestration of atmospheric CO 2 , a greenhouse gas, and nitrate, one cause of harmful algae blooms. On the other hand, microalgae sensitively respond to changes in their chemical environment, which initiates an adaptation of their chemical composition. Analytical methodologies were developed in this study that utilize microalgae's adaptation as a novel approach for in-situ environmental monitoring. Longterm applications of these novel methods are investigations of environmental impacts on phytoplankton's sequestration performance and their nutritional value to higher organisms feeding on them. In order to analyze the chemical composition of live microalgae cells (Nannochloropsis oculata), FTIR-ATR spectroscopy has been employed. From time series of IR spectra, the formation of bio-sediment can be monitored and it has been shown that the nutrient availability has a small but observable impact. Since this bio-sediment formation is governed by several biological parameters of the cells such as growth rate, size, buoyancy, number of cells, etc., this enables studies of chemical environment's impact on biomass formation and the cells' physical parameters. Moreover, the spectroscopic signature of these microalgae has been determined from cultures grown under 25 different CO 2 and NO 3 − mixtures (200 ppm-600 ppm CO 2 , 0.35 mM-0.75 mM NO 3 − ). A novel, nonlinear modeling methodology coined ‘Predictor Surfaces’ is being presented by means of which the nonlinear responses of the cells to their chemical environment could reliably be described. This approach has been utilized to measure the CO 2 concentration in the atmosphere over the phytoplankton culture as well as the nitrate concentration dissolved in their growing

  20. Microalgae as embedded environmental monitors

    Ogburn, Zachary L.; Vogt, Frank, E-mail: fvogt@utk.edu

    2017-02-15

    In marine ecosystems, microalgae are an important component as they transform large quantities of inorganic compounds into biomass and thereby impact environmental chemistry. Of particular relevance is phytoplankton's sequestration of atmospheric CO{sub 2}, a greenhouse gas, and nitrate, one cause of harmful algae blooms. On the other hand, microalgae sensitively respond to changes in their chemical environment, which initiates an adaptation of their chemical composition. Analytical methodologies were developed in this study that utilize microalgae's adaptation as a novel approach for in-situ environmental monitoring. Longterm applications of these novel methods are investigations of environmental impacts on phytoplankton's sequestration performance and their nutritional value to higher organisms feeding on them. In order to analyze the chemical composition of live microalgae cells (Nannochloropsis oculata), FTIR-ATR spectroscopy has been employed. From time series of IR spectra, the formation of bio-sediment can be monitored and it has been shown that the nutrient availability has a small but observable impact. Since this bio-sediment formation is governed by several biological parameters of the cells such as growth rate, size, buoyancy, number of cells, etc., this enables studies of chemical environment's impact on biomass formation and the cells' physical parameters. Moreover, the spectroscopic signature of these microalgae has been determined from cultures grown under 25 different CO{sub 2} and NO{sub 3}{sup −} mixtures (200 ppm-600 ppm CO{sub 2}, 0.35 mM-0.75 mM NO{sub 3}{sup −}). A novel, nonlinear modeling methodology coined ‘Predictor Surfaces’ is being presented by means of which the nonlinear responses of the cells to their chemical environment could reliably be described. This approach has been utilized to measure the CO{sub 2} concentration in the atmosphere over the phytoplankton culture as well as the nitrate

  1. Biodiesel from microalgae beats bioethanol.

    Chisti, Yusuf

    2008-03-01

    Renewable biofuels are needed to displace petroleum-derived transport fuels, which contribute to global warming and are of limited availability. Biodiesel and bioethanol are the two potential renewable fuels that have attracted the most attention. As demonstrated here, biodiesel and bioethanol produced from agricultural crops using existing methods cannot sustainably replace fossil-based transport fuels, but there is an alternative. Biodiesel from microalgae seems to be the only renewable biofuel that has the potential to completely displace petroleum-derived transport fuels without adversely affecting supply of food and other crop products. Most productive oil crops, such as oil palm, do not come close to microalgae in being able to sustainably provide the necessary amounts of biodiesel. Similarly, bioethanol from sugarcane is no match for microalgal biodiesel.

  2. Acclimation and tolerance of Artemia salina to copper salts

    Saliba, L.J.; Krzyz, R.M.

    1976-01-01

    The brine shrimp Artemia salina L. was acclimated in sea water with cupric chloride, acetate, carbonate, and sulfate, each at concentrations of 0.1, 0.05 and 0.025 ppM Cu/sup + +/, together with sea water controls. Growth inhibition was observed in all four compounds, generally in direct relationship to the concentration. It was least in sulfate, and increased progressively in chloride, acetate and carbonate in that order. In toxicity tests, 2-week old larvae from each solution were exposed to concentrations of 10, 7.5, 5, 2.5 and 1 ppM Cu/sup + +/ of the same compounds, together with unacclimated larvae of the same age. Similar tests were held with 6-week old adults. Toxicity to unacclimated larvae and adults differed with the compounds, carbonate being the least toxic, followed by sulfate, chloride and acetate in increasing order. Larvae acclimated in chloride and sulfate showed an increased tolerance to 1 and 2.5 ppM Cu/sup + +/ compared to untreated controls. Tolerance was not enhanced from 5 ppM Cu/sup + +/ upwards. In both compounds, adults acclimated in 0.1 ppM Cu/sup + +/ showed an increased tolerance to concentrations between 1 and 7.5 ppM Cu/sup + +/ compared to controls. Considerable precipitation occurred with the high levels of this compound, thus effecting the ''final'' concentrations. No acclimation effect was observed in acetate for either larvae or adults. It is suggested that in A. salina, copper toxicity depends on the particular form of the metal, and that this difference is also evident in growth inhibition and in the potential acquisition of increased tolerance through exposure to low concentrations.

  3. Evaluation of the bioactivities of some Myanmar medicinal plants using brine shrimp (Artemia salina) toxicity test

    Sabai; Khin Khin Win Aung; Nwe Ni Thin; Kyi Shwe; Tin Myint Htwe

    2001-01-01

    For a variety of toxic substances, brine shrimp larvae (Artemia salina) are usually used as a simple bioassay method and it is also applied for natural product research. The brine shrimp larvae (nauplii) are obtained by natural hatching method from Artemia cysts. By using the larvae, the results from these experiments lead to the lethal dose, LD 50 values of extracts of selected medicinal plants. Activities of a broad range of plant extracts are manifested as toxicity to the brine shrimp. Screening results with six plant extracts are compared with pure caffeine. This method is rapid, reliable, inexpensive and convenient. (author)

  4. New records of rotifers (Rotifera: Eurotatoria from Deepor Beel - a Ramsar site of India with an update on its rich rotifer diversity.

    B.K. Sharma

    2015-03-01

    Full Text Available Plankton samples collected from Deepor Beel (a Ramsar site, during July 2011 to June 2013, revealed 155 species of Rotifera, belonging to 35 genera and 20 families.  Of these, 16 species belonging to eight genera and seven families are new records to the rotifer fauna of this wetland of northeast India.  Our observations raise the total richness of the phylum known till date from this important floodplain lake (beel of the Brahmaputra river basin to 171 species and thus highlight its biodiversity value as one of the globally rich Rotifera habitats.  The updated list is interesting for following meta-analyses of rotifer occurrence in this only well sampled freshwater ecosystem of the Indian sub-region. 

  5. Microalgae production in a biofilm photobioreactor

    Blanken, Ward

    2016-01-01

    Microalgae can be used to produce high-value compounds, such as pigments or high value fatty acids, or as a feedstock for lower value products such as food and feed compounds, biochemicals, and biofuels. In order to produce these bulk products competitively, it is required to lower microalgae

  6. Production of biofuels obtained from microalgae

    Luis Carlos Fernández-Linares

    2012-09-01

    Full Text Available A review of the situation of bio-fuels in the world, mainly of biodiesel is made. A comparison among the different raw materials for the synthesis of biodiesel is done and it is emphasized in the production of biodiesel from microalgae. The different fresh and salt water micro-algae in its lipid content and productivity are compared. A review of the process of biosynthesis of lipids in microalgae and how to improve the production of lipids in microalgae is shown. It is discussed the importance of the genetic manipulation to highly lipid-producing microalgae (example: Botryrococuus braunni, Nannochloropsis sp, Noechlorisoleobundans and Nitschia sp.. A study of the advantages and disadvantages of the different systems of cultivation of microalgae is also made. Finally, it is shown a perspective of biofuels from microalgae. Among the main challenges to overcome to produce biodiesel from microalgae are: the cost of production of biomass, which involves the optimization of media, selection and manipulation of strains and photobioreactors design. The processof separation of biomass, the extraction of oils and by-products, the optimization of the process of transesterification, purification and use of by-products must also be considered.

  7. Harvesting and cell disruption of microalgae

    Lam, 't Gerard Pieter

    2017-01-01

    Microalgae are a potential feedstock for various products. At the moment, they are already used as feedstock for high-valuable products (e.g. aquaculture and pigments).

    Microalgae pre-dominantly consist out of proteins, lipids and carbohydrates. This makes algae an interesting feedstock

  8. Microalgae for biofuels production and environmental applications ...

    This review presents the current classification of biofuels, with special focus on microalgae and their applicability for the production of biodiesel. The paper considered issues related with the processing and culturing of microalgae, for not only those that are involved in biofuel production, but as well as the possibility of their ...

  9. Are bacteria an important food source for rotifers in eutrophic lakes?

    Ooms-Wilms, A.L.

    1997-01-01

    In situ grazing measurements using fluorescent particles of 0.5, 2.4 and 6.3 mu m diameter in eutrophic Lake Loosdrecht (The Netherlands) showed that Anuraeopsis fissa, a small rotifer, filtered the smallest, bacteria sized particles as efficiently or more efficiently than the larger particles. In

  10. Rotifer fecundity in relation to components of microbial food web in a eurotrophic reservoir

    Devetter, Miloslav; Seďa, Jaromír

    2003-01-01

    Roč. 504, - (2003), s. 167-175 ISSN 0018-8158. [Reservoir Limnology and Water Quality /4./. České Budějovice, 12.08.2002-16.08.2002] Institutional research plan: CEZ:AV0Z6017912 Keywords : rotifers * microbial food web Subject RIV: EH - Ecology, Behaviour Impact factor: 0.720, year: 2003

  11. Decline of clear-water rotifer populations in a reservoir: the role of resource limitation

    Devetter, Miloslav; Seďa, Jaromír

    2005-01-01

    Roč. 546, č. 1 (2005), s. 509-518 ISSN 0018-8158 Institutional research plan: CEZ:AV0Z60660521 Keywords : resource limitation * rotifers * birth rate Subject RIV: EH - Ecology, Behaviour Impact factor: 0.978, year: 2005

  12. USING ROTIFER POPULATION DEMOGRAPHIC PARAMETERS TO ASSESS IMPACTS OF THE DEGRADATION PRODUCTS FROM TRINITROTOLUENE PHYTOREMEDIATION

    The objective of this study was to evaluate the aquatic chronic lethal and sublethal toxicity effects from the phytoremediation of water contaminated with 2,4,6-trinitrotoluene (2,4,6-TNT) by the wetland plant species Myriophyllum aquaticum (parrot feather). Rotifers (Brachionus...

  13. The complete mitochondrial genome of Pallisentis celatus (Acanthocephala) with phylogenetic analysis of acanthocephalans and rotifers.

    Pan, Ting Shuang; Nie, Pin

    2013-07-01

    Acanthocephalans are a small group of obligate endoparasites. They and rotifers are recently placed in a group called Syndermata. However, phylogenetic relationships within classes of acanthocephalans, and between them and rotifers, have not been well resolved, possibly due to the lack of molecular data suitable for such analysis. In this study, the mitochondrial (mt) genome was sequenced from Pallisentis celatus (Van Cleave, 1928), an acanthocephalan in the class Eoacanthocephala, an intestinal parasite of rice-field eel, Monopterus albus (Zuiew, 1793), in China. The complete mt genome sequence of P. celatus is 13 855 bp long, containing 36 genes including 12 protein-coding genes, 22 transfer RNAs (tRNAs) and 2 ribosomal RNAs (rRNAs) as reported for other acanthocephalan species. All genes are encoded on the same strand and in the same direction. Phylogenetic analysis indicated that acanthocephalans are closely related with a clade containing bdelloids, which then correlates with the clade containing monogononts. The class Eoacanthocephala, containing P. celatus and Paratenuisentis ambiguus (Van Cleave, 1921) was closely related to the Palaeacanthocephala. It is thus indicated that acanthocephalans may be just clustered among groups of rotifers. However, the resolving of phylogenetic relationship among all classes of acanthocephalans and between them and rotifers may require further sampling and more molecular data.

  14. CONSUMPTIONS RATES OF SUMMER FLOUNDER LARVAE ON ROTIFER AND BRINE SHRIMP PREY DURING LARVAL REARING

    Larval summer flounder Paralichthys dentatus were hatched and reared through metamorphosis in the laboratory. At several points in the rearing cycle, larvae were removed from their rearing chambers and placed in small bowls, where they were fed known quantities of the rotifer Bra...

  15. Primary succession of soil rotifers in clays of brown coal post-mining dumps

    Devetter, Miloslav; Frouz, J.

    2011-01-01

    Roč. 96, č. 2 (2011), s. 164-174 ISSN 1434-2944 R&D Projects: GA MŠk 2B08023 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil rotifers * post mining dumps * primary succession Subject RIV: EH - Ecology, Behaviour Impact factor: 1.190, year: 2011

  16. Survival of the probiotic bacteria Lactobacillus rhamnosus in seawater and its bioencapsulation in the brine shrimp Artemia

    Claudia Ofelio

    2014-06-01

    The results obtained in the first test showed that the L. rhamnosus was able to survive in seawater during the whole experiment (30h, maintaining densities of 10e7 CFU/ml during the first 6h although decreasing progressively afterwards (10e3 CFU/ml at 30h. This allows adequate levels at sufficient time for Artemia to incorporate the probiotic. In fact, bioencapsulation test demonstrated that Artemia metanauplii were able to bioencapsulate the probiotic, reaching the highest concentration in Artemia after 30 min of bioencapsulation (10e4 CFU/Artemia. A slight further decrease (10e3 CFU/Artemia was observed after 24h. Interestingly, L. rhamnosus reduced in 1Log total Vibrionaceae bacteria in Artemia during the 3 first hours. Therefore, 3 hours was the time established for the bioencapsulation protocol and further studies are in progress to determine the ability of Artemia metanauplii to maintain bioencapsulated L. rhamnosus once transferred to rearing tanks. Also, the capability of the probiotic to inhibit potential pathogenic or opportunistic bacteria will be assessed.

  17. Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepod Tisbe holothuriae

    Steenfeldt, Svend Jørgen; Nielsen, Johan W.

    2010-01-01

    down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers. We tested flubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe...... holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L−1. There was no significant effect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L−1 flubendazole. We conclude that flubendazole is an effective drug for control of B. plicatilis...

  18. Highly valuable microalgae: biochemical and topological aspects.

    Pignolet, Olivier; Jubeau, Sébastien; Vaca-Garcia, Carlos; Michaud, Philippe

    2013-08-01

    The past decade has seen a surge in the interest in microalgae culture for biodiesel production and other applications as renewable biofuels as an alternative to petroleum transport fuels. The development of new technologies for the culture of these photosynthetic microorganisms and improved knowledge of their biochemical composition has spurred innovation in the field of high-value biomolecules. These developments are only economically viable if all the microalgae fractions are valorized in a biorefinery strategy. Achieving this objective requires an understanding of microalgae content and the cellular localization of the main biomolecular families in order to develop efficient harvest and sequential recovery technologies. This review summarizes the state of the art in microalgae compositions and topologies using some examples of the main industrially farmed microalgae.

  19. Review of the African distribution of the brine shrimp genus Artemia

    2006-10-04

    Oct 4, 2006 ... The life cycle of Artemia can begin as an embryo ..... belong to different salt production companies and, although geo- graphically close to each other, were not listed as being the same due to different management. Similarly, sites listed under the name Velddrif do not all belong to the same salt company. In.

  20. Evaluation of different feeds for optimal growth and survival of parthenogenetic brine shrimp, Artemia

    Sumitra-Vijayaraghavan; Krishnakumari, L.; Royan, J.P.

    intestinalis and Ulva fasciata). Rice bran yielded best growth at an optimal level of 0.1 and 0.5 mg.ml-1 d-1 respectively for 1-4 and 4-8 d old larvae. Rice bran was also the best food for outdoor cultures. Artemia fed rice bran took shortest time to reach...

  1. Assessment of cyst production potential of a natural population of brine shrimp Artemia

    Royan, J.P.; Sumitra-Vijayaraghavan; Krishnakumari, L.

    Studies on a natural population of Artemia in the salterns of Jamnagar indicated that the population is parthenogenetic. These shrimps reach a maximum size of 9 mm. Number of cysts per brood varies from 10-32. Adults form about 68% of the total...

  2. Review of the African distribution of the brine shrimp genus Artemia ...

    Brine shrimp (genus Artemia) are small (8 to 12 mm long) cosmopolitan crustaceans (Anostraca) found predominately in hypersaline water bodies such as inland salt lakes and pans, coastal lagoons, and salt works at salinity levels above 40 g·ℓ-1. They have been extensively studied due to their high monetary value as ...

  3. Seasonal quantitative dynamics and ecology of pelagic rotifers in an acidified boreal lake

    Svein Birger Wærvågen

    2017-12-01

    Full Text Available Lake Gjerstadvann is a dimictic, oligotrophic, slightly acidified boreal lake in southern Norway (northwest Europe. The planktonic rotifer community of this lake was studied quantitatively during one year in order to investigate the impacts of the local environment and biotic interactions on seasonal succession and habitat selection. Pure suspension feeders (mainly Keratella spp., Conochilus spp., and Kellicottia longispina together with raptorial graspers or specialised feeders (mainly Polyarthra spp. and Collotheca spp. dominated the rotifer community over prolonged periods, whereas carnivorous/omnivorous species (mainly Asplanchna priodonta were extremely uncommon. Low bicarbonate buffering capacity resulted in a distinctive seasonal oscillating pH between 5.0 and 5.6, defining a special acid-transition lake category. The pH values were highest in the productive period during summer, and lowest during ice break-up coinciding with the peak reactive aluminium concentrations of 250-300 mg L-1. As in typical Norwegian boreal perch lakes, the most abundant cladoceran was Bosmina longispina due to perch predation on the genus Daphnia. Rotifer community structure was significantly related to temperature and oxygen (P=0.001 and P=0.022, illustrating the important effects of the seasonal cycle and vertical density stratification. The most significant competition indicator species were B. longispina and Eudiaptomus gracilis (both with P=0.001. A variance partitioning indicated that 14% of the total community composition variance could only be explained by biotic interactions, while 19% of the variance could be attributed to environmental gradients. Of the variance, 23% could not be resolved between biotic interactions and environmental gradients, while a residual of 44% was not explainable by any of the variables. Acid conditions alone cannot account for all the observed changes in the rotifer community of this lake with low humic content, since

  4. Use of Lecane rotifers for limiting Thiothrix filamentous bacteria in bulking activated sludge in a dairy wastewater treatment plant

    Kowalska Ewa

    2014-01-01

    Full Text Available Excessive growth of filamentous bacteria is a serious problem in many dairy wastewater treatment plants (WWTPs. The objective of the study was to determine whether Lecane inermis rotifers were able to reduce the density of Thiothrix bacteria in activated sludge originating from a dairy WWTP, as well as to identify the impact of rotifers on other organisms in sludge. On a laboratory scale, three experiments were conducted in which activated sludge with a predominance of Thiothrix was inoculated with rotifers at an initial concentration of app. 600 individuals/mL. The results showed that the rotifers, by feeding on the bacterium filaments, are able to reduce significantly the quantity of Thiothrix. A decline in Thiothrix abundance coincided with an improvement of the sedimentation properties of activated sludge. In addition, it was proven that Lecane inermis did not negatively affect the number of Protozoa and Metazoa in activated sludge.

  5. Bacterial diversity associated with the rotifer Brachionus plicatilis sp. complex determined by culture-dependent and -independent methods.

    Ishino, Ryota; Iehata, Shunpei; Nakano, Miyo; Tanaka, Reiji; Yoshimatsu, Takao; Maeda, Hiroto

    2012-03-01

    The bacterial communities associated with rotifers (Brachionus plicatilis sp. complex) and their culture water were determined using culture-dependent and -independent methods (16S rRNA gene clone library). The bacterial communities determined by the culture-independent method were more diverse than those determined by the culture-dependent method. Although the culture-dependent method indicated the bacterial community of rotifers was relatively similar to that of the culture water, 16S rRNA gene clone library analyses revealed a great difference between the two microbiotas. Our results suggest that most bacteria associated with rotifers are not easily cultured using conventional methods, and that the microbiota of rotifers do not correspond with that of the culture water completely.

  6. The genus Artemia Leach, 1819 (Crustacea: Branchiopoda: I. True and false taxonomical descriptions El género Artemia Leach, 1819 (Crustacea: Branchiopoda: I. Descripciones taxonómicas verdaderas y falsas

    Alireza Asem

    2010-01-01

    Full Text Available The brine shrimp Artemia is important for aquaculture since it is bighly nutritious. It is also used widely in biological studies because it is easy to culture. The aim of the present study is to review the literature on the taxonomical nomenclature of Artemia. The present study indicates the existence of seven species: three living in the Americas, one in Europe, and three in Asia.El camarón de salmuera Artemia es importante para la acuicultura por su alta calidad nutricional y es muy utilizado para estudios biológicos por ser de fácil cultivo. El objetivo del presente estudio es revisar la literatura sobre la nomenclatura taxonómica de Artemia. Se determina la existencia de siete especies; tres de ellas viven en América, una en Europa y tres en Asia.

  7. Magnetically modified microalgae and their applications

    Šafařík, Ivo; Procházková, G.; Pospíšková, K.; Brányik, T.

    2016-01-01

    Roč. 36, č. 5 (2016), s. 931-941 ISSN 0738-8551 R&D Projects: GA ČR GA13-13709S; GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : oleaginous chlorella sp * fresh-water microalgae * magnetophoretic separation * high-gradient * harvesting microalgae * alexandrium-fundyense * polymer binder * algal blooms * cells * removal * Harvesting algal cells * magnetic labeling * magnetic modification * magnetic separation * microalgae Subject RIV: EI - Biotechnology ; Bionics Impact factor: 6.542, year: 2016

  8. Comparative ecotoxicity of polystyrene nanoparticles in natural seawater and reconstituted seawater using the rotifer Brachionus plicatilis.

    Manfra, L; Rotini, A; Bergami, E; Grassi, G; Faleri, C; Corsi, I

    2017-11-01

    The impact of nanoplastics using model polystyrene nanoparticles (PS NPs), anionic (PS-COOH) and cationic (PS-NH 2 ), has been investigated on the marine rotifer Brachionus plicatilis, a major component of marine zooplanktonic species. The role of different surface charges in affecting PS NP behaviour and toxicity has been considered in high ionic strength media. To this aim, the selected media were standardized reconstituted seawater (RSW) and natural sea water (NSW), the latter resembling more natural exposure scenarios. Hatched rotifer larvae were exposed for 24h and 48h to both PS NPs in the range of 0.5-50μg/ml using PS NP suspensions made in RSW and NSW. No effects on lethality upon exposure to anionic NPs were observed despite a clear gut retention was evident in all exposed rotifers. On the contrary, cationic NPs caused lethality to rotifer larvae but LC 50 values resulted lower in rotifers exposed in RSW (LC 50 =2.75±0.67µg/ml) compared to those exposed in NSW (LC 50 =6.62±0.87µg/ml). PS NPs showed similar pattern of aggregation in both high ionic strength media (RSW and NSW) but while anionic NPs resulted in large microscale aggregates (Z-average 1109 ± 128nm and 998±67nm respectively), cationic NP aggregates were still in nano-size forms (93.99 ± 11.22nm and 108.3 ± 12.79nm). Both PDI and Z-potential of PS NPs slightly differed in the two media suggesting a role of their different surface charges in affecting their behaviour and stability. Our findings confirm the role of surface charges in nanoplastic behaviour in salt water media and provide a first evidence of a different toxicity in rotifers using artificial media (RSW) compared to natural one (NSW). Such evidence poses the question on how to select the best medium in standardized ecotoxicity assays in order to properly assess their hazard to marine life in natural environmental scenarios. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening

    Mayorga,Pablo; Pérez,Karen R.; Cruz,Sully M.; Cáceres,Armando

    2010-01-01

    Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest) and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest), were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq.) Kunth ex ...

  10. Influence of Chemical Parameters on Artemia sp. (Crustacea: Anostraca Population in Al Wathba Lake in the Abu Dhabi Emirate, UAE

    Anitha Saji

    2016-04-01

    Full Text Available Long term monitoring programme on Brine shrimp (Artemia sp. is being carried out by the Environment Agency, Abu Dhabi, United Arab Emirates (EAD with the prime purpose of understanding the population dynamics, ecology and habitat requirements of Artemia at Al Wathba Lake, situated within Al Wathba Wetland Reserve, which is an artificial wetland near Abu Dhabi City. The present study, being a component of this programme, intends to understand the influence of chemical parameters such as dissolved oxygen, nitrate, nitrite, phosphate, ammonia and total organic carbon on Artemia biomass and cyst production at different sites of the Al Wathba Lake. The study was carried out by sampling lake water quarterly for a period of 5 years from 2010 to 2014. The Artemia population was found to have direct impact of the above mentioned parameters on its abundance. The abundance was highest during the year 2010. Further, temperature, dissolved oxygen, nitrate and cadmium were found to be the most crucial parameters for production of Artemia. The study further aimed to determine the significant relationship between physico-chemical parameters and Artemia sp. population dynamics and cyst production.

  11. Screening of antioxidant activity in microalgae

    Mariana F.G. Assunção

    2014-06-01

    Both sets of results indicate an interesting antioxidant potential in microalgae belonging to the groups Eustigmatophyceae and Chlorophyceae. Tested species of these groups showed ABTS•+ values comparable to grape and raspberry ethanolic extracts, confirmed also by the DPPH• method.

  12. Modeling and visual simulation of Microalgae photobioreactor

    Zhao, Ming; Hou, Dapeng; Hu, Dawei

    Microalgae is a kind of nutritious and high photosynthetic efficiency autotrophic plant, which is widely distributed in the land and the sea. It can be extensively used in medicine, food, aerospace, biotechnology, environmental protection and other fields. Photobioreactor which is important equipment is mainly used to cultivate massive and high-density microalgae. In this paper, based on the mathematical model of microalgae which grew under different light intensity, three-dimensional visualization model was built and implemented in 3ds max, Virtools and some other three dimensional software. Microalgae is photosynthetic organism, it can efficiently produce oxygen and absorb carbon dioxide. The goal of the visual simulation is to display its change and impacting on oxygen and carbon dioxide intuitively. In this paper, different temperatures and light intensities were selected to control the photobioreactor, and dynamic change of microalgal biomass, Oxygen and carbon dioxide was observed with the aim of providing visualization support for microalgal and photobioreactor research.

  13. Biologically Active Metabolites Synthesized by Microalgae

    Michele Greque de Morais

    2015-01-01

    Full Text Available Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences.

  14. Responses of the rotifer Brachionus plicatilis to flame retardant (BDE-47) stress.

    Jian, Xiaoyang; Tang, Xuexi; Xu, Ningning; Sha, Jingjing; Wang, You

    2017-03-15

    A series of short-term toxicological tests were conducted on the rotifer Brachionus plicatilis to assess the toxicity of the flame retardant 2,2',4,4'-tetrabrominated biphenyl ether (BDE-47). BDE-47 increased mortality, morphological damage, and altered population dynamics and fecundity of rotifer. Antioxidant enzymes were differentially changed to maintain the balance between antioxidant and pro-oxidant activity. However, with increases in the concentration of BDE-47, the metabolic and antioxidant activity decreased. Moreover, the reactive oxygen species (ROS) and malondialdehyde contents increased and the ratio between glutathione and glutathione-SH decreased, indicating oxidative stress. The addition of the ROS-inhibitor N-acetylcysteine alleviated the degree of damage and stimulated the activity of xenobiotic-metabolizing and antioxidant system, which suggested that ROS were the most important loop in the stress response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. GABA, 5-HT and amino acids in the rotifers Brachionus plicatilis and Brachionus rotundiformis.

    Gallardo, W G; Hagiwara, A; Hara, K; Soyano, K; Snell, T W

    2000-11-01

    gamma-Aminobutyric acid (GABA) and 5-hydroxytryptamine (5-HT) have been shown to increase the reproduction of the Brachionus plicatilis (NH3L strain). In the present study, the endogenous presence of GABA and 5-HT in the rotifers B. plicatilis (NH3L and Kamiura strains) and Brachionus rotundiformis (Langkawi strain) were confirmed by dot blot immunoassay and high-performance liquid chromatography (HPLC). HPLC showed that GABA and 5-HT concentrations in the three rotifer strains range from 71 to 188 pmol/mg and from 12 to 64 pmol/mg, respectively. A total of 33 amino acids were also detected in B. plicatilis and B. rotundiformis, with glutamic acid, serine, glycine, taurine, threonine, alanine, arginine, proline, valine and isoleucine in high concentrations relative to other amino acids.

  16. Planktonic rotifer assemblages of the Danube River at Budapest after the red sludge pollution in Hungary.

    Schöll, Károly; Szövényi, Gergely

    2011-08-01

    In the autumn of 2010 an industrial red sludge spill occurred in Hungary. The toxic chemical waste with high alkalinity (pH 13.5) reached the Danube 2 days later, where no change was expected because of the high level of dilution. The planktonic rotifer assemblages of the Danube were investigated at Budapest during the contamination. The median of community density decreased from 500 ind. 100 L(-1) to zero, the species richness from 3.00 to 0.00, Shannon-Weaver diversity from 1.10 to 0.00 after the arrival of the contamination. The rotifer assemblages seemed to have recovered after 3 weeks, but the initial levels of diversity and density were not reached again.

  17. From tiny microalgae to huge biorefineries

    Gouveia, L.

    2014-01-01

    Microalgae are an emerging research field due to their high potential as a source of several biofuels in addition to the fact that they have a high-nutritional value and contain compounds that have health benefits. They are also highly used for water stream bioremediation and carbon dioxide mitigation. Therefore, the tiny microalgae could lead to a huge source of compounds and products, giving a good example of a real biorefinery approach. This work shows and presents examples of experimental...

  18. Comparison between direct transesterification of microalgae and hydrochar

    Vo Thanh Phuoc

    2017-07-01

    Full Text Available Hydrothermal carbonization (HTC of microalgae is one of processes that can effectively remove moisture from microalgae. In addition, the hydrochar retains most of fatty acids from microalgae feedstock, and the content of fatty acids in hydrochar is doubled. This research concentrates on the comparison between direct transesterification of microalgae and hydrochar. The result shows that the biodiesel yields of hydrochar were higher than those of microalgae at the same reaction conditions due to the higher extraction rate of fatty acids from hydrochar. Finally, the amount of methanol and catalyst which is required for a given amount of microalgae can be reduced to a half through the direct transesterification of hydrochar.

  19. Genome-wide transcriptomics of aging in the rotifer Brachionus manjavacas, an emerging model system.

    Gribble, Kristin E; Mark Welch, David B

    2017-03-01

    Understanding gene expression changes over lifespan in diverse animal species will lead to insights to conserved processes in the biology of aging and allow development of interventions to improve health. Rotifers are small aquatic invertebrates that have been used in aging studies for nearly 100 years and are now re-emerging as a modern model system. To provide a baseline to evaluate genetic responses to interventions that change health throughout lifespan and a framework for new hypotheses about the molecular genetic mechanisms of aging, we examined the transcriptome of an asexual female lineage of the rotifer Brachionus manjavacas at five life stages: eggs, neonates, and early-, late-, and post-reproductive adults. There are widespread shifts in gene expression over the lifespan of B. manjavacas; the largest change occurs between neonates and early reproductive adults and is characterized by down-regulation of developmental genes and up-regulation of genes involved in reproduction. The expression profile of post-reproductive adults was distinct from that of other life stages. While few genes were significantly differentially expressed in the late- to post-reproductive transition, gene set enrichment analysis revealed multiple down-regulated pathways in metabolism, maintenance and repair, and proteostasis, united by genes involved in mitochondrial function and oxidative phosphorylation. This study provides the first examination of changes in gene expression over lifespan in rotifers. We detected differential expression of many genes with human orthologs that are absent in Drosophila and C. elegans, highlighting the potential of the rotifer model in aging studies. Our findings suggest that small but coordinated changes in expression of many genes in pathways that integrate diverse functions drive the aging process. The observation of simultaneous declines in expression of genes in multiple pathways may have consequences for health and longevity not detected by

  20. Acute toxicity of toluene, hexane, xylene, and benzene to the rotifers Brachionus calyciflorus and Brachionus plicatilis

    Ferrando, M.D.; Andreu-Moliner, E. (Univ. of Valencia (Spain))

    1992-08-01

    A large number of studies on the biological effects of oil pollution in the aquatic environment deal with the effects of whole crude or refined oils or their water-soluble fractions. However, low boiling, aromatic hydrocarbons, which are probably the most toxic constituents of oil, have until now not been examined in sufficient detail. Toluene, benzene and xylene, constitute a major component of various oils. They may be readily lost by weathering but are toxic in waters that are relatively stagnant and are chronically polluted. Korn et al. have stated that toluene is more toxic than many other hydrocarbons such as benzene, though the latter are more water-soluble. Report of the effects of exposure to organic solvents like hexane or toluene are still limited although organic solvents are a well-known group of neurointoxicants. Various benzene derivates continue to be used as chemical intermediates, solvents, pesticides, so on, in spite of incomplete knowledge of their chronic toxicity. The majority of toxicity studies about the effects of pollution on aquatic organisms under controlled conditions have used either fish or the cladoceran Daphnia magna and there are few studies reported using rotifers. The effects of herbicides on population variables of laboratory rotifer cultures have been investigated. Rotifers are one of the main sources of zooplankton production and they have an important ecological significance in the aquatic environment. The present work was designed to investigate the effect of short-term exposure to some petroleum derivates which might be expected to occur immediately under an oil-slick, on freshwater and brackish environment rotifers. 18 refs., 1 tab.

  1. The significance of some methodological effects on filtration and ingestion rates of the rotifer Brachionus plicatilis

    Schlosser, H. J.; Anger, K.

    1982-06-01

    Filtration rate (F) and ingestion rate (I) were measured in the rotifer Brachionus plicatilis feeding on the flagellate Dunaliella spec. and on yeast cells (Saccharomyces cerevisiae). 60-min experiments in rotating bottles served as a standard for testing methodological effects on levels of F and I. A lack of rotation reduced F values by 40 %, and a rise in temperature from 18° to 23.5 °C increased them by 42 %. Ingestion rates increased significantly up to a particle (yeast) concentration of ca. 600-800 cells · μl-1; then they remained constant, whereas filtration rates decreased beyond this threshold. Rotifer density (up to 1000 ind · ml-1) and previous starvation (up to 40 h) did not significantly influence food uptake rates. The duration of the experiment proved to have the most significant effect on F and I values: in 240-min experiments, these values were on the average more than 90 % lower than in 15-min experiments. From this finding it is concluded that ingestion rates obtained from short-term experiments (60 min or less) cannot be used in energy budgets, because they severely overestimate the actual long-term feeding capacity of the rotifers. At the lower end of the particle size spectrum (2 to 3 µm) there are not only food cells, but apparently also contaminating faecal particles. Their number increased with increasing duration of experiments and lead to an underestimation of F and I. Elemental analyses of rotifers and their food suggest that B. plicatilis can ingest up to 0.6 mJ or ca. 14 % of its own body carbon within 15 min. The long term average was estimated as 3.4 mJ · ind-1 · d-1 or ca. 75 % of body carbon · d-1.

  2. Hsp60-induced tolerance in the rotifer Brachionus plicatilis exposed to multiple environmental contaminants.

    Wheelock, C E; Wolfe, M F; Olsen, H; Tjeerdema, R S; Sowby, M L

    1999-04-01

    Hsp60 induction was selected as a sublethal endpoint of toxicity for Brachionus plicatilis exposed to a water accommodated fraction (WAF) of Prudhoe Bay crude oil (PBCO), a PBCO/dispersant (Corexit 9527(R)) fraction and Corexit 9527(R) alone. To examine the effect of multiple stressors, exposures modeled San Francisco Bay, where copper levels are approximately 5 microgram/L, salinity is 22 per thousand, significant oil transport and refining occurs, and petroleum releases have occurred historically. Rotifers were exposed to copper at 5 microgram/L for 24 h, followed by one of the oil/dispersant preparations for 24 h. Batch-cultured rotifers were used in this study to model wild populations instead of cysts. SDS-PAGE with Western Blotting using hsp60-specific antibodies and chemiluminescent detection were used to isolate, identify, and measure induced hsp60 as a percentage of control values. Both PBCO/dispersant and dispersant alone preparations induced significant levels of hsp60. However, hsp60 expression was reduced to that of controls at high WAF concentrations, suggesting interference with protein synthesis. Rotifers that had been preexposed to copper maintained elevated levels of hsp60 upon treatment with WAF at all concentrations. Results suggest that induction of hsp60 by chronic low-level exposure may serve as a protective mechanism against subsequent or multiple stressors and that hsp60 levels are not additive for the toxicants tested in this study, giving no dose-response relationship. The methods employed in this study could be useful for quantifying hsp60 levels in wild rotifer populations.

  3. Marine Microalgae with Anti-Cancer Properties.

    Martínez Andrade, Kevin A; Lauritano, Chiara; Romano, Giovanna; Ianora, Adrianna

    2018-05-15

    Cancer is the leading cause of death globally and finding new therapeutic agents for cancer treatment remains a major challenge in the pursuit for a cure. This paper presents an overview on microalgae with anti-cancer activities. Microalgae are eukaryotic unicellular plants that contribute up to 40% of global primary productivity. They are excellent sources of pigments, lipids, carotenoids, omega-3 fatty acids, polysaccharides, vitamins and other fine chemicals, and there is an increasing demand for their use as nutraceuticals and food supplements. Some microalgae are also reported as having anti-cancer activity. In this review, we report the microalgal species that have shown anti-cancer properties, the cancer cell lines affected by algae and the concentrations of compounds/extracts tested to induce arrest of cell growth. We also report the mediums used for growing microalgae that showed anti-cancer activity and compare the bioactivity of these microalgae with marine anticancer drugs already on the market and in phase III clinical trials. Finally, we discuss why some microalgae can be promising sources of anti-cancer compounds for future development.

  4. Biomass production of Artemia in air-water-lift raceway system

    Royan, J.P.; Vijayaraghavan, S.; Krishnakumari, L

    - from Venkataraman, 1983). Crude Protein (N x6.25) Lipid Carbohydrate Crude Fiber Ash Moisture 55-65 2-6 10-15 1-4 6-15 5-10 o· ClS'- •• •• lM6M StrGft •~S,I LUlu STrOI,. • tOO A eo 10 ~ • i:f e & .... 0. eo E I w ,. .. en c eo en ~ c • z " 2 a 1M 0 U ji...!:Ta:Vijayaraghavan, Wafar andRoyail~l~n~n.Good growthrates wereobserved in Penaeui indicus, P. monoceros andM. monodon when fed with live adult Artemia (Royan, Sumitra-Vijayaraghavanand Krishna Kumari, 1987). Thus adult Artemia biomass can be used as an ingredient...

  5. Bioactivity evaluation against Artemia salina Leach of medicinal plants used in Brazilian Northeastern folk medicine.

    Arcanjo, D D R; Albuquerque, A C M; Melo-Neto, B; Santana, L C L R; Medeiros, M G F; Citó, Amgl

    2012-08-01

    The brine shrimp (Artemia salina Leach) lethality bioassay offers an advantage in standardization and quality control of botanical products. This test is well correlated with antitumor activity (cytotoxicity) and can be used to monitor the activity of bioactive natural products. This paper reports the bioactivity of ethanol extracts from seven medicinal plants from the Northeast of Brazil (Acmella uliginosa, Ageratum conyzoides, Eugenia uniflora, Plectranthus neochilus, Moringa oleifera, Justicia pectoralis and Equisetum sp.) against Artemia salina. Biological activity was evaluated for extracts at 1, 10, 100, and 1000 µg/mL in triplicate, and the mean lethal concentration values (LC50) were obtained by probit analysis. The species Acmella uliginosa showed the highest bioactivity, and its flower extract was more active than its leaf extract.

  6. Bioremediation of wastewater using microalgae

    Chalivendra, Saikumar

    Population expansion and industrial development has deteriorated the quality of freshwater reservoirs around the world and has caused freshwater shortages in certain areas. Discharge of industrial effluents containing toxic heavy metals such as Cd and Cr into the environment have serious impact on human, animal and aquatic life. In order to solve these problems, the present study was focused on evaluating and demonstrating potential of microalgae for bioremediation of wastewater laden with nitrogen (N) in the form of nitrates, phosphorous (P) in the form of phosphates, chromium (Cr (VI)) and cadmium (Cd (II)). After screening several microalgae, Chlorella vulgaris and algae taken from Pleasant Hill Lake were chosen as candidate species for this study. The viability of the process was demonstrated in laboratory bioreactors and various experimental parameters such as contact time, initial metal concentration, algae concentration, pH and temperature that would affect remediation rates were studied. Based on the experimental results, correlations were developed to enable customizing and designing a commercial Algae based Wastewater Treatment System (AWTS). A commercial AWTS system that can be easily customized and is suitable for integration into existing wastewater treatment facilities was developed, and capital cost estimates for system including installation and annual operating costs were determined. The work concludes that algal bioremediation is a viable alternate technology for treating wastewater in an economical and sustainable way when compared to conventional treatment processes. The annual wastewater treatment cost to remove N,P is ~26x lower and to remove Cr, Cd is 7x lower than conventional treatment processes. The cost benefit analysis performed shows that if this technology is implemented at industrial complexes, Air Force freight and other Department of Defense installations with wastewater treatment plants, it could lead to millions of dollars in

  7. Diversity of Monogononta rotifer species among standing waterbodies in northern Cambodia

    Ratha Sor

    2014-08-01

    Full Text Available The incidence and abundance of Monogononta rotifer species were recorded from lakes and reservoirs in the upper part of the Cambodian Mekong River basin in April and November 2010. One hundred and seven species are reported, 25 of which are new records to Cambodia and 8 taxa were unidentifiable to species level. Species richness at the regional and local scale was not significantly different between habitat types or between seasons, whether it was estimated using incidence or abundance data. Comparison of incidence data also revealed no significant difference from species richness of ponds concurrently sampled in the same region. There appeared to be a high level of diversity among sites that could not be attributed to nestedness or to the 5 environmental variables measured. Each habitat type and season offered substantially different rotifer communities, with the proportion of unshared species between sample sets ranging from 14-49%. Non-metric multidimensional scaling and PERMANOVA analyses also revealed clustering and significant differences among sample sets based on habitat type and season. Therefore, each habitat type and season contributed to the overall rotifer biodiversity. When the incidence data from this study are combined with those in previously reported studies, the overall species richness estimate for Cambodia is 403 species (95% CI = 386-432 and the number of species records has reached 306. 

  8. Effects of copper and tributyltin on stress protein abundance in the rotifer Brachionus plicatilis.

    Cochrane, B J; Irby, R B; Snell, T W

    1991-01-01

    1. Exposure of the rotifer Brachionus plicatilis to elevated temperature resulted in the synthesis of a number of proteins, including a prominent one of 58,000 Da (SP58). 2. This protein is immunologically crossreactive with the 65,000 Da heat shock protein of the moth Heliothis virescens, which is a member of a highly conserved family of mitochondrial proteins. 3. Exposure of rotifers to sublethal doses of CuSO4 leads to a 4-5-fold increase in abundance of SP58, with maximum increase occurring at a dose that is approximately 5% of the LC50 for that compound. 4. A similar response was seen with tributyl tin (TBT). Kinetics of induction were sigmoidal, with induction occurring in the range of 20-30 micrograms/l. 5. No response was observed when rotifers were exposed to aluminum chloride, mercury chloride, pentachlorophenol, sodium arsenite, sodium azide, sodium dodecyl sulfate, or zinc chloride. 6. These results indicate that changes in stress protein abundance may prove useful as a biomarker of exposure to particular toxicants.

  9. Effects of diet on population development of the rotifer Brachionus plicatilis in culture

    Planas, M.; Estévez, A.

    1989-06-01

    Experiments were conducted in order to observe the effect of five diets on the population development of the rotifer Brachionus plicatilis Müller under laboratory conditions. Diets were based on baker’s yeast ( Saccharomyces cerevisiae) and the algae Tetraselmis suecica and Isochrysis galbana, mixed, or as simple diets. Growth rates, fecundity and biometric parameters were studied for 15 days. The cultures were divided in a logarithmic phase and a harvesting phase. Rotifers fed on Tetraselmis, alone or mixed with yeast or Isochrysis, gave good performances with the best results in all the parameters studied. Average growth rates in all diets were similar during the exponential phase, with values ranging from 0.72 ( Tetraselmis and Tetraselmis + yeast) to 0.47 (yeast). During the harvesting phase there were high differences between diets, with rates highly reduced in the yeast-group (0.17) and good rates when Tetraselmis was ingested (0.65 0.51). This alga had a positive influence on the rotifers, increasing individual growth and fecundity.

  10. Evaluación de dietas artificiales con artemia adulta en la maduración y reproducción de penaeus vannamei

    Zambrano Carranza, Byron R.

    1999-01-01

    Evaluación de dietas artificiales con Artemia adulta en la maduración y reproducción de Penaeus vannamei Un experimento de maduración y reproducción de P. vannamei fue llevado a cabo en tanques de 18 toneladas para (a) comprobar los efectos de la Artemia adulta como ingrediente principal en dietas artificiales, (b) investigar si existen diferencias entre la implementación de liofilizado de Artemia adulta y Artemia adulta congelada, y finalmente (c), comparar estos efectos y resultados con ...

  11. Toxicities of diuron and irgarol on the hatchability and early stage development of Artemia salina

    ALYÜRÜK, Hakan; ÇAVAŞ, Levent

    2013-01-01

    Booster biocides are widely used in antifouling paints as bioactive agents against fouling organisms. In previously published reports, acute toxicity tests on Artemia salina (Linnaeus, 1758) were only focused on a part of the life cycle of the organism. The aim of this study was to investigate the toxicities of diuron and irgarol on the hatching stage of A. salina. According to the results, diuron significantly decreased the hatching percentage of A. salina cysts and prevented the hatching of...

  12. Morphological changes about Artemia Salina by the effect of gamma radiation

    Dvorak, P.; Kunova, V; Kratochvil, B.; Salplachta, J.; Benova, K.

    2004-01-01

    Direction Council of Europe require restriction of laboratory vertebrae in biological experiments. Once by possibilities is using biological test II. generation among which belongs to and test for Artemia salina. Still this time published test however value only lethality in dependence on dose, exposition and time survival. This work document possibility watch of expressive morphological changes, which consist in retardation development brine shrimps stage in dependence on dose gamma radiation 60 Co. (authors)

  13. Microalgae growth on the aqueous phase from Hydrothermal Liquefaction of the same microalgae

    Garcia Alba, Laura; Torri, Cristian; Fabbri, Daniele; Kersten, Sascha R.A.; Brilman, Derk Willem Frederik

    2013-01-01

    Cultivation of Desmodesmus sp. microalgae in the recycled aqueous phase (AP) recovered after Hydrothermal Liquefaction (HTL) of the same microalgae was studied to evaluate the potential of nutrients recycling. AP dilution ratio was systematically varied, using either water or water enriched with

  14. Effect of juvenile hormone and serotonin (5-HT) on mixis induction of the rotifer Brachionus plicatilis Muller.

    Gallardo; Hagiwara; Snell

    2000-09-05

    Juvenile hormone (JH) and serotonin (5-HT) were previously shown to enhance mictic (sexual) female production of the rotifer Brachionus plicatilis in batch cultures. To explore the basis of these effects, experiments were conducted on isolated individuals. JH treatment of maternal rotifers with 5 and 50 µgml(-1) (18.8 and 187.7 µM) resulted in significantly higher (P<0.05) mictic female production in the second (F(2)) and third (F(3)) generations. JH treatment was effective even at a lower food concentration of 7x10(5) cellsml(-1), but it was not effective when free ammonia was added at 2.4 and 3.1 µgml(-1). Mictic female production was not increased with exposure to 5-HT up to 50 µgml(-1) (129.1 µM) concentrations. When food level was reduced to 7x10(5) cellsml(-1), however, 5-HT-treated rotifers produced significantly (P<0.05) more mictic females than the control, particularly in F(3) generation. Mictic female production of 5-HT-treated rotifers did not differ from that of the control with or without free ammonia, but the intrinsic rate of natural increase (r) of 5-HT-treated rotifers at 3.1 µgml(-1) free ammonia was significantly higher than the control. These results show that juvenile hormone increases mictic female production under optimum and sub-optimum food levels, whereas 5-HT increases both mictic female production at low food level and population growth rate at high free ammonia concentrations. These compounds could be used to manage rotifer cultures and probe the mechanisms controlling the rotifer life cycle as it switches to mictic reproduction.

  15. The study of fkbp and ubiquitin reveals interesting aspects of Artemia stress history.

    Maniatsi, Stefania; Farmaki, Theodora; Abatzopoulos, Theodore J

    2015-08-01

    Research on stress responses in animals has increased greatly during the last decades. Though most studies focus on the cellular and molecular bases of the stress response mechanisms, the ecological and evolutionary aspects of stress responses gain more and more interest. Here, we use species and parthenogenetic strains of the genus Artemia, an extremophile model organism, to study, for the first time, a protein well known for its chaperone activity and its involvement in stress responses. More specifically, transcription and protein accumulation of an FK506-Binding Protein (FKBP) homologue were investigated under heat and salt stresses. Additionally, the mRNA levels of ubiquitin, a heat-inducible protein related to the proteasomal pathway, were quantitated under these conditions. Biochemical and phylogenetic analyses showed that the studied FKBP orthologue is a typical representative of the family that clusters with other crustacean sequences. The expression was increased in both fkbp and ubiquitin genes after salt and heat stresses. However, our results in combination with the fact that Artemia species and parthenogenetic strains, selected for this study, exhibit different heat or salt tolerance provide useful hints about the evolutionary significance of FKBP and ubiquitin. Regarding FKBP, mRNA expression and protein accumulation seem to depend on the environmental conditions and the evolutionary history of each Artemia population while ubiquitin has a clear and more conserved role under heat shock. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Transfer and accumulation of 106Ru from phytoplankton (Dunaliella bioculata) to zooplankton (Artemia salina)

    Izumo, Yoshiro; Takase, Akira

    1982-01-01

    106 Ru is one of the most abundant radionuclides to be released from the unclear-spent fuel reprocessing plant to oceans. This paper deals with transfer and accumulation of the radionuclide from phytoplankton (Dunaliella) to zooplankton (Artemia) in the graizing food chain of marine organisms. Each plankton was reared in the radioactive sea water A (filtrated and circulated through sandy mud, and the radioactive concentration decreased and atteined to constant after addition of 106 Ru), B (not filtrated and circulated, and the radioactive concentration decreased and atteined to constant) and C (not filtrated and circulated, the radioactive concentration decreased, but did not attein to constant), respectively, and investigated accumulations of 106 Ru. Then, accumulations of 106 Ru in Artemia by the ingestion of each diet (Dunaliella) contaminated with 106 Ru in each water, were investigated and compared with those from each water. Concentration factors of 106 Ru for the planktons reared in the radioactive sea waters were different among these waters. The difference can be attributable to that of physicochemical states of 106 Ru in the waters. It was found that 106 Ru would be accumulated by Artemia from the water A about 10 times higher than from the contaminated diet (Dunaliella) in this water, however from the contaminated diet (Dunaliella) in the water B about 2.2 times higher than from the last water. (author)

  17. Efficacy of a commercial probiotic relative to oxytetracycline as Gram-negative bacterial control agents in a rotifer (Brachionus plicatilis) batch culture

    Two trials were conducted to evaluate two gram-negative bacterial control strategies in batch cultures of the rotifer Brachionus plicatilis. In the first trial, rotifers at an initial density of 47/mL were cultured for 5 d and dosed with a 10-mg/L solution of either oxytetracycline or a commercial p...

  18. Microalgae bulk growth model with application to industrial scale systems

    Quinn, J.; Winter, de L.; Bradley, T.

    2011-01-01

    The scalability of microalgae growth systems is a primary research topic in anticipation of the commercialization of microalgae-based biofuels. To date, there is little published data on the productivity of microalgae in growth systems that are scalable to commercially viable footprints. To inform

  19. Harvesting microalgae by bio-flocculation and autoflocculation

    Salim, S.

    2013-01-01

    Harvesting in commercial microalgae production plants is generally done by centrifugation, but this requires upto about 50% of the total energy gained from the microalgae. The energy needed for harvesting can be reduced considerably by pre-concentration of the microalgae prior to further dewatering.

  20. Cultivation of the microalga, Chlorella pyrenoidosa , in biogas ...

    Therefore, the microalga was introduced to be cultivated in the biogas wastewater, which could not only bioremediate the wastewater, but also produce plenty of the microalga biomass that could be used for the exploitation of fertilizers, feed additives and biofuels. This study showed that the microalga, C. pyrenoidosa could ...

  1. An Overview of Biocement Production from Microalgae

    Dessy Ariyanti

    2011-12-01

    Full Text Available The invention of microorganism’s involvement in carbonate precipitation, has lead the exploration of this process in the field of construction engineering. Biocement is a product innovation from developing bioprocess technology called biocementation. Biocement refers to CaCO3 deposit that formed due to microorganism activity in the system rich of calcium ion. The primary role of microorganism in carbonate precipitation is mainly due to their ability to create an alkaline environment (high pH and DIC increase through their various physiological activities. Three main groups of microorganism that can induce the carbonate precipitation: (i photosynthetic microorganism such as cyanobacteria and microalgae; (ii sulphate reducing bacteria; and (iii some species of microorganism involved in nitrogen cycle. Microalgae are photosynthetic microorganism and utilize urea using urease or urea amidolyase enzyme, based on that it is possible to use microalgae as media to produce biocement through biocementation. This paper overviews biocement in general, biocementation, type of microorganism and their pathways in inducing carbonate precipitation and the prospect of microalgae to be used in biocement production.  Keywords— Biocement, Biocementation, Microalgae, CaCO3 precipitation

  2. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening

    Pablo Mayorga

    2010-10-01

    Full Text Available Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest, were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq. Kunth ex Walp., Fabaceae, Neurolaena lobata (L. Cass., Asteraceae, Petiveria alliacea L., Phytolaccaceae, and Ocimum campechianum Mill., Lamiaceae. The five others: Curatella americana L., Dilleniaceae, Prunus barbata Koehne, Rosaceae, Quercus crispifolia Trel., Fagaceae, Rhizophora mangle L., Rhizophoraceae, and Smilax domingensis Willd., Smilacaceae, do not. All plants without anti-Artemia activity had no lethal effects in both assays with A. salina. For the plants with anti-Artemia activity the Artoxkit M was not sensitive to G. sepium and the conventional Artemia test was not sensitive to S. americanum, G. sepium and N. lobata. All the plant extracts, except for that of C. americana, had lethal effects on T. platyurus and the lethal median concentration (LC50 levels for this organism were in all cases substantially lower than those of the salt-water test species. This study revealed that T. platyurus is a promising test species worth further in depth investigation for toxicity screening of plant extracts with potential medicinal properties.

  3. Selenium Utilization Strategy by Microalgae

    Hiroya Araie

    2009-11-01

    Full Text Available The diversity of selenoproteins raises the question of why so many life forms require selenium. Selenoproteins are found in bacteria, archaea, and many eukaryotes. In photosynthetic microorganisms, the essential requirement for selenium has been reported in 33 species belonging to six phyla, although its biochemical significance is still unclear. According to genome databases, 20 species are defined as selenoprotein-producing organisms, including five photosynthetic organisms. In a marine coccolithophorid, Emiliania huxleyi (Haptophyta, we recently found unique characteristics of selenium utilization and novel selenoproteins using 75Se-tracer experiments. In E. huxleyi, selenite, not selenate, is the main substrate used and its uptake is driven by an ATP-dependent highaffinity, active transport system. Selenite is immediately metabolized to low-molecular mass compounds and partly converted to at least six selenoproteins, named EhSEP1–6. The most (EhSEP2 and second-most abundant selenoproteins (EhSEP1 are disulfide isomerase (PDI homologous protein and thioredoxin reductase (TR 1, respectively. Involvement of selenium in PDI is unique in this organism, while TR1 is also found in other organisms. In this review, we summarize physiological, biochemical, and molecular aspects of selenium utilization by microalgae and discuss their strategy of selenium utilization.

  4. Can Microalgae Remove Pharmaceutical Contaminants from Water?

    Xiong, Jiu-Qiang; Kurade, Mayur B; Jeon, Byong-Hun

    2018-01-01

    The increase in worldwide water contamination with numerous pharmaceutical contaminants (PCs) has become an emerging environmental concern due to their considerable ecotoxicities and associated health issues. Microalgae-mediated bioremediation of PCs has recently gained scientific attention, as microalgal bioremediation is a solar-power driven, ecologically comprehensive, and sustainable reclamation strategy. In this review, we comprehensively describe the current research on the possible roles and applications of microalgae for removing PCs from aqueous media. We summarize several novel approaches including constructing microbial consortia, acclimation, and cometabolism for enhanced removal of PCs by microalgae, which would improve practical feasibility of these technologies. Some novel concepts for degrading PCs using integrated processes and genetic modifications to realize algal-based bioremediation technologies are also recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Mixotrophic cultivation of microalgae for biodiesel production: status and prospects.

    Wang, Jinghan; Yang, Haizhen; Wang, Feng

    2014-04-01

    Biodiesel from microalgae provides a promising alternative for biofuel production. Microalgae can be produced under three major cultivation modes, namely photoautotrophic cultivation, heterotrophic cultivation, and mixotrophic cultivation. Potentials and practices of biodiesel production from microalgae have been demonstrated mostly focusing on photoautotrophic cultivation; mixotrophic cultivation of microalgae for biodiesel production has rarely been reviewed. This paper summarizes the mechanisms and virtues of mixotrophic microalgae cultivation through comparison with other major cultivation modes. Influencing factors of microalgal biodiesel production under mixotrophic cultivation are presented, development of combining microalgal biodiesel production with wastewater treatment is especially reviewed, and bottlenecks and strategies for future commercial production are also identified.

  6. Biotic or abiotic factors: which has greater influence in determining the structure of rotifers in semi-arid reservoirs?

    Daniele Jovem da Silva Azevêdo

    2015-03-01

    Full Text Available ObjectiveThe objective of this study is to evaluate whether the distribution of structural attributes of rotifers in reservoirs in the semiarid region is more strongly influenced by abiotic or biotic environmental factors (density of cyanobacteria.MethodSampling occurred in two reservoirs in the Paraíba Basin, northeastern Brazil (Poções and Camalaú during April and June 2012. Eight sampling points were distributed at two stations in each reservoir: the region near the entrance of the main tributary and region of the dam and collections were made in the limnetic and littoral zone in every season. To assess the abiotic influence and density of cyanobacteria in the distribution of the structural attributes of rotifers, environmental variables bivariate correlation was conducted in series.ResultsIn Poções reservoir, the distribution of rotifer biomass was negatively related to the density of cyanobacteria; among the environmental variables, chlorophyll-a and total nitrogen were negatively related to all of the tested structural attributes, while the concentrations of total phosphorus were strongly related to the abundance of rotifers. In the Camalaú reservoir, the biomass was a structural attribute with a stronger correlation to the density of cyanobacteria; between the environmental variables and Egeria densa, nitrate was negatively related to all of the attributes tested, while transparency was moderately related to the abundance, biomass and richness as well as Chara sp. with abundance.ConclusionsAssemblages of rotifers are more clearly related to environmental conditions, especially those indicative of trophic conditions, despite the density of cyanobacteria having been a factor that was positively related to the structural characteristics of rotifers and thus indicative of such structural assemblies. This can be used for analysis of local environmental condition factors.

  7. MICROALGAS E SEU POTENCIAL DE USO

    Barcellos, Amanda Desireux; UFBA; Barreto, Antonio Geraldo da Silva Sá; UFBA; Machado, Bruna Aparecida Souza; UFBA; Druzian, Janice Izabel; UFBA

    2014-01-01

    As microalgas são organismos predominantemente microscópicos unicelulares, procariontes ou eucariontes, dotados de pigmentos e fotoautotróficos. Estes seres possuem um alto potencial biológico, ecológico e econômico. O objetivo desta prospecção tecnológica foi identificar as patentes, teses e artigos científicos referentes a microalgas quanto ao seu emprego nos mais diversos setores, bem como sua tecnologia de cultivo. Para tanto, foi realizada uma pesquisa aos bancos de dados de patentes nac...

  8. Filming of zooplankton: a case study of rotifer males and Daphnia magna

    Pierluigi Colangeli

    2015-11-01

    Full Text Available Filming live organisms can give new insights into the hidden life of plankton. Accessibly priced digital cameras are now available for a large range of users. Here, we demonstrate the technical setup and workflow of using a single-lens reflex (DSLR camera to film the behaviour of males of two rotifer species, Brachionus angularis Gosse (1851 and Keratella cochlearis Gosse (1851, and of the cladoceran Daphnia magna Straus (1820. Rotifers are cyclical parthenogens that produce males only under certain environmental conditions. Thus, knowledge on rotifer males is still limited because of their ephemeral nature and because they are often smaller than females. We filmed males of B. angularis and K. cochlearis with a DSLR camera connected to a compound microscope to better understand their morphology and behaviour in comparison to conspecific females. While written descriptions have their scientific value, seeing is complementary because everyone can verify what has been described. We made our videos publicly accessible through links connected to the paper. Our videos are, to our best knowledge, the first on males of B. angularis and K. cochlearis. Furthermore, we filmed the behavioural response of D. magna to ultraviolet (UV radiation with a macro lens attached to the DSLR camera. Approaches like this are valuable tools in environmental teaching. To see live organisms with one’s own eyes may contribute to raising public awareness about the value of water resources and their hidden communities. In summary, filming can be a valuable tool to ignite scientific discussion, but the videos need an open-access platform where they can be referenced in a topic-related order.

  9. Germ cell specification and ovary structure in the rotifer Brachionus plicatilis.

    Smith, James M; Cridge, Andrew G; Dearden, Peter K

    2010-08-02

    The segregation of the germline from somatic tissues is an essential process in the development of all animals. Specification of the primordial germ cells (PGCs) takes place via different strategies across animal phyla; either specified early in embryogenesis by the inheritance of maternal determinants in the cytoplasm of the oocyte ('preformation') or selected later in embryonic development from undifferentiated precursors by a localized inductive signal ('epigenesis'). Here we investigate the specification and development of the germ cells in the rotifer Brachionus plicatilis, a member of the poorly-characterized superphyla Lophotrochozoa, by isolating the Brachionus homologues of the conserved germ cell markers vasa and nanos, and examining their expression using in situ hybridization. Bpvasa and Bpnos RNA expression have very similar distributions in the Brachionus ovary, showing ubiquitous expression in the vitellarium, with higher levels in the putative germ cell cluster. Bpvas RNA expression is present in freshly laid eggs, remaining ubiquitous in embryos until at least the 96 cell stage after which expression narrows to a small cluster of cells at the putative posterior of the embryo, consistent with the developing ovary. Bpnos RNA expression is also present in just-laid eggs but expression is much reduced by the four-cell stage and absent by the 16-cell stage. Shortly before hatching of the juvenile rotifer from the egg, Bpnos RNA expression is re-activated, located in a subset of posterior cells similar to those expressing Bpvas at the same stage. The observed expression of vasa and nanos in the developing B. plicatilis embryo implies an epigenetic origin of primordial germ cells in Rotifer.

  10. Acute and chronic toxicity of copper to the euryhaline rotifer, Brachionus plicatilis ("L" strain).

    Arnold, W R; Diamond, R L; Smith, D S

    2011-02-01

    This article presents data from original research, intended for the use in the development of copper (Cu) criteria for the protection of estuarine and marine organisms and their uses in the United States. Two 48-h static-acute toxicity tests-one with and one without added food-and a 96-h static multigeneration life-cycle test (P1-F2 generations) were performed concurrently using the euryhaline rotifer Brachionus plicatilis ("L" strain) to develop a Cu acute-to-chronic ratio (ACR) for this species. Tests were performed at 15 g/L salinity, at 25°C, and the exposure concentrations of dissolved Cu were verified. Supplemental chemical analyses were performed and reported for the development of a Cu-saltwater biotic ligand model (BLM). Supplemental analyses included alkalinity, calcium, chloride, dissolved organic carbon (DOC), hardness, magnesium, potassium, sodium, and temperature. The acute toxicity test measurement end points were the dissolved Cu median lethal concentration (LC₅₀) values based on rotifer survival. The chronic measurement end points were the dissolved Cu no-observed-effect concentration (NOEC), lowest-observed-effect concentration (LOEC), EC₂₅, EC₂₀, and EC₁₀ based on the intrinsic rate of rotifer population increase (r). The 48-h LC₅₀(Fed), 48-h LC₅₀(Unfed), 96-h NOEC, 96-h LOEC, EC₂₅, EC₂₀, and EC₁₀ were 20.8, 13.4, 6.1, 10.3, 11.7, 10.9, and 8.8 μg Cu/L, respectively. The ACRs were calculated as ratios of each 48-h LC₅₀ value [fed and unfed) and each of the 96-h chronic values (ChV; geometric mean of NOEC and LOEC)], EC₁₀, EC₂₀, and EC₂₅. The ACRs ranged from 1.15 to 2.63.

  11. Population density, sexual reproduction and diapause in monogonont rotifers: new data for Brachionus and a review

    John J. GILBERT

    2004-09-01

    Full Text Available Diapausing, fertilized eggs in monogonont rotifers typically are formed after an environmental signal induces amictic females to produce mictic daughters. Mictic females lay haploid eggs that may develop parthenogenetically into males, or that may be fertilized and develop into diapausing, female embryos called resting eggs. Laboratory experiments demonstrate that crowding is the signal for production of mictic females in strains of Brachionus calyciflorus from Texas, Spain and Germany, and in a strain of Brachionus variabilis from Spain. In these experiments, newborn amictic females were cultured singly in large and small volumes to give lowand high-density treatments. Therefore, the induction of mictic females is due exclusively to population density and cannot be attributed to a grouping effect involving some interaction among individuals. B. variabilis is very sensitive to population density; females had to be cultured in 30 ml to prevent appreciable production of mictic daughters. Crowding is now known to be the signal for initiation of sexuality and diapause in four species of Brachionus, two species of Epiphanes, and Rhinoglena frontalis. The chemical that mediates this response somehow influences oocytes in the maternal body cavity to differentiate into mictic females. Aggregation of individuals in natural systems may facilitate the production of mictic females. In some of these rotifers, the response to crowding is suppressed in early generations from the resting egg, assuring that clonal populations will attain higher population densities before committing to sexual reproduction. Fitness benefits of the mictic-female response to crowding, and to other environmental signals in other rotifers (dietary tocopherol, long photoperiod, are discussed.

  12. Germ cell specification and ovary structure in the rotifer Brachionus plicatilis

    Smith James M

    2010-08-01

    Full Text Available Abstract Background The segregation of the germline from somatic tissues is an essential process in the development of all animals. Specification of the primordial germ cells (PGCs takes place via different strategies across animal phyla; either specified early in embryogenesis by the inheritance of maternal determinants in the cytoplasm of the oocyte ('preformation' or selected later in embryonic development from undifferentiated precursors by a localized inductive signal ('epigenesis'. Here we investigate the specification and development of the germ cells in the rotifer Brachionus plicatilis, a member of the poorly-characterized superphyla Lophotrochozoa, by isolating the Brachionus homologues of the conserved germ cell markers vasa and nanos, and examining their expression using in situ hybridization. Results Bpvasa and Bpnos RNA expression have very similar distributions in the Brachionus ovary, showing ubiquitous expression in the vitellarium, with higher levels in the putative germ cell cluster. Bpvas RNA expression is present in freshly laid eggs, remaining ubiquitous in embryos until at least the 96 cell stage after which expression narrows to a small cluster of cells at the putative posterior of the embryo, consistent with the developing ovary. Bpnos RNA expression is also present in just-laid eggs but expression is much reduced by the four-cell stage and absent by the 16-cell stage. Shortly before hatching of the juvenile rotifer from the egg, Bpnos RNA expression is re-activated, located in a subset of posterior cells similar to those expressing Bpvas at the same stage. Conclusions The observed expression of vasa and nanos in the developing B. plicatilis embryo implies an epigenetic origin of primordial germ cells in Rotifer.

  13. The hard parts (trophi) of the rotifer mastax do contain chitin: evidence from studies on Brachionus plicatilis.

    Klusemann, J; Kleinow, W; Peters, W

    1990-01-01

    The jaws (trophi) of the rotifer Brachionus plicatilis are soluble in strong acids but are resistant to long treatments by strong alkali. They show the same buoyant density as chitin and also as the chitin-containing layers of rotifer egg-shells. The presence of chitin in these structures was confirmed using the following techniques: chitosan-tests, thin-layer chromatography of trophi-hydrolysates which revealed glucosamine, by dissolving trophi with chitinase and electron microscopic WGA/gold-labelling. The content of chitin in the trophi was estimated by two different methods to be approx. 64% (50-75%).

  14. Nutrient recycle from defatted microalgae (Aurantiochytrium) with hydrothermal treatment for microalgae cultivation.

    Aida, Taku Michael; Maruta, Ryouma; Tanabe, Yuuhiko; Oshima, Minori; Nonaka, Toshiyuki; Kujiraoka, Hiroki; Kumagai, Yasuaki; Ota, Masaki; Suzuki, Iwane; Watanabe, Makoto M; Inomata, Hiroshi; Smith, Richard L

    2017-03-01

    Defatted heterotrophic microalgae (Aurantiochytrium limacinum SR21) was treated with high temperature water (175-350°C, 10-90min) to obtain nitrogen and phosphorous nutrients as a water soluble fraction (WS). Yields of nitrogen and phosphorous recovered in WS varied from 38 to 100% and from 57 to 99%, respectively. Maximum yields of nitrogen containing compounds in WS were proteins (43%), amino acids (12%) and ammonia (60%) at treatment temperatures of 175, 250 and 350°C, respectively. Maximum yield of phosphorous in WS was 99% at a treatment temperature of 250°C. Cultivation experiments of microalgae (A. limacinum SR21) using WS obtained at 200 and 250°C showed positive growth. Water soluble fractions from hydrothermal treatment of defatted microalgae are effective nitrogen and phosphorous nutrient sources for microalgae cultivation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Evolutionary origin and phylogeography of the diploid obligate parthenogen Artemia parthenogenetica (Branchiopoda: Anostraca.

    Joaquín Muñoz

    2010-08-01

    Full Text Available Understanding the evolutionary origin and the phylogeographic patterns of asexual taxa can shed light on the origin and maintenance of sexual reproduction. We assessed the geographic origin, genetic diversity, and phylogeographic history of obligate parthenogen diploid Artemia parthenogenetica populations, a widespread halophilic crustacean.We analysed a partial sequence of the Cytochrome c Oxidase Subunit I mitochondrial gene from an extensive set of localities (including Eurasia, Africa, and Australia, and examined their phylogeographic patterns and the phylogenetic relationships of diploid A. parthenogenetica and its closest sexual relatives. Populations displayed an extremely low level of mitochondrial genetic diversity, with one widespread haplotype shared by over 79% of individuals analysed. Phylogenetic and phylogeographic analyses indicated a multiple and recent evolutionary origin of diploid A. parthenogenetica, and strongly suggested that the geographic origin of parthenogenesis in Artemia was in Central Asia. Our results indicate that the maternal sexual ancestors of diploid A. parthenogenetica were an undescribed species from Kazakhstan and A. urmiana.We found evidence for multiple origin of parthenogenesis in Central Asia. Our results indicated that, shortly after its origin, diploid A. parthenogenetica populations underwent a rapid range expansion from Central Asia towards the Mediterranean region, and probably to the rest of its current geographic distribution. This contrasts with the restricted geographic distribution, strong genetic structure, and regional endemism of sexual Artemia lineages and other passively dispersed sexual continental aquatic invertebrates. We hypothesize that diploid parthenogens might have reached their current distribution in historical times, with a range expansion possibly facilitated by an increased availability of suitable habitat provided by anthropogenic activities, such as the spread of solar

  16. Evaluation of Alpha and Gamma Aluminum Oxide Nanoparticle Accumulation, Toxicity and Depuration in Artemia Salina Larvae

    Ates, Mehmet; Demir, Veysel; Arslan, Zikri; Daniels, James; Farah, Ibrahim O.; Bogatu, Corneliu

    2014-01-01

    In this study, Artemia salina (crustacean filter feeders) larvae were used as a test model to investigate the toxicity of aluminum oxide nanoparticles (Al2O3 NPs) on marine microorganisms. The uptake, toxicity and elimination of α-Al2O3 (50 nm and 3.5 μm) and γ-Al2O3 (5 nm and 0.4 μm) NPs were studied. Twenty-four and ninety-six hour exposures of different concentrations of Al2O3 NPs to Artemia larvae were conducted in a seawater medium. When suspended in water, Al2O3 NPs aggregated substantially with the sizes ranging from 6.3 nm to > 0.3 μm for spherical NPs, and from 250 to 756 nm for rod-shaped NPs. The phase contrast microscope images revealed that NPs deposited inside the guts as aggregates. ICP-MS analysis showed that large particles (3.5 μm α-Al2O3) were not taken up by Artemia, while fine NPs (0.4 μm γ-Al2O3) and ultra-fine NPs (5 nm γ-Al2O3 and 50 nm α-Al2O3) accumulated substantially. Differences in toxicity were detected as changing with NP size and morphology. The malondialdehyde (MDA) levels indicated that smaller γ-Al2O3 (5 nm) NPs were more toxic than larger γ-Al2O3 (0.4 μm) particulates in 96 h. The highest mortality was measured as 34% in 96 h for γ-Al2O3 NPs (5 nm) at 100 mg/L (LC50 > 100 mg/L). γ-Al2O3 NPs were more toxic than α-Al2O3 NPs at in all conditions. PMID:24753078

  17. May arsenic pollution contribute to limiting Artemia franciscana invasion in southern Spain?

    Marta I. Sánchez

    2016-02-01

    Full Text Available Limited information exists regarding the complex interactions between biological invasions, pollution, and climate change. Most studies indicate that pollution tends to favor invasive species. Here, we provide evidence that arsenic (As pollution may have a role in limiting the invasion of the exotic brine shrimp Artemia franciscana. We tested As toxicity in natural populations of Artemia parthenogenetica (a native taxon and A. franciscana from localities in southern Spain with differing degrees of As contamination. Tests were conducted both under current mean temperature conditions (25 °C, and as per a future climate scenario (i.e., an increase in mean temperature of 4 °C. Acute toxicity was estimated on the basis of the median lethal concentration (at 24 h, and chronic toxicity was evaluated by measuring Artemia survival and growth under sublethal exposures (after 26 days. At 25 °C, native A. parthenogenetica from the highly polluted Odiel and Tinto estuary was much more resistant to acute As stress (LC50-24 h, 24.67 mg L−1 than A. franciscana (15.78 mg L−1 and A. parthenogenetica from unpolluted sites (12.04 mg L−1–suggesting that local adaptation to polluted conditions may occur. At 29 °C, resistance of A. parthenogenetica from Odiel decreased significantly, and there were no statistical differences in sensitivity between the three species/populations, suggesting that climate change may enhance the probability of invasion. Resistance increased with developmental stage from nauplii to adults, and was extremely high in cysts which still hatched at As concentrations of up to 6400 mg L−1. Under sublethal chronic exposure A. franciscana performed better (survival and growth than A. parthenogenetica, and both species experienced a faster growth when exposed to As, compared with unexposed (control individuals, probably due to the hormesis. We discuss the ecological implications of our results.

  18. Mercury antagonists: loss of photoactive response in the brine shrimp Artemia and its prevention by thiamine

    Yaeger, E.; Siegel, B.Z.; Siegel, S.M.; Lasconia, M.; Correal, T.

    1986-01-01

    The positive photoatactic behavior of Artemia was disturbed when larvae cultured in 0.25 M NaCl were introduced into 10/sup -7/ to 10/sup -5/ M HgCl/sub 2/. At 10/sup -8/ M, and in controls, Hg had no effect either on orientation or mortality, and 65% of the larvae were collected at the light source in 30 min or less. In contrast, at 10/sup -6/ M, only 29% were able to do so. The presence of 10/sup -4/ M thiamine hydrochloride in the excystment medium prevented fully the loss of light-sensitivity.

  19. Fine structure and function of the alimentary epithelium in Artemia salina nauplii

    Hootman, S R; Conte, F P

    1974-01-01

    The fine structure of the alimentary tract in the second instar nauplius of the brine shrimp, Artemia salina, has been described. The foregut and hindgut of the larva are composed of cuboidal epithelium which is cuticularized. The epithelium of the midgut and gastric caeca is columnar and is characterized by apical microvilli, basal membrane infolds, and abundant mitochondria. The structural characteristics of the midgut cells correlate with previous physiological and biochemical evidence on both adult and larval brine shrimp which indicates that the midgut plays an important role in absorption and osmoregulation in these animals.

  20. Phaeobacter inhibens as Probiotic Bacteria in Non-Axenic Artemia and Algae Cultures

    Grotkjær, Torben; D'Alvise, Paul; Bentzon-Tilia, Mikkel

    2015-01-01

    Bacterial diseases are a major constraint in aquaculture, especially in larviculture. Antibiotics that can control pathogens should be avoided due to risk of antibiotic resistance. We have shown in axenic systems of live larval feed that marine Roseobacter clade bacteria can antagonize fish patho...... demonstrates that probiotic bacteria can be introduced at the stage of live feed and have a pathogen reducing effect in both an Artemia and a D. tertiolecta challenge setup. This can potentially limit the subsequent use of antibiotics for control of pathogenic bacteria....

  1. Potentials of Microalgae Biodiesel Production in Nigeria

    Prof. Ogunji

    production industries in Nigeria will have positive effects on socio-economic development ... Keywords: bio-energy; climatic conditions; fossil fuel; microalgae; production economics ... of affordable land and labour (Sielhorst et al., ..... by clouds. Closed photobioreactors are scarcely influenced by rainfall pattern; however, ...

  2. Secondary wastewater treatment by microalgae isolated from ...

    Microalgae play a fundamental role in primary and secondary wastewater treatment. In this work the growth, photosynthetic activity and removal of phosphorus from wastewater effluents by indigenous blue-green algal species, Spirulina and Oscillatoria, isolated from Gaborone oxidation ponds was studied. Oscillatoria and ...

  3. Hydrothermal Liquefaction of the Microalgae Phaeodactylum tricornutum

    Sigaard Christensen, Per; Peng, Gaël; Vogel, Frédéric

    2014-01-01

    The microalgae Phaeodactylum tricornutum was processed by hydrothermal liquefaction in order to assess the influence of reaction temperature and reaction time on the product and elemental distribution. The experiments were carried out at different reaction times (5 and 15 min) and over a wide range...

  4. Harvesting of microalgae by bio-flocculation

    Salim, S.; Bosma, R.; Vermuë, M.H.; Wijffels, R.H.

    2011-01-01

    The high-energy input for harvesting biomass makes current commercial microalgal biodiesel production economically unfeasible. A novel harvesting method is presented as a cost and energy efficient alternative: the bio-flocculation by using one flocculating microalga to concentrate the

  5. Microalgae biorefineries: The Brazilian scenario in perspective.

    Brasil, B S A F; Silva, F C P; Siqueira, F G

    2017-10-25

    Biorefineries have the potential to meet a significant part of the growing demand for energy, fuels, chemicals and materials worldwide. Indeed, the bio-based industry is expected to play a major role in energy security and climate change mitigation during the 21th century. Despite this, there are challenges related to resource consumption, processing optimization and waste minimization that still need to be overcome. In this context, microalgae appear as a promising non-edible feedstock with advantages over traditional land crops, such as high productivity, continuous harvesting throughout the year and minimal problems regarding land use. Importantly, both cultivation and microalgae processing can take place at the same site, which increases the possibilities for process integration and a reduction in logistic costs at biorefinery facilities. This review describes the actual scenario for microalgae biorefineries integration to the biofuels and petrochemical industries in Brazil, while highlighting the major challenges and recent advances in microalgae large-scale production. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Antenna size reduction in microalgae mass culture

    Mooij, de T.

    2016-01-01

    The thesis describes the potential of microalgae with a reduced light harvesting antenna for biomass production under mass culture conditions (high biomass density, high light intensity). Theoretically, the lower chlorophyll content reduces the light harvesting capacity and with that the amount

  7. Production of structured triacylglycerols from microalgae

    Řezanka, Tomáš; Lukavský, Jaromír; Nedbalová, Linda; Sigler, Karel

    2014-01-01

    Roč. 104, AUG 2014 (2014), s. 95-104 ISSN 0031-9422 R&D Projects: GA ČR(CZ) GAP503/11/0215 Institutional support: RVO:61388971 ; RVO:67985939 Keywords : microalgae * enantiomers * chiral LC Subject RIV: EE - Microbiology, Virology Impact factor: 2.547, year: 2014

  8. Fatty Acid Content of Indonesian Aquatic Microalgae

    TRI PRARTONO

    2010-12-01

    Full Text Available High utilization of fossil fuel increases the level of carbon dioxide in the atmosphere and results in global warming phenomenon. These things establish the world's thought to look for the other alternative energy that can reduce the use of fossil fuel even to be replaced by the substitute. Recently, Indonesia has been doing the research of microalgae as a feedstock of an alternative biofuel. Fatty acid content that microalgae have is also high to produce biofuel. The steps used in this research is a 7 days cultivation, harvesting, extraction using hexane, and fatty acid identification using Gas Chromatography of microalgae species. Fatty acid component in some species such as Chlorella sp., Scenedesmus sp., Nannochloropsis sp., and Isochrysis sp. is between 0.21-29.5%; 0.11-25.16%; 0.30-42.32%; 2.06-37.63%, respectively, based on dry weight calculation. The high content of fatty acid in some species of microalgae showed the potential to be the feedstock of producing biofuel in overcoming the limited utilization from petroleum (fossil fuel presently.

  9. Investigation of microalgae with photon density waves

    Frankovitch, Christine; Reich, Oliver; Löhmannsröben, Hans-Gerd

    2007-09-01

    Phototropic microalgae have a large potential for producing valuable substances for the feed, food, cosmetics, pigment, bioremediation, and pharmacy industries as well as for biotechnological processes. Today it is estimated that the microalgal aquaculture worldwide production is 5000 tons of dry matter per year (not taking into account processed products) making it an approximately $1.25 billion U.S. per year industry. For effective observation of the photosynthetic growth processes, fast on-line sensor systems that analyze the relevant biological and technical process parameters are preferred. The optical properties of the microalgae culture influence the transport of light in the photobioreactor and can be used to extract relevant information for efficient cultivation practices. Microalgae cultivation media show a combination of light absorption and scattering, which are influenced by the concentrations and the physical and chemical properties of the different absorbing and scattering species (e.g. pigments, cell components, etc.). Investigations with frequency domain photon density waves (PDW) allow for the examination of absorption and scattering properties of turbid media, namely the absorption and reduced scattering coefficient. The reduced scattering coefficient can be used to characterize physical and morphological properties of the medium, including the cell concentration, whereas the absorption coefficient correlates with the pigment content. Nannochloropsis oculata, a single-cell species of microalgae, were examined in a nutrient solution with photon density waves. The absorption and reduced scattering coefficients were experimentally determined throughout the cultivation process, and applied to gain information about the cell concentration and average cell radius.

  10. hydroprocessing processing processing microalgae derived h

    eobe

    higher yield of fuel per unit microalgae than the other ... used for the bio-crude production, it is not mandatory ... convert the whole biomass into primarily liquid .... Typical catalysts reportedly used for hydroprocessing ... design and economics for the conversion of whole ... separate reactors or a two-in-one reactor with a.

  11. Scenario evaluation of open pond microalgae production

    Slegers, P.M.; Lösing, M.B.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    To evaluate microalgae production in large scale open ponds under different climatologic conditions, a model-based framework is used to study the effect of light conditions, water temperature and reactor design on trends in algae productivity. Scenario analyses have been done for two algae species

  12. Harvesting microalgae with microwave synthesized magnetic microparticles

    Procházková, G.; Šafařík, Ivo; Brányik, T.

    2013-01-01

    Roč. 130, FEB (2013), s. 472-477 ISSN 0960-8524 R&D Projects: GA MŠk LH12190 Institutional support: RVO:67179843 Keywords : harvesting microalgae * iron oxide magnetic microparticles * non-covalent interactions * microwave treatment * cell demagnetization Subject RIV: EI - Biotechnology ; Bionics Impact factor: 5.039, year: 2013

  13. A study of oxidative stress induced by two polybrominated diphenyl ethers in the rotifer Brachionus plicatilis.

    Zhang, Jing; Wang, You; Sun, Kai-Ming; Fang, Kuan; Tang, Xuexi

    2016-12-15

    Polybrominated diphenyl ethers (PBDEs) are widely dispersed persistent organic pollutants in the marine ecosystem. However, their toxic mechanisms in marine organisms, especially invertebrates, remain poorly understood. Two common congeners of PBDEs, tetrabrominated diphenyl ether-47 (BDE-47) and decabrominated diphenyl ether-209 (BDE-209), were investigated. Their toxic mechanisms, with a focus on oxidative stress, were examined in rotifer Brachionus plicatilis. Overproduction of reactive oxygen species (ROS) was induced by two PBDEs. The expression of superoxide dismutase (SOD) mRNA was increased, suggesting SOD play a main role in ROS-scavenging. The intercellular concentrations of calcium ([Ca 2+ ] in ) and the expression of calmodulin (CaM) mRNA were increased. This indicates the calcium ion (Ca 2+ ) signaling channel is involved in PBDEs stress. Further analysis showed that the reproductive system might be the target site for toxicity of PBDEs. Moreover, high value of detection indexes in BDE-47 experimental groups suggested BDE-47 might cause higher oxidative damage than BDE-209 in rotifers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. [Effects of Alexandrium tamarense and Prorocentrum donghaiense on rotifer Brachionus plicatilis population].

    Wang, Liping; Yan, Tian; Tan, Zhijun; Zhou, Mingjiang

    2003-07-01

    The effects of Prorocentrum donghaiense and Alexandrium sp., causative species of harmful algal bloom of East China Sea in May 2002, on rotifer Brachionus plicatilis population were studied in the laboratory. The results showed that Alexandrium tamarense (ATHK) had a lethal effect on B. plicatilis and the 48hLC50 was about 1300 cell.ml-1. The toxin comparison of different fractions showed that the algal culture and re-suspended algal cells had the adverse effects, and the alga at earlier growth phases showed a stronger impact, indicating that the inhibitory effect was related with the activity of the living algal cells. P. donghaiense at high densities (4 x 10(4), 5 x 10(4) and 10 x 10(4) cell.ml-1) had an adverse effect on B. plicatilis population, while at low densities (1 x 10(4), 2 x 10(4) and 3 x 10(4) cell.ml-1), the alga could be used as food for rotifer population. When the two algae were mixed, the lethal effect of A. tamarense could be decreased by P. donghaiense. The results indicated that the above HAB event could affect the micro-zooplankton population in the occurrence area of East China Sea.

  15. Variable selectivity and the role of nutritional quality in food selection by a planktonic rotifer

    Sierszen, M.E.

    1990-01-01

    To investigate the potential for selective feeding to enhance fitness, I test the hypothesis that an herbivorous zooplankter selects those food items that best support its reproduction. Under this hypothesis, growth and reproduction on selected food items should be higher than on less preferred items. The hypothesis is not supported. In situ selectivity by the rotifer Keratella taurocephala for Cryptomonas relative to Chlamydomonas goes through a seasonal cycle, in apparent response to fluctuating Cryptomonas populations. However, reproduction on a unialgal diet of Cryptomonas is consistently high and similar to that on Chlamydomonas. Oocystis, which also supports reproduction equivalent to that supported by Chlamydomonas, is sometimes rejected by K. taurocephala. In addition, K. taurocephala does not discriminate between Merismopedia and Chlamydomonas even though Merismopedia supports virtually no reproduction by the rotifer. Selection by K. taurocephala does not simply maximize the intake of food items that yield high reproduction. Selectivity is a complex, dynamic process, one function of which may be the exploitation of locally or seasonally abundant foods. (author)

  16. Evaluation of the toxicity of the methanolic extract of Caesalpinia Pyramidalis, subjected to gamma radiation, compared to saline artemias; Avaliacao da toxicidade do extrato metanolico de Caesalpinia Pyramidalis, submetido a radiacao gama, frente a artemias salinas

    Pessoa, Juanna G.; Santos, Mariana L.O.; Costa, Michelle C.A.; Siqueira, Williams N.; Silva, Luanna R.S.; Cabral, Daniela L.V.; Amancio, Francisco F.; Melo, Ana M.M.A., E-mail: marianasantos_ufpe@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2013-07-01

    The present study aimed to investigate the possible effect of irradiation of 60 Co in methanol extract of Caesalpinia pyramidalis (catingueira) with function of reducing the toxicity of the extract at concentrations of 1000, 500, 250 and 125 ppm irradiating them with doses of 5 kGy 7 kGy and 10 kGy, using lethality tests with saline Artemias.

  17. Risk associated with toxic blooms of marine phytoplankton functional groups on Artemia franciscana

    Ana D’ors

    2014-08-01

    Full Text Available Objective: To study mortality of copepod Artemia franciscana against the occurrence of harmful marine algae and possible toxicological changes exhibited by binary and tertiary combinations of these harmful algae toxins. Methods: Tweenty four hours acute toxicity assays were performed with selected concentrations of Alexandrium minutum, Prorocentrum lima and Nitzschia N1c1 living cells. Additionally, the results were analyzed using the median-effect/combination index (CI-isobologram equation to assess possible changes in the toxic effect induced by phytoplankton functional groups. Results: Biotoxin equivalent values obtained by immunodetection were (2.12±0.10, (8.60±1.30 and (4.32±1.67 pg/cell for saxitoxin, okadaic acid and domoic acid, respectively. The 24-h LC50 values estimated to saxitoxin and okadaic acid equivalents were 4.06 and 6.27 µg/L, significantly below the value obtained for Nitzschia N1c1, which was established at 467.33 µg/L. CI analysis applied on phytoplankton assemblages showed that both ternary mixture as the binary combinations exhibited antagonic action on toxic effects in Artemia nauplii, which were significantly lower than the toxic effect exhibited by each species studied. Conclusions: These results show that, although these harmful algae represent a serious risk to estuarine zooplankton community, the presence of phytoplankton functional groups within the same bloom can reduce the potential risk compared to the expected risk when each of the phytoplankton groups are evaluated individually.

  18. Cytotoxicity of Dorema auchri, Achillea millefolium and Artemisia aucheri by Artemia

    M Ghavamizadeh

    2013-09-01

    Full Text Available Abstract Background & aim: Nowadays, toxic compounds derived from plants used against microbes and cancer cells. The aim of this study was to evaluate cytotoxicity of Dorema aucheri, Achillea millefollium and Artemisia aucheri using brine shrimp, Artemia urmiana, lethality test. Methods: In this experimental study, the plants were collected from the Kohgiluyeh and Boyer-Ahmad Province, then identified by a botanist. Clean and air-dried aerial parts of plants were extracted with suitable solvents. Cytotoxicity evaluation was performed using larvae hatched cysts were purchased from Urmia. Live larvae were exposed to different concentrations of extract and the numbers of live and dead larvae were counted after 24 hours. Mean of LC 50 of any extracts from control and exposed live larvae were examined. The data were analyzed using the Finney’s Probit analysis. Results: Hydro ethanol and chloroform extracts of Achillea millefolium, Dorema aucheri and Artemisia aucheri exhibited potent brine shrimp lethality with LC50 67.8±0.53μg.ml-1, 76.50±0.60μg.ml-1, 92.70±6.05μg.ml-1 respectively. The degree of lethality was found to be directly proportional to the concentration of extracts. Conclusion: According to BSLT, LC50 of D. aucheri, A. millefolium and A. aucheri, they were considered as toxic. So these plants could be a source of new compounds with biological activity. Key words: Artemia urmiana, Dorema auchri, Achillea millefolium, Artemisia aucheri, Cytotoxicity

  19. A gene catalogue for post-diapause development of an anhydrobiotic arthropod Artemia franciscana

    Yu Jun

    2009-01-01

    Full Text Available Abstract Background Diapause is a reversible state of developmental suspension and found among diverse taxa, from plants to animals, including marsupials and some other mammals. Although previous work has accumulated ample data, the molecular mechanism underlying diapause and reactivation from it remain elusive. Results Using Artemia franciscana, a model organism to study the development of post-diapause embryos in Arthropod, we sequenced random clones up to a total of 28,039 ESTs from four cDNA libraries made from dehydrated cysts and three time points after rehydration/reactivation, which were assembled into 8,018 unigene clusters. We identified 324 differentially-expressed genes (DEGs, P Conclusion We found that the first 5-hour period after rehydration is most important for embryonic reactivation of Artemia. As the total number of expressed genes increases significantly, the majority of DEGs were also identified in this period, including a group of water-deficient-induced genes. A group of genes with similar functions have been described in plant seeds; for instance, one of the novel LEA members shares ~70% amino-acid identity with an Arabidopsis EM (embryonic abundant protein, the closest animal relative to plant LEA families identified thus far. Our findings also suggested that not only nutrition, but also mRNAs are produced and stored during cyst formation to support rapid development after reactivation.

  20. A Seasonal Study Reveals the Occurrence of Exotic Rotifers, the River Antigua, Veracruz, Close to the Gulf of Mexico

    Nandini, S.; Sarma, S. S. S.; Gulati, R. D.

    Zooplankton studies in Mexican rivers are few despite the fact that Mexico has >200 rivers. We present data on the seasonal diversity of rotifers during 2013–2014 from the river La Antigua, near Veracruz. We collected samples from 15 stations along a horizontal gradient of ~5 km, from the upper

  1. Ratio between autoflocculating and target microalgae affects the energy-efficient harvesting by bio-flocculation

    Salim, S.; Vermuë, M.H.; Wijffels, R.H.

    2012-01-01

    The effect of ratio between autoflocculating and target microalgae in bio-flocculation was studied with emphasis on the recovery, sedimentation rate and energy demand for harvesting the target microalgae. When the autoflocculating microalgae Ettlia texensis, Ankistrodesmus falcatus and Scenedesmus

  2. Morphology and ultrastructure of the freshwater rotifer Brachionus bidentatus (Monogononta: Brachionidae) using scanning and transmission electron microscopy.

    Guerrero-Jiménez, Gerardo; Zavala-Padilla, Guadalupe; Silva-Briano, Marcelo; Rico-Martínez, Roberto

    2013-12-01

    The study of sexual reproductive behavior supported by ultrastructural evidence is important in rotifers to describe differences among potential cryptic species. In this research, the morphology of the rotifer Brachionus bidentatus is described at the ultrastructural level, using electronic microscopy, together with a brief description and discussion of its sexual reproductive behavior. The characteristics of the (a) male, (b) the female, (c) the sexual egg or cyst, (d) the partenogenic egg, (e) the no-fecundated sexual egg (male egg), and (f) the trophi, were described. Another part of this research is dedicated to the ultrastructure of the sex cells of the male rotifer B. bidentatus. Samples were obtained from La Punta pond in Cosio, Aguascalientes, Mexico (22 degrees 08' N - 102 degrees 24' W), and a culture was maintained in the laboratory. Fifty organisms, from different stages of the rotifer Brachionus bidentatus, were fixed in Formol at 4% and then prepared; besides, for the trophi, 25 female rotifer Brachionus bidentatus were prepared for observation in a JEOL 5900 LV scanning electronic microscope. In addition, for the observation of male sex cells, 500 males of Brachionus bidentatus were isolated, fixed and observed in a JEOL 1010 transmission microscope. Females of B. bidentatus in laboratory cultures had a lifespan of five days (mean+one SD = 4.69 +/- 0.48; N=13), and produced 4.5 +/- 3.67 (N=6) parthenogenetic eggs during such lifespan. In the case of non-fertilized sexual eggs, they produced up to 18 eggs (mean+one SD = 13 +/- 4.93; N=7). Sexual females produced a single cyst on average (mean +/- one SD = I +/- 0; N=20). For the sexual cycle, the time of copulation between male and female ranged from 10 to 40 seconds (mean +/- one SD = 17.33 +/- 10.55, N=7). The spermatozoa are composed of a celular body and a flagellum, the size of the body is of 300 nm while the flagellum measures 1 700nm. The rods have a double membrane. Their mean length is almost

  3. Intentional introduction of Artemia sinica (Anostraca) in the high-altitude Tibetan lake Dangxiong Co: the new population and consequences for the environment and for humans

    Jia, Qinxian; Anufriieva, Elena; Liu, Xifang; Kong, Fanjing; Shadrin, Nickolai

    2015-11-01

    The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now. Salt lakes in Tibet may contribute to the solution of the problem. In Northern Tibet there are 26 saline lakes whose salinity and temperature may support Artemia survival at an altitude of 4 000-5 100 m. We found Artemia in 15 of these lakes. The saline lakes with Artemia populations mainly belong to the shallow basin lakes, and the majority of these lakes are small in area. The total area of lakes without Artemia is more than 1 000 km2. Lake Dangxiong Co (Co means lake in Tibet) was chosen for the intentional introduction of Artemia sinica. In 2004, 850 g of A. sinica cysts, originating from Qinghai, were introduced in the lake. Surveys in 2006-2014 showed that the average abundance of Artemia adults in the lake gradually increased from 20 ind./m3 in 2006 to 1950 ind./m3 in 2013. We assume that two subpopulations of A. sinica, separated by depth, may exist in the lake. The new Artemia population caused an increase in the number of species of phytoplankton and heterotrophic protozoa with a decrease of their total abundance. Water transparency also increased. Dominance in phytoplankton passed from cyanobacteria to diatoms. Changes occurred not only in the lake ecosystem; the number of water birds using the lakes also dramatically increased. Preliminary calculations showed that is it possible to harvest at least about 150 t cysts per year from the lake as well as 3.2 thousand tons of frozen or 350 t of dried biomass of adult Artemia.

  4. The history, present status and prospects of the availability of Artemia cysts for aquaculture

    Lavens, P.; Sorgeloos, P.

    2000-01-01

    This paper provides an overview of the history of Artemia cyst provision worldwide since the 1950s. It allows a better assessment of the current situation, characterized by poor yields from the main harvest site, the Great Salt Lake in Utah, USA, and to make prognoses about future supplies and demands.

  5. Determination of trace elements in freshwater rotifers and ciliates by total reflection X-ray fluorescence spectrometry

    Woelfl, S.; Óvári, M.; Nimptsch, J.; Neu, T. R.; Mages, M.

    2016-02-01

    Element determination in plankton is important for the assessment of metal contamination of aquatic environments. Until recently, it has been difficult to determine elemental content in rotifers or ciliates derived from natural plankton samples because of the difficulty in handling and separation of these fragile organisms. The aim of this study was to evaluate methods for separation of rotifers and large ciliates from natural plankton samples (μg range dry weight) and subsequent analysis of their elemental content using total-reflection X-ray fluorescence spectrometry (TXRF). Plankton samples were collected from different aquatic environments (three lakes, one river) in Chile, Argentina and Hungary. From one to eighty specimens of five rotifer species (Brachionus calyciflorus, Brachionus falcatus, Asplanchna sieboldii, Asplanchna sp., Philodina sp.) and four to twelve specimens of one large ciliate (Stentor amethystinus) were prepared according to the dry method originally developed for microcrustaceans, and analysed by TRXF following in situ microdigestion. Our results demonstrated that it possible to process these small and fragile organisms (individual dry mass: 0.17-9.39 μg ind- 1) via careful washing and preparation procedures. We found species-dependent differences of the element mass fractions for some of the elements studied (Cr, Mn, Fe, Ni, Cu, Zn, As, Pb), especially for Cu, Fe and Mn. One large rotifer species (A. sieboldii) also showed a negative correlation between individual dry weight and the element content for Pb, Ni and Cr. We conclude that our application of the in situ microdigestion-TRXF method is suitable even for rotifers and ciliates, greatly expanding the possibilities for use of plankton in biomonitoring of metal contamination in aquatic environments.

  6. Evaluation of the Antioxidant Activity of Cell Extracts from Microalgae

    F. Xavier Malcata; Pedro Moradas-Ferreira; Paula Tamagnini; A. C. Silva Ferreira; Maria S. Gião; Rui Seabra; A. Catarina Guedes

    2013-01-01

    A growing market for novel antioxidants obtained from non-expensive sources justifies educated screening of microalgae for their potential antioxidant features. Characterization of the antioxidant profile of 18 species of cyanobacteria (prokaryotic microalgae) and 23 species of (eukaryotic) microalgae is accordingly reported in this paper. The total antioxidant capacity, accounted for by both water- and lipid-soluble antioxidants, was evaluated by the (radical cation) ABTS method. For complem...

  7. Lipid extraction from microalgae using a single ionic liquid

    Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

    2013-05-28

    A one-step process for the lysis of microalgae cell walls and separation of the cellular lipids for use in biofuel production by utilizing a hydrophilic ionic liquid, 1-butyl-3-methylimidazolium. The hydrophilic ionic liquid both lyses the microalgae cell walls and forms two immiscible layers, one of which consists of the lipid contents of the lysed cells. After mixture of the hydrophilic ionic liquid with a suspension of microalgae cells, gravity causes a hydrophobic lipid phase to move to a top phase where it is removed from the mixture and purified. The hydrophilic ionic liquid is recycled to lyse new microalgae suspensions.

  8. Review on biofuel oil and gas production processes from microalgae

    Amin, Sarmidi

    2009-01-01

    Microalgae, as biomass, are a potential source of renewable energy, and they can be converted into energy such as biofuel oil and gas. This paper presents a brief review on the main conversion processes of microalgae becoming energy. Since microalgae have high water content, not all biomass energy conversion processes can be applied. By using thermochemical processes, oil and gas can be produced, and by using biochemical processes, ethanol and biodiesel can be produced. The properties of the microalgae product are almost similar to those of offish and vegetable oils, and therefore, it can be considered as a substitute of fossil oil.

  9. Learning sustainability by developing a solar dryer for microalgae retrieval

    Benedita Malheiro

    2016-01-01

    Full Text Available Excessive fossil fuel consumption is driving the search for alternative energy production solutions and, in particular, for sustainable sources of energy such as microalgae, from which biodiesel, among other useful compounds, can be obtained. After producing the microalgae, they must be harvested and dried. Existing drying solutions consume too much energy and are, therefore, expensive and unsustainable. The goal of this EPS@ISEP Spring 2013 project was to develop a solar microalgae dryer for the microalgae laboratory of ISEP. A multinational team of five students from distinct fields of study was responsible for designing and building the solar microalgae dryer prototype. The prototype includes a control system to ensure that the microalgae are not destroyed during the drying process. The solar microalgae dryer works as a distiller, extracting the excess water from the microalgae suspension. This paper details the design steps, the building technologies, the ethical and sustainable concerns and compares the prototype with existing solutions. The proposed sustainable microalgae drying process is competitive as far as energy usage is concerned. Finally, the project contributed to increase the team’s sustainable development awareness, active learning and motivation.

  10. Discovering genes associated with dormancy in the monogonont rotifer Brachionus plicatilis.

    Denekamp, Nadav Y; Thorne, Michael A S; Clark, Melody S; Kube, Michael; Reinhardt, Richard; Lubzens, Esther

    2009-03-13

    Microscopic monogonont rotifers, including the euryhaline species Brachionus plicatilis, are typically found in water bodies where environmental factors restrict population growth to short periods lasting days or months. The survival of the population is ensured via the production of resting eggs that show a remarkable tolerance to unfavorable conditions and remain viable for decades. The aim of this study was to generate Expressed Sequence Tags (ESTs) for molecular characterisation of processes associated with the formation of resting eggs, their survival during dormancy and hatching. Four normalized and four subtractive libraries were constructed to provide a resource for rotifer transcriptomics associated with resting-egg formation, storage and hatching. A total of 47,926 sequences were assembled into 18,000 putative transcripts and analyzed using both Blast and GO annotation. About 28-55% (depending on the library) of the clones produced significant matches against the Swissprot and Trembl databases. Genes known to be associated with desiccation tolerance during dormancy in other organisms were identified in the EST libraries. These included genes associated with antioxidant activity, low molecular weight heat shock proteins and Late Embryonic Abundant (LEA) proteins. Real-time PCR confirmed that LEA transcripts, small heat-shock proteins and some antioxidant genes were upregulated in resting eggs, therefore suggesting that desiccation tolerance is a characteristic feature of resting eggs even though they do not necessarily fully desiccate during dormancy. The role of trehalose in resting-egg formation and survival remains unclear since there was no significant difference between resting-egg producing females and amictic females in the expression of the tps-1 gene. In view of the absence of vitellogenin transcripts, matches to lipoprotein lipase proteins suggest that, similar to the situation in dipterans, these proteins may serve as the yolk proteins in

  11. Discovering genes associated with dormancy in the monogonont rotifer Brachionus plicatilis

    Kube Michael

    2009-03-01

    Full Text Available Abstract Background Microscopic monogonont rotifers, including the euryhaline species Brachionus plicatilis, are typically found in water bodies where environmental factors restrict population growth to short periods lasting days or months. The survival of the population is ensured via the production of resting eggs that show a remarkable tolerance to unfavorable conditions and remain viable for decades. The aim of this study was to generate Expressed Sequence Tags (ESTs for molecular characterisation of processes associated with the formation of resting eggs, their survival during dormancy and hatching. Results Four normalized and four subtractive libraries were constructed to provide a resource for rotifer transcriptomics associated with resting-egg formation, storage and hatching. A total of 47,926 sequences were assembled into 18,000 putative transcripts and analyzed using both Blast and GO annotation. About 28–55% (depending on the library of the clones produced significant matches against the Swissprot and Trembl databases. Genes known to be associated with desiccation tolerance during dormancy in other organisms were identified in the EST libraries. These included genes associated with antioxidant activity, low molecular weight heat shock proteins and Late Embryonic Abundant (LEA proteins. Real-time PCR confirmed that LEA transcripts, small heat-shock proteins and some antioxidant genes were upregulated in resting eggs, therefore suggesting that desiccation tolerance is a characteristic feature of resting eggs even though they do not necessarily fully desiccate during dormancy. The role of trehalose in resting-egg formation and survival remains unclear since there was no significant difference between resting-egg producing females and amictic females in the expression of the tps-1 gene. In view of the absence of vitellogenin transcripts, matches to lipoprotein lipase proteins suggest that, similar to the situation in dipterans, these

  12. Novel mesostructured inclusions in the epidermal lining of Artemia franciscana ovisacs show optical activity

    Elena Hollergschwandtner

    2017-10-01

    Full Text Available Background Biomineralization, e.g., in sea urchins or mollusks, includes the assembly of mesoscopic superstructures from inorganic crystalline components and biopolymers. The resulting mesocrystals inspire biophysicists and material scientists alike, because of their extraordinary physical properties. Current efforts to replicate mesocrystal synthesis in vitro require understanding the principles of their self-assembly in vivo. One question, not addressed so far, is whether intracellular crystals of proteins can assemble with biopolymers into functional mesocrystal-like structures. During our electron microscopy studies into Artemia franciscana (Crustacea: Branchiopoda, we found initial evidence of such proteinaceous mesostructures. Results EM preparations with high-pressure freezing and accelerated freeze substitution revealed an extraordinary intracellular source of mesostructured inclusions in both the cyto-and nucleoplasm of the epidermal lining of ovisacs of A. franciscana. Confocal reflection microscopy not only confirmed our finding; it also revealed reflective, light dispersing activity of these flake-like structures, their positioning and orientation with respect to the ovisac inside. Both the striation of alternating electron dense and electron-lucent components and the sharp edges of the flakes indicate self-assembly of material of yet unknown origin under supposed participation of crystallization. However, selected area electron diffraction could not verify the status of crystallization. Energy dispersive X-ray analysis measured a marked increase in nitrogen within the flake-like inclusion, and the almost complete absence of elements that are typically involved in inorganic crystallization. This rise in nitrogen could possibility be related to higher package density of proteins, achieved by mesostructure assembly. Conclusions The ovisac lining of A. franciscana is endowed with numerous mesostructured inclusions that have not been

  13. Microalgae: cultivation techniques and wastewater phycoremediation.

    Pacheco, Marcondes M; Hoeltz, Michele; Moraes, Maria S A; Schneider, Rosana C S

    2015-01-01

    Generation of liquid and gaseous effluents is associated with almost all anthropogenic activities. The discharge of these effluents into the environment without treatment has reduced the availability and quality of natural resources, representing a serious threat to the balance of different ecosystems and human health. Universal access to water and global warming are topics of intense concern and are listed as priorities in the vast majority of global scientific, social and political guidelines. Conventional techniques to treat liquid and gaseous effluents pose economic and/or environmental limitations that prevent their use in certain applications. The technique of phycoremediation, which uses microalgae, macroalgae, and cyanobacteria for the removal or biotransformation of pollutants, is an emerging technology that has been highlighted due to its economic viability and environmental sustainability. This literature review discusses different techniques of microalgae cultivation and their use in the phycoremediation of contaminants in wastewater.

  14. Microalgae for Biofuels and Animal Feeds

    John Benemann

    2013-11-01

    Full Text Available The potential of microalgae biomass production for low-cost commodities—biofuels and animal feeds—using sunlight and CO2 is reviewed. Microalgae are currently cultivated in relatively small-scale systems, mainly for high value human nutritional products. For commodities, production costs must be decreased by an order of magnitude, and high productivity algal strains must be developed that can be stably cultivated in large open ponds and harvested by low-cost processes. For animal feeds, the algal biomass must be high in digestible protein and long-chain omega-3 fatty acids that can substitute for fish meal and fish oils. Biofuels will require a high content of vegetable oils (preferably triglycerides, hydrocarbons or fermentable carbohydrates. Many different cultivation systems, algal species, harvesting methods, and biomass processing technologies are being developed worldwide. However, only raceway-type open pond systems are suitable for the production of low-cost commodities.

  15. Effect of Kind and Dosage of Enrichment Materials on the Nutritional Quality of Rotifers Especially n3-HUFA

    Muhammad Agus Suprayudi

    2003-05-01

    Full Text Available This experiment was conducted to evaluate the quality of rotifer enriched with four  kinds of enrichement materials from the stand point of essensial fatty acids. Rotifer was enriched at 24 - 25oC for 18 hours at a density of 1000 ind/ml.  Rotifers were treated by four kinds of enrichment materials such as oleic acid (R-OA, two different density of Nannochloropsis oculata, (4x107 and 16x107 cell/ml; R-N18 and R-N42 two different levels of eicosapentaenoic acids (EPA triglyceride type (EPA-TAG (20 and 40 ml/ml; R-E20, R-E40 and two different level of EPA ethyl ester (EPA-EE (R-EE25 and R-EE50% respectively. Rotifers enriched with Nannochloropsis oculata and EPA-EE type have a similar profile of essensial fatty acid especially on n3-HUFA that dominated by EPA, while DHA was in a trace amount or not detected.  In addition Nannochloropsis oculata as an enrichment material showed the highest population density of rotifers during enrichment periods.  Rotifer enriched with EPA-TAG has a more complete of essential fatty acid profile compared to other enrichment materials due to their contained both of EPA and DHA. We conclude that rotifer enriched with EPA-TAG as enrichment material showed the best nutritional quality of rotifers from the stand point of essential fatty acid. Key words :  Rotifers, enrichment, eicosapentaenoic acid, docosaheksaenoic acid,  n3-HUFA   ABSTRAK Penelitian ini dilakukan untuk mengetahui profil asam lemak rotifera yang diperkaya dengan berbagai macam jenis dan dosis pengkaya. Rotifera dengan kepadatan 1000 ind./ml diperkaya dengan bebagai bahan pengkaya seperti asam oleat (R-OA; Nannochloropsis oculata dengan kepadatan 4x107 dan 16x107 sel/ml (R-N18 dan R-N42; eicosapentaenoic acid (EPA tipe triglicerida (EPA-TAG  dengan dosis 20 dan 40 μl (R-E20 dan R-E40 dan EPA tipe ethyl esther (EPA-EE  dengan dosis 25 dan 50 μl per liter (R-EE25 and R-EE50%. Rotifera diperkaya selama 18 jam pada suhu 24-25oC. Rotifera yang

  16. Antioxidant activity of the microalga Spirulina maxima

    Miranda M.S.; Cintra R.G.; Barros S.B.M.; Mancini-Filho J.

    1998-01-01

    Spirulina maxima, which is used as a food additive, is a microalga rich in protein and other essential nutrients. Spirulina contains phenolic acids, tocopherols and ß-carotene which are known to exhibit antioxidant properties. The aim of the present study was to evaluate the antioxidant capacity of a Spirulina extract. The antioxidant activity of a methanolic extract of Spirulina was determined in vitro and in vivo. The in vitro antioxidant capacity was tested on a brain homogenate incubated ...

  17. Energy from biomass production - photosynthesis of microalgae?

    Lamparter, Tilman [Universitaet Karlsruhe, Botanisches Institut, Geb. 10.40, Kaiserstr. 2, D-76131 Karlsruhe (Germany)

    2009-07-01

    The composition of our atmosphere in the past, present and future is largely determined by photosynthetic activity. Other biological processes such as respiration consume oxygen and produce, like the use of the limited fossil fuel resources, CO{sub 2} whose increasing atmospheric concentration is a major concern. There is thus a demand on the development of alternative energy sources that replace fossil fuel. The use of crop plants for the production of biofuel is one step towards this direction. Since most often the same areas are used as for the production of food, the increased production of biofuel imposes secondary problems, however. In this context, the use of microalgae for biomass production has been proposed. Not only algae in the botanical sense (lower plants, photosynthetic eukaryotes) but also cyanobacteria, which belong to the prokaryotes, are used as ''microalgae''. The conversion of light energy into biomass can reach much higher efficiencies than in crop plants, in which a great portion of photosynthesis products is used to build up non-photosynthetic tissues such as roots or stems. Microalgae can grow in open ponds or bioreactors and can live on water of varying salinity. It has been proposed to grow microalgae in sea water on desert areas. Ongoing research projects aim at optimizing growth conditions in bioreactors, the recycling of CO{sub 2} from flue gases (e.g. from coal-fired power plants), the production of hydrogen, ethanol or lipids, and the production of valuable other substances such as carotenoids.

  18. Innovative natural functional ingredients from microalgae.

    Plaza, Merichel; Herrero, Miguel; Cifuentes, Alejandro; Ibáñez, Elena

    2009-08-26

    Nowadays, a wide variety of compounds such as polyphenols, polyunsaturated fatty acids (PUFA), or phytosterols obtained, for example, from wine, fish byproducts, or plants are employed to prepare new functional foods. However, unexplored natural sources of bioactive ingredients are gaining much attention since they can lead to the discovery of new compounds or bioactivities. Microalgae have been proposed as an interesting, almost unlimited, natural source in the search for novel natural functional ingredients, and several works have shown the possibility to find bioactive compounds in these organisms. Some advantages can be associated with the study of microalgae such as their huge diversity, the possibility of being used as natural reactors at controlled conditions, and their ability to produce active secondary metabolites to defend themselves from adverse or extreme conditions. In this contribution, an exhaustive revision is presented involving the research for innovative functional food ingredients from microalgae. The most interesting results in this promising field are discussed including new species composition and bioactivity and new processing and extraction methods. Moreover, the future research trends are critically commented.

  19. Production of biodiesel from Coelastrella sp. microalgae

    Mansur, Dieni; Fitriady, Muhammad Arifuddin; Susilaningsih, Dwi; Simanungkalit, Sabar Pangihutan

    2017-11-01

    Microalgae have a wide area of usage and one of them it can be used for biodiesel production. In biodiesel production, lipids containing triglyceride or free fatty acid are converted into methyl ester through trans/esterification reactions. Lipids from microalgae can be extracted by acetone and dimethyl carbonate using homogenizer. Esterification of the lipids was investigated using various catalysts and source of methyl group. Activity of homogeneous catalyst such as HCl and H2SO4 and heterogeneous catalysts such as montmorillonit K-10 and ledgestone was investigated. Moreover, methanol and dimethyl carbonate as source of methyl group were also studied. Among of catalysts with methanol as source of methyl group, it was found that yield of crude biodiesel derived from Choelestrella Sp. microalgae was high over H2SO4 catalyst. On the other hand, over H2SO4 catalyst using dimethyl carbonate as source of methyl group, yield of crude biodiesel significant increase. However, FAME composition of crude biodiesel was high over HCl catalyst.

  20. Production of the rotifer Brachionus plicatilis (Ploimida: Brachionidae) in a Brazilian coastal lagoon.

    Castilho, M S; Arcifa, M S

    2000-12-01

    Secondary production, density and biomass fluctuations, and some reproductive aspects of the rotifer Brachionus plicatilis were studied weekly for two years in a Brazilian coastal lagoon. Food (and secondarily temperature) seemed to be the main factor involved in the summer increments. In the first summer, a mass mortality of fish caused changes in the phytoplankton, which switched from the dominance of Cyanophyceae to Chlorophyceae and other groups. For two months, production, density and biomass were relatively high until the recovery of the Cyanophyceae dominance. In the second summer, peaks of shorter duration and higher values of production, in comparison to the first one, were found. The contribution of resting eggs hatching, in the first summer, and the increment in parthenogenetic reproduction, in the second summer, would account for the population increases observed. Males and mictic females occurred when densities were high.

  1. Production of the rotifer Brachionus plicatilis (Ploimida: Brachionidae in a Brazilian coastal lagoon

    Maria Stela Maioli Castilho

    2000-12-01

    Full Text Available Secondary production, density and biomass fluctuations, and some reproductive aspects of the rotifer Brachionus plicatilis were studied weekly for two years in a Brazilian coastal lagoon. Food (and secondarily temperature seemed to be the main factor involved in the summer increments. In the first summer, a mass mortality of fish caused changes in the phytoplankton, which switched from the dominance of Cyanophyceae to Chlorophyceae and other groups. For two months, production, density and biomass were relatively high until the recovery of the Cyanophyceae dominance. In the second summer, peaks of shorter duration and higher values of production, in comparison to the first one, were found. The contribution of resting eggs hatching, in the first summer, and the increment in parthenogenetic reproduction, in the second summer, would account for the population increases observed. Males and mictic females occurred when densities were high.

  2. The effect of sex on the mean and variance of fitness in facultatively sexual rotifers.

    Becks, L; Agrawal, A F

    2011-03-01

    The evolution of sex is a classic problem in evolutionary biology. While this topic has been the focus of much theoretical work, there is a serious dearth of empirical data. A simple yet fundamental question is how sex affects the mean and variance in fitness. Despite its importance to the theory, this type of data is available for only a handful of taxa. Here, we report two experiments in which we measure the effect of sex on the mean and variance in fitness in the monogonont rotifer, Brachionus calyciflorus. Compared to asexually derived offspring, we find that sexual offspring have lower mean fitness and less genetic variance in fitness. These results indicate that, at least in the laboratory, there are both short- and long-term disadvantages associated with sexual reproduction. We briefly review the other available data and highlight the need for future work. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  3. Effect of different densities of live and dead Chlorella vulgaris on the population growth of rotifers Brachionus calyciflorus and Brachionus patulus (Rotifera

    E. Lucía-Pavón

    2001-12-01

    Full Text Available In order to maintain rotifer populations during periods of low algal production, it is necessary to offer alternate diets, some of which include forms of preserved algae. The present work is based on the effect of live and dead Chlorella vulgaris on the population growth of Brachionus calyciflorus and Brachionus patulus. The experimental design consisted of 3 algal levels (0.5x10(6, 1.5x10(6 and 4.5x10(6 cells ml-1 offered in 3 forms (living, frozen and heat-killed. The maximal population density values for B. calyciflorus ranged from 55±1 ind. ml-1 (at 0.5x10(6 cells ml-1 to 471±72 ind. ml-1 (at 4.5x10(6 cells ml-1 with live Chlorella, but was much lower (6±1 to 26±6 ind. ml-1 with frozen or heat-killed alga under comparable food levels. However, the maximum population density of B. patulus under live or or heat-killed Chlorella was similar at comparable algal levels but when offered frozen algae it was four times less. The highest mean peak population density was 1227±83 ind. ml-1 under 4.5x10(6 cells ml-1. The rate of population increase for B. calyciflorus varied from 0.50 to 0.79 using live Chlorella, but under comparable conditions, this range was lower (0.21 to 0.31 for B. patulus. Results have been discussed in light of possible application for aquaculturePara mantener poblaciones de rotíferos durante periodos con escasez de microalgas, es necesario ofrecer dietas alternativas, incluyendo algunas formas de microalgas preservadas. El presente trabajo analiza el efecto de Chlorella vulgaris viva y muerta sobre el crecimiento poblacional de Brachionus calyciflorus y Brachonus patulus. El diseño experimental consistió en tres niveles de algas (0.5x10(6, 1.5x10(6 y 4.5x10(6 células ml-1 ofrecidas en tres formas (viva, congelada y muerta con agua caliente. Las abundancias máximas de población de B. calyciflorus variaron desde 55±1 ind. ml-1 (en 0.5x10(6 células ml-1 a 471±72 ind. ml-1 (en 4.5x10(6 células ml-1 con Chlorella viva

  4. Efficient recovery of uranium using genetically improved microalgae; Recuperacion eficaz de uranio utilizando microalgas geneticamente mejoradas

    Lopez-Rodas, V.; Conde Vilda, E.; Garcia-Balboa, C.

    2015-07-01

    We propose an alternative process for the efficient recovery of dissolved uranium based on genetically improved microalgae. We isolate Chlamydomonas cf. fonticola from a pond extremely contaminated by uranium (∼ 25 ppm) from ENUSA U-mine, Saelices (Salamanca, Spain). After a process of genetic improvement we obtained a strain capable to recover 115 mg of U per g of dry weight, by mean of bio-adsorption on the cell wall (mostly) and intra-cytoplasm bioaccumulation. Such a genetically improved microalgae resist extremes of acidity and pollution, but even its dead biomass is still able to recover a large amount of uranium. (Author)

  5. IDENTIFIKASI DAN UJI AKTIVITAS ANTIKANKER EKSTRAK SPONS Ianthella basta TERHADAP LARVA Artemia salina L.

    Ni Wayan Sri Sukmarianti

    2013-05-01

    Full Text Available The main purpose of this research is to determine the toxicity of extracts sponge Ianthella basta against Artemia salina larvae and to identify the chemical compounds contained in those toxic isolates. The preliminary test of the anticancer activity has conducted by Brine Shrimp Letalithy (BST test. The results showed that the chloroform extract was the most toxic with LC50 value of 22,39 ppm. Futher, the cloroform extract was separated and purified by coloumn chromatography using eluent of solvent mixture of chloroform : ethyl acetate : n-hexane by 7 : 2 : 1 and 4 fractions were obtained. The most toxic fraction was the fraction C with LC50 value of 35,36 ppm. Based on the GC-MS results, the toxic isolate is allegedly containing chemicals compound of hexadecanoic methyl ester and hexadecanoic acid.

  6. First secondary metabolites from Herissantia crispa L (Brizicky) and the toxicity activity against Artemia salina Leach

    Costa, Danielly Albuquerque da; Matias, Wemerson Neves; Lima, Igara Oliveira; Xavier, Aline Lira; Costa, Vivian Bruna Machado; Diniz, Margareth de Fatima Formiga Melo; Agra, Maria de Fatima; Batista, Leonia Maria; Souza, Maria de Fatima Vanderlei de [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica Prof. Delby Fernandes de Medeiros; Silva, Davi Antas e [Universidade Federal Rural de Pernambuco, Serra Talhada, PE (Brazil). Dept. de Quimica

    2009-07-01

    The phytochemical investigation of Herissantia crispa led to the isolation of seven compounds, identified as: sitosterol 3-O-{beta}-D-glucopyranoside, stigmasterol 3-O-{beta}-D-glucopyranoside, 3,5,7,4'-tetrahydroxyflavone (kaempferol), 3,5,7,3',4'-pentahydroxyflavone (quercetin), unpublished in the genus Herissantia, besides {beta}-sitosterol, kaempferol 3-O-{beta}-D-(6''-E-p-coumaroil) (tiliroside) glucopyranoside and kaempferol 3,7-di-O-{alpha}-L-ramnopyranoside (lespedin), described for the first time in the species. The structural determination of the compounds was made by means of spectroscopy methods such as Infrared Spectroscopy, {sup 1}H and {sup 13}C Nuclear Magnetic Resonance, with the aid of two dimensional techniques, and by comparison with literature data. The toxicity activity of the MeOH extract and lespedin on Artemia salina Leach. was also carried out. (author)

  7. Interaction of Low Doses of Ionizing Radiation, Potassium Dichromate and Cadmium Chloride in Artemia franciscana Biotest

    K. Beňová

    2007-01-01

    Full Text Available The influence of cadmium chloride (at concentrations of 100 and 200 mg l-1 and potassium dichromate (at a concentration of 50 mg l-1 along with the effect of gamma radiation 60Co (at a dose of 10 and 50 Gy on lethality to Artemia franciscana was investigated. Four different interactions were studied, namely, those of potassium dichromate and gamma radiation, cadmium chloride and gamma radiation, and combinations of potassium dichromate and cadmium chloride in interaction with gamma radiation. A significant (α = 0.05 decrease was observed in lethality due to exposure to radiation (10 Gy in comparison with action of only potassium dichromate and cadmium chloride or their combination without exposure to gamma rays. These results support the theory of hormesis.

  8. Oxygen-rich hierarchical porous carbon derived from artemia cyst shells with superior electrochemical performance.

    Zhao, Yufeng; Ran, Wei; He, Jing; Song, Yanfang; Zhang, Chunming; Xiong, Ding-Bang; Gao, Faming; Wu, Jinsong; Xia, Yongyao

    2015-01-21

    In this study, three-dimensional (3D) hierarchical porous carbon with abundant functional groups is produced through a very simple low-cost carbonization of Artemia cyst shells. The unique hierarchical porous structure of this material, combining large numbers of micropores and macropores, as well as reasonable amount of mesopores, is proven favorable to capacitive behavior. The abundant oxygen functional groups from the natural carbon precursor contribute stable pseudocapacitance. As-prepared sample exhibits high specific capacitance (369 F g(-1) in 1 M H2SO4 and 349 F g(-1) in 6 M KOH), excellent cycling stability with capacitance retention of 100% over 10 000 cycles, and promising rate performance. This work not only describes a simple way to produce high-performance carbon electrode materials for practical application, but also inspires an idea for future structure design of porous carbon.

  9. The application of bioflocs technology to protect brine shrimp (Artemia franciscana) from pathogenic Vibrio harveyi.

    Crab, R; Lambert, A; Defoirdt, T; Bossier, P; Verstraete, W

    2010-11-01

    To study the potential biocontrol activity of bioflocs technology. Glycerol-grown bioflocs were investigated for their antimicrobial and antipathogenic properties against the opportunistic pathogen Vibrio harveyi. The bioflocs did not produce growth-inhibitory substances. However, bioflocs and biofloc supernatants decreased quorum sensing-regulated bioluminescence of V. harveyi. This suggested that the bioflocs had biocontrol activity against this pathogen because quorum sensing regulates virulence of vibrios towards different hosts. Interestingly, the addition of live bioflocs significantly increased the survival of gnotobiotic brine shrimp (Artemia franciscana) larvae challenged to V. harveyi. Bioflocs grown on glycerol as carbon source inhibit quorum sensing-regulated bioluminescence in V. harveyi and protect brine shrimp larvae from vibriosis. The results presented in this study indicate that in addition to water quality control and in situ feed production, bioflocs technology could help in controlling bacterial infections within the aquaculture pond. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  10. Preliminary results of the Artemia salina experiments in biostack on LDEF

    Graul, E.H.; Ruether, W.; Hiendl, C.O.

    1992-01-01

    The mosaic egg of the brine shrimp, Artemia salina, resting in blastula or gastrula state represents a system that during further development, proceeds without any further development to the larval stage, the free swimming nauplius. Therefore, injury to a single cell of the egg will be manifest in the larvae. In several experiments, it was shown that the passage of a single heavy ion through the shrimp egg damaged a cellular area large enough to disturb either embryogenesis or further development of the larvae, or the integrity of the adult individual. Emergence from the egg shell was heavily disturbed by the heavy ions as was hatching. Additional late effects, due to a hit by a heavy ion, are delayed of growth and of sexual maturity, and reduced fertility. Anomalies in the body and the extremities could be observed more frequently for the nauplii which had developed from eggs hit by heavy ions

  11. First secondary metabolites from Herissantia crispa L (Brizicky) and the toxicity activity against Artemia salina Leach

    Costa, Danielly Albuquerque da; Matias, Wemerson Neves; Lima, Igara Oliveira; Xavier, Aline Lira; Costa, Vivian Bruna Machado; Diniz, Margareth de Fatima Formiga Melo; Agra, Maria de Fatima; Batista, Leonia Maria; Souza, Maria de Fatima Vanderlei de; Silva, Davi Antas e

    2009-01-01

    The phytochemical investigation of Herissantia crispa led to the isolation of seven compounds, identified as: sitosterol 3-O-β-D-glucopyranoside, stigmasterol 3-O-β-D-glucopyranoside, 3,5,7,4'-tetrahydroxyflavone (kaempferol), 3,5,7,3',4'-pentahydroxyflavone (quercetin), unpublished in the genus Herissantia, besides β-sitosterol, kaempferol 3-O-β-D-(6''-E-p-coumaroil) (tiliroside) glucopyranoside and kaempferol 3,7-di-O-α-L-ramnopyranoside (lespedin), described for the first time in the species. The structural determination of the compounds was made by means of spectroscopy methods such as Infrared Spectroscopy, 1 H and 13 C Nuclear Magnetic Resonance, with the aid of two dimensional techniques, and by comparison with literature data. The toxicity activity of the MeOH extract and lespedin on Artemia salina Leach. was also carried out. (author)

  12. Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

    Carmen Gabaldón

    Full Text Available Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating. Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as

  13. Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

    Gabaldón, Carmen; Carmona, María José; Montero-Pau, Javier; Serra, Manuel

    2015-01-01

    Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating). Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as stabilizing

  14. Improvement of survival and development of Pacific white shrimp Litopenaeus vannamei larvae by feeding taurine enriched rotifers

    Dedi Jusadi

    2015-03-01

    Full Text Available ABSTRACTThe objective of the present experiment was to study the most optimum taurine enrichment concentration of rotifers in improving Pacific white shrimp larva Litopenaeus vannamei survival and development. White shrimp larvae at sixth naupliar stage were reared in 12 units of 500 L fibre glass tanks with a stocking density of 125 ind/L. Starting from zoea two stage (Z-2, the larva was provided with rotifers with different taurine enrichment concentration according to the treatments, i.e. 0 mg/L enrichment medium (A, 25 mg/L (B, 50 mg/L(C, and 100 mg/L (D. The results show that different taurine concentration in the enrichment media increased taurine level in rotifers. Furthermore, the administration of taurine enriched rotifers up to 50 mg/L significantly improved larval survival and may accelerate larval development. The experimental results also concluded that a concentration of 50 mg/L is the most optimum taurine enrichment concentration of rotifers for the improvement of white shrimp larval survival and developmental stage.Keywords: taurine, rotifer, white shrimp, enrichmentABSTRAKPenelitian ini bertujuan untuk mengkaji konsentrasi optimum taurin melalui pengayaan pada rotifera terhadap tingkat kelangsungan hidup dan perkembangan stadia larva udang vaname Litopenaeus vannamei. Larva udang vaname stadia naupli-6 dipelihara dalam 12 tangki fiberglass volume 500 L dengan kepadatan 125 ind/L. Dimulai sejak stadia zoea 2 (Z-2 larva diberi rotifera yang diperkaya dengan taurin dengan konsentrasi yang berbeda sesuai dengan perlakuan, yaitu 0 mg/L media pengkaya (A, 25 mg/L (B, 50mg/L (C, dan 100mg/L (D. Hasil penelitian menunjukkan pengayaan taurin pada konsentrasi yang berbeda menyebabkan peningkatan kandungan taurin rotifera. Sementara pemberian rotifera yang diperkaya taurin hingga 50 mg/L meningkatkan kelangsungan hidup dan mempercepat perkembangan stadia larva udang. Berdasarkan hasil penelitian ini dapat disimpulkan bahwa pemberian

  15. Involvement of cyclin K posttranscriptional regulation in the formation of Artemia diapause cysts.

    Yang Zhao

    Full Text Available BACKGROUND: Artemia eggs tend to develop ovoviviparously to yield nauplius larvae in good rearing conditions; while under adverse situations, they tend to develop oviparously and encysted diapause embryos are formed instead. However, the intrinsic mechanisms regulating this process are not well understood. PRINCIPAL FINDING: This study has characterized the function of cyclin K, a regulatory subunit of the positive transcription elongation factor b (P-TEFb in the two different developmental pathways of Artemia. In the diapause-destined embryo, Western blots showed that the cyclin K protein was down-regulated as the embryo entered dormancy and reverted to relatively high levels of expression once development resumed, consistent with the fluctuations in phosphorylation of position 2 serines (Ser2 in the C-terminal domain (CTD of the largest subunit (Rpb1 of RNA polymerase II (RNAP II. Interestingly, the cyclin K transcript levels remained constant during this process. In vitro translation data indicated that the template activity of cyclin K mRNA stored in the postdiapause cyst was repressed. In addition, in vivo knockdown of cyclin K in developing embryos by RNA interference eliminated phosphorylation of the CTD Ser2 of RNAP II and induced apoptosis by inhibiting the extracellular signal-regulated kinase (ERK survival signaling pathway. CONCLUSIONS/SIGNIFICANCE: Taken together, these findings reveal a role for cyclin K in regulating RNAP II activity during diapause embryo development, which involves the post-transcriptional regulation of cyclin K. In addition, a further role was identified for cyclin K in regulating the control of cell survival during embryogenesis through ERK signaling pathways.

  16. Alternative mitochondrial respiratory chains from two crustaceans: Artemia franciscana nauplii and the white shrimp, Litopenaeus vannamei.

    Rodriguez-Armenta, Chrystian; Uribe-Carvajal, Salvador; Rosas-Lemus, Monica; Chiquete-Felix, Natalia; Huerta-Ocampo, Jose Angel; Muhlia-Almazan, Adriana

    2018-04-01

    Mitochondrial ATP is synthesized by coupling between the electron transport chain and complex V. In contrast, physiological uncoupling of these processes allows mitochondria to consume oxygen at high rates without ATP synthesis. Such uncoupling mechanisms prevent reactive oxygen species overproduction. One of these mechanisms are the alternative redox enzymes from the mitochondrial respiratory chain, which may help cells to maintain homeostasis under stress independently of ATP synthesis. To date, no reports have been published on alternative redox enzymes in crustaceans mitochondria. Specific inhibitors were used to identify alternative redox enzymes in mitochondria isolated from Artemia franciscana nauplii, and the white shrimp, Litopenaeus vannamei. We report the presence of two alternative redox enzymes in the respiratory chain of A. franciscana nauplii, whose isolated mitochondria used glycerol-3-phosphate as a substrate, suggesting the existence of a glycerol-3-phosphate dehydrogenase. In addition, cyanide and octyl-gallate were necessary to fully inhibit this species' mitochondrial oxygen consumption, suggesting an alternative oxidase is present. The in-gel activity analysis confirmed that additional mitochondrial redox proteins exist in A. franciscana. A mitochondrial glycerol-3-phosphate dehydrogenase oxidase was identified by protein sequencing as part of a branched respiratory chain, and an alternative oxidase was also identified in this species by western blot. These results indicate different adaptive mechanisms from artemia to face environmental challenges related to the changing levels of oxygen concentration in seawater through their life cycles. No alternative redox enzymes were found in shrimp mitochondria, further efforts will determine the existence of an uncoupling mechanism such as uncoupling proteins.

  17. Feeding adult of Artemia salina (Crustacea-Branchiopoda on the dinoflagellate Gyrodinium corsicum (Gymnodiniales and the Chryptophyta Rhodomonas baltica

    Rauquírio André Albuquerque Marinho da Costa

    2005-07-01

    Full Text Available Experiments were carried out on feeding performance and survival rates of adult Artemia salina exposed to no axenic strains of the dinoflagellate Gyrodinium corsicum and of the Chryptophyta Rhodomonas baltica. Filtration rates on R. baltica and G. corsicum varied from 3.35 to 7.14 ml.artemia-1.h-1 and from 2.97 to 15.86 ml.artemia-1.h-1, respectively. The ingestion rates observed for A. salina did not indicate any digestive dysfunction or physiological impairment for organisms fed on G. corsicum and their functional response were similar to those observed for other organisms like copepod fed on different food concentrations. Mortality rates oscillated from 2.5% to 100% when A. salina was fed on R. baltica or G. corsicum, respectively. Highest mortality rates observed for organisms fed on G. corsicum indicated that this dinoflagellate presented a hazard effect on A. salina that was not possible to confirm if it was related to toxin production or to nutritive inadequacy of this dinoflagellate as food for organisms of this species.Experimentos foram desenvolvidos para estudar as taxas de alimentação e de sobrevivência de Artemia salina alimentada com cepas não tóxicas do dinoflagelado Gyrodinium corsicum e da Chryptophyta Rhodomonas baltica. As taxas de filtração sobre R. baltica e G. corsicum variaram entre 3,35 e 7,14 ml.artemia-1.h-1 e 2,97 e 15,86 ml.artemia-1.h-, respectivamente. As taxas de ingestão observadas para A. salina não indicaram disfunção digestiva ou prejuízo fisiológico nos organismos alimentados com G. corsicum, sendo a resposta funcional destes organismos similar a observada em copépodos alimentados com diferentes concentrações de alimento. As taxas de mortalidade de A. salina oscilaram entre 2,5 e 100% quando alimentada com R. baltica e G. corsicum, respectivamente. As maiores taxas de mortalidade observadas para os organismos alimentados com G. corsicum indicam que este dinoflagelado apresenta algum efeito

  18. Assessment of microalgae-influenced biodeterioration of concrete ...

    The aim of this study was to isolate microalga involved in the biodeterioration of concrete structures. The growth of algae was monitored between day 1 and 18 using a spectrophotometer (Spectronic 721 model) at varying pH (4.2 and 9.4). To identify the microalgae, aliquots of the isolates was placed on microscope slides ...

  19. Novel protocol for lutein extraction from microalga Chlorella vulgaris

    D'Este, Martina; De Francisci, Davide; Angelidaki, Irini

    2017-01-01

    Lutein is a pigment generally extracted from marigold flowers. However, lutein is also found in considerable amounts in microalgae. In this study a novel method was developed to improve the extraction efficiency of lutein from microalga C. vulgaris. Differently from conventional methods, ethanol...

  20. Chemical Profiles of Microalgae with Emphasis on Lipids: Final Report

    Benemann, J. R.; Tillett, D. M.; Suen, Y.; Hubbard, J.; Tornabene, T. G.

    1986-02-01

    This final report details progress during the third year of this subcontract. The overall objective of this subcontract was two fold: to provide the analytical capability required for selecting microalgae strains with high energy contents and to develop fundamental knowledge required for optimizing the energy yield from microalgae cultures. The progress made towards these objectives during this year is detailed in this report.

  1. Techno-economical evaluation of protein extraction for microalgae biorefinery

    Sari, Y.W.; Sanders, J.P.M.; Bruins, M.

    2016-01-01

    Due to scarcity of fossil feedstocks, there is an increasing demand for biobased fuels. Microalgae are considered as promising biobased feedstocks. However, microalgae based fuels are not yet produced at large scale at present. Applying biorefinery, not only for oil, but also for other

  2. A mathematical model of microalgae growth in cylindrical photobioreactor

    Bakeri, Noorhadila Mohd; Jamaian, Siti Suhana

    2017-08-01

    Microalgae are unicellular organisms, which exist individually or in chains or groups but can be utilized in many applications. Researchers have done various efforts in order to increase the growth rate of microalgae. Microalgae have a potential as an effective tool for wastewater treatment, besides as a replacement for natural fuel such as coal and biodiesel. The growth of microalgae can be estimated by using Geider model, which this model is based on photosynthesis irradiance curve (PI-curve) and focused on flat panel photobioreactor. Therefore, in this study a mathematical model for microalgae growth in cylindrical photobioreactor is proposed based on the Geider model. The light irradiance is the crucial part that affects the growth rate of microalgae. The absorbed photon flux will be determined by calculating the average light irradiance in a cylindrical system illuminated by unidirectional parallel flux and considering the cylinder as a collection of differential parallelepipeds. Results from this study showed that the specific growth rate of microalgae increases until the constant level is achieved. Therefore, the proposed mathematical model can be used to estimate the rate of microalgae growth in cylindrical photobioreactor.

  3. Whole-mount in situ hybridization in the rotifer Brachionus plicatilis representing a basal branch of lophotrochozoans.

    Boell, Louis A; Bucher, Gregor

    2008-08-01

    In order to broaden the comparative scope of evolutionary developmental biology and to refine our picture of animal macroevolution, it is necessary to establish new model organisms, especially from previously underrepresented groups, like the Lophotrochozoa. We have established the culture and protocols for molecular developmental biology in the rotifer species Brachionus plicatilis Müller (Rotifera, Monogononta). Rotifers are nonsegmented animals with enigmatic basal position within the lophotrochozoans and marked by several evolutionary novelties like the wheel organ (corona), the median eye, and the nonpaired posterior foot. The expression of Bp-Pax-6 is shown using whole-mount in situ hybridization. The inexpensive easy culture and experimental tractability of Brachionus as well as the range of interesting questions to which it holds the key make it a promising addition to the "zoo" of evo-devo model organisms.

  4. Prospecção fitoquímica de Sonchus oleraceus e sua toxicidade sobre o microcrustáceo Artemia salina Phytochemical prospecting of Sonchus oleraceus and its toxicity to Artemia salina

    J.M. Lima

    2009-03-01

    Full Text Available A espécie vegetal Sonchus oleraceus é uma planta daninha presente em diversas culturas no Brasil e de utilização na medicina popular. Neste trabalho, realizou-se a prospecção fitoquímica dessa espécie com extratos em etanol, água e diclorometano, bem como testes de toxicidade sobre o microcrustáceo Artemia salina. O extrato aquoso apresentou em sua composição açúcares redutores, compostos fenólicos, taninos, flavonóides e cumarinas. No extrato etanólico, observaram-se os mesmos compostos qualificados no extrato aquoso, com exceção de cumarinas. Em diclorometano, verificou se a presença de saponinas, derivados triterpênicos e esteróides. No teste de toxicidade sobre Artemia salina, os dados convergiram para frações de extrato aquoso de 5.117,2 ppm, indicando ser um extrato de baixa toxicidade.Sonchus oleraceus is a common weed in Brazil, also used as a medicinal plant. Phytochemical prospecting of this species was carried out in this work using extracts obtained in ethanol, water and dichloromethane. A toxicity study of the aqueous extract was also conducted, using the micro crustaceous Artemia salina. The aqueous extract presented sugar reducers, phenolic compounds, tannins, flavonoids and coumarins in its composition. The compounds found in the aqueous extract were also detected in the ethanol extract, except for the coumarins. Saponin, triterpenes and steroids were identified in the dichloromethane extract. The toxicity test on Artemia salina pointed to aqueous extract fractions of 5,117.2 ppm, indicative of low toxicity.

  5. Results on artemia cysts, lettuce and tobacco seeds in the Biobloc 4 experiment flown aboard the Soviet biosatellite Cosmos 1129

    Gaubin, Y.; Planel, H.; Gasset, G.; Pianezzi, B.

    1983-01-01

    The effects of space flight factors, in particular the heavy ion component of cosmic rays, on dormant stages of life forms were investigated as part of the Biobloc 4 experiment flown aboard the Cosmos 1129 biosatellite. Artemia cysts and seeds of tobacco and lettuce plants were placed in tubes and in monolayers sandwiched between layers of visual particle track detectors. Although Artemia cysts exposed in the dry state did not differ from ground controls, hydrated cysts exhibited a slight decrease in hatchability and reduced (C-14)O2 incorporation and protein and nucleic acid synthesis. For cysts held in the monolayers, hits by HZE particles were observed to stimulate emergence, hatching and survival. Higher proportions of chromosomal aberrations were found in lettuce seeds hit by HZE particles, while space flight produced a stimulatory effect on both germination rate and abnormality frequency in both hit and nonhit tobacco seeds. 9 references

  6. Characterization of PHB1 and its role in mitochondrial maturation and yolk platelet degradation during development of Artemia embryos.

    Xiang Ye

    Full Text Available BACKGROUND: To cope with harsh environments, crustaceans such as Artemia produce diapause gastrula embryos (cysts with suppressed metabolism. Metabolism and development resume during post-diapause development, but the mechanism behind these cellular events remains largely unknown. PRINCIPAL FINDING: Our study investigated the role of prohibitin 1 (PHB1 in metabolic reinitiation during post-diapause development. We found that PHB1 was developmentally regulated via changes in phosphorylation status and localization. Results from RNA interference experiments demonstrated PHB1 to be critical for mitochondrial maturation and yolk degradation during development. In addition, PHB1 was present in yolk platelets, and it underwent ubiquitin-mediated degradation during the proteolysis of yolk protein. CONCLUSIONS/SIGNIFICANCE: PHB1 has an indispensable role in coordinating mitochondrial maturation and yolk platelet degradation during development in Artemia. This novel function of PHB1 provides new clues to comprehend the roles of PHB1 in metabolism and development.

  7. Rotifer assemblages (Rotifera: Eurotatoria of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India

    Bhushan Kumar Sharma

    2014-12-01

    Full Text Available Our plankton and semi-plankton collections from twelve floodplain lakes (beels of Majuli River Island, Upper Assam reveal 124 rotifer species (32 genera and 17 families; these merit biodiversity value as ~52.0% and ~30.0% of species, ~68.0 and ~45.0% of  genera and ~74.0 and ~65.0% of the families of the Phylum known from northeast India (NEI and India, respectively. Two species are new to India with Trichocerca uncinata as new record to the Oriental region.  Eleven species are new to the study area and we provide an updated list (144 species for following meta-analyses of Majuli Rotifera. Biogeographically important elements include one Australasian, four Oriental, four Palaeotropical and one cosmo (sub tropical species while several species are of regional distribution interest. The rotifer fauna is predominantly tropical and Lecanidae > Lepadellidae collectively include ~53.0% species but it records paucity of Brachionus species. Individual beels record total richness of 60-100 (77 ± 12 species, monthly richness between 24 ± 7-34 ± 7 species and maximum up to 54 species/sample. The results are characterized by high community similarities (59.7-90.4% vide Sørensen’s index, more rotifer homogeneity amongst beels, lack of any pattern of temporal richness variations and much limited influence of abiotic parameters.

  8. Seasonal variations of rotifers from a high altitude urban shallow water body, La Cantera Oriente (Mexico City, Mexico)

    Gutiérrez, Sergio González; Sarma, S. S. S.; Nandini, S.

    2017-11-01

    La Cantera Oriente is a shallow freshwater volcanic water body located at an altitude of 2 270 m above sea level in the Ecological Reserve of San Angel Pedregal of Mexico City (Mexico). In order to ensure the conservation of its biological heritage including zooplankton, the present work was undertaken to quantify the seasonal changes in the diversity and density of rotifers and the selected physico-chemical variables during 2013-2014. Qualitative analysis of the zooplankton samples yielded 68 rotifer species which represented 24 genera in 15 families. B rachionus calyciflorus Pallas, 1766, B. quadridentatus Hermann, 1783, Polyarthra vulgaris Carlin, 1943, Lecane closterocerca (Schmarda, 1859) and Keratella cochlearis (Gosse, 1851) were the most common species. Preston plots of species frequency-density revealed that as many as 30% of the rotifer taxa were dominant throughout the year. The species with high population densities were Brachionus quadridentatus, Lecane closterocerca, Keratella cochlearis, and Lepadella patella; their peak densities were 2 000, 1 000, 180 and 90 ind./L, all occurring in summer. Canonical correspondence analysis showed that Platyias quadricornis was related to the concentration of phosphates available in the environment and the conductivity, while B. quadridentatus was positively correlated with chlorophyll- a. The trophic status of the lake was eutrophic based on Chl- a content but oligotrophic with relation to the Brachionus: Trichocerca ratio.

  9. Multiple γ-glutamylation: A novel type of post-translational modification in a diapausing Artemia cyst protein

    Hasegawa, Mai; Ikeda, Yuka; Kanzawa, Hideaki; Sakamoto, Mika; Goto, Mina; Tsunasawa, Susumu; Uchiumi, Toshio; Odani, Shoji

    2010-01-01

    A highly hydrophilic, glutamate-rich protein was identified in the aqueous phenol extract from the cytosolic fraction of brine shrimp (Artemia franciscana) diapausing cysts and termed Artemia phenol soluble protein (PSP). Mass spectrometric analysis revealed the presence of many protein peaks around m/z 11,000, separated by 129 atomic mass units; this value corresponds to that of glutamate, which is strongly suggestive of heterogeneous polyglutamylation. Polyglutamylation has long been known as the functionally important post-translational modification of tubulins, which carry poly(L-glutamic acid) chains of heterogeneous length branching off from the main chain at the γ-carboxy groups of a few specific glutamate residues. In Artemia PSP, however, Edman degradation of enzymatic peptides revealed that at least 13, and presumably 16, glutamate residues were modified by the attachment of a single L-glutamate, representing a hitherto undescribed type of post-translational modification: namely, multiple γ-glutamylation or the addition of a large number of glutamate residues along the polypeptide chain. Although biological significance of PSP and its modification is yet to be established, suppression of in vitro thermal aggregation of lactate dehydrogenase by glutamylated PSP was observed.

  10. Microalgae for Bioenergy; Key Technology Nodes

    Maléterová, Ywetta; Kaštánek, František; Rousková, Milena; Matějková, Martina; Kaštánek, P.; Šolcová, Olga

    2015-01-01

    Roč. 2015, č. 2015 (2015), s. 597618 ISSN 1537-744X R&D Projects: GA MŠk LJ12002 Institutional support: RVO:67985858 Keywords : microalgae * oil production * water recycling Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.219, year: 2013 http://apps.webofknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=14&SID=V2kH1WLyceq9ctvzW8I&page=1&doc=1

  11. Towards Sustainable Production of Biofuels from Microalgae

    Hans Ragnar Giselrød

    2008-07-01

    Full Text Available Renewable and carbon neutral biofuels are necessary for environmental and economic sustainability. The viability of the first generation biofuels production is however questionable because of the conflict with food supply. Microalgal biofuels are a viable alternative. The oil productivity of many microalgae exceeds the best producing oil crops. This paper aims to analyze and promote integration approaches for sustainable microalgal biofuel production to meet the energy and environmental needs of the society. The emphasis is on hydrothermal liquefaction technology for direct conversion of algal biomass to liquid fuel.

  12. Coadaptation: lessons from the brine shrimp Artemia, "the aquatic Drosophila" (Crustacea; Anostraca Coadaptación: lecciones desde el camarón de salmuera Artemia, "la Drosophila acuática" (Crustacea; Anostraca

    GONZALO GAJARDO

    2001-03-01

    Full Text Available During the fifties Brncic and the Dobzhansky's school, using the fruit fly Drosophila as a test organism, introduced the term integration of the genotype, or genetic coadaptation, which has had great impact on thinking in today's evolutionary biology. In this work we use the brine shrimp Artemia - in many respects a sort of aquatic Drosophila- as a model organism to evaluate the relationship between population structure, potential for divergence and the degree of morphological and/or genetic change. These aspects, tightly linked with the organization of the genotype, are important to understanding how recombination and adaptive release of genetic and phenotypic variation affect the speciation process in Artemia. Analysis of genetic (allozyme, diploid and chromocentre numbers, morphological (Mahalanobis distances and reproductive data (cross-fertility tests available for populations of the bisexual, endemic species of the Americas, Artemia franciscana and A. persimilis, indicate that: (i A. franciscana and A. persimilis are morphologically distinct in correspondence with observed genetic differences (D Nei > 1; 2n = 42 and 44; 12.5 and 1.5 mean chromocentre numbers, respectively; (ii populations from Chile and other South American localities (mainly A. franciscana display high levels of genetic variability and a trend to develop large genetic distances between populations; (iii the plasticity of Artemia gene pool is associated, at least in part, with ecological heterogeneity. Hence an adaptive divergence mode is thought to best define the speciation process in Artemia; (iv the succesful production of laboratory hybrids in the allopatric Artemia populations studied in the Americas, a feature seen in other anostracods, could be explained by the fact that formerly allopatric populations have not achieved later sympatry, as required by the allopatric speciation paradigmEn los años cincuenta Brncic y la escuela de Dobzhansky introdujeron el t

  13. Toxicity and trophic transfer of P25 TiO2 NPs from Dunaliella salina to Artemia salina: Effect of dietary and waterborne exposure.

    Bhuvaneshwari, M; Thiagarajan, Vignesh; Nemade, Prateek; Chandrasekaran, N; Mukherjee, Amitava

    2018-01-01

    The recent increase in nanoparticle (P25 TiO 2 NPs) usage has led to concerns regarding their potential implications on environment and human health. The food chain is the central pathway for nanoparticle transfer from lower to high trophic level organisms. The current study relies on the investigation of toxicity and trophic transfer potential of TiO 2 NPs from marine algae Dunaliella salina to marine crustacean Artemia salina. Toxicity was measured in two different modes of exposure such as waterborne (exposure of TiO 2 NPs to Artemia) and dietary exposure (NP-accumulated algal cells are used to feed the Artemia). The toxicity and accumulation of TiO 2 NPs in marine algae D. salina were also studied. Artemia was found to be more sensitive to TiO 2 NPs (48h LC 50 of 4.21mgL -1 ) as compared to marine algae, D. salina (48h LC 50 of 11.35mgL -1 ). The toxicity, uptake, and accumulation of TiO 2 NPs were observed to be more in waterborne exposure as compared to dietary exposure. Waterborne exposure seemed to cause higher ROS production and antioxidant enzyme (SOD and CAT) activity as compared to dietary exposure of TiO 2 NPs in Artemia. There were no observed biomagnification (BMF) and trophic transfer from algae to Artemia through dietary exposure. Histopathological studies confirmed the morphological and internal damages in Artemia. This study reiterates the possible effects of the different modes of exposure on trophic transfer potential of TiO 2 NPs and eventually the consequences on aquatic environment. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Photobioreactor cultivation strategies for microalgae and cyanobacteria.

    Johnson, Tylor J; Katuwal, Sarmila; Anderson, Gary A; Gu, Liping; Zhou, Ruanbao; Gibbons, William R

    2018-03-08

    The current burden on fossil-derived chemicals and fuels combined with the rapidly increasing global population has led to a crucial need to develop renewable and sustainable sources of chemicals and biofuels. Photoautotrophic microorganisms, including cyanobacteria and microalgae, have garnered a great deal of attention for their capability to produce these chemicals from carbon dioxide, mineralized water, and solar energy. While there have been substantial amounts of research directed at scaling-up production from these microorganisms, several factors have proven difficult to overcome, including high costs associated with cultivation, photobioreactor construction, and artificial lighting. Decreasing these costs will substantially increase the economic feasibility of these production processes. Thus, the purpose of this review is to describe various photobioreactor designs, and then provide an overview on lighting systems, mixing, gas transfer, and the hydrodynamics of bubbles. These factors must be considered when the goal of a production process is economic feasibility. Targets for improving microalgae and cyanobacteria cultivation media, including water reduction strategies will also be described. As fossil fuel reserves continue to be depleted and the world population continues to increase, it is imperative that renewable chemical and biofuel production processes be developed toward becoming economically feasible. Thus, it is essential that future research is directed toward improving these processes. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

  15. Emergent Sources of Prebiotics: Seaweeds and Microalgae.

    de Jesus Raposo, Maria Filomena; de Morais, Alcina Maria Miranda Bernardo; de Morais, Rui Manuel Santos Costa

    2016-01-28

    In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS) or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen.

  16. Emergent Sources of Prebiotics: Seaweeds and Microalgae

    Maria Filomena de Jesus Raposo

    2016-01-01

    Full Text Available In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen.

  17. Electrokinetically controlled fluid injection into unicellular microalgae.

    Zhou, Xuewen; Zhang, Xixi; Boualavong, Jonathan; Durney, Andrew R; Wang, Tonghui; Kirschner, Scott; Wentz, Michaela; Mukaibo, Hitomi

    2017-10-01

    Electrokinetically controlled microinjection is reported as an effective transport mechanism for microinjection into the wild-type strain of the widely studied model microalga Chlamydomonas reinhardtii. A microinjection system using glass capillary pipettes was developed to capture and impale the motile cells. To apply an electric field and induce electrokinetic flow (e.g., electrophoresis and electroosmosis), an electrode was inserted directly into the solution inside the impaling injection pipette and another electrode was inserted into the external cell media. The viability of the impaled cells was confirmed for more than an hour under 0.01 V using the fluorescein diacetate/propidium iodide dual fluorescent dye based assay. The viability was also found to increase almost logarithmically with decreasing voltage and to depend strongly on the solution within the injection pipette. Successful electrokinetic microinjection into cells was confirmed by both an increase in cell volume under an applied voltage and electric field dependent delivery of fluorescent fluorescein molecules into an impaled cell. Our study offers novel opportunities for quantitative delivery of biomolecules into microalgae and advancing the research and development of these organisms as biosynthetic factories. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Heterotrophic cultivation of microalgae for production of biodiesel.

    Mohamed, Mohd Shamzi; Wei, Lai Zee; Ariff, Arbakariya B

    2011-08-01

    High cell density cultivation of microalgae via heterotrophic growth mechanism could effectively address the issues of low productivity and operational constraints presently affecting the solar driven biodiesel production. This paper reviews the progress made so far in the development of commercial-scale heterotrophic microalgae cultivation processes. The review also discusses on patentable concepts and innovations disclosed in the past four years with regards to new approaches to microalgal cultivation technique, improvisation on the process flow designs to economically produced biodiesel and genetic manipulation to confer desirable traits leading to much valued high lipid-bearing microalgae strains.

  19. The impact assessment of anticancer drug imatinib on the feeding behavior of rotifers with an integrated perspective: Exposure, post-exposure and re-exposure.

    Yan, Zhengyu; Yan, Kun; He, Xingliang; Liu, Yanhua; Zhang, Jie; Lopez Torres, Oscar; Guo, Ruixin; Chen, Jianqiu

    2017-10-01

    The anticancer drugs are getting increasing attention as an emerging contaminant in the aquatic environments. In the present study, feeding behavior of the rotifer Brachionus calyciflorus under the impact of anticancer drug imatinib was evaluated. Traditional toxicological studies usually focus on dose-effect relationship at a given exposure time, while ignore the possible impact after the exposure. Thus, how the impact varied in the post-exposure and re-exposure was also considered in the present study. The feeding depression of the rotifers was attributed to the increased concentration of imatinib. Although the filtration and ingestion rate of the rotifers recovered to a certain extent after the exposure, the significant feeding inhibition still persisted even if the exposure was ended. In the re-exposure period, the feeding behavior was less depressed than those of the exposure period, which implied that rotifers might develop a tolerance to the same toxics. The activities of acetylcholine esterase (AchE) and the levels of reactive oxygen species (ROS) in rotifers were also detected. Imatinib inhibited the activities of AchE in the exposure and re-exposure while ROS levels increased significantly in the re-exposure period. Our present study provided an integrated assessment the potential environmental risks of imatinib at a new perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    Pablo Mayorga; Karen R. Pérez; Sully M. Cruz; Armando Cáceres

    2010-01-01

    Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest) and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest), were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq.) Kunth ex ...

  1. The impact of impoundment on the rotifer communities in two tropical floodplain environments: interannual pulse variations

    CC. Bonecker

    Full Text Available Hydrological pulses are the main factor regulating the structure of biological communities in floodplains. Reservoirs above this ecosystem change the environment's dynamics and the community's biodiversity. This study evaluated the structure and stability of the rotifer community in response to changes in hydrological pulses after the Porto Primavera impoundment in the Upper Paraná River floodplain. The community was studied in a river and in a floodplain lake downstream of the dam over a four-year period before and after the impoundment. A decrease in species richness and abundance was observed soon after the impoundment, followed by an increase in these attributes and in specific diversity when the hydrometric level of the Paraná River rose and, consequently, increased the connectivity between the floodplain environments. Conochilus coenobasis, Filinia longiseta, Keratella cochlearis, Lecane proiecta and Polyarthra dolichoptera persisted throughout the study and contributed to community stability (the maintenance of rank in species abundance over time, which was high in the floodplain lake, mainly after the impoundment. Reductions in the frequency, intensity and amplitude of potamophase pulses after the impoundment led to the decrease in species richness and the increases in abundance, community stability, and species diversity, which determine community resilience.

  2. Réflexions sur les rotifères en tant qu'indicateurs biologiques

    POURRIOT R.

    1976-01-01

    Full Text Available Quelques espèces de Rotifères fournissent un bon exemple d'indicateurs écologiques pour un facteur limitant : Synchaeta lakowitziana, Conochitoides natans, Notholca spp (température, Brachionus plicatilis (salinité. Le système d'indexation des espèces à la qualité des eaux est discuté. Les espèces strictement édaphiques (non aquatiques, les espèces rares appartenant à des genres où la variabilité est grande et les espèces euryoecques, peu caractéristiques, devraient être exclues des listes d'indicateurs établies par SLADECEK (1973, car elles ne facilitent pas l'application de ce système. Il s'avère nécessaire d'améliorer le poids indicatif et la valeur de saprobité des espèces, de ne conserver que les plus caractéristiques par leur constance et leur fidélité. Il serait, de plus, intéressant de se référer à des index plus dynamiques que statiques.

  3. Complete mitochondrial genome of the monogonont rotifer, Brachionus koreanus (Rotifera, Brachionidae).

    Hwang, Dae-Sik; Suga, Koushirou; Sakakura, Yoshitaka; Park, Heum Gi; Hagiwara, Atsushi; Rhee, Jae-Sung; Lee, Jae-Seong

    2014-02-01

    The complete mitochondrial genome was obtained from the assembled genome data sequenced by next generation sequencing (NGS) technology from the monogonont rotifer Brachionus koreanus. The mitochondrial genome of B. koreanus was composed of two circular chromosomes designated as mtDNA-I (10,421 bp) and mtDNA-II (11,923 bp). The gene contents of B. koreanus were identical with previously reported B. plicatilis mitochondrial genomes. However, gene orders of B. koreanus showed one rearrangement between the two species. Of 12 protein-coding genes (PCGs), 3 genes (ATP6, ND1, and ND3) had an incomplete stop codon. The A + T base composition of B. koreanus mitochondrial genome was high (68.81%). They also showed anti-G bias (12.03% and 10.97%) on the second and third position of PCGs as well as slight anti-C bias (15.96% and 14.31%) on the first and third position of PCGs.

  4. Influence of salinity and dissolved organic carbon on acute Cu toxicity to the rotifer Brachionus plicatilis.

    Cooper, Christopher A; Tait, Tara; Gray, Holly; Cimprich, Giselle; Santore, Robert C; McGeer, James C; Wood, Christopher M; Smith, D Scott

    2014-01-21

    Acute copper (Cu) toxicity tests (48-h LC50) using the euryhaline rotifer Brachionus plicatilis were performed to assess the effects of salinity (3, 16, 30 ppt) and dissolved organic carbon (DOC, ∼ 1.1, ∼ 3.1, ∼ 4.9, ∼ 13.6 mg C L(-1)) on Cu bioavailability. Total Cu was measured using anodic stripping voltammetry, and free Cu(2+) was measured using ion-selective electrodes. There was a protective effect of salinity observed in all but the highest DOC concentrations; at all other DOC concentrations the LC50 value was significantly higher at 30 ppt than at 3 ppt. At all salinities, DOC complexation significantly reduced Cu toxicity. At higher concentrations of DOC the protective effect increased, but the increase was less than expected from a linear extrapolation of the trend observed at lower concentrations, and the deviation from linearity was greatest at the highest salinity. Light-scattering data indicated that salt induced colloid formation of DOC could be occurring under these conditions, thereby decreasing the number of available reactive sites to complex Cu. When measurements of free Cu across DOC concentrations at each individual salinity were compared, values were very similar, even though the total Cu LC50 values and DOC concentrations varied considerably. Furthermore, measured free Cu values and predicted model values were comparable, highlighting the important link between the concentration of bioavailable free Cu and Cu toxicity.

  5. Use of rotifers for the maintenance of monoalgal mass cultures of Spirulina

    Mitchell, S.A.; Richmond, A.

    1987-01-01

    Zooplankton was successfully used for the biological control of unicellular algal contaminants in Spirulina mass cultures even under conditions adverse to the growth of Spirulina (maximal winter daily temperature of approximately 10 degrees C and very low bicarbonate concentration). Brachionus plicatilis (Rotifera) was the most successful species of zooplankton used. The interrelationships between Spirulina, green unicellular contaminant, and B. plicatilis were studied under various conditions. Two species of unicellular contaminant were used; Monoraphidium minutum was isolated from local cultures and Chlorella vulgaris, obtained from contaminated Spirulina cultures in Israel. The rotifer B. plicatilis successfully controlled the population size of both contaminants whether they were introduced in a single addition or as a daily dose. The biological control of the unicellular contaminants allows Spirulina to be cultured in a medium low in bicarbonate, thereby reducing the cost of the medium and increasing the quantity of CO2 that may be freely absorbed from the atmosphere at the optimal pH for Spirulina cultivation. (Refs. 9).

  6. Vibrio rotiferianus sp. nov., isolated from cultures of the rotifer Brachionus plicatilis.

    Gomez-Gil, B; Thompson, F L; Thompson, C C; Swings, J

    2003-01-01

    Five Gram-negative bacterial strains, oxidase-positive, motile by means of more than one polar flagella, facultative anaerobe, arginine dihydrolase-negative, lysine- and omithine decarboxylase-positive, sensitive to the vibriostatic agent O/129, were isolated from a flow-through rotifer culture system in Gent, Belgium, and previously characterized by fluorescent amplified fragment length polymorphism. Comparison of the 16S rDNA sequence of strain LMG 21460T indicated close relationships (approximately 99% similarity) to Vibrio campbellii, Vibrio harveyi, Vibrio alginolyticus and Vibrio parahaemolyticus. However, DNA hybridization experiments revealed similarity values below 70% with its closest species V. campbellii and V. harveyi. Additionally, the analysed strains differ from related Vibrio species by the utilization of melibiose and production of acid from L-arabinose and amygdalin. Among the strains analysed, differences were observed in some phenotypic characters, particularly susceptibility to ampicillin, polymyxin B and amikacin, and urease activity. The major fatty acids identified were 16:0, 18:1 omega7c, 14:0, 12:0 3-OH and 18:0. Vibrio rotiferianus sp. nov. is proposed, with type strain LMG 21460T (=CAIM 577T); it has a DNA G+C content of 44.5 +/- 0.01 mol%.

  7. Characterization of Satellite DNA Sequences from the Commercially Important Marine Rotifers Brachionus rotundiformis and Brachionus plicatilis.

    Boehm; Gibson; Lubzens

    2000-01-01

    This study was initiated to search for species-specific and strain-specific satellite DNA sequences for which oligonucleotide primers could be designed to differentiate between various commercially important strains of the marine monogonont rotifers Brachionus rotundiformis and Brachionus plicatilis. Two unrelated, highly reiterated satellite sequences were cloned and characterized. The eight sequenced monomers from B. rotundiformis and six from B. plicatilis had low intrarepeat variability and were similar in their overall lengths, A + T compositions, and high degrees of repeated motif substructure. However, hybridizations to 19 representative strains, sequence characterizations, and GenBank searches indicated that these two satellites are morphotype-specific and population-specific, respectively, and share little homology to each other or to other characterized sequences in the database. Primer pairs designed for the B. rotundiformis satellite confirmed hybridization specificities on polymerase chain reaction and could serve as a useful molecular diagnostic tool to identify strains belonging to the SS morphotype, which are gaining widespread usage as first feeds for marine fish in commercial production.

  8. Environmental and endogenous control of sexuality in a rotifer life cycle: developmental and population biology.

    Gilbert, John J

    2003-01-01

    Induction of mictic females, and hence initiation of sexuality, in the life cycle of some Brachionus requires an environmental stimulus associated with crowding. The inducing stimulus appears to be a taxonomically specific chemical released into the environment by the rotifers. Oocytes are induced to develop into mictic females before they are oviposited by their amictic mothers and begin cleavage divisions. Thus, the inducer affects the oocyte in the maternal body cavity either directly or indirectly by altering the physiology of its mother. The level of sexual reproduction expressed in populations of a Florida strain of B. calyciflorus is controlled by two types of endogenous factors and by the degree of crowding. First, some fraction of genetically identical oocytes in a clonal population fails to respond to even extreme crowding conditions, thus ensuring some potential for continued population growth by female parthenogenesis. Second, the propensity of amictic females to produce mictic daughters is extremely low when they hatch from fertilized resting eggs and then gradually increases to an asymptote after about 12 parthenogenetic generations. This multigenerational parental effect likely is due to a cytoplasmic factor in fertilized eggs that inhibits expression of the mictic-female phenotype and that is gradually diluted in successive parthenogenetic generations. The effect may increase a clone's genetic contribution to the resting-egg bank by increasing its population size through parthenogenetic generations before mictic females are induced.

  9. Interference from ordinarily used solvents in the outcomes of Artemia salina lethality test

    Sahgal Geethaa

    2013-01-01

    Full Text Available Methanol, ethanol, Tween 20 and dimethyl sulfoxide (DMSO are widely used as dissolving agents in Artemia salina lethality test (aka brine shrimp lethality test [BSLT] to screen the pharmaceutical properties of natural products. Nevertheless, there is lack of toxicity level of these solvents against brine shrimp. High concentration of these organic solvent might be toxic for this zoology invertebrate and interfere in the experimental outcomes. To avoid this, permissible concentration of the solvents used in BSLT was identified. BSLT was performed to evaluate the toxicity effect of Tween 20, methanol, ethanol and DMSO at 24 h post-treatment time point against A. salina. The suggested maximum working concentration (v/v for DMSO, methanol, ethanol was found to be 1.25% and that for Tween 20 was 0.16%. LC 50 for the solvents were 8.5% (DMSO, 6.4% (methanol, 3.4% (ethanol and 2.5% (Tween 20. The findings have shown a toxicity level among the solvents in descending order as Tween 20 > ethanol > methanol > DMSO. DMSO is a safer solvent to be used in BSLT compared with other tested solvents, whereas Tween 20 has been shown to be the most stringent solvent among the tested solvents. The findings are resourcefully useful to avoid interference of solvents in the assessment of natural products using BSLT.

  10. Evaluation of the photodynamic activity of Xanthene Dyes on Artemia salina described by chemometric approaches

    Diogo S. Pellosi

    2013-10-01

    Full Text Available The development of drugs for photodynamic therapy (PDT is an important area of research due to their growing use in medical applications. Therefore, it is important to develop new bioassay methods for PDT photosensitizers that are inexpensive, easy to handle and highly sensitive to environmental conditions. Xanthene dyes (fluorescein, rose bengal B, erythrosine B and eosin Y with LED light sources were investigated using Artemia salina as a bioindicator of photodynamic activity. In this study, three factors were investigated: (i photosensitizers concentration, (ii the LED irradiation time and (iii the waiting time between the addition of the photosensitizers and the beginning of the irradiation. To analyze the photo-killing of A. salina, it was employed a 23 full factorial design. The death of A. salina was related to dye structure and the interaction between the irradiation time and the photosensitizers concentration. About 60% of crustaceans death was obtained using rose bengal B, which presentes the highest quantum yield of singlet oxygen due to the number of iodide substituents in the xanthenes ring. The proposed bioassay using A. salina, xanthene dyes and LED irradiation was found suitable for quantitative PDT drug evaluation.

  11. Study of interaction of low doses of ionizing radiation with selected pesticides on Artemia franciscana

    Michaela Špalková

    2015-01-01

    Full Text Available The aim of our study was to observe the effect of low doses of ionizing radiation, azoxystrobin and glyphosate separately as well as in their mutual combinations on the lethality of Artemia franciscana. Increasing intensity of agricultural production leads to continual exposure of animals to pesticide residues. Animals could be exposed to these negative factors in case of possible nuclear accident. A total of 1000 nauplia, randomly placed in 20 groups (1 control and 19 experimental groups, were irradiated with gamma rays (0, 20, 30, 40 or 50 Gy and were kept in solution of standardized sea water and standardized sea water with addition of pesticides (azoxystrobin at a concentration of 0.0001 g·l-1 and glyphosate at a concentration of 0.5 g·l-1 individually or in combination. A significant increase of lethality was observed after 48, 72 and 96 h of exposure to only azoxystrobin, but also in the group exposed to the combined effect of azoxystrobin and glyphosate at all time intervals. On the other hand, a significant decrease of lethality was observed in those groups exposed to ionizing radiation even at the dose of 30 Gy at all time intervals compared to non-irradiated groups. These results confirm the toxicity of azoxystrobin to aquatic organisms; non-toxicity of glyphosate to crustaceans and support the theory of radiation hormesis at the level of 30 Gy radiation dose.

  12. Isolasi Senyawa Aktif Ekstrak Etanol Biji Alpukat (Persea americana dan Uji Toksisitas Terhadap Artemia Salina Leach

    Andi Nur Fitriani Abubakar

    2014-07-01

    Full Text Available Avocado seed (Persea americana is recognized as one of medicinal plants. It contains several secondary metabolites, which have toxic activity. However, efforts to identify active compounds from avocado seeds (Persea americana are still relatively rare. Therefore, isolation and toxicity assay have been conducted foward the active compound of avocado seed. Maceration one kilogram of seed dried powder by ethanol obtained 49,7464 gram extract. Separation of etanol extract by column chromatography generated 0,0698 grams of pure white needle crytal, which is positively triterpenoid based on Lieberman-Buchard test. In addition, infrared spectrum showed the existence of OH, C=C, C-C, C=O, -C-H, -CH3,-CH2 and C-O stretch, which support the presumed compound. The result of toxicity test on Artemia salina Leach showed that the extract, fraction and pure isolates of the etanol extract are toxic with LC50 values 13,274 g/mL; 9,528 g/mL and 8,128 g/mL, respectively.

  13. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

    Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms

  14. Isolation, Characterization and Identification of Microalgae from the Red Sea

    Luque Alaní s, Patricio

    2013-01-01

    Eukaryotic microalgae from the Red Sea were isolated, characterized and identified with the purpose of building a culture collection that will serve future research activities in the area of industrial microbiology. Seven sampling locations were

  15. Phototrophic pigment production with microalgae: biological constraints and opportunities

    Mulders, K.J.M.; Lamers, P.P.; Martens, D.E.; Wijffels, R.H.

    2014-01-01

    There is increasing interest in naturally produced colorants, and microalgae represent a bio-technologically interesting source due to their wide range of colored pigments, including chlorophylls (green), carotenoids (red, orange and yellow), and phycobiliproteins (red and blue). However, the

  16. Hydrothermal Disintegration and Extraction of Different Microalgae Species

    Michael Kröger

    2018-02-01

    Full Text Available For the disintegration and extraction of microalgae to produce lipids and biofuels, a novel processing technology was investigated. The utilization of a hydrothermal treatment was tested on four different microalgae species (Scenedesmus rubescens, Chlorella vulgaris, Nannochloropsis oculata and Arthorspira platensis (Spirulina to determine whether it has an advantage in comparison to other disintegration methods for lipid extraction. It was shown, that hydrothermal treatment is a reasonable opportunity to utilize microalgae without drying and increase the lipid yield of an algae extraction process. For three of the four microalgae species, the extraction yield with a prior hydrothermal treatment elevated the lipid yield up to six times in comparison to direct extraction. Only Scenedesmus rubescens showed a different behaviour. Reason can be found in the different cell wall of the species. The investigation of the differences in cell wall composition of the used species indicate that the existence of algaenan as a cell wall compound plays a major role in stability.

  17. Isolation of microalgae species from arid environments and ...

    Isolation of microalgae species from arid environments and evaluation of their potentials for biodiesel production. ... African Journal of Biotechnology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives.

  18. Climate conditions, and changes, affect microalgae communities… should we worry?

    Gimenez Papiol, Gemma

    2018-03-01

    Microalgae play a pivotal role in the regulation of Earth's climate and its cycles, but are also affected by climate change, mainly by changes in temperature, light, ocean acidification, water stratification, and precipitation-induced nutrient inputs. The changes and impacts on microalgae communities are difficult to study, predict, and manage, but there is no doubt that there will be changes. These changes will have impacts beyond microalgae communities, and many of them will be negative. Some actions are currently ongoing for the mitigation of some of the negative impacts, such as harmful algal blooms and water quality, but global efforts for reducing CO 2 emissions, temperature rises, and ocean acidification are paramount for reducing the impact of climate change on microalgae communities, and eventually, on human well-being. Integr Environ Assess Manag 2018;14:181-184. © 2018 SETAC. © 2018 SETAC.

  19. Microalgae as healthy ingredients for functional food: a review.

    Matos, J; Cardoso, C; Bandarra, N M; Afonso, C

    2017-08-01

    Microalgae are very interesting and valuable natural sources of highly valuable bioactive compounds, such as vitamins, essential amino acids, polyunsaturated fatty acids, minerals, carotenoids, enzymes and fibre. Due to their potential, microalgae have become some of the most promising and innovative sources of new food and functional products. Moreover, microalgae can be used as functional ingredients to enhance the nutritional value of foods and, thus, to favourably affect human health by improving the well-being and quality of life, but also by curtailing disease and illness risks. This review provides an overview of the current knowledge of the health benefits associated with the consumption of microalgae, bioactive compounds, functional ingredients, and health foods.

  20. Antibacterial and antifungal activities of selected microalgae and cyanobacteria

    Najdenski, H. M.; Gigova, L. G.; Iliev, I. I.; Pilarski, P. S.; Lukavský, Jaromír; Tsvetkova, I. V.; Ninova, M. S.; Kussovski, V. K.

    2013-01-01

    Roč. 48, č. 7 (2013), s. 1533-1540 ISSN 0950-5423 Institutional support: RVO:67985939 Keywords : antimicrobial activity * cyanobacteria * microalgae Subject RIV: EF - Botanics Impact factor: 1.354, year: 2013

  1. Hydrodynamic study of an internal airlift reactor for microalgae culture.

    Rengel, Ana; Zoughaib, Assaad; Dron, Dominique; Clodic, Denis

    2012-01-01

    Internal airlift reactors are closed systems considered today for microalgae cultivation. Several works have studied their hydrodynamics but based on important solid concentrations, not with biomass concentrations usually found in microalgae cultures. In this study, an internal airlift reactor has been built and tested in order to clarify the hydrodynamics of this system, based on microalgae typical concentrations. A model is proposed taking into account the variation of air bubble velocity according to volumetric air flow rate injected into the system. A relationship between riser and downcomer gas holdups is established, which varied slightly with solids concentrations. The repartition of solids along the reactor resulted to be homogenous for the range of concentrations and volumetric air flow rate studied here. Liquid velocities increase with volumetric air flow rate, and they vary slightly when solids are added to the system. Finally, liquid circulation time found in each section of the reactor is in concordance with those employed in microalgae culture.

  2. Microalgae, a Potential Natural Functional Food Source – a Review

    Villarruel-López Angélica

    2017-12-01

    Full Text Available Microalgae are a group of microorganisms used in aquaculture. The number of studies regarding their use as a functional food has recently increased due to their nutritional and bioactive compounds such as polysaccharides, fatty acids, bioactive peptides, and pigments. Specific microalgal glucans (polysaccharides can activate the immune system or exert antioxidant and hypocholesterolemic effects. The importance of algal lipids is based on their polyunsaturated fatty acids, their anti-inflammatory effects, their modulation of lipid pathways, and their neuroprotective action. Microalgae peptides can bind or inhibit specific receptors in cardiovascular diseases and cancer, while carotenoids can act as potent antioxidants. The beneficial biological activity will depend on the specific microalga and its chemical constituents. Therefore, knowledge of the composition of microalgae would aid in identifying, selecting, and studying their functional effects.

  3. POSSIBILITIES OF CARBON DIOXIDE FIXATION BY MICROALGAE IN REFINERY

    Šingliar, Michal; Mikulec, Jozef; Kušnir, Patrik; Polakovičova, Gabriela

    2013-01-01

    Capture and sequestration of carbon dioxide is one of the most critical challenges today for businesses and governments worldwide. Thousands of emitting power plants and industries worldwide face this costly challenge – reduce the CO2 emissions or pay penalties. One possibility for carbon dioxide sequestration is its fixation in microalgae. Microalgae can sequester CO2 from flue gases emitted from fossil fuel-fired refinery plants and units, thereby reducing emissions of a major greenhouse ga...

  4. Biodiesel de microalgas: avanços e desafios

    André Luiz Custódio Franco

    2013-01-01

    Full Text Available Microalgae biomass has been described by several authors as the raw material with the greatest potential to meet the goals of replacing petroleum diesel by biodiesel while not competing with arable land suitable for food production. Research groups in different countries are seeking the most appropriate production model for productivity, economic viability and environmental sustainability. This review focused on recent advances and challenges of technology for the production of biodiesel from microalgae, including the procedures used to obtain biomass.

  5. Lipid profiling of some authotrophic microalgae grown on waste water

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Per

    Microalgae can be a new source of lipids for the aquaculture industry. Moreover, their potential as natural sources of antioxidants has gained recent attention. About 40 species of microalgae are used in aquaculture worldwide. A full characterization of lipid components is critical for selecting...... by membrane microfiltration and analyzed for fatty acid (GC), triacylglycerol (HPLC), sterol (GC) and tochol (HPLC) composition and also for amounts of phospholipids . Lipid composition in micro algae varied strongly between species....

  6. Microalgal CO2 sequestering – Modeling microalgae production costs

    Bilanovic, Dragoljub; Holland, Mark; Armon, Robert

    2012-01-01

    Highlights: ► Microalgae production costs were modeled as a function of specific expenses. ► The effects of uncontrollable expenses/factors were incorporated into the model. ► Modeled microalgae production costs were in the range $102–1503 t −1 ha −1 y −1 . - Abstract: Microalgae CO 2 sequestering facilities might become an industrial reality if microalgae biomass could be produced at cost below $500.00 t −1 . We develop a model for estimation of total production costs of microalgae as a function of known production-specific expenses, and incorporate into the model the effects of uncontrollable factors which affect known production-specific expenses. Random fluctuations were intentionally incorporated into the model, consequently into generated cost/technology scenarios, because each and every logically interconnected equipment/operation that is used in design/construction/operation/maintenance of a production process is inevitably subject to random cost/price fluctuations which can neither be eliminated nor a priori controlled. A total of 152 costs/technology scenarios were evaluated to find 44 scenarios in which predicted total production costs of microalgae (PTPCM) was in the range $200–500 t −1 ha −1 y −1 . An additional 24 scenarios were found with PTCPM in the range of $102–200 t −1 ha −1 y −1 . These findings suggest that microalgae CO 2 sequestering and the production of commercial compounds from microalgal biomass can be economically viable venture even today when microalgae production technology is still far from its optimum.

  7. Harvesting of freshwater microalgae biomass by Scenedesmus sp. as bioflocculant

    Rinanti, A.; Purwadi, R.

    2018-01-01

    This study is particularly expected to provide information on the diversity of microalgae as the flocculant agent that gives the highest biomass yield. Bioflocculation was done by using one of the flocculating microalgae i.e. Scenedesmus obliquus to concentrate on non-flocculating microalgae Chlorella vulgaris. The freshwater microalgae S. obliquus tested it ability to harvest other non-flocculating microalgae, increased sedimentation rate in the flocculation process and increased biomass yield. The flocculation of biomass microalgae with chemical flocculant as comparison was done by adding alum (K2SO4·Al2 (SO4)3·24H2O). The addition of alum (K2SO4·Al2 (SO4)3·24H2O) as flocculant at pH 11 and S. obliquus sp. as bioflocculant caused significant alteration of nutrition of microalgae. Overall, the essential content produced by flocculation method with addition of alum or with bioflocculation (%, mg/100 mg dry weight) are lipid 31,64; 38,69, protein 30,79; 38.50%, and chlorophyll 0.6253; 0.8420). Harvesting with bioflocculation methods conducted at the end of the cultivation period increase the amount of biomass significantly and can accelerate the settling time of biomass. Harvesting microalgae cells by bioflocculation method becomes an economically competitive harvesting method compared to alum as a chemical flocculant because of the cheaper cost of flocculant, not toxic so it does not require further water treatment after harvesting due to the use of alum as chemical flocculants.

  8. Techno-Economic Assessment of Micro-Algae Production Systems

    Hoffman, Justin

    2016-01-01

    Global oil consumption is rising at an unprecedented rate renewing interest in alternative fuels. Micro-algae represents a promising feedstock due to inherent advantages such as high solar energy efficiencies, large lipid fractions, and utilization of various waste streams including industrial flue gas. Current technological challenges have limited the commercial viability of microalgae based biofuel production systems. This study directly evaluates and compares the economic viability of biom...

  9. Vibrating membrane filtration as improved technology for microalgae dewatering

    Nurra, C.; Clavero, E.; Salvadó, J.; Torras, C.

    2014-01-01

    10.1016/j.biortech.2014.01.115 The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean ...

  10. Bacterial influence on alkenones in live microalgae.

    Segev, Einat; Castañeda, Isla S; Sikes, Elisabeth L; Vlamakis, Hera; Kolter, Roberto

    2016-02-01

    The microalga Emiliania huxleyi produces alkenone lipids that are important proxies for estimating past sea surface temperatures. Field calibrations of this proxy are robust but highly variable results are obtained in culture. Here, we present results suggesting that algal-bacterial interactions may be responsible for some of this variability. Co-cultures of E. huxleyi and the bacterium Phaeobacter inhibens resulted in a 2.5-fold decrease in algal alkenone-containing lipid bodies. In addition levels of unsaturated alkenones increase in co-cultures. These changes result in an increase in the reconstructed growth temperature of up to 2°C relative to axenic algal cultures. © 2015 Phycological Society of America.

  11. Marine microalgae attack and feed on metazoans

    Berge, Terje; Poulsen, Louise K.; Moldrup, Morten

    2012-01-01

    Free-living microalgae from the dinoflagellate genus Karlodinium are known to formmassive blooms in eutrophic coastal waters worldwide and are often associated with fish kills. Natural bloom populations, recently shown to consist of the two mixotrophic and toxic species Karlodinium armiger...... and Karlodinium veneficum have caused fast paralysis and mortality of finfish and copepods in the laboratory, and have been associated with reduced metazooplankton biomass in-situ. Here we show that a strain of K. armiger (K-0688) immobilises the common marine copepod Acartia tonsa in a densitydependent manner...... and collectively ingests the grazer to promote its own growth rate. In contrast, four strains of K. veneficum did not attack or affect the motility and survival of the copepods. Copepod immobilisation by the K. armiger strain was fast (within 15min) and caused by attacks of swarming cells, likely through...

  12. Microalgae - A promising tool for heavy metal remediation.

    Suresh Kumar, K; Dahms, Hans-Uwe; Won, Eun-Ji; Lee, Jae-Seong; Shin, Kyung-Hoon

    2015-03-01

    Biotechnology of microalgae has gained popularity due to the growing need for novel environmental technologies and the development of innovative mass-production. Inexpensive growth requirements (solar light and CO2), and, the advantage of being utilized simultaneously for multiple technologies (e.g. carbon mitigation, biofuel production, and bioremediation) make microalgae suitable candidates for several ecofriendly technologies. Microalgae have developed an extensive spectrum of mechanisms (extracellular and intracellular) to cope with heavy metal toxicity. Their wide-spread occurrence along with their ability to grow and concentrate heavy metals, ascertains their suitability in practical applications of waste-water bioremediation. Heavy metal uptake by microalgae is affirmed to be superior to the prevalent physicochemical processes employed in the removal of toxic heavy metals. In order to evaluate their potential and to fill in the loopholes, it is essential to carry out a critical assessment of the existing microalgal technologies, and realize the need for development of commercially viable technologies involving strategic multidisciplinary approaches. This review summarizes several areas of heavy metal remediation from a microalgal perspective and provides an overview of various practical avenues of this technology. It particularly details heavy metals and microalgae which have been extensively studied, and provides a schematic representation of the mechanisms of heavy metal remediation in microalgae. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

    Wijffels, René H; Kruse, Olaf; Hellingwerf, Klaas J

    2013-06-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms for the production of small molecules that can be secreted such as ethanol, butanol, fatty acids and other organic acids. Eukaryotic microalgae are interesting for products for which cellular storage is important such as proteins, lipids, starch and alkanes. For the development of new and promising lines of production, strains of both cyanobacteria and eukaryotic microalgae have to be improved. Transformation systems have been much better developed in cyanobacteria. However, several products would be preferably produced with eukaryotic microalgae. In the case of cyanobacteria a synthetic-systems biology approach has a great potential to exploit cyanobacteria as cell factories. For eukaryotic microalgae transformation systems need to be further developed. A promising strategy is transformation of heterologous (prokaryotic and eukaryotic) genes in established eukaryotic hosts such as Chlamydomonas reinhardtii. Experimental outdoor pilots under containment for the production of genetically modified cyanobacteria and microalgae are in progress. For full scale production risks of release of genetically modified organisms need to be assessed. Copyright © 2013. Published by Elsevier Ltd.

  14. Microalgae as sustainable renewable energy feedstock for biofuel production.

    Medipally, Srikanth Reddy; Yusoff, Fatimah Md; Banerjee, Sanjoy; Shariff, M

    2015-01-01

    The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

  15. Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

    Srikanth Reddy Medipally

    2015-01-01

    Full Text Available The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

  16. Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

    Yusoff, Fatimah Md.; Shariff, M.

    2015-01-01

    The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties. PMID:25874216

  17. TECHNOLOGICAL APPLICATION OF MICROALGAE IN POWER INDUSTRY AND ENVIRONMENTAL PROTECTION

    Ilmutdin M. Abdulagatov

    2018-01-01

    Full Text Available Abstract. Aim. The aim of the study is to show the possibility and efficiency of large-scale industrial production of microalgae in the Republic of Dagestan for the development of agriculture (feed for animals and poultry and other technological applications in the food and pharmaceutical industries for the production of algalin flour (eco bread, polyunsaturated fatty acids (omega-3, omega-6 physiologically necessary for humans, biologically active substances (astaxanthin, phycocyanin, new-generation antibiotics, biofuels and other high added value biotechnological products. The problems of using microalgae for bioremediation of the environment, in particular, purification of geothermal waters from phenols before discharging into the sewage system are considered. Methods. Microalgae are grown in closed and open type plants. Valuable algae components can be extracted using supercritical fluid technology of continuous action. Results. We give a comparative evaluation of the efficiency of using microalgae as a biological raw material in comparison with traditionally used oilseeds. Conclusion. For Dagestan, located on the shore of the Caspian Sea, with its warm climate and an abundance of solar and geothermal energy, the development of this technology is a task of great economic importance. The advantages of microalgae technologies are the basis for the creation of large-scale production of microalgae in southern Russia. Biotechnology in Dagestan can become not only profitable, but also a high-tech and innovative industry.

  18. Bioelectricity Production from Microalgae-Microbial Fuel Cell Technology (MMFC

    da Costa Carlito

    2018-01-01

    Full Text Available Microbial fuel cell is an ecological innovative technology producing bioelectricity by utilizing microbes activity. Substituent energy is produced by changing the chemical energy to electrical energy through the catalytic reaction of microorganism. The research aims to find out the potency of bioelectricity produced by microalgae microbial fuel cell technology by utilizing the combination of tapioca wastewater and microalgae cultivation. This research is conducted through the ingredients preparation stage – microalgae culture, wastewater characterization, membrane and graphite activation, and the providing of other supporting equipment. The next stage is the MMFC arrangement, while the last one is bioelectricity measurement. The result of optimal bioelectricity production on the comparison of electrode 2 : 2, the power density is 44,33 mW/m2 on day 6, meanwhile, on that of 1 : 1, 20,18 mW/m2 power density on day 1 is obtained. It shows that bioelectricity can be produced from the combination of tapioca wastewater and microalgae culture through the microalgae-microbial fuel cell (MMFC technology.This research is expected to be a reference for the next research particularly the one that observes the utilizing of microalgae as the part of new and renewable energy sources.

  19. Effect of low doses of ionizing radiation, azoxystrobin and selected heavy metals on the model organism of species Artemia franciscana; Posobenie nizkych davok ionizujuceho ziarenia, azoxystrobinu a vybranych tazkych kovov na modelovy organizmus druhu Artemia franciscana

    Spalkova, M.; Danova, D. [Univerzita veterinarskeho lekarstva a farmacie, Katedra biologie a genetiky, Ustav biologie, zoologie a radiobiologie, 04181 Kosice (Slovakia); Falis, M. [Univerzita veterinarskeho lekarstva a farmacie, Katedra farmakologie a toxikologie, Ustav toxikologie, 04181 Kosice (Slovakia); Zdarsky, M. [Veterinarni a farmaceuticka univerzita Brno, Ustav biochemie, chemie a biofyziky, 61242 Brno (Czech Republic)

    2013-04-16

    The aim of our study was to observe the effect of low doses of ionizing radiation, azoxystrobin, zinc and chrome on the lethality of Artemia franciscana. Significant increase of the lethality was observed after 72 and 96 hours of exposure to azoxystrobin and chrome as well as to azoxystrobin, chrome and irradiation. On the other hand, we observed significant decrease of the lethality in the groups exposed to pesticide and chrome or pesticide and zinc in combination with ionizing radiation with the dose of 50 Gy at time interval of 96 hours in comparison to non-irradiated groups. (authors)

  20. Prospecção fitoquímica de Sonchus oleraceus e sua toxicidade sobre o microcrustáceo Artemia salina Phytochemical prospecting of Sonchus oleraceus and its toxicity to Artemia salina

    J.M. Lima; C.A. Silva; M.B. Rosa; J.B. Santos; T.G. Oliveira; M.B. Silva

    2009-01-01

    A espécie vegetal Sonchus oleraceus é uma planta daninha presente em diversas culturas no Brasil e de utilização na medicina popular. Neste trabalho, realizou-se a prospecção fitoquímica dessa espécie com extratos em etanol, água e diclorometano, bem como testes de toxicidade sobre o microcrustáceo Artemia salina. O extrato aquoso apresentou em sua composição açúcares redutores, compostos fenólicos, taninos, flavonóides e cumarinas. No extrato etanólico, observaram-se os mesmos compostos qual...

  1. Investigations of the effects of cosmic rays on Artemia cysts and tobacco seeds: results of Exobloc II experiment, flown aboard Biocosmos 1887

    Gaubin, Y; Pianezzi, B; Gasset, G; Planel, H [Laboratoire de Biologie Medicale, Faculte de Medecine, Toulouse (France); Delpoux, M [Laboratoire de Biogeographie, Faculte des Sciences, Toulouse (France); Heilmann, C [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires

    1990-01-01

    Artemia (Brine shrimp) cysts and tobacco seeds, dormant biological material devoid of metabolic activity, were flown aboard the Soviet Biocosmos 1887 in order to investigate the effects of cosmic rays. Artemia cysts and tobacco seeds were used in bulk or in monolayers sandwiched with track detectors. Biological and physical units were located outside and inside the spacecraft. Stacks included lead shielding in order to expose the objects to different doses of radiation. Total dosimetry was performed using thermoluminescent detectors. In spite of low levels of doses, the space flight resulted in a decrease in developmental capacity of Artemia cysts, and in a higher mutation rate in tobacco seeds. The more obvious responses occurred, in both cases, in biological objects exposed to the highest doses. These results are compared to those of previous space experiments. (author).

  2. Composición del contenido de ácidos grasos en tres poblaciones mexicanas de Artemia franciscana de aguas epicontinentales

    Aída Malpica Sánchez

    2004-03-01

    Full Text Available En este trabajo se presenta la composición y el porcentaje de ácidos grasos de tres poblaciones mexicanas de Artemia franciscana de aguas epicontinentales; dos provienen de lugares silvestres (Coahuila y San Luis Potosí y una (Texcoco de un cultivo alimentado con Spirulina. Para la determinación de los ácidos grasos de cada población se extrajeron los lípidos totales por el método soxhlet y se esterificaron los ácidos grasos; posteriormente, mediante cromatografía de gases se determinó la composición y el porcentaje de los mismos. Los resultados muestran que la población de Texcoco contiene los seis ácidos grasos relevantes para peces y crustáceos en la acuicultura (16:0; 16:1; 18:1; 18:2w6; 18:3w3 y 20:5w3; mientras que la Artemia de San Luis Potosí resultó ser la más pobre en estos ácidos y la población de Coahuila, aunque mostró un perfil amplio, carece del ácido linolénico, ácido esencial y precursor de otros. Al comparar estos resultados, con datos ecológicos de estas tres poblaciones publicados previamente, se puede señalar que el ambiente es determinante para este crustáceo ya que Artemia de Texcoco provenía de un cultivo alimentado con Spirulina y fue la población que mostró mayor variedad de ácidos grasos. Las otras dos poblaciones son silvestres, con hábitats diferentes, la Artemia de Coahuila vive en aguas ricas en sulfatos y la de San Luis Potosí habita en vasos evaporadores de sal construidos con piedra de cantera y por lo tanto con escaso crecimiento de fitoplancton, ambas poblaciones mostraron deficiencias de ácidos grasos esenciales, sobre todo ésta últimaIn this paper is presented the percentage of fatty acids composition of three Artemia franciscana Mexican populations of epicontinentals waters; two are from natural environments (Coahuila and San Luis Potosí and one (Texcoco is a culture fed with Spirulina. Determination of fatty acids composition in each population, was performed by

  3. Brachionus plicatilis (Rotifer'in Farklı Besin Ortamlarında Büyümesi.

    Bircan Özbaş

    2015-12-01

    Full Text Available Farklı besin diyetlerinin rotifer (Brachionus plicatilis kültürlerinin büyümesi üzerindeki etkilerinin araştırıldığı bu çalışmada, rotiferler Nannochloropsis sp., ekmek mayası (Saccharomyces cerevisiae ve kurutulmuş Spirulina tozu ile beslendi. İlk denemede, optimum Spirulina konsantrasyonu günde 0.01 g / 106 rotifer olarak bulundu. Deneme gruplarında alg, alg+maya, alg+Spirulina, maya+Spirulina ve maya/2+Spirulina olmak üzere 5 deneme grubu oluşturuldu. Mikroskobik gözlemlerde, Spirulina partikülleri havanda ezilmiş olmasına rağmen rotiferler tarafından tüketilemeyecek boyutta idi. Sonuç olarak, alg içeren grupların en iyi büyümeyi gösterdiği tespit edildi. Spirulina ise partikül büyüklüğünden dolayı rotiferler tarafından alınamadı. Maya hücreleri ise rotifer hücreleri için optimum büyüklükte olmasına rağmen, ortam kirliliğine neden olması bakımından alg ile beslenen gruplara göre daha düşük bir büyüme gösterdi

  4. High prevalence of cestodes in Artemia spp. throughout the annual cycle: relationship with abundance of avian final hosts

    Sánchez, Marta I.; Nikolov, Pavel N.; GEorgieva, Darina D.; Georgiev, Boyko B.; Vasileva, Gergana P.; Pankov, Plamen; Paracuellos, Mariano; Lafferty, Kevin D.; Green, Andy J.

    2013-01-01

    Brine shrimp, Artemia spp., act as intermediate hosts for a range of cestode species that use waterbirds as their final hosts. These parasites can have marked influences on shrimp behavior and fecundity, generating the potential for cascading effects in hypersaline food webs. We present the first comprehensive study of the temporal dynamics of cestode parasites in natural populations of brine shrimp throughout the annual cycle. Over a 12-month period, clonal Artemia parthenogenetica were sampled in the Odiel marshes in Huelva, and the sexual Artemia salina was sampled in the Salinas de Cerrillos in Almería. Throughout the year, 4–45 % of A. parthenogenetica were infected with cestodes (mean species richness = 0.26), compared to 27–72 % of A. salina (mean species richness = 0.64). Ten cestode species were recorded. Male and female A. salina showed similar levels of parasitism. The most prevalent and abundant cestodes were those infecting the most abundant final hosts, especially the Greater Flamingo Phoenicopterus ruber. In particular, the flamingo parasite Flamingolepis liguloides had a prevalence of up to 43 % in A. parthenogenetica and 63.5 % in A. salina in a given month. Although there was strong seasonal variation in prevalence, abundance, and intensity of cestode infections, seasonal changes in bird counts were weak predictors of the dynamics of cestode infections. However, infection levels of Confluaria podicipina in A. parthenogenetica were positively correlated with the number of their black-necked grebe Podiceps nigricollis hosts. Similarly, infection levels of Anomotaenia tringae and Anomotaenia microphallos in A. salina were correlated with the number of shorebird hosts present the month before. Correlated seasonal transmission structured the cestode community, leading to more multiple infections than expected by chance.

  5. Persistent genetic signatures of colonization in Brachionus manjavacas rotifers in the Iberian Peninsula.

    Gómez, Africa; Montero-Pau, Javier; Lunt, David H; Serra, Manuel; Campillo, Sergi

    2007-08-01

    Recent phylogeographical assessments have consistently shown that continental zooplankton display high levels of population subdivision, despite the high dispersal capacity of their diapausing propagules. As such, there is an apparent paradox between observed cosmopolitanism in the zooplankton that is associated with long-distance dispersal, and strong phylogeographical structures at a regional scale. Such population dynamics, far from migration-drift equilibrium, have been shown in the rotifer species complex Brachionus plicatilis, a group of over a dozen species inhabiting salt lakes and coastal lagoons worldwide. Here we present the mitochondrial DNA phylogeography of one of these species, Brachionus manjavacas, in the Iberian Peninsula, where it often co-occurs with the morphologically similar species B. plicatilis sensu stricto. We obtained sequences from 233 individuals from diapausing eggs and clonal cultures from 16 lakes in the Iberian Peninsula, and a Tunisian lake. Two strongly supported deep mitochondrial DNA clades were found (A and B). Phylogenetic and nested clade analysis showed that clade A has a strong phylogeographical structure, with a strong similarity of phylogeographical patterns between B. manjavacas clade A and B. plicatilis s.s. These include (i) signatures of allopatric fragmentation between central and southern populations, and (ii) range expansions in the Iberian Peninsula, both likely to have occurred during the Pleistocene. We find evidence for a glacial refugium in the Guadiana basin. Clades A and B co-occurred in several of these lakes because of range expansion and secondary contact between both clades. The co-occurrence between B. plicatilis s.s. and B. manjavacas is not recent, and both species might have experienced similar environmental challenges during the Pleistocene. The strong correlation of genetic and geographical distance found suggests that historical events can lead to such correlation, mirroring the effects of

  6. A novel adhering junction in the apical ciliary apparatus of the rotifer Brachionus plicatilis (Rotifera, Monogononta).

    Dallai, R; Lupetti, P; Lane, N J

    1996-10-01

    Cultures of the rotifer Brachionus plicatilis were examined with regard to their interepithelial junctions after infiltration with the extracellular tracer lanthanum, freeze-fracturing or quick-freeze deep-etching. The lateral borders between ciliated cells have an unusual apical adhering junction. This apical part of their intercellular cleft looks desmosome-like, but it is characterized by unusual intramembranous E-face clusters of particles. Deep-etching reveals that these are packed together in short rows which lie parallel to one another in orderly arrays. The true membrane surface in these areas features filaments in the form of short ribbons; these are produced by projections, possibly part of the glycocalyx, emerging from the membranes, between which the electron-dense tracer lanthanum permeates. These projections appear to overlap with each other in the centre of the intercellular cleft; this would provide a particularly flexible adaptation to maintain cell-cell contact and coordination as a consequence. The filamentous ribbons may be held in position by the intramembranous particle arrays since both have a similar size and distribution. These contacts are quite different from desmosomes and appear to represent a distinct new category of adhesive cell-cell junction. Beneath these novel structures, conventional pleated septate junctions are found, exhibiting the undulating intercellular ribbons typical of this junctional type, as well as the usual parallel alignments of intramembranous rows of EF grooves and PF particles. Below these are found gap junctions as close-packed plaques of intramembranous particles on either the P-face or E-face. After freeze-fracturing, the complementary fracture face to the particles shows pits, usually on the P-face, arrayed with a very precise hexagonal pattern.

  7. Optofluidic technology for monitoring rotifer Brachionus calyciflorus responses to regular light pulses

    Cartlidge, Rhys; Campana, Olivia; Nugegoda, Dayanthi; Wlodkowic, Donald

    2016-12-01

    Behavioural alterations can occur as a result of a toxicant exposure at concentrations significantly lower than lethal effects that are commonly measured in acute toxicity testing. The use of alternating light and dark photoperiods to test phototactic responses of aquatic invertebrates in the presence of environmental contaminants provides an attractive analytical avenue. Quantification of phototactic responses represents a sublethal endpoint that can be employed as an early warning signal. Despite the benefits associated with the assessment of these endpoints, there is currently a lack of automated and miniaturized bioanalytical technologies to implement the development of toxicity testing with small aquatic species. In this study we present a proof-of-concept microfluidic Lab-on-a-Chip (LOC) platform for the assessment of rotifer swimming behavior in the presence of the toxicant copper sulfate. The device was designed to assess impact of toxicants at sub-lethal concentrations on freshwater crustacean Brachionus calyciflorus, testing behavioral endpoints such as animal swimming distance, speed and acceleration. The LOC device presented in this work enabled straightforward caging of microscopic crustaceans as well as non-invasive analysis of rapidly swimming animals in a focal plane of a video-microscopy system. The chip-based technology was fabricated using a new photolithography method that enabled formation of thick photoresist layers with minimal distortion. Photoresist molds were then employed for replica molding of LOC devices with poly(dimethylsiloxane) (PDMS) elastomer. The complete bioanalytical system consisted of: (i) microfluidic PDMS chip-based device; (ii) peristaltic microperfusion pumping manifold; (iii) miniaturized CMOS camera for video data acquisition; and (iv) video analysis software algorithms for quantification of changes in swimming behaviour of B. calyciflorus in response to reference toxicants.

  8. Toxicоlogical evaluation of the plant products using Brine Shrimp (Artemia salina L. model

    Меntor R. Hamidi

    2014-04-01

    Full Text Available Many natural products could serve as the starting point in the development of modern medicines because of their numerous biological and pharmacological activities. However, some of them are known to carry toxicological properties as well. In order to achieve a safe treatment with plant products, numerous research studies have recently been focused on both pharmacology and toxicity of medicinal plants. Moreover, these studies employed efforts for alternative biological assays. Brine Shrimp Lethality Assay is the most convenient system for monitoring biological activities of various plant species. This method is very useful for preliminary assessment of toxicity of the plant extracts. Rapidness, simplicity and low requirements are several advantages of this assay. However, several conditions need to be completed, especially in the means of standardized experimental conditions (temperature, pH of the medium, salinity, aeration and light. The toxicity of herbal extracts using this assay has been determined in a concentration range of 10, 100 and 1000 µg/ml of the examined herbal extract. Most toxicity studies which use the Brine Shrimp Lethality Assay determine the toxicity after 24 hours of exposure to the tested sample. The median lethal concentration (LC50 of the test samples is obtained by a plot of percentage of the dead shrimps against the logarithm of the sample concentration. LC50 values are estimated using a probit regression analysis and compared with either Meyer’s or Clarkson’s toxicity criteria. Furthermore, the positive correlation between Meyer’s toxicity scale for Artemia salina and Gosselin, Smith and Hodge’s toxicity scale for higher animal models confirmed that the Brine Shrimp Lethality Assay is an excellent predictive tool for the toxic potential of plant extracts in humans.

  9. Recreating the seawater mixture composition of HOCs in toxicity tests with Artemia franciscana by passive dosing

    Rojo-Nieto, E., E-mail: elisa.rojo@uca.es [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Smith, K.E.C. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark); Perales, J.A. [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Mayer, P. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark)

    2012-09-15

    The toxicity testing of hydrophobic organic compounds (HOCs) in aquatic media is generally challenging, and this is even more problematic for mixtures. The hydrophobic properties of these compounds make them difficult to dissolve, and subsequently to maintain constant exposure concentrations. Evaporative and sorptive losses are highly compound-specific, which can alter not only total concentrations, but also the proportions between the compounds in the mixture. Therefore, the general aim of this study was to explore the potential of passive dosing for testing the toxicity of a PAH mixture that recreates the mixture composition found in seawater from a coastal area of Spain, the Bay of Algeciras. First, solvent spiking and passive dosing were compared for their suitability to determine the acute toxicity to Artemia franciscana nauplii of several PAHs at their respective solubility limits. Second, passive dosing was applied to recreate the seawater mixture composition of PAHs measured in a Spanish monitoring program, to test the toxicity of this mixture at different levels. HPLC analysis was used to confirm the reproducibility of the dissolved exposure concentrations for the individual PAHs and mixtures. This study shows that passive dosing has some important benefits in comparison with solvent spiking for testing HOCs in aquatic media. These include maintaining constant exposure concentrations, leading to higher reproducibility and a relative increase in toxicity. Passive dosing is also able to faithfully reproduce real mixtures of HOCs such as PAHs, in toxicity tests, reproducing both the levels and proportions of the different compounds. This provides a useful approach for studying the toxicity of environmental mixtures of HOCs, both with a view to investigating their toxicity but also for determining safety factors before such mixtures result in detrimental effects.

  10. Biological screening of chitosan derivatives using Artemia spp. (brine shrimp test)

    Rozaini Mohd Zohdi; Norimah Yusof; Asnah Hassan

    2006-01-01

    The present study reported on the screening of six selected chitosan derivatives using the brine shrimp lethality bioassay. In addition, the irradiation effects towards the compounds at 25 kGy were also studied. Chitosan is a natural polysaccharide derived from chitin, extracted from the exoskeletons of crustaceans and insects as well as walls of some bacteria and fungi. Brine shrimp test is employed for the screening of toxicity of chitosan derivatives. Toxicity test was carried out by adding different concentrations of tested samples to approximately 5 to 15 Artemia salina larvae. Biological activity using the brine shrimp bioassay was recorded as LC 50 i.e. lethal concentration that kills 50% of the larvae within 24 hours of contact with the samples. Compounds are considered toxic when the LC 50 value is lower than 1 mg/ml by brine shrimp bioassay and practically non-toxic when the value is larger. Of the samples tested, none were toxic to the brine shrimp (LC 50 > 1 mg/ml). The LC 50 values of all chitosan derivatives tested, control and irradiated at 25 kGy were above 1 mg/ml thus all tested samples are considered non-toxic. This study demonstrated that irradiation at 25 kGy showed no significant effects towards the toxicity of the chitosan derivatives. After irradiation, only NO-CMC exhibited marked decrease in LC 50 value, reduced by 3-fold from 34.96 mg/ml to 11.07 mg/ml while O-CMC (5.45 mg/ml to 5 mg/ml) showed no clear differences based on rough estimation. This study suggested that brine shrimp bioassay is a simple, reliable and convenient method that could provide useful clues of the relative toxic potential of the sample tested. (Author)

  11. Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae.

    Bergami, Elisa; Bocci, Elena; Vannuccini, Maria Luisa; Monopoli, Marco; Salvati, Anna; Dawson, Kenneth A; Corsi, Ilaria

    2016-01-01

    Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on the impact of nano-sized plastics on marine organisms. Therefore, the present study aims to evaluate the effects of 40nm anionic carboxylated (PS-COOH) and 50nm cationic amino (PS-NH2) polystyrene nanoparticles (PS NPs) on brine shrimp Artemia franciscana larvae. No signs of mortality were observed at 48h of exposure for both PS NPs at naplius stage but several sub-lethal effects were evident. PS-COOH (5-100μg/ml) resulted massively sequestered inside the gut lumen of larvae (48h) probably limiting food intake. Some of them were lately excreted as fecal pellets but not a full release was observed. Likewise, PS-NH2 (5-100µg/ml) accumulated in larvae (48h) but also adsorbed at the surface of sensorial antennules and appendages probably hampering larvae motility. In addition, larvae exposed to PS-NH2 undergo multiple molting events during 48h of exposure compared to controls. The activation of a defense mechanism based on a physiological process able to release toxic cationic NPs (PS-NH2) from the body can be hypothesized. The general observed accumulation of PS NPs within the gut during the 48h of exposure indicates a continuous bioavailability of nano-sized PS for planktonic species as well as a potential transfer along the trophic web. Therefore, nano-sized PS might be able to impair food uptake (feeding), behavior (motility) and physiology (multiple molting) of brine shrimp larvae with consequences not only at organism and population level but on the overall ecosystem based on the key role of zooplankton on marine food webs. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Effects of heavy metals and pesticides on survival of Artemia franciscana

    Marcel Falis

    2014-01-01

    Full Text Available Assessment of the potential risk of pesticides is an important part of registration procedures in many countries. However, risk assessment of several pesticides used during the growing season has not been carried out. The aim of this study was to investigate the effects of pesticides (azoxystrobin and glyphosate, heavy metals (cadmium chloride, potassium dichromate, zinc disulphate and their combinations on lethality to Artemia franciscana. In total, 1,250 freshly hatched nauplii of A. franciscana were used in the study. They were placed in 125 Petri dishes (10 nauplii in one Petri dish containing 10 ml of azoxystrobin, glyphosate, cadmium chloride, potassium dichromate and zinc sulphate separately, or their combinations; the control dish contained only sea water. Each experimental set consisted of 50 nauplii which were divided into five replicates of 10 nauplii per replicate. Live A. franciscana were counted after 24, 48, 72 and 96 h and the numbers were compared with the control group. A significant (P after exposure to azoxystrobin in combination with glyphosate after 48, 72 and 96 h of exposure, in combination with glyphosate and potassium dichromate after 48 h of exposure, and in combination with glyphosate and zinc disulphate after 48, 72 and 96 h of exposure. The results of this study provide information about the combined toxicity of pesticides used during the growing season and some heavy metals as major pollutants of the rural environment. A study of this kind has not been conducted yet. Further research for investigation of the combined toxicity of pollutants and pesticides is required.

  13. Neutral lipid accumulation at elevated temperature in conditional mutants of two microalgae species

    Yao, Shuo; Brandt, Anders Bøving; Egsgaard, Helge

    2012-01-01

    Triacylglycerols, an energy storage compound in microalgae, are known to be accumulated after nitrogen starvation of microalgae cells. Microalgae could be of importance for future biodiesel production due to their fast growth rate and high oil content. In collections of temperature sensitive...... accumulation in microalgae and suggest possibilities for biodiesel production by specific induction of lipid accumulation in miroalgal cultures by cell-cycle inhibition....

  14. A novel method for rearing first-feeding larval zebrafish: polyculture with Type L saltwater rotifers (Brachionus plicatilis).

    Best, Jason; Adatto, Isaac; Cockington, Jason; James, Althea; Lawrence, Christian

    2010-09-01

    Promoting high rates of growth and survival can be a major challenge in zebrafish culture, especially during the first-feeding stage. Here we describe a new rearing technique in which zebrafish larvae are polycultured in static tanks with Type "L" saltwater rotifers (Brachionus plicatilis) for the first 5 days of feeding (days 5-9 postfertilization). To demonstrate the effectiveness of this technique, we conducted rearing trials using fish from two different strains: AB and nacre. Growth, survival, water quality, and rotifer density were assayed daily through the polyculture phase (days 5-9), and during the transition to standard rearing conditions (days 10-12). After that point, once the fish were fully integrated onto recirculating systems, parameters were measured once per week out to day 30. In all trials, the fish displayed high rates of growth and survival throughout the three phases (polyculture, transition, and recirculating flow), indicating that this method may be employed during the critical first-feeding stage to help improve rearing performance in zebrafish facilities. Additionally, water quality parameters observed during the polyculture phase of the trials reveal that early zebrafish larvae are much more tolerant of elevated levels of ammonia and salinity than previously believed.

  15. Experimental study on the interspecific interactions between the two bloom-forming algal species and the rotifer Brachionus plicatilis

    Xie, Zhihao; Xiao, Hui; Tang, Xuexi; Cai, Hengjiang

    2009-06-01

    The interspecific interactions between the rotifer Brachionus plicatilis and two harmful algal blooms (HAB) species were investigated experimentally by single culture method. B. plicatilis population and the growth of the two algae were compared at different algal cell densities. The results demonstrated that the B. plicatilis obtained sufficient nutrition from Prorocentrum donghaiense to support net population increase. With exposure to 2.5×104 cells mL-1 of P. donghaiense, the number of B. plicatilis increased faster than it did when exposed to other four algal densities (5, 10, 15 and 20 ×104 cells mL-1), and the increase rate of B. plicatilis population ( r) at this algal density was 0.104 ± 0.015 rd-1. Cell densities of P. donghaiense decreased due to the grazing of B. plicatilis. In contrast, Heterosigma akashiwo had an adverse effect on B. plicatilis population and its growth was largely unaffected by rotifer grazing. In this case, B. plicatilis population decreased and H. akashiwo grew at a rate similar to that of the control.

  16. Combined effects of Corexit EC 9500A with secondary abiotic and biotic factors in the rotifer Brachionus plicatilis.

    Williams, Michael B; Powell, Mickie L; Watts, Stephen A

    2016-10-01

    We examined lethality and behavioral effects of Corexit EC 9500A (C-9500A) exposure on the model marine zooplankton Brachionus plicatilis singularly and in combination with abiotic and biotic factors. C-9500A exposure at standard husbandry conditions (17.5ppt, 24°C, 200 rotifer*mL(-1) density) identified the 24h median lethal concentration, by Probit analysis, to be 107ppm for cultured B. plicatilis. Rotifers surviving exposure to higher concentrations (100 and 150ppm) exhibited a decreased swimming velocity and a reduced net to gross movement ratio. Significant interaction between C-9500A exposure and temperature or salinity was observed. Upper thermal range was reduced and maximal salinity stress was seen as ca. 25ppt. Increased or decreased nutritional availability over the exposure period did not significantly alter mortality of B. plicatilis populations at the concentrations tested. Results from this study may be useful for predicting possible outcomes on marine zooplankton following dispersant application under diverse natural conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Benefits of Microalgae for Human Space Exploration

    Verrecchia, Angelique; Bebout, Brad M.; Murphy, Thomas

    2015-01-01

    Algae have long been known to offer a number of benefits to support long duration human space exploration. Algae contain proteins, essential amino acids, vitamins, and lipids needed for human consumption, and can be produced using waste streams, while consuming carbon dioxide, and producing oxygen. In comparison with higher plants, algae have higher growth rates, fewer environmental requirements, produce far less "waste" tissue, and are resistant to digestion and/or biodegradation. As an additional benefit, algae produce many components (fatty acids, H2, etc.) which are useful as biofuels. On Earth, micro-algae survive in many harsh environments including low humidity, extremes in temperature, pH, and as well as high salinity and solar radiation. Algae have been shown to survive inmicro-gravity, and can adapt to high and low light intensity while retaining their ability to perform nitrogen fixation and photosynthesis. Studies have demonstrated that some algae are resistant to the space radiation environment, including solar ultraviolet radiation. It remains to be experimentally demonstrated, however, that an algal-based system could fulfil the requirements for a space-based Bioregenerative Life Support System (BLSS) under comparable spaceflight power, mass, and environmental constraints. Two specific challenges facing algae cultivation in space are that (i) conventional growth platforms require large masses of water, which in turn require a large amount of propulsion fuel, and (ii) most nutrient delivery mechanisms (predominantly bubbling) are dependent on gravity. To address these challenges, we have constructed a low water biofilm based bioreactor whose operation is enabled by capillary forces. Preliminary characterization of this Surface Adhering BioReactor (SABR) suggests that it can serve as a platform for cultivating algae in space which requires about 10 times less mass than conventional reactors without sacrificing growth rate. Further work is necessary to

  18. Phloroglucinol-Mediated Hsp70 Production in Crustaceans: Protection against Vibrio parahaemolyticus in Artemia franciscana and Macrobrachium rosenbergii

    Kumar, Vikash; Baruah, Kartik; Nguyen, Dung Viet; Smagghe, Guy; Vossen, Els; Bossier, Peter

    2018-01-01

    The halophilic aquatic bacterium, Vibrio parahaemolyticus, is an important aquatic pathogen, also capable of causing acute hepatopancreatic necrosis disease (AHPND) in shrimp resulting in significant economic losses. Therefore, there is an urgent need to develop anti-infective strategies to control AHPND. The gnotobiotic Artemia model is used to establish whether a phenolic compound phloroglucinol is effective against the AHPND strain V. parahaemolyticus MO904. We found that pretreatment with phloroglucinol, at an optimum concentration (30 µM), protects axenic brine shrimp larvae against V. parahaemolyticus infection and induced heat shock protein 70 (Hsp70) production (twofolds or more) as compared with the control. We further demonstrated that the Vibrio-protective effect of phloroglucinol was caused by its prooxidant effect and is linked to the induction of Hsp70. In addition, RNA interference confirms that phloroglucinol-induced Hsp70 mediates the survival of brine shrimp larvae against V. parahaemolyticus infection. The study was validated in xenic Artemia model and in a Macrobrachium rosenbergii system. Pretreatment of xenic brine shrimp larvae (30 µM) and Macrobrachium larvae (5 µM) with phloroglucinol increases the survival of xenic brine shrimp and Macrobrachium larvae against subsequent V. parahaemolyticus challenge. Taken together, our study provides substantial evidence that the prooxidant activity of phloroglucinol induces Hsp70 production protecting brine shrimp, A. franciscana, and freshwater shrimp, M. rosenbergii, against the AHPND V. parahaemolyticus strain MO904. Probably, phloroglucinol treatment might become part of a holistic strategy to control AHPND in shrimp.

  19. Identifikasi Metabolit Sekunder Ekstrak Etil Asetat Biji Alpukat (Persea americana Mill. dan Uji Toksisitas Terhadap Larva Udang Artemia salina Leach.

    Nurdia Asdar

    2014-07-01

    Full Text Available Identification of metabolite compound in acetone Extract from Fruits Avocado seed (Percea americana Mill and toxicity test against Artemia salina Leach. Aim of this research is to identify the secondary metabolite compound in aceton extract from fruits Avocado seed (Percea americana Mill and to determine the potential of secondary metabolites from an avocado extract as anticancer. The compound was obtained from Identification process in several stages, namely extraction, fractination, purification and identification. The identification process was color test, TLC, spectroscopy IR. The toxicity test by Brine Shrimp Lethality Test (BSLT to Artemia salina Leach. The compound obtained from this research was yellow-white crystalline needle-shaped, the purity test with TLC analysis showed a stain in three eluen system on the stain test on three eluent systems with Rf proportions as follows; 0,15 from chloroform:ethyl acetat (6:4, 0,33 from methanol:chloroform (1:9, 0,75 for acetone:ethyl acetat, and positively to the reagent Wagner and gave brown precipitate for indicate as alcaloid group. This result is supported by spectroscopy from compound.While toxicity tests showed condensed acetone extracts  and pure compounds are toxic with LC50 value of each is 20.61 mg/mL and 39,81 mg/mL.

  20. Genome-wide identification of 31 cytochrome P450 (CYP) genes in the freshwater rotifer Brachionus calyciflorus and analysis of their benzo[alpha]pyrene-induced expression patterns

    Han, Jeonghoon; Kim, Duck-Hyun; Kim, Hui-Su; Kim, Hee-Jin; Declerck, S.A.J.; Hagiwara, Atsushi; Lee, Jae-Seong

    2017-01-01

    While marine invertebrate cytochrome P450 (CYP) genes and their roles in detoxification mechanisms have been studied, little information is available regarding freshwater rotifer CYPs and their functions. Here, we used genomic sequences and RNA-seq databases to identify 31 CYP genes in the

  1. Genome-wide identification of 31 cytochrome P450 (CYP) genes in the freshwater rotifer Brachionus calyciflorus and analysis of their benzo[α]pyrene-induced expression patterns.

    Han, Jeonghoon; Kim, Duck-Hyun; Kim, Hui-Su; Kim, Hee-Jin; Declerck, Steven A J; Hagiwara, Atsushi; Lee, Jae-Seong

    2018-03-01

    While marine invertebrate cytochrome P450 (CYP) genes and their roles in detoxification mechanisms have been studied, little information is available regarding freshwater rotifer CYPs and their functions. Here, we used genomic sequences and RNA-seq databases to identify 31 CYP genes in the freshwater rotifer Brachionus calyciflorus. The 31 Bc-CYP genes with a few tandem duplications were clustered into CYP 2, 3, 4, mitochondrial, and 46 clans with two marine rotifers Brachionus plicatilis and Brachionus koreanus. To understand the molecular responses of these 31 Bc-CYP genes, we also examined their expression patterns in response to benzo[α]pyrene (B[α]P). Three Bc-CYP genes (Bc-CYP3044B3, Bc-CYP3049B4, Bc-CYP3049B6) were significantly upregulated (P<0.05) in response to B[α]P, suggesting that these CYP genes can be involved in detoxification in response to B[α]P exposure. These genes might be useful as biomarkers of B[α]P exposure in B. calyciflorus. Overall, our findings expand the repertoire of known CYPs and shed light on their potential roles in xenobiotic detoxification in rotifers. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Influence of the age of algae fed to rotifers (Brachionus plicatilis O.F. Müller) on the expression of mixis in their progenies.

    Lubzens, E; Minkoff, G

    1988-04-01

    The sequence of the appearance of mixis in the rotifer Brachionus plicatilis was followed among the descendents of amictic rotifers transferred from a high salinity media (40 S) to a low one (9 S). All the neonates that hatched from the amictic eggs, after being transferred to a low salinity, were amictic. Each one of these neonates was cultured individually and its offspring removed periodically every 8-10 h. It was observed that throughout their reproductive phase, these parental females retained their potential to produce either mictic or amictic offspring. All the first produced neonates developed into amictic females, but among those produced later, three patterns were prevalent. The prevalent pattern (type A) was one in which the probability of a neonate being mictic increased towards the middle of the parents' reproductive phase and was followed by a slow decline. In the second pattern (type B), the probability of a daughter being mictic was constant throughout the parents' reproductive phase. It is suspected that the quality of food supplied to the rotifers determines the appearance of patterns, A, B or C. It is postulated that the innate capacity of rotifers to undergo mixis is genetically controlled, while its expression is modulated by environmental conditions.

  3. Genome-wide identification of nuclear receptor (NR) genes and the evolutionary significance of the NR1O subfamily in the monogonont rotifer Brachionus spp.

    Kim, Duck-Hyun; Kim, Hui-Su; Hwang, Dae-Sik; Kim, Hee-Jin; Hagiwara, Atsushi; Lee, Jae-Seong; Jeong, Chang-Bum

    2017-10-01

    Nuclear receptors (NRs) are a large family of transcription factors that are involved in many fundamental biological processes. NRs are considered to have originated from a common ancestor, and are highly conserved throughout the whole animal taxa. Therefore, the genome-wide identification of NR genes in an animal taxon can provide insight into the evolutionary tendencies of NRs. Here, we identified all the NR genes in the monogonont rotifer Brachionus spp., which are considered an ecologically key species due to their abundance and world-wide distribution. The NR family was composed of 40, 32, 29, and 32 genes in the genomes of the rotifers B. calyciflorus, B. koreanus, B. plicatilis, and B. rotundiformis, respectively, which were classified into seven distinct subfamilies. The composition of each subfamily was highly conserved between species, except for NR1O genes, suggesting that they have undergone sporadic evolutionary processes for adaptation to their different environmental pressures. In addition, despite the dynamics of NR evolution, the significance of the conserved endocrine system, particularly for estrogen receptor (ER)-signaling, in rotifers was discussed on the basis of phylogenetic analyses. The results of this study may help provide a better understanding the evolution of NRs, and expand our knowledge of rotifer endocrine systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Assessment of the toxicity of the solid coating PV1 in a marine invironment, using biotests with algae, a rotifer and a bacteria

    Foekema, E.M.; Sneekes, A.C.

    2007-01-01

    The toxic potential of substances that may leach from the solid coating PV1 was tested using • the marine bacteria Vibrio fisheri in the Microtox® Basic test • the marine algae Skeletonema costatum in a 72h algal growth inhibition test • the marine rotifer Brachionus plicatilis in the 24 h ROTOX®

  5. Extracellular Metabolites from Industrial Microalgae and Their Biotechnological Potential

    Lu Liu

    2016-10-01

    Full Text Available Industrial microalgae, as a big family of promising producers of renewable biomass feedstock, have been commercially exploited for functional food, living feed and feed additives, high-value chemicals in nutraceuticals, cosmeceuticals, and chemical reagents. Recently, microalgae have also been considered as a group that might play an important role in biofuel development and environmental protection. Almost all current products of industrial microalgae are derived from their biomass; however, large amounts of spent cell-free media are available from mass cultivation that is mostly unexploited. In this contribution we discuss that these media, which may contain a remarkable diversity of bioactive substances are worthy to be recovered for further use. Obviously, the extracellular metabolites from industrial microalgae have long been neglected in the development of production methods for valuable metabolites. With the advances in the last ten years, more and more structures and properties from extracellular metabolites have been identified, and the potential utilization over wide fields is attracting attention. Some of these extracellular metabolites can be potentially used as drugs, antioxidants, growth regulators or metal chelators. The purpose of this review is to provide an overview of the known extracellular metabolites from industrial microalgae which might be of commercial interest. The attention mainly focuses on the reports of extracellular bioactive metabolites and their potential application in biotechnology.

  6. BIOREMOVAL OF LEAD IN INDUSTRIAL WASTEWATER BY MICROALGAE

    M. RANITHA

    2016-07-01

    Full Text Available The removal of heavy metals from our environment especially wastewater is now shifting from the use of conventional removal method such as chemical precipitation, coagulation and membrane filtration to the use of bioremoval method. The presence of heavy metals in the environment is of major concern because of their toxicity, bioaccumulating tendency, and threat to human life and the environment. In recent years, many low cost sorbents such as microalgae, fungi bacteria and lignocellulosic agricultural by-products have been investigated for their biosorption capacity towards heavy metals. In this project, the focus is on bioremoval of heavy metals in wastewater using marine microalgae. The study will be emphasize on the efficiency of two marine microalgae named Nannochloropsis oculata and Tetraselmis chuii in treating the Lead (Pb content in industrial wasterwater. An experiment on the effect of various Pb concentration (10/20/40/60/80/100mg/L towards the microalgae has been studied. The obtained result showed that the content of chlorophyll-A in the microalgae sample, after 7 days of exposures to Pb, decreased as the Pb concentration increased. Besides that, Tetraselmis chuii was found to be more sensitive compared to Nannochloropsis oculata where both were able to tolerate the Pb concentration of up to only 20mg/L and 60mg/L, respectively.

  7. Monitoring Growth and Lipid Production of Some Egyptian Microalgae

    El-Baghdady, K.Z.; Zakaria, A.E.; Mousa, L.A.; Sadek, H.N.; Abd El Fatah, H.M.

    2016-01-01

    Microalgae bio diesel is a green and renewable energy resource. This study aims to examine growth and lipid production by various isolates of icroalgae using different growth media and lipid extraction techniques. Ten microalgae isolates were isolated from different samples collected from Egypt. The purified isolates were identified microscopically as: Lyngbya confervoides, Phormidium bohneri, Oscillatoria pseudogeminata, Amorphonostoc sp., Nostoc paludosum, Anabaena sphaerica related to cyanobacteria (blue green algae) and Chlorella vulgaris, Chlorella ellipsoidea, Scened esmusacutus acutus, Chlamydomonas globose related to green algae. These organisms were cultivated on two media: Bold's Basal Medium(BBM medium) and Blue Green Medium (BG-11 medium) to examine the favorite medium which supports the growth of each isolate In order to examine lipid production potentials by cyanobacterial isolates and green microalgae, two solvent systems were applied for lipid extraction, the first was (Chloroform - methanol 1:1 ) and the second was (Hexane-ethanol 1:1). Chlorella vulgaris and Anabaena sphaerica were selected as models of green microalgae and cyanobacteria espectively. Hexane-ethanol solvent system revealed higher lipid extraction capacity as compared to Chloroform- methanol system. A comparison between ten organisms for lipid production was carried out by the selected solvent mixture. The percentages of lipid to dry weight produced by Oscillatoria pseudogeminata and Chlamydomonas globose were 19.8% and14 .6% respectively recording the highest lipid to dry weight percentage. They can be considered as a promising lipid producing microalgae

  8. Uptake of uranium from sea water by microalgae

    Sakaguchi, Takashi; Horikoshi, Takao; Nakajima, Akira

    1978-01-01

    The uptake of uranium from aqueous systems especially from sea water by various microalgae was investigated. The freshwater microalgae, Chlorella regularis, Scenedesmus bijuga, Scenedesmus chloreloides, Scenedesmus obliquus, Chlamydomonas angulosa, Chlamydomonas reinhardtii, accumulated relatively large amounts of uranium from the solution containing uranium only. The concentration factors of the above mentioned algae were: Chlorella regularis 3930, Chlamydomonas 2330 - 3400, Scenedesmus 803 - 1920. The uptake of uranium from sea water by Chlorella regularis was inhibited markedly by the co-existence of carbonate ions. Chlorella cells could take up a great quantity of uranium from decarbonated sea water. The uptake of uranium was affected by the pH of sea water, and the amount of uranium absorbed was maximum at pH 5. The experiment was carried out to screen marine microalgae which have the ability to accumulate a large amount of uranium from sea water. The uptake of uranium from sea water by marine microalgae of different species turned out to be in the following decreasing order: Synechococcus > Chlamydomonas >> Chlorella > Dunaliella > Platymonas > Calothrix > Porphyridium. The amount of uranium absorbed differed markedly with different species of marine microalgae. (author)

  9. Influence of Microalgae onto submerged surfaces on Fouling

    Kong, M.; Eom, C.; Yoon, B.; Yoon, H.; Kim, B.; Chung, K.

    2012-12-01

    Lots of algae together with organic matter deposited on the submerged surface can be easily observed occurring in the shallower water along the coast. This is mainly because only those organisms with the ability to adapt to the new situations created by man can firmly adhere enough to avoid being washed off. Chemical and microbiological characteristics of the fouling microalgae developed on various surfaces in contact with the seawater were made. The microbial compositions of the microalgae formed on the submerged surfaces were tested for. The quantities of the diverse microalgae in the samples developed on the prohibiting submerged surface were larger when there was no concern about materials for special selection for fouling. To confirm formation of microalgae on adsorbents was done SEM-EDS (Scanning Electron Microscope-Spectrometer) analysis. Microbial identified using optical microscope. In addition to, we quantified attaching microalgae as pass time. Experiment results, ten species which are Nitzshhia sp., Eucampia sp., Coscinodiscus sp., Licmophora sp., Rhizosolenia sp., Cylindrotheca sp., Striateela sp., Thalassionema sp., Guinardia sp., and Helicostomella sp. discovered to reservoir formed biofouling. They showed the important role microbial activity in fouling and corrosion of the surfaces in contact with the any seawater.

  10. Fuels from microalgae: Technology status, potential, and research requirements

    Neenan, B.; Feinberg, D.; Hill, A.; McIntosh, R.; Terry, K.

    1986-08-01

    Although numerous options for the production of fuels from microalgae have been proposed, our analysis indicates that only two qualify for extensive development - gasoline and ester fuel. In developing the comparisons that support this conclusion, we have identified the major areas of microalgae production and processing that require extensive development. Technology success requires developing and testing processes that fully utilize the polar and nonpolar lipids produced by microalgae. Process designs used in these analyses were derived from fragmented, preliminary laboratory data. These results must be substantiated and integrated processes proposed, tested, and refined to be able to evaluate the commercial feasibility from microalgae. The production of algal feedstocks for processing to gasoline or ester fuel requires algae of high productivity and high lipid content that efficiently utilize saline waters. Species screening and development suggest that algae can achieve required standards taken individually, but algae that can meet the integrated requirements still elude researchers. Effective development of fuels from microalgae technology requires that R and D be directed toward meeting the integrated standards set out in the analysis. As technology analysts, it is inappropriate for us to dictate how the R and D effort should proceed to meet these standards. We end our role by noting that alternative approaches to meeting the feasibility targets have been identified, and it is now the task of program managers and scientists to choose the appropriate approach to assure the greatest likelihood of realizing a commercially viable technology. 70 refs., 39 figs., 35 tabs.

  11. Nutrient and media recycling in heterotrophic microalgae cultures.

    Lowrey, Joshua; Armenta, Roberto E; Brooks, Marianne S

    2016-02-01

    In order for microalgae-based processes to reach commercial production for biofuels and high-value products such as omega-3 fatty acids, it is necessary that economic feasibility be demonstrated at the industrial scale. Therefore, process optimization is critical to ensure that the maximum yield can be achieved from the most efficient use of resources. This is particularly true for processes involving heterotrophic microalgae, which have not been studied as extensively as phototrophic microalgae. An area that has received significant conceptual praise, but little experimental validation, is that of nutrient recycling, where the waste materials from prior cultures and post-lipid extraction are reused for secondary fermentations. While the concept is very simple and could result in significant economic and environmental benefits, there are some underlying challenges that must be overcome before adoption of nutrient recycling is viable at commercial scale. Even more, adapting nutrient recycling for optimized heterotrophic cultures presents some added challenges that must be identified and addressed that have been largely unexplored to date. These challenges center on carbon and nitrogen recycling and the implications of using waste materials in conjunction with virgin nutrients for secondary cultures. The aim of this review is to provide a foundation for further understanding of nutrient recycling for microalgae cultivation. As such, we outline the current state of technology and practical challenges associated with nutrient recycling for heterotrophic microalgae on an industrial scale and give recommendations for future work.

  12. Is it photosensitization or photodegradation when UV-B irradiation is combined with BDE-47? Evidence from the growth and reproduction changes of rotifer Brachionus plicatilis.

    Liu, Chunchen; Tang, Xuexi; Zhou, Bin; Jiang, Yongshun; Lv, Mengchen; Zang, Yu; Wang, You

    2018-07-01

    Ecotoxicological methods were applied in the present study, and the marine rotifer Brachionus plicatilis was used as the toxic endpoint to depict what occurred when 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) was combined with solar ultraviolet-B radiation (UV-B). B. plicatilis was exposed to three different combination methods of BDE-47 and UV-B at an equal toxicity ratio, including normal rotifer co-cultured with UV-B-irradiated BDE-47 (known as Method I), UV-B-irradiated rotifer co-cultured with BDE-47 exposure (known as Method II) and normal rotifer co-cultured with the simultaneous addition of BDE-47 and UV-B irradiation (known as Method III). Acute and chronic experiments were preformed to determine the toxicity differentiation according to the growth and reproduction changes in the rotifer. Twenty-four-hour acute experiments showed that the modes of three combined methods changed from antagonism to additive, to synergistic with the concentration/dose increment, and the contribution rates of Method I and Method II to Method III were calculated by approximately 40.4% and 59.6%, respectively. Chronic exposure to either the single stressor or the combination of stressors inhibited the growth and reproduction of the rotifer, demonstrating the inhibition of the population growth rate and the decrease in the larvae production. Three combined groups presented more serious damages compared to groups with single stress exposure, and the ascending sequence of toxicity was Method I

  13. Nitrogen Removal from Landfill Leachate by Microalgae

    Pereira, Sérgio F. L.; Gonçalves, Ana L.; Moreira, Francisca C.; Silva, Tânia F. C. V.; Vilar, Vítor J. P.; Pires, José C. M.

    2016-01-01

    Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N–NH4+) concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus) removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N–NH4+ concentration. In terms of nutrients uptake, an effective removal of N–NH4+ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N–NO3− removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates. PMID:27869676

  14. Microalgae culture collection, 1986-1987

    Barclay, W.; Johansen, J.; Chelf, P.; Nagle, N.; Roessler, P.; Lemke, P.

    1986-12-01

    The SERI Microalgae Culture Collection provides a repository for strains identified or developed for mass culture biomass production and makes these strains readily available to the research community. The strains in the collection have been selected for their potential in biomass fuel applications, and many produce significant quantities of cellular storage lipids. All of the newly added strains have been recently isolated by SERI and its subcontractors in organized screening programs. Many have been tested in outdoor mass culture systems, and several have demonstrated excellent performance as biomass producers. The strains added to the collection this year have been isolated from inland saline waters and marine waters. We believe that the strains in this collection can provide a source of extremely useful organisms, both for laboratory experimentation and for mass culture research. Most of the strains are currently nonaxenic. Again this year, cultures will be shipped free of charge to interested researchers. An important function of the culture collection catalog, in addition to listing the available strains, is to provide culture and performance data for each of the organisms. By collecting a summary of the requirements and characteristics of these organisms, we hope to allow requestors of cultures to begin productive research with a minimum of preliminary work on culture techniques.

  15. Microalgae Culture Collection, 1985-1986

    1986-01-01

    The SERI Microalgae Culture Collection was established in support of the US Department of Energy's Biofuels Program to provide a repository for strains identified or developed for mass culture biomass production and to make these strains readily available to the research community. The strains in the collection have been selected for their potential in biomass fuel applications, and many produce significant quantities of cellular storage lipids. The Culture Collection Catalog lists 20 strains of ten species. Many have been tested in outdoor mass culture systems, and several have demonstrated excellent performance as biomass producers, with yields of up to 40 grams of organic matter per square meter per day. The majority of strains added to the collection this year have been isolated from inland saline waters, although marine species are included as well. We believe that the strains in this collection can provide a source of extremely useful organisms, both for laboratory experimentation and for mass culture research. 98 refs., 31 figs., 52 tabs.

  16. Antioxidant activity of the microalga Spirulina maxima

    M.S. Miranda

    1998-08-01

    Full Text Available Spirulina maxima, which is used as a food additive, is a microalga rich in protein and other essential nutrients. Spirulina contains phenolic acids, tocopherols and ß-carotene which are known to exhibit antioxidant properties. The aim of the present study was to evaluate the antioxidant capacity of a Spirulina extract. The antioxidant activity of a methanolic extract of Spirulina was determined in vitro and in vivo. The in vitro antioxidant capacity was tested on a brain homogenate incubated with and without the extract at 37oC. The IC50 (concentration which causes a 50% reduction of oxidation of the extract in this system was 0.18 mg/ml. The in vivo antioxidant capacity was evaluated in plasma and liver of animals receiving a daily dose of 5 mg for 2 and 7 weeks. Plasma antioxidant capacity was measured in brain homogenate incubated for 1 h at 37oC. The production of oxidized compounds in liver after 2 h of incubation at 37oC was measured in terms of thiobarbituric acid reactant substances (TBARS in control and experimental groups. Upon treatment, the antioxidant capacity of plasma was 71% for the experimental group and 54% for the control group. Data from liver spontaneous peroxidation studies were not significantly different between groups. The amounts of phenolic acids, a-tocopherol and ß-carotene were determined in Spirulina extracts. The results obtained indicate that Spirulina provides some antioxidant protection for both in vitro and in vivo systems.

  17. Growth of microalgae in autotrophic stationary systems

    Paulo Cunha

    2008-06-01

    Full Text Available In this paper we evaluate the growth of nine marine microalgae species (Nannochloropsis oculata, Thalassiosira pseudonana, Phaeodactylum tricornutum, Isochrysis galbana, Tetraselmis suecica, Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira fluviatilis and Isochrysis sp. and one freshwater species (Chlorella vulgaris under stationary autotrophy conditions, using erlenmeyers fl asks with 800mL of culture medium exposed to constant light intensities providing a photon flux density of about 150μmol.m-2.s-1 and 25±2oC temperature and constant air flow. The experiment was carried out in a controlled environment considering a block delineating randomized over time with three replicates. The Nannochloropsis oculata showed the highest value of maximum cellular density, but with a longer period of time and a lower growth rate. This was probably due to its tiny cell size, demanding a large number of cells per volume to attain its optimum conditions for light, nutrients, water and atmospheric carbon dioxide. In addition, in spite of showing one of the lowest values of maximum cellular density, Thalassiosira fluviatilis was the species that reached its maximum in a short period of time at the highest growth rate. Chlorella vulgaris was the only freshwater species tested and it showed the poorest performance for all the variables analyzed in the current study.

  18. Gold nanoparticles produced in a microalga

    Luangpipat, Tiyaporn; Beattie, Isabel R.; Chisti, Yusuf; Haverkamp, Richard G.

    2011-01-01

    An efficient biological route to production of gold nanoparticles which allows the nanoparticles to be easily recovered remains elusive. Live cells of the green microalga Chlorella vulgaris were incubated with a solution of gold chloride and harvested by centrifugation. Nanoparticles inside intact cells were identified by transmission electron microscopy and confirmed to be metallic gold by synchrotron based X-ray powder diffraction and X-ray absorption spectroscopy. These intracellular gold nanoparticles were 40–60 nm in diameter. At a concentration of 1.4% Au in the alga, a better than 97% recovery of the gold from solution was achieved. A maximum of 4.2% Au in the alga was obtained. Exposure of C. vulgaris to solutions containing dissolved salts of palladium, ruthenium, and rhodium also resulted in the production of the corresponding nanoparticles within the cells. These were surmised to be also metallic, but were produced at a much lower intracellular concentration than achieved with gold. Iridium was apparently toxic to the alga. No nanoparticles were observed using platinum solutions. C. vulgaris provides a possible route to large scale production of gold nanoparticles.

  19. Microalgae as bioreactors for bioplastic production

    Steinbüchel Alexander

    2011-10-01

    Full Text Available Abstract Background Poly-3-hydroxybutyrate (PHB is a polyester with thermoplastic properties that is naturally occurring and produced by such bacteria as Ralstonia eutropha H16 and Bacillus megaterium. In contrast to currently utilized plastics and most synthetic polymers, PHB is biodegradable, and its production is not dependent on fossil resources making this bioplastic interesting for various industrial applications. Results In this study, we report on introducing the bacterial PHB pathway of R. eutropha H16 into the diatom Phaeodactylum tricornutum, thereby demonstrating for the first time that PHB production is feasible in a microalgal system. Expression of the bacterial enzymes was sufficient to result in PHB levels of up to 10.6% of algal dry weight. The bioplastic accumulated in granule-like structures in the cytosol of the cells, as shown by light and electron microscopy. Conclusions Our studies demonstrate the great potential of microalgae like the diatom P. tricornutum to serve as solar-powered expression factories and reveal great advantages compared to plant based production systems.

  20. A Holistic Approach to Managing Microalgae for Biofuel Applications

    Pau Loke Show

    2017-01-01

    Full Text Available Microalgae contribute up to 60% of the oxygen content in the Earth’s atmosphere by absorbing carbon dioxide and releasing oxygen during photosynthesis. Microalgae are abundantly available in the natural environment, thanks to their ability to survive and grow rapidly under harsh and inhospitable conditions. Microalgal cultivation is environmentally friendly because the microalgal biomass can be utilized for the productions of biofuels, food and feed supplements, pharmaceuticals, nutraceuticals, and cosmetics. The cultivation of microalgal also can complement approaches like carbon dioxide sequestration and bioremediation of wastewaters, thereby addressing the serious environmental concerns. This review focuses on the factors affecting microalgal cultures, techniques adapted to obtain high-density microalgal cultures in photobioreactors, and the conversion of microalgal biomass into biofuels. The applications of microalgae in carbon dioxide sequestration and phycoremediation of wastewater are also discussed.

  1. Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

    Rui Manuel Santos Costa de Morais

    2013-01-01

    Full Text Available Marine microalgae have been used for a long time as food for humans, such as Arthrospira (formerly, Spirulina, and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The present review puts up-to-date the research on the biological activities and applications of polysaccharides, active biocompounds synthesized by marine unicellular algae, which are, most of the times, released into the surrounding medium (exo- or extracellular polysaccharides, EPS. It goes through the most studied activities of sulphated polysaccharides (sPS or their derivatives, but also highlights lesser known applications as hypolipidaemic or hypoglycaemic, or as biolubricant agents and drag-reducers. Therefore, the great potentials of sPS from marine microalgae to be used as nutraceuticals, therapeutic agents, cosmetics, or in other areas, such as engineering, are approached in this review.

  2. Multi-Product Microalgae Biorefineries: From Concept Towards Reality.

    't Lam, G P; Vermuë, M H; Eppink, M H M; Wijffels, R H; van den Berg, C

    2018-02-01

    Although microalgae are a promising biobased feedstock, industrial scale production is still far off. To enhance the economic viability of large-scale microalgae processes, all biomass components need to be valorized, requiring a multi-product biorefinery. However, this concept is still too expensive. Typically, downstream processing of industrial biotechnological bulk products accounts for 20-40% of the total production costs, while for a microalgae multi-product biorefinery the costs are substantially higher (50-60%). These costs are high due to the lack of appropriate and mild technologies to access the different product fractions such as proteins, carbohydrates, and lipids. To reduce the costs, simplified processes need to be developed for the main unit operations including harvesting, cell disruption, extraction, and possibly fractionation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Heterotrophic cultivation of microalgae for pigment production: A review.

    Hu, Jianjun; Nagarajan, Dillirani; Zhang, Quanguo; Chang, Jo-Shu; Lee, Duu-Jong

    Pigments (mainly carotenoids) are important nutraceuticals known for their potent anti-oxidant activities and have been used extensively as high end health supplements. Microalgae are the most promising sources of natural carotenoids and are devoid of the toxic effects associated with synthetic derivatives. Compared to photoautotrophic cultivation, heterotrophic cultivation of microalgae in well-controlled bioreactors for pigments production has attracted much attention for commercial applications due to overcoming the difficulties associated with the supply of CO 2 and light, as well as avoiding the contamination problems and land requirements in open autotrophic culture systems. In this review, the heterotrophic metabolic potential of microalgae and their uses in pigment production are comprehensively described. Strategies to enhance pigment production under heterotrophic conditions are critically discussed and the challenges faced in heterotrophic pigment production with possible alternative solutions are presented. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Microalgae Isolation and Selection for Prospective Biodiesel Production

    Peer M. Schenk

    2012-06-01

    Full Text Available Biodiesel production from microalgae is being widely developed at different scales as a potential source of renewable energy with both economic and environmental benefits. Although many microalgae species have been identified and isolated for lipid production, there is currently no consensus as to which species provide the highest productivity. Different species are expected to function best at different aquatic, geographical and climatic conditions. In addition, other value-added products are now being considered for commercial production which necessitates the selection of the most capable algae strains suitable for multiple-product algae biorefineries. Here we present and review practical issues of several simple and robust methods for microalgae isolation and selection for traits that maybe most relevant for commercial biodiesel production. A combination of conventional and modern techniques is likely to be the most efficient route from isolation to large-scale cultivation.

  5. Cultivation Of Microalgae (Chlorella vulgaris For Biodiesel Production

    Blinová Lenka

    2015-06-01

    Full Text Available Production of biofuel from renewable sources is considered to be one of the most sustainable alternatives to petroleum sourced fuels. Biofuels are also viable means of environmental and economic sustainability. Biofuels are divided into four generations, depending on the type of biomass used for biofuels production. At present, microalgae are presented as an ideal third generation biofuel feedstock because of their rapid growth rate. They also do not compete with food or feed crops, and can be produced on non-arable land. Cultivation conditions (temperature, pH, light, nutrient quantity and quality, salinity, aerating are the major factors that influence photosynthesis activity and behaviour of the microalgae growth rate. In this paper, we present an overview about the effect of cultivation conditions on microalgae growth.

  6. Microalga propels along vorticity direction in a shear flow

    Chengala, Anwar; Hondzo, Miki; Sheng, Jian

    2013-05-01

    Using high-speed digital holographic microscopy and microfluidics, we discover that, when encountering fluid flow shear above a threshold, unicellular green alga Dunaliella primolecta migrates unambiguously in the cross-stream direction that is normal to the plane of shear and coincides with the local fluid flow vorticity. The flow shear drives motile microalgae to collectively migrate in a thin two-dimensional horizontal plane and consequently alters the spatial distribution of microalgal cells within a given suspension. This shear-induced algal migration differs substantially from periodic rotational motion of passive ellipsoids, known as Jeffery orbits, as well as gyrotaxis by bottom-heavy swimming microalgae in a shear flow due to the subtle interplay between torques generated by gravity and viscous shear. Our findings could facilitate mechanistic solutions for modeling planktonic thin layers and sustainable cultivation of microalgae for human nutrition and bioenergy feedstock.

  7. Engineering fatty acid biosynthesis in microalgae for sustainable biodiesel.

    Blatti, Jillian L; Michaud, Jennifer; Burkart, Michael D

    2013-06-01

    Microalgae are a promising feedstock for biodiesel and other liquid fuels due to their fast growth rate, high lipid yields, and ability to grow in a broad range of environments. However, many microalgae achieve maximal lipid yields only under stress conditions hindering growth and providing compositions not ideal for biofuel applications. Metabolic engineering of algal fatty acid biosynthesis promises to create strains capable of economically producing fungible and sustainable biofuels. The algal fatty acid biosynthetic pathway has been deduced by homology to bacterial and plant systems, and much of our understanding is gleaned from basic studies in these systems. However, successful engineering of lipid metabolism in algae will necessitate a thorough characterization of the algal fatty acid synthase (FAS) including protein-protein interactions and regulation. This review describes recent efforts to engineer fatty acid biosynthesis toward optimizing microalgae as a biodiesel feedstock. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Thermogravimetric analysis of the gasification of microalgae Chlorella vulgaris.

    Figueira, Camila Emilia; Moreira, Paulo Firmino; Giudici, Reinaldo

    2015-12-01

    The gasification of microalgae Chlorella vulgaris under an atmosphere of argon and water vapor was investigated by thermogravimetric analysis. The data were interpreted by using conventional isoconversional methods and also by the independent parallel reaction (IPR) model, in which the degradation is considered to happen individually to each pseudo-component of biomass (lipid, carbohydrate and protein). The IPR model allows obtaining the kinetic parameters of the degradation reaction of each component. Three main stages were observed during the gasification process and the differential thermogravimetric curve was satisfactorily fitted by the IPR model considering three pseudocomponents. The comparison of the activation energy values obtained by the methods and those found in the literature for other microalgae was satisfactory. Quantification of reaction products was performed using online gas chromatography. The major products detected were H2, CO and CH4, indicating the potential for producing fuel gas and syngas from microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Ultrasonic assisted biodiesel production of microalgae by direct transesterification

    Kalsum, Ummu; Mahfud, Mahfud; Roesyadi, Achmad

    2017-03-01

    Microalgae are considered as the third generation source of biofuel and an excellent candidate for biofuel production to replace the fossil energy. The use of ultrasonic in producing biodiesel by direct transesterification of Nannochloropsis occulata using KOH as catalyst and methanol as a solvent was investigated. The following condition were determined as an optimum by experimental evaluates:: 1: 15 microalga to methanol (molar ratio); 3% catalyst concentration at temperature 40°C after 30 minute of ultrasonication. The highest yield of biodiesel produced was 30.3%. The main components of methyl ester from Nannochloropsis occulata were palmitic (C16 :0),, oleic (C18:1), stearic (C18;0), arahidic (C20:0) and myristic (C14:0). This stated that the application of ultrasounic for direct transesterificaiton of microalgae effectively reduced the reaction time compared to the reported values of conventional heating systems.

  10. Microalgae as source of biofuel: technology and prospective

    Ferraro, Angelo

    2017-12-01

    Microalgae are autotrophic organisms found in solitary cells or in groups of single cells connected together. Their natural environment are typically freshwater and marine systems. Microalgae produce, via photosynthesis, approximately one-half of oxygen generated on earth while simultaneously consume carbon dioxide (CO2). Among the technologies being examined to produce green fuels (e.g. biodiesel, bioethanol and syngas), microalgae are viewed by many in the scientific community as having the greatest potential to become economically viable fuels. Nevertheless, to reach economic parity with fossil fuels there are still several challenges to be tackle. These include improving harvesting and oil extraction processes as well as increasing biomass productivity and oil content. All of these challenges can be impacted by genetic, molecular, and ultimately synthetic biology techniques.

  11. Efeito alelopático e toxicidade frente à Artemia salina Leach dos extatos do fruto de Euterpe edulis Martius Allelopathic effects and toxicity against Artemia salina Leach of extracts of the fruit of Euterpe edulis Martius

    Cristina Peitz de Lima

    2011-06-01

    Full Text Available Alelopatia é um processo envolvendo metabólitos secundários produzidos por plantas que infl uenciam o crescimento e desenvolvimento de sistemas agrícolas. Devido à toxicidade dos herbicidas sintéticos para o meio ambiente e para a saúde humana tem-se aumentado o interesse na exploração da alelopatia como uma alternativa para o controle de plantas daninhas. O presente trabalho avaliou efeito dos extratos dos frutos de Euterpe edulis Martius sobre o desenvolvimento de cipselas e plântulas de Lactuca sativa Linné, foram determinados o índice de velocidade de germinação, o crescimento da radícula e do hipocótilo. Para a avaliação da toxicidade dos extratos foi realizado o ensaio de toxicidade frente ao microcrustáceo Artemia salina Leach determinando-se a CL50 e percentual de mortalidade. A fração remanescente demonstrou efeito alelopático, pois todas as concentrações alteraram os valores do índice de velocidade de germinação e as concentrações de 0,2 e 0,4 mg inibiram tanto o crescimento da radícula quanto o crescimento do hipocótilo. No ensaio de toxicidade todos os extratos apresentaram CL50 superior a 1000 ppm e 0% de mortalidade das artemias, indicando a não toxicidade dos extratos.Allelopathy is a process involving secondary metabolites produced by plants that influence growth and development of agricultural systems. Because of the toxicity of synthetic herbicides to the environment and human health, there has been increased interest in exploiting allelopathy as an alternative for weed control. This study evaluated the eff ect of extracts of Euterpe edulis Martius fruits on the development of cypselae and seedlings of Lactuca sativa Linné; the germination speed index, radicle and hypocotyl growth were determined. To evaluate the toxicity of the extracts the toxicity test against Artemia salina Leach was used, where the LC50 and mortality rate were determined. Th e remaining fraction showed allelopathic effect

  12. Embriões liofilizados e flocos de Artemia no cultivo pós-larval de Litopenaeus vannamei (Boone, 1931 = Use of freeze-dried embryos and Artemia flakes in the post-larval culture of Litopenaeus vannamei (Boone, 1931

    Pedro Hercílio de Oliveira Cavalcante

    2008-01-01

    Full Text Available O objetivo do estudo foi avaliar o crescimento e sobrevivência de 1pós-larvas de Litopenaeus vannamei que receberam embriões liofilizados (EMB e flocos (FLO de Artemia como suplementos alimentares a uma dieta microparticulada (DMP. Nos tratamentos T1,T2 e T3, os camarões receberam DMP e após 2h, acréscimos de FLO (T1; de EMB (T2; e da mesma DMP, anteriormente, ofertada (T3. No T4, as pós-larvas foram alimentadas com DMP, mas sem suplementações posteriores. Não houve diferença significativa (p > 0,05 na sobrevivência dos camarões após o período experimental de 21 dias. Por outro lado, o ganho de peso absoluto (mg peso seco das pós-larvas, cuja dieta foi suplementada com BEM, foi significativamente superior (p The objective of the study was to evaluate the growth and survival of Litopenaeus vannamei post-larvae fed with freeze-driedembryos and Artemia flakes as feeding supplements to a microparticulate diet (DMP. In treatments T1, T2 and T3, the shrimp were fed with DMP and after 2 hours, received supplements of FLO (T1; EMB (T2; and the same DMP previously offered (T3. In T4,post-larvae were fed with DMP but without additional supplementation. There was no significant difference (p > 0.05 in shrimp survival after the experimental period of 21 days. On the other hand, the absolute weight gain (mg of dry weight of post-larvae whose dietwas supplemented with EMB (T2 was significantly higher (p < 0.05 than growth found in the other experimental groups (T1, T3 and T4. Shrimp fed with DMP and EMB obtained a significantly higher absolute weight gain (6.7 mg than those found in treatments that used DMP and FLO (5.4 mg or DMP alone (5.8 mg in T3 and 5.7 mg in T4. Theseresults underline the nutritional value of freeze-dried Artemia embryos and recommend their inclusion in the post-larval diet of Litopenaeus vannamei.

  13. Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications.

    Luo, Xuan; Su, Peng; Zhang, Wei

    2015-07-09

    Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry.

  14. Biogas Production From Cassava Starch Effluent Using Microalgae As Biostabilisator

    B. Budiyono

    2011-07-01

    Full Text Available The rapid growing of Indonesian population is emerging several critical national issues i.e. energy, food, environmental, water, transportation, as well as law and human right. As an agricultural country, Indonesia has abundant of biomass wastes such as agricultural wastes include the cassava starch wastes. The problem is that the effluent from cassava starch factories is released directly into the river before properly treatment. It has been a great source of pollution and has caused environmental problems to the nearby rural population. The possible alternative to solve the problem is by converting waste to energy biogas in the biodigester. The main problem of the biogas production of cassava starch effluent is acid forming-bacteria quickly produced acid resulting significantly in declining pH below the neutral pH and diminishing growth of methane bacteria. Hence, the only one of the method to cover this problem is by adding microalgae as biostabilisator of pH. Microalgae can also be used as purifier agent to absorb CO2.The general objective of this research project was to develop an integrated process of biogas production and purification from cassava starch effluent by using biostabilisator agent microalgae. This study has been focused on the used of urea, ruminant, yeast, microalgae, the treatment of gelled and ungelled feed for biogas production, pH control during biogas production using buffer Na2CO3, and feeding management in the semi-continuous process of biogas production. The result can be concluded as follows: i The biogas production increased after cassava starch effluent and yeast was added, ii Biogas production with microalgae and cassava starch effluent, yeast, ruminant bacteria, and urea were 726.43 ml/g total solid, iii Biogas production without  microalgae was 189 ml/g total solid.

  15. Advances and perspectives in using microalgae to produce biodiesel

    Amaro, Helena M.; Guedes, A. Catarina; Malcata, F. Xavier

    2011-01-01

    Carbon-neutral renewable liquid biofuels are needed to displace petroleum-derived transport fuels in the near future - which contribute to global warming and are of a limited availability. A promising alternative is conveyed by microalgae, the oil content of which may exceed 80% (w/w DW ) - as compared with 5% of the best agricultural oil crops. However, current implementation of microalga-based systems has been economically constrained by their still poor volumetric efficiencies - which lead to excessively high costs, as compared with petrofuel prices. Technological improvements of such processes are thus critical - and this will require a multiple approach, both on the biocatalyst and bioreactor levels. Several bottlenecks indeed exist at present that preclude the full industrial exploitation of microalgal cells: the number of species that have been subjected to successful genetic transformation is scarce, which hampers a global understanding (and thus a rational design) of novel blue-biotechnological processes; the mechanisms that control regulation of gene expression are not fully elucidated, as required before effective bioprocesses based on microalgae can be scaled-up; and new molecular biology tools are needed to standardize genetic modifications in microalgae - including efficient nuclear transformation, availability of promoter or selectable marker genes, and stable expression of transgenes. On the other hand, a number of pending technological issues are also present: the relatively low microalga intrinsic lipid productivity; the maximum cell concentration attainable; the efficiency of harvest and sequential recovery of bulk lipids; and the possibility of by-product upgrade. This review briefly covers the state of the art regarding microalgae toward production of biofuels, both from the point of view of the microalgal cell itself and of the supporting bioreactor; and discusses, in a critical manner, current limitations and promising perspectives in this

  16. Microalgae as a raw material for biofuels production.

    Gouveia, Luisa; Oliveira, Ana Cristina

    2009-02-01

    Biofuels demand is unquestionable in order to reduce gaseous emissions (fossil CO(2), nitrogen and sulfur oxides) and their purported greenhouse, climatic changes and global warming effects, to face the frequent oil supply crises, as a way to help non-fossil fuel producer countries to reduce energy dependence, contributing to security of supply, promoting environmental sustainability and meeting the EU target of at least of 10% biofuels in the transport sector by 2020. Biodiesel is usually produced from oleaginous crops, such as rapeseed, soybean, sunflower and palm. However, the use of microalgae can be a suitable alternative feedstock for next generation biofuels because certain species contain high amounts of oil, which could be extracted, processed and refined into transportation fuels, using currently available technology; they have fast growth rate, permit the use of non-arable land and non-potable water, use far less water and do not displace food crops cultures; their production is not seasonal and they can be harvested daily. The screening of microalgae (Chlorella vulgaris, Spirulina maxima, Nannochloropsis sp., Neochloris oleabundans, Scenedesmus obliquus and Dunaliella tertiolecta) was done in order to choose the best one(s), in terms of quantity and quality as oil source for biofuel production. Neochloris oleabundans (fresh water microalga) and Nannochloropsis sp. (marine microalga) proved to be suitable as raw materials for biofuel production, due to their high oil content (29.0 and 28.7%, respectively). Both microalgae, when grown under nitrogen shortage, show a great increase (approximately 50%) in oil quantity. If the purpose is to produce biodiesel only from one species, Scenedesmus obliquus presents the most adequate fatty acid profile, namely in terms of linolenic and other polyunsaturated fatty acids. However, the microalgae Neochloris oleabundans, Nannochloropsis sp. and Dunaliella tertiolecta can also be used if associated with other

  17. Poly-ß-hydroxybutyrate content and dose of the bacterial carrier for Artemia enrichment determine the performance of giant freshwater prawn larvae.

    Thai, Truong Quoc; Wille, Mathieu; Garcia-Gonzalez, Linsey; Sorgeloos, Patrick; Bossier, Peter; De Schryver, Peter

    2014-06-01

    The beneficial effects of poly-β-hydroxybutyrate (PHB) for aquaculture animals have been shown in several studies. The strategy of applying PHB contained in a bacterial carrier has, however, hardly been considered. The effect of administering PHB-accumulated Alcaligenes eutrophus H16 containing 10 or 80 % PHB on dry weight, named A10 and A80, respectively, through the live feed Artemia was investigated on the culture performance of larvae of the giant freshwater prawn (Macrobrachium rosenbergii). Feeding larvae with Artemia nauplii enriched in a medium containing 100 and 1,000 mg L(-1) A80 significantly increased the survival with about 15 % and the development of the larvae with a larval stage index of about 1 as compared to feeding non-enriched Artemia. The survival of the larvae also significantly increased with about 35 % in case of a challenge with Vibrio harveyi. The efficiency of these treatments was equal to a control treatment of Artemia enriched in an 800 mg L(-1) PHB powder suspension, while Artemia enriched in 10 mg L(-1) A80, 100 mg L(-1) A10, and 1,000 mg L(-1) A10 did not bring similar effects. From our results, it can be concluded that PHB supplemented in a bacterial carrier (i.e., amorphous PHB) can increase the larviculture efficiency of giant freshwater prawn similar to supplementation of PHB in powdered form (i.e., crystalline PHB). When the level of PHB in the bacterial carrier is high, similar beneficial effects can be achieved as crystalline PHB, but at a lower live food enrichment concentration expressed on PHB basis.

  18. Terpenes as Green Solvents for Extraction of Oil from Microalgae

    Celine Dejoye Tanzi

    2012-07-01

    Full Text Available Herein is described a green and original alternative procedure for the extraction of oil from microalgae. Extractions were carried out using terpenes obtained from renewable feedstocks as alternative solvents instead of hazardous petroleum solvents such as n-hexane. The described method is achieved in two steps using Soxhlet extraction followed by the elimination of the solvent from the medium using Clevenger distillation in the second step. Oils extracted from microalgae were compared in terms of qualitative and quantitative determination. No significant difference was obtained between each extract, allowing us to conclude that the proposed method is green, clean and efficient.

  19. Potency of Microalgae as Biodiesel Source in Indonesia

    H Hadiyanto

    2012-04-01

    Full Text Available Within 20 years, Indonesia should find another energy alternative to substitutecurrent fossil oil. Current use of renewable energy is only 5% and need to be improved up to 17%of our energy mix program. Even though, most of the area in Indonesia is covered by sea, howeverthe utilization of microalgae as biofuel production is still limited. The biodiesel from currentsources (Jatropha, palm oil, and sorghum is still not able to cover all the needs if the fossil oilcannot be explored anymore. In this paper, the potency of microalgae in Indonesia was analysed asthe new potential of energy (biodiesel sources.

  20. Potency of Microalgae as Biodiesel Source in Indonesia

    H Hadiyanto

    2012-02-01

    Full Text Available Within 20 years, Indonesia should find another energy alternative to substitute current fossil oil. Current use of renewable energy is only 5% and need to be improved up to 17% of our energy mix program. Even though, most of the area in Indonesia is covered by sea, however the utilization of microalgae as biofuel production is still limited. The biodiesel from current sources (Jatropha, palm oil, and sorghum is still not able to cover all the needs if the fossil oil cannot be explored anymore. In this paper, the potency of microalgae in Indonesia was analysed as the new potential of energy (biodiesel sources.

  1. Microalgae: An alternative as sustainable source of biofuels?

    Amaro, Helena M.; Macedo, Ângela C.; Malcata, F. Xavier

    2012-01-01

    In recent decades, the world has been confronted with an energy crisis associated with irreversible depletion of traditional sources of fossil fuels, coupled with atmospheric accumulation of greenhouse gases that cause global warming. The urgent need to replace traditional fuels led to emergence of biodiesel and biohydrogen as interesting alternatives, both of which can be obtained via microalga-mediated routes. Microalgae are ubiquitous eukaryotic microorganisms, characterized by a remarkable metabolic plasticity. Their oil productivities are much higher than those of higher terrestrial plants, and they do not require high quality agricultural land. Microalgae may indeed be cultivated in brackish and wastewaters that provide suitable nutrients (e.g. NH 4 + ,NO 3 − andPO 4 3− ), at the expense of only sunlight and atmospheric CO 2 . On the other hand, metabolic engineering permits release of molecular hydrogen also via photosynthetic routes, which will easily be converted to electricity in fuel cells or mechanical power in explosion engines, with only water vapor as exhaust product in both cases. However, large-scale implementation of microalga-based systems to manufacture biodiesel and biohydrogen has been economically constrained by their still poor volumetric efficiencies, which imply excessively high costs when compared with current petrofuel prices. Technological improvements are accordingly critical, both on the biocatalyst and the bioreactor levels. The current bottlenecks that have apparently precluded full industrial exploitation of microalgae cells are critically discussed here, viz. those derived from the scarce knowledge on the mechanisms that control regulation of gene expression, the reduced number of species subjected to successful genetic transformation, the relatively low cell density attainable, the poor efficiency in harvesting, and the difficulties in light capture and use. Therefore, this paper provides an overview of the feasibility of

  2. Nanosilver microalgae biosynthesis: cell appearance based on SEM and EDX methods

    Pancasakti Kusumaningrum, Hermin; Zainuri, Muhammad; Marhaendrajaya, Indras; Subagio, Agus

    2018-05-01

    Microbial contamination has caused public health problems in the world population. This problem has spurred the development of methods to overcome and prevent microbial invasion. The extensive use of antibiotics has facilitated the continued emergence and spread of resistant organisms. Synthesized of silver nanoparticle (AgNPs) on microalgae Chlorella pyrenoidosa offer environmentally safe antimicrobial agent. The present study is focused on the biosynthesis of AgNPs using microalgae C. pyrenoidosa. The research methods was conducted by insertion of nanosilver particle into microalgae cells with and without agitation to speed up the process of formation nanosilver microalgae. The formation of microalgae SNP was analyzes by UV-Vis spectrophotometer, Scanning Electron Micrograph (SEM) and Energy-dispersive X-ray spectroscopy (EDX) methods. The research result showed that nanosilver microalgae biosynthesis using the agitation treatment was exhibited better performance in particle insertion and cell stability, comparing with no agitation treatment. However, synthesis of nanosilver microalgae tend to reduce the cell size.

  3. Wet torrefaction of microalga Chlorella vulgaris ESP-31 with microwave-assisted heating

    Bach, Quang-Vu; Chen, Wei-Hsin; Lin, Shih-Cheng; Sheen, Herng-Kuang; Chang, Jo-Shu

    2017-01-01

    Highlights: • A microwave-assisted heating system is used for wet torrefaction (WT) of microalga. • Microalga Chlorella vulgaris ESP-31 is adopted as the feedstock. • The ash content in the microalga is reduced after WT. • The calorific value of the microalga can be intensified up to 21% after WT. • At least 61.5% of energy in the biomass is retained after WT. - Abstract: Microalgae are a prime source of third generation biofuels. Many thermochemical processes can be applied to convert them into fuels and other valuable products. However, some types of microalgae are characterized by very high moisture and ash contents, thereby causing several problems in further conversion processes. This study presents wet torrefaction (WT) as a promising pretreatment method to overcome the aforementioned drawbacks coupled with microalgal biomass. For this purpose, a microwave-assisted heating system was used for WT of microalga Chlorella vulgaris ESP-31 at different reaction temperatures (160, 170, and 180 °C) and durations (5, 10, and 30 min). The results show several improvements in the fuel properties of the microalga after WT such as increased calorific value and hydrophobicity as well as reduced ash content. A correlation in terms of elemental analysis can be adopted to predict the higher heating value of the torrefied microalga. The structure analysis by Fourier transform infrared (FT-IR) spectroscopy reveals that the carbohydrate content in the torrefied microalgae is lowered, whereas their protein and lipid contents are increased if the WT extent is not severe. However, the protein and lipid contents are reduced significantly at more severe WT conditions. The thermogravimetric analysis shows that the torrefied microalgae have lower ignition temperatures but higher burnout temperatures than the raw microalga, revealing significant impact of WT on the combustion reactivity of the microalga. Overall, the calorific value of the microalga can be intensified up to

  4. Study on mixis potential of rotifer resting eggs ( Brachionus plicatilis) with different collection times and different preservation periods

    Zhou, Li; Zheng, Yan; Xiang, Jian-Hai

    2001-09-01

    The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985 1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

  5. Shifts in rotifer life history in response to stable isotope enrichment: testing theories of isotope effects on organismal growth

    2017-01-01

    In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effects in vivo. Here, I demonstrate profound changes in life histories of the rotifer Brachionus plicatilis fed 15N-enriched algae (0.4–5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies. PMID:28405367

  6. Impact of several harmful algal bloom (HAB) causing species, on life history characteristics of rotifer Brachionus plicatilis Müller

    Lin, Jianing; Yan, Tian; Zhang, Qingchun; Zhou, Mingjiang

    2016-07-01

    In recent years, harmful algal blooms (HABs) have occurred frequently along the coast of China, and have been exhibiting succession from diatom- to dinoflagellate-dominated blooms. To examine the effects of different diatom and dinoflagellate HABs, the life history parameters of rotifers ( Brachionus plicatilis Müller) were measured after exposure to different concentrations of HAB species. The HAB species examined included a diatom ( Skeletonema costatum) and four dinoflagellates ( Prorocentrum donghaiense, Alexandrium catenella, Prorocentrum lima and Karlodinium veneficum). Compared with the control treatment (CT), the diatom S. costatum showed no adverse impacts on rotifers. Exposure to dinoflagellates at densities equivalent to those measured in the field resulted in a reduction in all the life history parameters measured. This included a reduction in: lifetime egg production (CT: 20.34 eggs/ind.) reduced to 10.11, 3.22, 4.17, 7.16 eggs/ind., life span (CT: 394.53 h) reduced to 261.11, 162.90, 203.67, 196 h, net reproductive rate (CT: 19.51/ind.) reduced to 3.01, 1.26, 3.53, 5.96/ind., finite rate of increase (CT: 1.47/d) reduced to 1.16, 1.03, 1.33, 1.38/d, and intrinsic rate of population increase (CT: 0.39/d) reduced to 0.15, 0.03, 0.28, 0.32/d, for the dinoflagellates P. donghaiense, A. catenella, P. lima and K. veneficum, respectively. The results showed that the diatom S. costatum had no detrimental consequences on the reproduction and growth of B. plicatilis, however, the four dinoflagellates tested did show adverse effects. This suggests that dinoflagellate HABs may suppress microzooplankton, resulting in an increase in algal numbers.

  7. Two circular chromosomes of unequal copy number make up the mitochondrial genome of the rotifer Brachionus plicatilis.

    Suga, Koushirou; Mark Welch, David B; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

    2008-06-01

    The monogonont rotifer Brachionus plicatilis is an emerging model system for a diverse array of questions in limnological ecosystem dynamics, the evolution of sexual recombination, cryptic speciation, and the phylogeny of basal metazoans. We sequenced the complete mitochondrial genome of B. plicatilis sensu strictu NH1L and found that it is composed of 2 circular chromosomes, designated mtDNA-I (11,153 bp) and mtDNA-II (12,672 bp). Hybridization to DNA isolated from mitochondria demonstrated that mtDNA-I is present at 4 times the copy number of mtDNA-II. The only nucleotide similarity between the 2 chromosomes is a 4.9-kbp region of 99.5% identity including a transfer RNA (tRNA) gene and an extensive noncoding region that contains putative D-loop and control sequence. The mtDNA-I chromosome encodes 4 proteins (ATP6, COB, NAD1, and NAD2), 13 tRNAs, and the large and small subunit ribosomal RNAs; mtDNA-II encodes 8 proteins (COX1-3, NAD3-6, and NAD4L) and 9 tRNAs. Gene order is not conserved between B. plicatilis and its closest relative with a sequenced mitochondrial genome, the acanthocephalan Leptorhynchoides thecatus, or other sequenced mitochondrial genomes. Polymerase chain reaction assays and Southern hybridization to DNA from 18 strains of Brachionus suggest that the 2-chromosome structure has been stable for millions of years. The novel organization of the B. plicatilis mitochondrial genome into 2 nearly equal chromosomes of 4-fold different copy number may provide insight into the evolution of metazoan mitochondria and the phylogenetics of rotifers and other basal animal phyla.

  8. Acute toxicity tests using rotifers. 4. Effects of cyst age, temperature, and salinity on the sensitivity of Brachionus calyciflorus

    Snell, T.W.; Moffat, B.D.; Janssen, C.; Persoone, G. (University of Tampa, Florida (USA))

    1991-06-01

    Several aspects of the response to toxicants using a standardized toxicity test with the freshwater rotifer Brachionus calyciflorus are described. Test animals are obtained by hatching cysts which produce animals of similar age and physiological condition. The acute toxicity of 28 compounds is described with 24-hr LC50's. The LC50's span five orders of magnitude, from silver at 0.008 mg.liter-1 to benzene at more than 1000 mg.liter-1. Control mortality in 84 tests averaged 2% with a standard deviation of 3%, indicating very consistent test sensitivity. Only once in 84 trials did a test fail because of excessive control mortality, yielding a failure rate of 1.2%. Cyst age from 0 to 18 months had no effect on the sensitivity of neonates to reference toxicants. Both high and low temperatures increased rotifer sensitivity to reference toxicants. Copper sensitivity was greater at 10, 25, and 30 degrees C compared with results at 20 degrees C. Likewise, sodium pentachlorophenol toxicity was greater at 10 and 30 degrees C compared with results at 20 degrees C. Survivorship curves at 25 degrees C of neonates under control conditions indicated that mortality begins at about 30 hr. This places a practical limit on toxicant exposure for the assay of 24 hr. B. calyciflorus cysts hatch at salinities up to 5 ppt and acute toxicity tests using pentachlorophenol at this salinity yielded LC50's about one-half those of standard freshwater. B. calyciflorus is preferred over Brachionus plicatilis for toxicity tests in salinities up to 5 ppt because it is consistently more sensitive.

  9. Toxicity of Diuron and copper pyrithione on the brine shrimp, Artemia franciscana: the effects of temperature and salinity.

    Koutsaftis, Apostolos; Aoyama, Isao

    2008-12-01

    Diuron and copper pyrithione (CuPT) are two substances that have been used worldwide as alternatives to tributyltin (TBT) in antifouling paints for the protection of ship hulls. In this study their toxicity against the brine shrimp Artemia franciscana is examined under several combinations of salinity and temperature using the LC(20), LC(50) and LC(80) values found for the 25 degrees C and 35 per thousand standard conditions. A significant interaction between temperature and salinity effects was observed for both chemicals. Decreasing temperature almost eliminated Diuron's toxicity, while a toxicity reduction was also observed for CuPT. Decreasing salinity decreased Diuron's toxicity, while for CuPT the effect of salinity was more complex. These two natural environmental parameters had a profound influence on the ecotoxicity of the two tested chemicals, and this highlights the importance of considering the implications of such factors when conducting ecological risk assessment.

  10. Lethal and sublethal endpoints observed for Artemia exposed to two reference toxicants and an ecotoxicological concern organic compound.

    Manfra, Loredana; Canepa, Sara; Piazza, Veronica; Faimali, Marco

    2016-01-01

    Swimming speed alteration and mortality assays with the marine crustacean Artemia franciscana were carried out. EC50 and LC50 values after 24-48h exposures were calculated for two reference toxicants, copper sulphate pentahydrate (CuSO4·5H2O) and Sodium Dodecyl Sulphate (SDS), and an ecotoxicological concern organic compound, Diethylene Glycol (DEG). Different end-points have been evaluated, in order to point out their sensitivity levels. The swimming speed alteration (SSA) was compared to mortality values and also to the hatching rate inhibition (literature data). SSA resulted to be more sensitive than the mortality and with a sensitivity comparable to (or even higher than) the hatching rate endpoint. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Determination of biological and physicochemical parameters of Artemia franciscana strains in hypersaline environments for aquaculture in the Colombian Caribbean.

    Camargo, William N; Durán, Gabriel C; Rada, Orlando C; Hernández, Licet C; Linero, Juan-Carlos G; Muelle, Igor M; Sorgeloos, Patrick

    2005-10-26

    Artemia (Crustacea, Anostraca), also known as brine shrimp, are typical inhabitants of extreme environments. These hypersaline environments vary considerably in their physicochemical composition, and even their climatic conditions and elevation. Several thalassohaline (marine) environments along the Colombian Caribbean coast were surveyed in order to contribute to the knowledge of brine shrimp biotopes in South America by determining some vital biological and physicochemical parameters for Artemia survival. Additionally, cyst quality tests, biometrical and essential fatty acids analysis were performed to evaluate the economic viability of some of these strains for the aquaculture industry. In addition to the three locations (Galerazamba, Manaure, and Pozos Colorados) reported in the literature three decades ago in the Colombian Caribbean, six new locations were registered (Salina Cero, Kangaru, Tayrona, Bahía Hondita, Warrego and Pusheo). All habitats sampled showed that chloride was the prevailing anion, as expected, because of their thalassohaline origin. There were significant differences in cyst diameter grouping strains in the following manner according to this parameter: 1) San Francisco Bay (SFB-Control, USA), 2) Galerazamba and Tayrona, 3) Kangarú, 4) Manaure, and 5) Salina Cero and Pozos Colorados. Chorion thickness values were smaller in Tayrona, followed by Salina Cero, Galerazamba, Manaure, SFB, Kangarú and Pozos Colorados. There were significant differences in naupliar size, grouping strains as follows (smallest to largest): 1) Galerazamba, 2) Manaure, 3) SFB, Kangarú, and Salina Cero, 4) Pozos Colorados, and 5) Tayrona. Overall, cyst quality analysis conducted on samples from Manaure, Galerazamba, and Salina Cero revealed that all sites exhibited a relatively high number of cysts.g-1. Essential fatty acids (EFA) analysis performed on nauplii from cyst samples from Manaure, Galerazamba, Salina Cero and Tayrona revealed that cysts from all sites

  12. Proteomic analysis of acute responses to copper sulfate stress in larvae of the brine shrimp, Artemia sinica

    Zhou, Qian; Wu, Changgong; Dong, Bo; Li, Fuhua; Liu, Fengqi; Xiang, Jianhai

    2010-03-01

    Proteomics was used to reveal the differential protein expression profiles of acute responses to copper sulfate exposure in larvae of Artemia sinica. Fourteen differentially displayed protein spots were detected and seven of them were identified. Three spots were up-expressed and identified: actin, heat shock protein 70, and chaperone subunit 1; three down-regulated proteins were identified: arginine kinase, elongation factor-2, and glycine-rich protein; and a newly expressed protein was identified as peroxiredoxin. The study indicates the involvement of all the differentially expressed proteins in the early responses of protein expression, and in the survival of A. sinica in the presence of copper and other heavy metals; the findings improve understanding of the organism’s adaptive responses and resistance.

  13. Temperature-dose relationships with aflatoxin M1 in milk on the brine shrimp (Artemia salina larvae

    Lejla Duraković

    2011-06-01

    Full Text Available Temperature-dose relationships with aflatoxin M1 (AFM1 were studied using the brine shrimp Artemia salina larvae as an biological indicator in the temperature range from 20 °C to 40 °C. Increase in the incubation temperature resulted in sensitivity increase by the brine shrimp to AFM1. Optimum sensitivity occured at 30 °C. Positive results were obtained at 0.18 μg AFM1 x L-1 of whole pasteurized milk with a mortality of over 15%. Greater than 90 % mortality occurred at dose levels of 0.9 μg AFM1 x L-1 and above. The test can be conducted during 30-60 hours.

  14. Optimizing the co-feeding strategy of Persian sturgeon (Acipenser persicus larvae using Artemia nauplii and formulated diet

    Naser Agh

    2013-07-01

    Full Text Available High mortality and labor costs are associated with first-feeding sturgeon culture, particularly during the period of dietary transition from live to formulated feed. Therefore we investigated the effects of various feeding treatments on the survival and growth of the Persian sturgeon (Acipenser persicus larvae during a 20-day culture period. Three replicate groups (250 fish/replicate of first-feeding larvae were fed according to four main feeding regimes: (1 live food (live nauplii of brine shrimp Artemia urmiana; (2 indirect transition (5 days live food followed by gradual transition to formulated diet; (3 direct transition (using different combinations of live and formulated diet from the start feeding onwards; (4 formulated feed (FD from the start feeding. Results indicated that growth and survival were higher in the indirect transition feeding regime than in other regimes. Based on our study, co-feeding of A. persicus should start five days after prior feeding with live food.

  15. SEM study of diversity in the cyst surface topography of nine parthenogenetic Artemia (Crustacea: Anostraca) populations from China.

    Asem, Alireza; Sun, Shi-Chun

    2014-12-01

    The cysts of nine Chinese populations of parthenogenetic Artemia were studied by scanning electron microscope. In the 270 cysts examined, 15 different morphological patterns were recognized with most of them not recorded in previous studies and the "tubercled shell surface" being the most common pattern. Results also displayed high intrapopulation variability, with the maximum of 11 patterns (in 30 cysts) recorded from the Barkol population. No positive correlation between the diversity of cyst shell patterns and ploidy compositions was found. Principal components analysis suggests higher similarity among coastal populations than among inland populations, which may be attributed to the identity of physicochemical conditions among coastal salterns and dissimilarity among inland saline lakes. © 2014 Wiley Periodicals, Inc.

  16. Intracellular haemolytic agents of Heterocapsa circularisquama exhibit toxic effects on H. circularisquama cells themselves and suppress both cell-mediated haemolytic activity and toxicity to rotifers (Brachionus plicatilis).

    Nishiguchi, Tomoki; Cho, Kichul; Yasutomi, Masumi; Ueno, Mikinori; Yamaguchi, Kenichi; Basti, Leila; Yamasaki, Yasuhiro; Takeshita, Satoshi; Kim, Daekyung; Oda, Tatsuya

    2016-10-01

    A harmful dinoflagellate, Heterocapsa circularisquama, is highly toxic to shellfish and the zooplankton rotifer Brachionus plicatilis. A previous study found that H. circularisquama has both light-dependent and -independent haemolytic agents, which might be responsible for its toxicity. Detailed analysis of the haemolytic activity of H. circularisquama suggested that light-independent haemolytic activity was mediated mainly through intact cells, whereas light-dependent haemolytic activity was mediated by intracellular agents which can be discharged from ruptured cells. Because H. circularisquama showed similar toxicity to rotifers regardless of the light conditions, and because ultrasonic ruptured H. circularisquama cells showed no significant toxicity to rotifers, it was suggested that live cell-mediated light-independent haemolytic activity is a major factor responsible for the observed toxicity to rotifers. Interestingly, the ultrasonic-ruptured cells of H. circularisquama suppressed their own lethal effect on the rotifers. Analysis of samples of the cell contents (supernatant) and cell fragments (precipitate) prepared from the ruptured H. circularisquama cells indicated that the cell contents contain inhibitors for the light-independent cell-mediated haemolytic activity, toxins affecting H. circularisquama cells themselves, as well as light-dependent haemolytic agents. Ethanol extract prepared from H. circularisquama, which is supposed to contain a porphyrin derivative that displays photosensitising haemolytic activity, showed potent toxicity to Chattonella marina, Chattonella antiqua, and Karenia mikimotoi, as well as to H. circularisquama at the concentration range at which no significant toxicity to rotifers was observed. Analysis on a column of Sephadex LH-20 revealed that light-dependent haemolytic activity and inhibitory activity on cell-mediated light-independent haemolytic activity existed in two separate fractions (f-2 and f-3), suggesting that both

  17. Management of autotrophic mass cultures of micro-algae

    Toerien, DF

    1987-01-01

    Full Text Available Interest in the mass cultivation of micro-algae as feed and foodstuff has existed since the turn of the century (Robinson and Toerien, 1962). Experiments using algae in photosynthetic research (Warburg, 1919) also led to an appreciation...

  18. High Lipid Induction in Microalgae for Biodiesel Production

    Peer M. Schenk

    2012-05-01

    Full Text Available Oil-accumulating microalgae have the potential to enable large-scale biodiesel production without competing for arable land or biodiverse natural landscapes. High lipid productivity of dominant, fast-growing algae is a major prerequisite for commercial production of microalgal oil-derived biodiesel. However, under optimal growth conditions, large amounts of algal biomass are produced, but with relatively low lipid contents, while species with high lipid contents are typically slow growing. Major advances in this area can be made through the induction of lipid biosynthesis, e.g., by environmental stresses. Lipids, in the form of triacylglycerides typically provide a storage function in the cell that enables microalgae to endure adverse environmental conditions. Essentially algal biomass and triacylglycerides compete for photosynthetic assimilate and a reprogramming of physiological pathways is required to stimulate lipid biosynthesis. There has been a wide range of studies carried out to identify and develop efficient lipid induction techniques in microalgae such as nutrients stress (e.g., nitrogen and/or phosphorus starvation, osmotic stress, radiation, pH, temperature, heavy metals and other chemicals. In addition, several genetic strategies for increased triacylglycerides production and inducibility are currently being developed. In this review, we discuss the potential of lipid induction techniques in microalgae and also their application at commercial scale for the production of biodiesel.

  19. Improving microalgae for biotechnology - From genetics to synthetic biology

    Hlavová, Monika; Turóczy, Zoltán; Bišová, Kateřina

    2015-01-01

    Roč. 33, č. 6 (2015), s. 1194-1203 ISSN 0734-9750 R&D Projects: GA MŠk EE2.3.30.0059; GA MŠk ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Microalgae * Genetics * Mutagenesis Subject RIV: EE - Microbiology, Virology Impact factor: 9.848, year: 2015

  20. Potential of sponges and microalgae for marine biotechnology

    Wijffels, R.H.

    2008-01-01

    Marine organisms can be used to produce several novel products that have applications in new medical technologies, in food and feed ingredients and as biofuels. In this paper two examples are described: the development of marine drugs from sponges and the use of microalgae to produce bulk chemicals

  1. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae

    Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments.Cyanobacteria are promising host organisms for

  2. Photoacclimation state determines the photobehaviour of motile microalgae

    Ezequiel, João; Laviale, Martin; Frankenbach, Silja

    2015-01-01

    High productivity in intertidal microphytobenthic communities is achieved despite exposure to extreme and dynamic conditions (e.g. light, salinity, temperature). As an adaptation to this hostile environment, most of the microalgae species inhabiting fine-sediment habitats are motile, being able...

  3. MICROALGAE AS AN ALTERNATIVE TO BIOFUELS PRODUCTION. PART 1: BIOETHANOL

    Maiara Priscilla de Souza

    2013-02-01

    Full Text Available The demand from the energy sector is one of the culminating factors to do researches that enable innovations in the biotechnology sector and to boost biofuel production. The variability of the existing feedstocks provides benefits to energy production, however, we must choose the ones that present plausible characteristics depending on the type of product that we want to obtained. In this context, it is noted that the microalgae have suitable characteristics to producing different types of fuels, depending on the type of treatment are subjected, the species being analyzed as well as the biochemical composition of the biomass. Bioethanol production from microalgae is a promising and growing energy alternative under a view that biomass of these microorganisms has an enormous biodiversity and contain high levels of carbohydrates, an indispensable factor for the bioconversion of microalgae in ethanol. Due to these factors, there is a constant search for more viable methods for pretreatment of biomass, hydrolysis and fermentation, having as one of the major aspects the approach of effectives methodologies in the ambit of quality and yield of ethanol. Therefore, we have to search to increase the interest in the developing of biofuels reconciling with the importance of using microalgae, analyzing whether these micro-organisms are capable of being used in bioethanol production.

  4. Technical Note: Development of a Photobioreactor for Microalgae ...

    In view of the technical and biological limitations of open pond systems, a study was conducted to develop a cost-effective experimental photobioreactor that would permit efficient cultivation of microalgae for biodiesel production. The photobioreactor was developed using low cost materi- als, cylindrical translucent tubes ...

  5. Rapid biodiesel production using wet microalgae via microwave irradiation

    Wahidin, Suzana; Idris, Ani; Shaleh, Sitti Raehanah Muhamad

    2014-01-01

    Highlights: • Lipid was directly extracted from wet microalgae using microwave irradiation. • The microwave irradiation and water bath-assisted solvent extraction are applied. • Cell walls are significantly disrupted under microwave irradiation. • Highly disrupted cell walls led to higher biodiesel yield in microwave irradiation. • Microwave irradiation is a promising direct technique with high biodiesel yields. - Abstract: The major challenges for industrial commercialized biodiesel production from microalgae are the high cost of downstream processing such as dewatering and drying, utilization of large volumes of solvent and laborious extraction processes. In order to address these issues the microwave irradiation method was used to produce biodiesel directly from wet microalgae biomass. This alternative method of biodiesel production from wet microalgae biomass is compared with the conventional water bath-assisted solvent extraction. The microwave irradiation extracted more lipids and high biodiesel conversion was obtained compared to the water bath-assisted extraction method due to the high cell disruption achieved and rapid transesterification. The total content of lipid extracted from microwave irradiation and water bath-assisted extraction were 38.31% and 23.01% respectively. The biodiesel produced using microwave irradiation was higher (86.41%) compared to the conventional method. Thus microwave irradiation is an attractive and promising technology to be used in the extraction and transesterification process for efficient biodiesel production

  6. Cultivation of microalgae on artificial light comes at a cost

    Blanken, W.M.; Cuaresma Franco, M.; Wijffels, R.H.; Janssen, M.G.J.

    2013-01-01

    Microalgae are potential producers of bulk food and feed compounds, chemicals, and biofuels. To produce these bulk products competitively, it is important to keep costs of raw material low. Light energy can be provided by sun or lamps. Sunlight is free and abundant. Disadvantages of sunlight,

  7. Cultivation of microalgae in a high irradiance area

    Cuaresma, M.

    2011-01-01


    Microalgae are a promising source of high-value products (i.e. carotenoids, ω-3 fatty acids), as well as feedstocks for food, bulk chemicals and biofuels. Industrial production is, however, still limited because the technology needs further development. One of the main bottlenecks is the

  8. Microalgae for the production of bulk chemicals and biofuels

    Wijffels, R.H.; Barbosa, M.J.; Eppink, M.H.M.

    2010-01-01

    The feasibility of microalgae production for biodiesel was discussed. Although algae are not yet produced at large scale for bulk applications, there are opportunities to develop this process in a sustainable way. It remains unlikely, however, that the process will be developed for biodiesel as the

  9. Extremophilic micro-algae and their potential contribution in biotechnology.

    Varshney, Prachi; Mikulic, Paulina; Vonshak, Avigad; Beardall, John; Wangikar, Pramod P

    2015-05-01

    Micro-algae have potential as sustainable sources of energy and products and alternative mode of agriculture. However, their mass cultivation is challenging due to low survival under harsh outdoor conditions and competition from other, undesired, species. Extremophilic micro-algae have a role to play by virtue of their ability to grow under acidic or alkaline pH, high temperature, light, CO2 level and metal concentration. In this review, we provide several examples of potential biotechnological applications of extremophilic micro-algae and the ranges of tolerated extremes. We also discuss the adaptive mechanisms of tolerance to these extremes. Analysis of phylogenetic relationship of the reported extremophiles suggests certain groups of the Kingdom Protista to be more tolerant to extremophilic conditions than other taxa. While extremophilic microalgae are beginning to be explored, much needs to be done in terms of the physiology, molecular biology, metabolic engineering and outdoor cultivation trials before their true potential is realized. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Microalgae respond differently to nitrogen availability during culturing

    Variations in the exogenous nitrogen level are known to significantly affect the physiological status and metabolism of microalgae. However, responses of red, green and yellow-green algae to nitrogen (N) availability have not been compared yet. Porphyridium cruentum, Scenedesmus incrassatulus and Trachydiscus ...

  11. Cultivation of micro-algae in closed tubular reactor

    Gudin, C.; Bernard, A.; Chaumont, D.

    1983-11-01

    A description is presented of the three culture pilot utilities in activity under natural light, including glass tubular solar collector (30 mm diameter) in which the microalgae culture circulates. The utility is controled automatically (thermal regulation, gaseous transfers, continuous culture organization). The tests were conducted for the production of polysaccharides (Porphyridium cruentum, chlamydomonas mexicana) or hydrocarbons (Botriococcus braunii).

  12. Biodiesel production with microalgae as feedstock: from strains to biodiesel.

    Gong, Yangmin; Jiang, Mulan

    2011-07-01

    Due to negative environmental influence and limited availability, petroleum-derived fuels need to be replaced by renewable biofuels. Biodiesel has attracted intensive attention as an important biofuel. Microalgae have numerous advantages for biodiesel production over many terrestrial plants. There are a series of consecutive processes for biodiesel production with microalgae as feedstock, including selection of adequate microalgal strains, mass culture, cell harvesting, oil extraction and transesterification. To reduce the overall production cost, technology development and process optimization are necessary. Genetic engineering also plays an important role in manipulating lipid biosynthesis in microalgae. Many approaches, such as sequestering carbon dioxide from industrial plants for the carbon source, using wastewater for the nutrient supply, and maximizing the values of by-products, have shown a potential for cost reduction. This review provides a brief overview of the process of biodiesel production with microalgae as feedstock. The methods associated with this process (e.g. lipid determination, mass culture, oil extraction) are also compared and discussed.

  13. Production of bio-jet fuel from microalgae

    Elmoraghy, Marian

    The increase in petroleum-based aviation fuel consumption, the decrease in petroleum resources, the fluctuation of the crude oil price, the increase in greenhouse gas emission and the need for energy security are motivating the development of an alternate jet fuel. Bio-jet fuel has to be a drop in fuel, technically and economically feasible, environmentally friendly, greener than jet fuel, produced locally and low gallon per Btu. Bic jet fuel has been produced by blending petro-based jet fuel with microalgae biodiesel (Fatty Acid Methyl Ester, or simply FAME). Indoor microalgae growth, lipids extraction and transetrification to biodiesel are energy and fresh water intensive and time consuming. In addition, the quality of the biodiesel product and the physical properties of the bio-jet fuel blends are unknown. This work addressed these challenges. Minimizing the energy requirements and making microalgae growth process greener were accomplished by replacing fluorescent lights with light emitting diodes (LEDs). Reducing fresh water footprint in algae growth was accomplished by waste water use. Microalgae biodiesel production time was reduced using the one-step (in-situ transestrification) process. Yields up to 56.82 mg FAME/g dry algae were obtained. Predicted physical properties of in-situ FAME satisfied European and American standards confirming its quality. Lipid triggering by nitrogen deprivation was accomplished in order to increase the FAME production. Bio-jet fuel freezing points and heating values were measured for different jet fuel to biodiesel blend ratios.

  14. Evaluation of the Antioxidant Activity of Cell Extracts from Microalgae

    F. Xavier Malcata

    2013-04-01

    Full Text Available A growing market for novel antioxidants obtained from non-expensive sources justifies educated screening of microalgae for their potential antioxidant features. Characterization of the antioxidant profile of 18 species of cyanobacteria (prokaryotic microalgae and 23 species of (eukaryotic microalgae is accordingly reported in this paper. The total antioxidant capacity, accounted for by both water- and lipid-soluble antioxidants, was evaluated by the (radical cation ABTS method. For complementary characterization of cell extracts, a deoxyribose assay was carried out, as well as a bacteriophage P22/Salmonella-mediated approach. The microalga Scenedesmus obliquus strain M2-1 exhibited the highest (p > 0.05 total antioxidant capacity (149 ± 47 AAU of intracellular extracts. Its scavenger activity correlated well with its protective effects against DNA oxidative damage induced by copper(II-ascorbic acid; and against decay in bacteriophage infection capacity induced by H2O2. Finally, performance of an Ames test revealed no mutagenic effects of the said extract.

  15. Combustion of Microalgae Oil and Ethanol Blended with Diesel Fuel

    Saddam H. Al-lwayzy

    2015-12-01

    Full Text Available Using renewable oxygenated fuels such as ethanol is a proposed method to reduce diesel engine emission. Ethanol has lower density, viscosity, cetane number and calorific value than petroleum diesel (PD. Microalgae oil is renewable, environmentally friendly and has the potential to replace PD. In this paper, microalgae oil (10% and ethanol (10% have been mixed and added to (80% diesel fuel as a renewable source of oxygenated fuel. The mixture of microalgae oil, ethanol and petroleum diesel (MOE20% has been found to be homogenous and stable without using surfactant. The presence of microalgae oil improved the ethanol fuel demerits such as low density and viscosity. The transesterification process was not required for oil viscosity reduction due to the presence of ethanol. The MOE20% fuel has been tested in a variable compression ratio diesel engine at different speed. The engine test results with MOE20% showed a very comparable engine performance of in-cylinder pressure, brake power, torque and brake specific fuel consumption (BSFC to that of PD. The NOx emission and HC have been improved while CO and CO2 were found to be lower than those from PD at low engine speed.

  16. Biomass of Microalgae as a Source of Renewable Energy

    Głowacka Natalia

    2017-05-01

    Full Text Available Algae represent a potential source of energy via anaerobic digestion. The aim of the study was to obtain the possible potential of green microalgae, which could replace the commonly used corn silage for the production of biogas in the future. The intensive construction of new biogas plants stations across Europe and the lack of arable land suitable for the cultivation of biomass for energy purposes are the fundamental reasons behind looking for the alternative raw materials for energy production as a substitute for commonly used input materials. When comparing green microalgae with conventional crops the high productivity potential (high oil content as well as the possibility of their production during the whole year can be noticed. It is necessary to find the effective way to produce biomass from green microalgae, proper for energy conversion, while ensuring the economic and environmental aspects. The interim research results mentioned in this article indicate that microalgae present appropriate alternative material for the process of anaerobic digestion.

  17. Biodiesel Production from Microalgae by Extraction – Transesterification Method

    Nguyen Thi Phuong Thao

    2013-11-01

    Full Text Available The environmental impact of using petroleum fuels has led to a quest to find a suitable alternative fuel source. In this study, microalgae were explored as a highly potential feedstock to produce biodiesel fuel. Firstly, algal oil is extracted from algal biomass by using organic solvents (n–hexan.  Lipid is contained in microalgae up to 60% of their weight. Then, Biodiesel is created through a chemical reaction known as transesterification between algal oil and alcohol (methanol with strong acid (such as H2SO4 as the catalyst. The extraction – transesterification method resulted in a high biodiesel yield (10 % of algal biomass and high FAMEs content (5.2 % of algal biomass. Biodiesel production from microalgae was studied through experimental investigation of transesterification conditions such as reaction time, methanol to oil ration and catalyst dosage which are deemed to have main impact on reaction conversion efficiency. All the parameters which were characterized for purified biodiesel such as free glycerin, total glycerin, flash point, sulfur content were analyzed according to ASTM standardDoi: http://dx.doi.org/10.12777/wastech.1.1.6-9Citation:  Thao, N.T.P., Tin, N.T., and Thanh, B.X. 2013. Biodiesel Production from Microalgae by Extraction – Transesterification Method. Waste Technology 1(1:6-9. Doi: http://dx.doi.org/10.12777/wastech.1.1.6-9

  18. Prospective of biodiesel production utilizing microalgae as the cell ...

    Microalgae are sunlight-driven miniature factories that convert atmospheric CO2 to polar and neutral lipids which after esterification can be utilized as an alternative source of petroleum. Further, other metabolic products such as bioethanol and biohydrogen produced by algal cells are also being considered for the same ...

  19. Physicochemical approach to freshwater microalgae harvesting with magnetic particles

    Procházková, G.; Podolová, N.; Šafařík, Ivo; Zachleder, Vilém; Brányik, T.

    2013-01-01

    Roč. 112, DEC 2013 (2013), s. 213-218 ISSN 0927-7765 R&D Projects: GA ČR(CZ) GAP503/10/1270 Institutional support: RVO:67179843 ; RVO:61388971 Keywords : microalgae * cell adhesion * magnetic beads * surface interactions * XDLVO theory Subject RIV: EH - Ecology, Behaviour; EI - Biotechnology ; Bionics (MBU-M) Impact factor: 4.287, year: 2013

  20. Lichen microalgae are sensitive to environmental concentrations of atrazine.

    Traba, Helena Moreno; Domínguez-Morueco, Noelia; Barreno, Eva; Catalá, Myriam

    2017-04-03

    The identification of new organisms for environmental toxicology bioassays is currently a priority, since these tools are strongly limited by the ecological relevance of taxa used to study global change. Lichens are sensitive bioindicators of air quality and their microalgae are an untapped source for new low-cost miniaturized bioassays with ecological importance. In order to increase the availability of a wider range of taxa for bioassays, the sensitivity of two symbiotic lichen microalgae, Asterochloris erici and Trebouxia sp. TR9, to atrazine was evaluated. To achieve this goal, axenic cultures of these phycobionts in suspension were exposed to a range of environmental concentrations of the herbicide atrazine, a common water pollutant. Optical density and chlorophyll autofluorescence were used as endpoints of ecotoxicity and ecophysiology on cell suspensions. Results show that lichen microalgae show high sensitivity to very low doses of atrazine, being higher in Asterochloris erici than in Trebouxia sp. TR9. We conclude that environmental concentrations of atrazine could modify population dynamics probably through a shift in reproduction strategies of these organisms. This seminal work is a breakthrough in the use of lichen microalgae in the assessment of micropollution effects on biodiversity.

  1. Edible oils from microalgae: insights in TAG accumulation

    Klok, A.J.; Lamers, P.P.; Martens, D.E.; Draaisma, R.B.; Wijffels, R.H.

    2014-01-01

    Microalgae are a promising future source for sustainable edible oils. To make microalgal oil a cost-effective alternative for common vegetable oils, increasing TAG productivity and TAG content are of high importance. Fulfilling these targets requires proper understanding of lipid metabolism in

  2. Hazard and risk of herbicides for marine microalgae

    Sjollema, S.B.; Martínez-García, G.; van der Geest, H.G.; Kraak, M.H.S.; Booij, P.; Vethaak, A.D.; Admiraal, W.

    2014-01-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects

  3. Hazard and risk of herbicides for marine microalgae

    Sjollema, Sascha B.; MartínezGarcía, Gema; Geest, Harm G. van der; Kraak, Michiel H.S.; Booij, Petra; Vethaak, A. Dick; Admiraal, Wim

    2014-01-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol ® 1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. - Highlights: • The hazard of herbicides for microalgae is compound and species specific. • In general a low risk although occasional potential effect levels are reached. • Current legislation does not protect marine microalgae sufficiently. - The hazard of herbicides in the coastal waters is compound and species specific and although the general risk in the field is low, occasionally potential effect levels are reached

  4. Analysis and stability of fatty acid esterified xanthophylls from microalgae

    Weesepoel, Y.J.A.

    2014-01-01

    Fatty acid esterified xanthophylls (e.g. astaxanthin) produced by microalgae are regarded as a natural alternative for food colourants, but little is known on the stability of these compounds in foods. The aims of this research were (i) to develop protocols to analyze esterified

  5. Vibrating membrane filtration as improved technology for microalgae dewatering.

    Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

    2014-04-01

    The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2μm) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. A techno-economic analysis of biodiesel production from microalgae

    Olivieri, G.; Guida, T.; Salatino, P.; Marzocchella, A.

    2013-01-01

    The preliminary assessment of a cost-effective flow-sheet for the production of biodiesel from microalgae lipid fraction was carried out. The study was based on approximated cost-estimation methods integrated with the simulation software Aspen Plus (R). Several scenarios were investigated to compare

  7. Suitability of Nigerian Weather Conditions for Cultivation of Microalgae

    Client

    compared with optimal conditions for cultivation of various species of microalgae. ... The results of average hours of sunshine showed that Jos has the lowest number of hours ... Temperature stratification in ponds within Abakaliki was ... question of how we will feed the starving masses of our ever increasing world population.

  8. Phloroglucinol-Mediated Hsp70 Production in Crustaceans: Protection against Vibrio parahaemolyticus in Artemia franciscana and Macrobrachium rosenbergii

    Vikash Kumar

    2018-05-01

    Full Text Available The halophilic aquatic bacterium, Vibrio parahaemolyticus, is an important aquatic pathogen, also capable of causing acute hepatopancreatic necrosis disease (AHPND in shrimp resulting in significant economic losses. Therefore, there is an urgent need to develop anti-infective strategies to control AHPND. The gnotobiotic Artemia model is used to establish whether a phenolic compound phloroglucinol is effective against the AHPND strain V. parahaemolyticus MO904. We found that pretreatment with phloroglucinol, at an optimum concentration (30 µM, protects axenic brine shrimp larvae against V. parahaemolyticus infection and induced heat shock protein 70 (Hsp70 production (twofolds or more as compared with the control. We further demonstrated that the Vibrio-protective effect of phloroglucinol was caused by its prooxidant effect and is linked to the induction of Hsp70. In addition, RNA interference confirms that phloroglucinol-induced Hsp70 mediates the survival of brine shrimp larvae against V. parahaemolyticus infection. The study was validated in xenic Artemia model and in a Macrobrachium rosenbergii system. Pretreatment of xenic brine shrimp larvae (30 µM and Macrobrachium larvae (5 µM with phloroglucinol increases the survival of xenic brine shrimp and Macrobrachium larvae against subsequent V. parahaemolyticus challenge. Taken together, our study provides substantial evidence that the prooxidant activity of phloroglucinol induces Hsp70 production protecting brine shrimp, A. franciscana, and freshwater shrimp, M. rosenbergii, against the AHPND V. parahaemolyticus strain MO904. Probably, phloroglucinol treatment might become part of a holistic strategy to control AHPND in shrimp.

  9. Analysis of toxicity of Anacardium occidentale L. extract submitted to ionizing radiation on embryos of Biomphalaria glabrata and Artemia salina

    Silva, Hianna A.M.F.; Sa, Jose L.F.; Lima, Claudia S.A.; Amancio, Francisco F.; Melo, Ana M.M.A.; Ribeiro, Luanna R.S.; Santos, Gustavo H.F.; Silva, Edvane B.

    2013-01-01

    The use of gamma radiation as a sterilization method for herbs, herbal medicines and foods, shows positive results regarding the retention of such products, economy and safety of the method. However, it is known that this method of processing plant material can cause chemical changes in these products related to the type of material, its components and the dose received. Evaluated, in the present study, the action of gamma radiation as a modifier of toxicity extract of Anacardium occidentale Linn. To evaluate the toxicity of the extract irradiated at doses of 5.0, 7.5 and 10.0 kGy and concentrations of 250, 500 and 1000 mg/L was used bioassays with Artemia salina and Biomphalaria glabrata. For the test to A. salina, 520 specimens were used divided into groups of 10 larvae. For the bioassay with B. glabrata, 3900 specimens were used divided into groups of, approximately, 100 embryos. Larvae of A. salina and embryos were subjected to extracts irradiated and unirradiated for 24 hours. The bioassay with A. salina, showed a decrease, compared to extract unirradiated and irradiated at doses of 5.0 and 7.5 kGy, of extract irradiated with 10 kGy, where the mortality did not differ from the control group. In tests with embryos was observed an increase in the toxicity of the extract at a dose of 7.5 kGy and a decrease in the dose of 10.0 kGy. The radiation promoted changes in the toxicity of leaves extracts of Anacardium occidentale Linn. on embryos of Biomphalaria glabrata and Artemia salina. (author)

  10. Analysis of toxicity of Anacardium occidentale L. extract submitted to ionizing radiation on embryos of Biomphalaria glabrata and Artemia salina

    Silva, Hianna A.M.F.; Sa, Jose L.F.; Lima, Claudia S.A.; Amancio, Francisco F.; Melo, Ana M.M.A., E-mail: hiannaamfs@gmail.com, E-mail: luismuma6@gmail.com, E-mail: claudia.salima@gmail.com, E-mail: amancioff@bol.com.br, E-mail: amdemelo@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Biofisica e Radiobiologia; Ribeiro, Luanna R.S.; Santos, Gustavo H.F.; Silva, Edvane B., E-mail: luannaribeiro_lua@hotmail.com, E-mail: santosghf@hotmail.com, E-mail: edvborges@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia

    2013-07-01

    The use of gamma radiation as a sterilization method for herbs, herbal medicines and foods, shows positive results regarding the retention of such products, economy and safety of the method. However, it is known that this method of processing plant material can cause chemical changes in these products related to the type of material, its components and the dose received. Evaluated, in the present study, the action of gamma radiation as a modifier of toxicity extract of Anacardium occidentale Linn. To evaluate the toxicity of the extract irradiated at doses of 5.0, 7.5 and 10.0 kGy and concentrations of 250, 500 and 1000 mg/L was used bioassays with Artemia salina and Biomphalaria glabrata. For the test to A. salina, 520 specimens were used divided into groups of 10 larvae. For the bioassay with B. glabrata, 3900 specimens were used divided into groups of, approximately, 100 embryos. Larvae of A. salina and embryos were subjected to extracts irradiated and unirradiated for 24 hours. The bioassay with A. salina, showed a decrease, compared to extract unirradiated and irradiated at doses of 5.0 and 7.5 kGy, of extract irradiated with 10 kGy, where the mortality did not differ from the control group. In tests with embryos was observed an increase in the toxicity of the extract at a dose of 7.5 kGy and a decrease in the dose of 10.0 kGy. The radiation promoted changes in the toxicity of leaves extracts of Anacardium occidentale Linn. on embryos of Biomphalaria glabrata and Artemia salina. (author)

  11. Defense systems in developing Artemia franciscana nauplii and their modulation by probiotic bacteria offer protection against a Vibrio anguillarum challenge.

    Giarma, Eleni; Amanetidou, Eleni; Toufexi, Alexia; Touraki, Maria

    2017-07-01

    The alterations of immune responses of Artemia franciscana nauplii as a function of culture time and after a challenge with the pathogen Vibrio anguillarum were studied. The effect of the administration of the probiotic bacteria Bacillus subtilis, Lactobacillus plantarum and Lactococcus lactis either alone or in combination with the pathogen was evaluated. The activity of the antioxidant enzymes superoxide dismutase (SOD), Glutathione reductase (GRed), Glutathione transferase (GST) and Phenoloxidase (PO) presented a significant increase as a function of culture time, appeared elevated following probiotic administration and were depleted 48 h following the experimental challenge. Lipid peroxidation reached peak levels at 48 h of culture, when nauplii start feeding and returned to lower values at 144 h, remaining however significantly higher than control (P probiotics significantly reduced lipid peroxidation in comparison with the corresponding control, while challenge with the pathogen resulted in its threefold increase. Survival of nauplii remained high throughout culture and was either increased or remained at control levels following the administration of the probiotics. The challenge with the pathogen resulted in a significantly decreased survival of 15.3% for the positive control, while in the probiotic treated series survival values were not significantly different from the negative control (P > 0.05). Following a combined administration of each probiotic and the pathogen the activities of all enzymes tested were significantly lower (P probiotic). Lipid peroxidation was significantly lower in the probiotic treated series in comparison to the positive control (P probiotics B. subtilis, L. plantarum and L. lactis protect Artemia against a V. anguillarum challenge by enhancing its immune responses thus contributing to reduced oxidative damage and increased survival. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Techno-economical evaluation of protein extraction for microalgae biorefinery

    Sari, Y. W.; Sanders, J. P. M.; Bruins, M. E.

    2016-01-01

    Due to scarcity of fossil feedstocks, there is an increasing demand for biobased fuels. Microalgae are considered as promising biobased feedstocks. However, microalgae based fuels are not yet produced at large scale at present. Applying biorefinery, not only for oil, but also for other components, such as carbohydrates and protein, may lead to the sustainable and economical microalgae-based fuels. This paper discusses two relatively mild conditions for microalgal protein extraction, based on alkali and enzymes. Green microalgae (Chlorella fusca) with and without prior lipid removal were used as feedstocks. Under mild conditions, more protein could be extracted using proteases, with the highest yields for microalgae meal (without lipids). The data on protein extraction yields were used to calculate the costs for producing 1 ton of microalgal protein. The processing cost for the alkaline method was € 2448 /ton protein. Enzymatic method performed better from an economic point of view with € 1367 /ton protein on processing costs. However, this is still far from industrially feasible. For both extraction methods, biomass cost per ton of produced product were high. A higher protein extraction yield can partially solve this problem, lowering processing cost to €620 and 1180 /ton protein product, using alkali and enzyme, respectively. Although alkaline method has lower processing cost, optimization appears to be better achievable using enzymes. If the enzymatic method can be optimized by lowering the amount of alkali added, leading to processing cost of € 633/ton protein product. Higher revenue can be generated when the residue after protein extraction can be sold as fuel, or better as a highly digestible feed for cattle.

  13. From transient response of a compact photobioreactor for microalgae cultivation

    Dilay, Emerson; Ribeiro, Robert Luis Lara; Pulliam, Raevon; Mariano, Andre Bellin [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Nucleo de Pesquisa e Desenvolvimento em Energia Auto-Sustentavel; Ordonez, Juan Carlos [Florida State University, Tallahassee, FL (United States). Dept. of Mechanical Engineering and Center for Advanced Power Systems], E-mail: ordonez@caps.fsu.edu; Vargas, Jose Viriato Coelho [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica

    2010-07-01

    Biofuels from microalgae are currently the subject of funded scientific research in many countries due to their high productivity of oil when compared with other crops. Microalgae can also be used in many important applications such as to obtain compounds of interest for food, chemicals, and pharmaceuticals. The high productivity of microalgae when compared with other crops is achieved because agricultural land is not mandatory for their cultivation, since they can be grown in open ponds, sea or vertical photo bioreactors. In this paper, a mathematical model is introduced for assessing the transient microalgae growth as a function of variable light intensity, temperature and environmental conditions in the daily cycle. Photo bioreactor geometry is considered as well. Light intensity is obtained from sun position, photo bioreactor geometry, and the installation location in the world. The photo bioreactor was discretized in space by the the volume element method. Balances of energy and species together with thermodynamics, heat transfer and chemistry empirical and theoretical correlations are applied to each volume element. Therefore, a system of ordinary differential equations with respect to time only is capable of delivering temperatures and concentrations as functions of space and time, even with a coarse mesh. The numerical results are capable of predicting the transient and steady state photo bioreactor biomass production with low computational time. Microalgae specific growth rate as a function of average light intensity inside the tubes and time was calculated. As a result, the model is expected to be a useful tool for simulation, design, and optimization of compact photo bioreactors. (author)

  14. Effects of bisphenol A and its analogs bisphenol F and S on life parameters, antioxidant system, and response of defensome in the marine rotifer Brachionus koreanus.

    Park, Jun Chul; Lee, Min-Chul; Yoon, Deok-Seo; Han, Jeonghoon; Kim, Moonkoo; Hwang, Un-Ki; Jung, Jee-Hyun; Lee, Jae-Seong

    2018-06-01

    To understand the adverse outcome in response to bisphenol A and its analogs bisphenol F and S (BPA, BPF, and BPS), we examined acute toxicity, life parameter, and defensome in the marine rotifer Brachionus koreanus. Among the bisphenol analogs, BPA showed the highest acute toxicity and then BPF and BPS, accordingly in the view of descending magnitude of toxicity. In life parameters including life span and reproduction, BPA, BPF, and BPS were found to cause adverse effect. Both intracellular ROS level and GST activity were significantly increased (P bisphenol analogs exposures. In response to bisphenol analogs, defensomes of phase I, II, and III detoxification mechanism demonstrated inverse relationship between the lipophilicity of bisphenol analogs and the expression patterns of defensomes. BPA and BPF were found to have significant modulation (P bisphenol A and its analogs F and S demonstrated specific detoxification mechanism in rotifer. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Effects of chlorpyrifos on life cycle parameters, cytochrome P450S expression, and antioxidant systems in the monogonont rotifer Brachionus koreanus.

    Kim, Ryeo-Ok; Kim, Bo-Mi; Jeong, Chang-Bum; Lee, Jae-Seong; Rhee, Jae-Sung

    2016-06-01

    Chlorpyrifos is a widely used organophosphorus insecticide for controlling diverse insect pests of crops. In the monogonont rotifer Brachionus koreanus, population growth retardation with the inhibition of lifespan, fecundity, and individual body size of ovigerous females was shown over 10 d in response to chlorpyrifos exposure. At the molecular and biochemical levels, the rotifer B. koreanus defensome, composed of cytochrome P450 complements, heat shock protein 70, and antioxidant enzymatic systems (i.e., glutathione, glutathione peroxidase, glutathione reductase, and glutathione S-transferase), was significantly induced in response to different concentrations of chlorpyrifos. Thus, chlorpyrifos strongly induced a defensome system to mitigate the deleterious effects of chlorpyrifos at in vivo and in vitro levels as a trade-off in fitness costs. Environ Toxicol Chem 2016;35:1449-1457. © 2015 SETAC. © 2015 SETAC.

  16. The nucleotide sequences of 5S rRNAs from a rotifer, Brachionus plicatilis, and two nematodes, Rhabditis tokai and Caenorhabditis elegans.

    Kumazaki, T; Hori, H; Osawa, S; Ishii, N; Suzuki, K

    1982-11-11

    The nucleotide sequences of 5S rRNAs from a rotifer, Brachionus plicatilis, and two nematodes, Rhabditis tokai and Caenorhabditis elegans have been determined. The rotifer has two 5S rRNA species that are composed of 120 and 121 nucleotides, respectively. The sequences of these two 5S rRNAs are the same except that the latter has an additional base at its 3'-terminus. The 5S rRNAs from the two nematode species are both 119 nucleotides long. The sequence similarity percents are 79% (Brachionus/Rhabditis), 80% (Brachionus/Caenorhabditis), and 95% (Rhabditis/Caenorhabditis) among these three species. Brachionus revealed the highest similarity to Lingula (89%), but not to the nematodes (79%).

  17. Using population demographic parameters to assess impacts of two polybrominated diphenyl ethers (BDE-47, BDE-209) on the rotifer Brachionus plicatilis.

    Sha, Jingjing; Wang, You; Chen, Hongmei; Wang, Ming; Wang, Hong; Li, Xiaohong; Qi, Lei; Tang, Xuexi

    2015-09-01

    Polybrominated diphenyl ethers (PBDEs) are highly persistent anthropogenic contaminants found in the environment, posing a risk to aquatic ecosystems, whereas there is a lack of data concerning their impacts on marine invertebrates. The objective of this study was to assess the relative lethal and sublethal aquatic toxicity effects of two PBDEs, BDE-47 and BDE-209 congeners, on marine zooplankton rotifer Brachionus plicatilis associated with PBDE concentrations and time of exposure. Gas chromatography-mass spectrometry (GC-MS) analyses were performed to determine actual PBDE concentrations. Rotifer population demographic parameters from life tables, including age-specific survivorship (lx), age-specific fecundity (mx), net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), life expectancy (E0) and generation time (T), were used as measures of treatment effects. Results from this study have revealed increasingly intense negative effects on many of the rotifer demographic parameters with elevated PBDE concentrations. The population growth curves of B. plicatilis showed almost no lag phase and reached peak abundances within 11 days, while B. plicatilis exposed to BDE-209 had a lag phase of about 5 days. In addition, increased PBDE levels reduced the population abundances and peak population densities of B. plicatilis. The two PBDEs have caused the carrying capacity (K) suppressed and the negative influence turned more serious as the concentration rose. Results also revealed that the time to reach growth curve inflection point (Tp) was shortened by PBDEs to different degrees. This study not only indicated that life table demography and population growth curve studies were two important aspects used to evaluate toxicant PBDE effects, but also compared the two PBDE disruptions to the population growth and reproduction of the rotifer. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Feeding preference and daily ration of 12 dominant copepods on mono and mixed diets of phytoplankton, rotifers, and detritus in a tropical coastal water.

    Jagadeesan, L; Jyothibabu, R; Arunpandi, N; Anjusha, A; Parthasarathi, S; Pandiyarajan, R S

    2017-09-11

    Results of the experimental studies on the feeding habit and daily ration (DR) of 12 dominant copepods from a tropical coastal water (off Kochi, Southwest coast of India) on different food items (phytoplankton, rotifers, and detritus) are presented. Even though, all species of copepods consumed all types of food items in the experiments, they showed noticeable feeding preferences, having important ecological implications. Calanoid Paracalanus parvus and Acrocalanus gracilis consumed phytoplankton and rotifers equally in mono diets (74-89% of DR) and mixed diets (53-82% of DR), which indicated their ability to shift their diet in natural environment based on the availability of food items. Calanoid Acartia erythraea and A. danae consumed more phytoplankton (DR 83 and 72%, respectively) than rotifers (DR 51 and 46%, respectively) in mono diets, and in mixed diets, their consumption was high in phytoplankton combined food mixtures (P + R DR and P + D DR) rather than the R + D food type, indicated their preference for mixed diets of phytoplankton. Similarly, Calanoid Temora turbinata, Pseudodiaptomus serricaudatus, and Centropages tenuiremis preferred a herbivorous diet as evidenced by their high ingestion rate on phytoplankton mono (70 to 87% to their DR) and mixed diets (58 to 80% of DR). On the other hand, Cyclopoid Oithona similis and Poecilostomatoid Corycaeus danae preferred a carnivorous diet, consuming more rotifers (> 80% of DR) than phytoplankton (18-20% of DR) and detritus (5-6% of DR). Harpacticoids Macrosetella gracilis and Euterpina acutifrons equally preferred phytoplankton (78-92% of DR) and detritus (65-89% of DR). The study showed that the dominant copepods in the coastal waters off Kochi occupy different trophic niches available in the environment, which may be applicable in other similar environments as well.

  19. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    Pablo Mayorga

    2010-12-01

    Full Text Available Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest, were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq. Kunth ex Walp., Fabaceae, Neurolaena lobata (L. Cass., Asteraceae, Petiveria alliacea L., Phytolaccaceae, and Ocimum campechianum Mill., Lamiaceae. The five others: Curatella americana L., Dilleniaceae, Prunus barbata Koehne, Rosaceae, Quercus crispifolia Trel., Fagaceae, Rhizophora mangle L., Rhizophoraceae, and Smilax domingensis Willd., Smilacaceae, do not. All plants without anti-Artemia activity had no lethal effects in both assays with A. salina. For the plants with anti-Artemia activity the Artoxkit M was not sensitive to G. sepium and the conventional Artemia test was not sensitive to S. americanum, G. sepium and N. lobata. All the plant extracts, except for that of C. americana, had lethal effects on T. platyurus and the lethal median concentration (LC50 levels for this organism were in all cases substantially lower than those of the salt-water test species. This study revealed that T. platyurus is a promising test species worth further in depth investigation for toxicity screening of plant extracts with potential medicinal properties.Três bioensaios de letalidade com o crustáceo de água salgada Artemia salina Leach, Artemiidae, (teste convencional em microplaca de 96 poós Artoxkit microbiotest M e o crustáceo de água doce Thamnocephalus platyurus Packard, Thamnocephalidae (Thamnotoxkit microbiotest F, foram comparados utilizando extratos de dez espécies de plantas da Guatemala. Foi previamente observado que cinco delas possuem atividade anti-Artemia

  20. Biotechnological production of value-added carotenoids from microalgae: Emerging technology and prospects.

    Wichuk, Kristine; Brynjólfsson, Sigurður; Fu, Weiqi

    2014-01-01

    We recently evaluated the relationship between abiotic environmental stresses and lutein biosynthesis in the green microalga Dunaliella salina and suggested a rational design of stress-driven adaptive evolution experiments for carotenoids production in microalgae. Here, we summarize our recent findings regarding the biotechnological production of carotenoids from microalgae and outline emerging technology in this field. Carotenoid metabolic pathways are characterized in several representative algal species as they pave the way for biotechnology development. The adaptive evolution strategy is highlighted in connection with enhanced growth rate and carotenoid metabolism. In addition, available genetic modification tools are described, with emphasis on model species. A brief discussion on the role of lights as limiting factors in carotenoid production in microalgae is also included. Overall, our analysis suggests that light-driven metabolism and the photosynthetic efficiency of microalgae in photobioreactors are the main bottlenecks in enhancing biotechnological potential of carotenoid production from microalgae.

  1. Molecular and expression analysis of manganese superoxide dismutase (Mn-SOD) gene under temperature and starvation stress in rotifer Brachionus calyciflorus.

    Yang, Jianghua; Dong, Siming; Zhu, Huanxi; Jiang, Qichen; Yang, Jiaxin

    2013-04-01

    Superoxide dismutase (SOD) is an important antioxidant enzyme that protects organs from damage by reactive oxygen species. We cloned cDNA encoding SOD activated with manganese (Mn-SOD) from the rotifer Brachionus calyciflorus Pallas. The full-length cDNA of Mn-SOD was 1,016 bp and had a 669 bp open reading frame encoding 222 amino acids. The deduced amino acid sequence of B. calyciflorus Mn-SOD showed 89.1, 71.3, and 62.1 % similarity with the Mn-SOD of the marine rotifer Brachionus plicatilis, the nematode Caenorhabditis elegans, and the fruit fly Drosophila melanogaster, respectively. The phylogenetic tree constructed based on the amino acid sequences of Mn-SODs from B. calyciflorus and other organisms revealed that this rotifer is closely related to nematodes. Analysis of the mRNA expression of Mn-SOD under different conditions revealed that expression was enhanced 5.6-fold (p 0.05). Moderate starvation promoted Mn-SOD mRNA expression (p 12 < 0.01, p 36 < 0.05), which reached a maximum value (15.3 times higher than control, p 24 < 0.01) at 24 h. SOD and CAT activities also elevated at the 12 h-starved group. These results indicate that induction of Mn-SOD expression by stressors likely plays an important role in aging of B. calyciflorus.

  2. cis-Canthaxanthins: unusual carotenoids in the eggs and the reproductive system of female brine shrimp Artemia

    Nelis, H.J.C.F.; Lavens, P.; Moens, L.; Sorgeloos, P.; Jonckheere, J.A.; Criel, G.R.J.; De Leenheer, A.P.

    1984-01-01

    The significance of carotenoid accumulation in crustacean eggs remains obscure, particularly because neither eggs nor female animals have been found to display specific pigment patterns in relation to reproduction. We report here the first example of carotenoids found exclusively in the ovaries, the eggs, and the hemolymph, but not in the carcass of a female, reproductively active crustacean, i.e. the brine shrimp Artemia . These pigments are virtually absent in males and in immature animals ...

  3. Aplicación del bioensayo de Artemia salina en el análisis general de plantas medicinales brasileñas

    Montanher, Ana Beatriz Pimentel; Pizzolatti, Moacir Geraldo; Brighente, Inês Maria Costa

    2002-01-01

    Extractos de once especies de la flora brasileña fueron estudiados para evaluar la actividad citotóxica por el test de Artemia salina. Las plantas seleccionadas fueron: Baccharis pseudotenuifolia, Baccharis ligustrina, Baccharis platypoda, Baccharis coridifolia, Polygala paniculata, Polygala sabulosa, Croton celtidifolius, Cyathea phalerata, Trichilia catigua, Eugenia uniflora y Schinus molle. Los resultados obtenidos para los extractos crudos de B. pseudotenuifolia, B. ligustrina, B. c...

  4. Transgene Expression in Microalgae-From Tools to Applications.

    Doron, Lior; Segal, Na'ama; Shapira, Michal

    2016-01-01

    Microalgae comprise a biodiverse group of photosynthetic organisms that reside in water sources and sediments. The green microalgae Chlamydomonas reinhardtii was adopted as a useful model organism for studying various physiological systems. Its ability to grow under both photosynthetic and heterotrophic conditions allows efficient growth of non-photosynthetic mutants, making Chlamydomonas a useful genetic tool to study photosynthesis. In addition, this green alga can grow as haploid or diploid cells, similar to yeast, providing a powerful genetic system. As a result, easy and efficient transformation systems have been developed for Chlamydomonas, targeting both the chloroplast and nuclear genomes. Since microalgae comprise a rich repertoire of species that offer variable advantages for biotech and biomed industries, gene transfer technologies were further developed for many microalgae to allow for the expression of foreign proteins of interest. Expressing foreign genes in the chloroplast enables the targeting of foreign DNA to specific sites by homologous recombination. Chloroplast transformation also allows for the introduction of genes encoding several enzymes from a complex pathway, possibly as an operon. Expressing foreign proteins in the chloroplast can also be achieved by introducing the target gene into the nuclear genome, with the protein product bearing a targeting signal that directs import of the transgene-product into the chloroplast, like other endogenous chloroplast proteins. Integration of foreign genes into the nuclear genome is mostly random, resulting in large variability between different clones, such that extensive screening is required. The use of different selection modalities is also described, with special emphasis on the use of herbicides and metabolic markers which are considered to be friendly to the environment, as compared to drug-resistance genes that are commonly used. Finally, despite the development of a wide range of transformation

  5. Transgene expression in microalgae – from tools to applications

    Lior eDoron

    2016-04-01

    Full Text Available Microalgae comprise a biodiverse group of photosynthetic organisms that reside in water sources and sediments. The green microalgae Chlamydomonas reinhardtii was adopted as a useful model organism for studying various physiological systems. Its ability to grow under both photosynthetic and heterotrophic conditions allows efficient growth of non-photosynthetic mutants, making Chlamydomonas a useful genetic tool to study photosynthesis. In addition, this green alga can grow as haploid or diploid cells, similar to yeast, providing a powerful genetic system. As a result, easy and efficient transformation systems have been developed for Chlamydomonas, targeting both the chloroplast and nuclear genomes. Since microalgae comprise a rich repertoire of species that offer variable advantages for biotech and biomed industries, gene transfer technologies were further developed for many microalgae to allow for the expression of foreign proteins of interest. Expressing foreign genes in the chloroplast enables the targeting of foreign DNA to specific sites by homologous recombination. Chloroplast transformation also allows for the introduction of genes encoding several enzymes from a complex pathway, possibly as an operon. Expressing foreign proteins in the chloroplast can also be achieved by introducing the target gene into the nuclear genome, with the protein product bearing a targeting signal that directs import of the transgene-product into the chloroplast, like other endogenous chloroplast proteins. Integration of foreign genes into the nuclear genome is mostly random, resulting in large variability between different clones, such that extensive screening is required. The use of different selection modalities is also described, with special emphasis on the use of herbicides and metabolic markers which are considered to be friendly to the environment, as compared to drug-resistance genes that are commonly used. Finally, despite the development of a wide

  6. Effects of Fluctuating Environments on the Selection of High Yielding Microalgae

    Benemann, J. R.; Tillett, D. M.

    1987-02-27

    Microalgae have the potential of producing biomass with a high content of lipids at high productivities using seawater or saline ground water resources. Microalgal lipids are similar to vegetable oils and suitable for processing to liquid fuels. Engineering cost analysis studies have concluded that, at a favorable site, microalgae cultivation for fuel production could be economically viable. The major uncertainties involve the microalgae themselves: biomass and lipid productivity and culture stability.

  7. Sudden weaning of angel fish pterophyllum scalare (Lichtenstein) (Pisces; Cichlidae) larvae from brine shrimp (Artemia sp) nauplii to formulated larval feed.

    Herath, Sandamali Sakunthala; Atapaththu, Kerthi Sri Senarathna

    2013-12-01

    This study investigated the effects of sudden weaning of angel fish larvae (Pteraphylum scalari) from Artemia nauplii to commercial larval feed. Four days post hatch (DPH) larvae were reared in four different weaning protocols (TR1-TR4) with triplicates in a complete randomize design. Larvae in TR1 and TR4 were exclusively fed Artemia nauplii and dry feed respectively. In TR2 and TR3, larvae were initially fed Artemia nauplii and suddenly wean to formulated feed on 14 DPH and 7 DPH respectively. The experiment was lasted for 28 days. At the end of the experiment, final mean weight (FW), total length (FL), height (FH), Daily Weight Gain (DWG), Specific Growth Rate (SGR), survival and stress index were compared. Significantly highest (P larvae solely fed formulated feed. Survival and the stress index were independent from weaning methods. Although sudden weaning is possible on 7 DPH, larvae showed comparatively higher growth when switch off to formulate feed on 14 DPH.

  8. Virulence of luminescent and non-luminescent isogenic vibrios towards gnotobiotic Artemia franciscana larvae and specific pathogen-free Litopenaeus vannamei shrimp.

    Phuoc, L H; Defoirdt, T; Sorgeloos, P; Bossier, P

    2009-04-01

    This study was conducted to test the virulence of luminescent (L) and non-luminescent (NL) isogenic strains of Vibrio campbellii LMG21363, Vibrio harveyi BB120 (wild type) and quorum-sensing mutant strains derived from the wild type such as Vibrio harveyi BB152, BB170, MM30 and BB886. The NL strains could be obtained by culturing rifampicin-resistant luminescent strains in the dark under static condition. The virulence of the L and NL strains was tested in gnotobiotic Artemia franciscana larvae challenged with 10(4) CFU ml(-1) of bacteria. All luminescent isogenic tested strains showed higher virulence compared to the NL strains. The virulence of L and NL V. campbellii and V. harveyi BB120 was also tested in specific pathogen-free juvenile shrimp upon intramuscular injection with 10(6) CFU of bacteria. In contrast with Artemia, there was no significant difference in mortality between the groups challenged with L and NL strains (P > 0.05). The non-luminescent strains were not able to revert back to the luminescent state and quorum sensing did not influence this phenotypic shift. Luminescent Vibrio strains can switch to a non-luminescent state by culturing them in static conditions. The NL strains become less virulent as verified in Artemia. The luminescent state of Vibrio cells in a culture needs to be verified in order to assure maintenance of virulence.

  9. Anticipation of Artemia sp. supply in the larviculture of the barber goby Elacatinus figaro (Gobiidae: Teleostei influenced growth, metamorphosis and alkaline protease activity

    Maria Fernanda da Silva-Souza

    2015-09-01

    Full Text Available The barber goby Elacatinus figaro is considered endangered due to overexploitation by the ornamental industry. Farming marine ornamental fishes, especially the threatened ones, can be one of the measures to minimize the pressure on the natural stocks. Among the priority issues for their production is the determination of the most appropriate feeding management. The feeding protocol commonly used in the larviculture of barber goby, when the start of Artemia sp. offer occurred at the 18th DAH (days after hatching (treatment T18, was modified, by anticipating brine shrimp supply in 6 days (treatment T12. Alkaline proteases activity, growth and metamorphosis of larvae were evaluated in both protocols. Juveniles at T12 showed higher weight (0.04 ± 0.001 g and lower activity of total alkaline proteases (1.3 ± 0.2 mU mg-1 protein compared to T18 (0.02 ± 0.001 g; 2.8 ± 0.4 mU mg-1 protein, respectively. With anticipation of brine shrimp, the commencing and end of larval transformation was observed earlier (at 24 and 34 DAH, respectively in comparison to those with the supply of Artemia sp. at 18 DAH (27 and 41 DAH, respectively. Thus, the Artemia sp. anticipation was beneficial during the larviculture of the barber goby, considering that larvae reached metamorphosis earlier.

  10. A Method for Microalgae Proteomics Analysis Based on Modified Filter-Aided Sample Preparation.

    Li, Song; Cao, Xupeng; Wang, Yan; Zhu, Zhen; Zhang, Haowei; Xue, Song; Tian, Jing

    2017-11-01

    With the fast development of microalgal biofuel researches, the proteomics studies of microalgae increased quickly. A filter-aided sample preparation (FASP) method is widely used proteomics sample preparation method since 2009. Here, a method of microalgae proteomics analysis based on modified filter-aided sample preparation (mFASP) was described to meet the characteristics of microalgae cells and eliminate the error caused by over-alkylation. Using Chlamydomonas reinhardtii as the model, the prepared sample was tested by standard LC-MS/MS and compared with the previous reports. The results showed mFASP is suitable for most of occasions of microalgae proteomics studies.

  11. Potential of microalgae in the bioremediation of water with chloride content

    Ramírez, M. E.; Vélez, Y. H.; Rendón, L.; Alzate, E.

    2017-01-01

    Abstract In this work it was carried out the bioremediation of water containing chlorides with native microalgae (MCA) provided by the Centre for study and research in biotechnology (CIBIOT) at Universidad Pontificia Bolivariana. Microalgae presented an adaptation to the water and so the conditions evaluated reaching a production of CO2 in mg L-1 of 53.0, 26.6, 56.0, 16.0 and 30.0 and chloride removal efficiencies of 16.37, 26.03, 40.04, 25.96 and 20.25% for microalgae1, microalgae2, microalg...

  12. Detection of viability of micro-algae cells by optofluidic hologram pattern.

    Wang, Junsheng; Yu, Xiaomei; Wang, Yanjuan; Pan, Xinxiang; Li, Dongqing

    2018-03-01

    A rapid detection of micro-algae activity is critical for analysis of ship ballast water. A new method for detecting micro-algae activity based on lens-free optofluidic holographic imaging is presented in this paper. A compact lens-free optofluidic holographic imaging device was developed. This device is mainly composed of a light source, a small through-hole, a light propagation module, a microfluidic chip, and an image acquisition and processing module. The excited light from the light source passes through a small hole to reach the surface of the micro-algae cells in the microfluidic chip, and a holographic image is formed by the diffraction light of surface of micro-algae cells. The relation between the characteristics in the hologram pattern and the activity of micro-algae cells was investigated by using this device. The characteristics of the hologram pattern were extracted to represent the activity of micro-algae cells. To demonstrate the accuracy of the presented method and device, four species of micro-algae cells were employed as the test samples and the comparison experiments between the alive and dead cells of four species of micro-algae were conducted. The results show that the developed method and device can determine live/dead microalgae cells accurately.

  13. Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review

    Miazek, Krystian; Iwanek, Waldemar; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

    2015-01-01

    Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles) from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed. PMID:26473834

  14. Microalgae community shifts during the biogas upgrading in an alkaline open photobioreactor.

    Granada-Moreno, C I; Aburto-Medina, A; de Los Cobos Vasconcelos, D; González-Sánchez, A

    2017-10-01

    To achieve the functional specialization of a microalgae community through operational tuning of an open photobioreactor used for biogas upgrading under alkaline conditions. An open photobioreactor was inoculated with an indigenous microalgae sample from the Texcoco Soda Lake. A microalgae community was adapted to fix CO 2 from synthetic biogas through different culture conditions reaching a maximum of 220 mg CO 2  l -1 per day. Picochlorum sp. and Scenedesmus sp. were identified as the prominent microalgae genera by molecular fingerprinting (partial sequencing of 16S rRNA and 18S rRNA genes) but only the first was detected by microscopy screening. Changes in the microalgae community profile were monitored by a range-weighted richness index, reaching the lowest value when biogas was upgraded. A robust microalgae community in the open photobioreactor was obtained after different culture conditions. The specialization of microalgae community for CO 2 fixation under H 2 S presence was driven by biogas upgrading conditions. The alkaline conditions enhance the CO 2 absorption from biogas and could optimize specialized microalgae communities in the open photobioreactor. Denaturing gradient gel electrophoresis fingerprinting and richness index comparison are useful methods for the evaluation of microalgae community shifts and photosynthetic activity performance, particularly in systems intended for CO 2 removal from biogas where the CO 2 assimilation potential can be related to the microbial richness. © 2017 The Society for Applied Microbiology.

  15. Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review

    Krystian Miazek

    2015-10-01

    Full Text Available Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed.

  16. Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review.

    Miazek, Krystian; Iwanek, Waldemar; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

    2015-10-09

    Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles) from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed.

  17. Simulation of temperature effect on microalgae culture in a tubular photo bioreactor for local solar irradiance

    Shahriar, M.; Deb, Ujjwal Kumar; Rahman, Kazi Afzalur

    2017-06-01

    Microalgae based biofuel is now an emerging source of renewable energy alternative to the fossil fuel. This paper aims to present computational model of microalgae culture taking effect of solar irradiance and corresponding temperature in a photo bioreactor (PBR). As microalgae is a photosynthetic microorganism, so irradiance of sunlight is one of the important limiting factors for the proper growth of microalgae cells as temperature is associated with it. We consider the transient behaviour of temperature inside the photo bioreactor for a microalgae culture. The optimum range of temperature for outdoor cultivation of microalgae is about 16-35°c and out of this range the cell growth inhibits. Many correlations have already been established to investigate the heat transfer phenomena inside a tubular PBR. However, none of them are validated yet numerically by using a user defined function in a simulated model. A horizontal tubular PBR length 20.5m with radius 0.05m has taken account to investigate the temperature effect for the growth of microalgae cell. As the solar irradiance varies at any geographic latitude for a year so an empirical relation is established between local solar irradiance and temperature to simulate the effect. From our simulation, we observed that the growth of microalgae has a significant effect of temperature and the solar irradiance of our locality is suitable for the culture of microalgae.

  18. Harvesting and processing of microalgae biomass fractions for biodiesel production

    Munir, M.; Sharif, N.; Naz, S.; Saleem, F.; Manzoor, F.

    2013-01-01

    There has been a recent resurgent interest in microalgae as an oil producer for biofuel applications. An adequate supply of nutrients and carbon dioxide enables algae to successfully transform light energy of the sun into energy - rich chemical compounds through photosynthesis. A strain with high lipids, successfully grown and harvested, could provide oil for most of our process by volume, which would then provide the most profitable output. Significant advances have also been made in upstream processing to generate cellular biomass and oil. However, the process of extracting and purifying of oil from algae continues to prove a significant challenge in producing both microalgae bioproducts and biofuel, as the oil extraction from algae is relatively energy-intensive and expensive. The aim of this review is to focus on different harvesting and extraction processes of algae for biodiesel production reported within the last decade. (author)

  19. Hazard and risk of herbicides for marine microalgae.

    Sjollema, Sascha B; Martínezgarcía, Gema; van der Geest, Harm G; Kraak, Michiel H S; Booij, Petra; Vethaak, A Dick; Admiraal, Wim

    2014-04-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol(®)1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Recent developments on biofuels production from microalgae and macroalgae

    Kumar, Kanhaiya; Ghosh, Supratim; Angelidaki, Irini

    2016-01-01

    and infrastructure requirement. Hydrogen production by microalgae through biophotolysis seems interesting as it directly converts the solar energy into hydrogen. However, the process has not been scaled-up till today. Hydrothermal liquefaction (HTL) is more promising due to handling of wet biomass at moderate......Biofuels from algae are considered as promising alternatives of conventional fossil fuels, as they can eliminate most of the environmental problems. The present study focuses on all the possible avenues of biofuels production through biochemical and thermochemical conversion methods in one place......, bringing together both microalgae and macroalgae on the same platform. It provides a brief overview on the mechanism of different biofuel production from algae. Factors affecting the biofuel process and the associated challenges have been highlighted alongwith analysis of techno-economic study available...

  1. Biorefinery of microalgae - opportunities and constraints for different production scenarios.

    Hariskos, Ioanna; Posten, Clemens

    2014-06-01

    In order to design economically feasible production processes it is necessary, as part of the biorefinery concept, to valorize all constituents of the microalgal biomass. Such an approach requires appropriate biorefinery side-process strategies to be adapted to production of the primary product. These strategies are particularly valid for microalgae, since the composition and amount of residual biomass can vary significantly depending on cell stoichiometry and cultivation techniques. This review investigates opportunities and constraints for biorefinery concepts in production scenarios for four different products from microalgae with different market volumes, including high- and medium-value products, whole cells and biodiesel. Approaches to close material and energy balances, as well as to adapt the biorefinery according to biological potential, process routes, and market needs are presented, which will further contribute to making the biorefinery concept a success. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Anisotropic transport of microalgae Chlorella vulgaris in microfluidic channel

    Ishak, Nur Izzati; Muniandy, S V; Periasamy, Vengadesh; Ng, Fong-Lee; Phang, Siew-Moi

    2017-01-01

    In this work, we study the regional dependence of transport behavior of microalgae Chlorella vulgaris inside microfluidic channel on applied fluid flow rate. The microalgae are treated as spherical naturally buoyant particles. Deviation from the normal diffusion or Brownian transport is characterized based on the scaling behavior of the mean square displacement (MSD) of the particle trajectories by resolving the displacements in the streamwise (flow) and perpendicular directions. The channel is divided into three different flow regions, namely center region of the channel and two near-wall boundaries and the particle motions are analyzed at different flow rates. We use the scaled Brownian motion to model the transitional characteristics in the scaling behavior of the MSDs. We find that there exist anisotropic anomalous transports in all the three flow regions with mixed sub-diffusive, normal and super-diffusive behavior in both longitudinal and transverse directions. (paper)

  3. Improving biogas production from microalgae by enzymatic pretreatment.

    Passos, Fabiana; Hom-Diaz, Andrea; Blanquez, Paqui; Vicent, Teresa; Ferrer, Ivet

    2016-01-01

    In this study, enzymatic pretreatment of microalgal biomass was investigated under different conditions and evaluated using biochemical methane potential (BMP) tests. Cellulase, glucohydrolase and an enzyme mix composed of cellulase, glucohydrolase and xylanase were selected based on the microalgae cell wall composition (cellulose, hemicellulose, pectin and glycoprotein). All of them increased organic matter solubilisation, obtaining high values already after 6h of pretreatment with an enzyme dose of 1% for cellulase and the enzyme mix. BMP tests with pretreated microalgae showed a methane yield increase of 8 and 15% for cellulase and the enzyme mix, respectively. Prospective research should evaluate enzymatic pretreatments in continuous anaerobic reactors so as to estimate the energy balance and economic cost of the process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Applications of Diatoms as Potential Microalgae in Nanobiotechnology

    Ahmad Yari Khosroushahi; Miguel de la Guardia; Mohamad Moradi Ghorakhlu; Ali Akbar Jamali; Fariba Akbari

    2012-01-01

    Introduction: Diatoms are single cell eukaryotic microalgae, which present in nearly every water habitat make them ideal tools for a wide range of applications such as oil explora­tion, forensic examination, environmental indication, biosilica pattern generation, toxicity testing and eutrophication of aqueous ecosystems. Methods: Essential information on diatoms were reviewed and discussed towards impacts of diatoms on biosynthesis and bioremediation. Results: In this review, we present the ...

  5. A Novel Enclosed Online Control System for Microalgae Production

    Bin Li

    2014-03-01

    Full Text Available Microalgae are single celled microscopic organisms which, like plants, convert solar energy into bio-energy through photosynthesis. They can be used to produce a variety of bio-based products, such as bio-food and biodiesel. Large scale algae production can be achieved in open or closed systems. An enclosed online microalgae control production system is presented in this paper. The designed system is composed of a reactor which is placed inside a box with light reflecting surface. Lighting system, CO2 supply, heating, as well as online cell mass monitoring via spectrophotometer, were integrated. The online monitoring of cell mass concentration is coupled to two pumps which remove a certain amount of cell suspension, and take fresh media as an alternative. Also, a LabView program was developed to collect data from a spectrophotometer and processed in a computer. Considering the limited experimental conditions and the pollution possibility for its high productivity if liquid is not properly disposed, food color was used to test the designed novel system in this paper. The results showed that, the system could detect a change in absorption over time with periodic sampling for every 4.8 minutes. When absorption value reach a pre-set gate, pump1 immediately starts to pump out a certain amount of solution?then pump2 starts to pump in fresh media according to the calculated time. The concentration could be controlled below the threshold value. From the continuous test using food color, the designed system showed good stability and controlling accuracy. It provides a good reference for the following microalgae testing experiment in future. Considering the applications of microalgae in agriculture, this research also provides resources for bio-fertilizer.

  6. "Rational" management of dichlorophenols biodegradation by the microalga Scenedesmus obliquus.

    Papazi, Aikaterini; Kotzabasis, Kiriakos

    2013-01-01

    The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps) under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp - no meta-substitution) consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp - one meta-chloride) was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp - two meta-chlorides) could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity) was higher, than group I (lower toxicity) and the biodegradation of dichlorophenols (higher toxicity) was higher than the corresponding monochlorophenols (lower toxicity). The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as "smart" bioenergetic "machines", that have the ability to continuously "calculate" the energy reserves and "use" the most energetically

  7. Spectral optical properties of selected photosynthetic microalgae producing biofuels

    Lee, Euntaek; Heng, Ri-Liang; Pilon, Laurent

    2013-01-01

    This paper presents the spectral complex index of refraction of biofuel producing photosynthetic microalgae between 400 and 750 nm. They were retrieved from their experimentally measured average absorption and scattering cross-sections. The microalgae were treated as homogeneous polydisperse spheres with equivalent diameter such that their surface area was identical to that of their actual spheroidal shape. An inverse method was developed combining Lorentz–Mie theory as the forward method and genetic algorithm. The unicellular green algae Chlamydomonas reinhardtii strain CC125 and its truncated chlorophyll antenna transformants tla1, tlaX, and tla1-CW + as well as Botryococcus braunii, Chlorella sp., and Chlorococcum littorale were investigated. These species were selected for their ability to produce either hydrogen gas or lipids for liquid fuel production. Their retrieved real and imaginary parts of the complex index of refraction were continuous functions of wavelength with absorption peaks corresponding to those of in vivo Chlorophylls a and b. The T-matrix method was also found to accurately predict the experimental measurements by treating the microalgae as axisymmetric spheroids with the experimentally measured major and minor diameter distributions and the retrieved spectral complex index of refraction. Finally, pigment mass fractions were also estimated from the retrieved absorption index. The method and/or the reported optical properties can be used in various applications from ocean remote sensing, carbon cycle study, as well as photobiological carbon dioxide mitigation and biofuel production. -- Highlights: ► Retrieval of optical properties from average absorption and scattering cross-sections. ► Inverse method based on Lorentz–Mie theory and genetic algorithm. ► Refraction and absorption indices of selected microalgae between 400 and 750 nm. ► Determination of pigment concentrations from absorption index. ► Good agreement between T

  8. CO{sub 2} capture and biofuels production with microalgae

    Benemann, J.R. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    Microalgae cultivation in large open ponds is the only biological process capable of directly utilizing power plant flue gas CO{sub 2} for production of renewable fuels, such as biodiesel, thus mitigating the potential for global warming. Past and recent systems studies have concluded that in principle this concept could be economically feasible, but that this technology still requires both fundamental and applied long-term R&D.

  9. Algevir: An Expression System for Microalgae Based on Viral Vectors

    Bernardo Bañuelos-Hernández

    2017-06-01

    Full Text Available The use of recombinant algae for the production of valuable compounds is opening promising biotechnological applications. However, the development of efficient expression approaches is still needed to expand the exploitation of microalgae in biotechnology. Herein, the concept of using viral expression vectors in microalgae was explored for the first time. An inducible geminiviral vector leading to Rep-mediated replication of the expression cassette allowed the production of antigenic proteins at high levels. This system, called Algevir, allows the production of complex viral proteins (GP1 from Zaire ebolavirus and bacterial toxin subunits (B subunit of the heat-labile Escherichia coli enterotoxin, which retained their antigenic activity. The highest achieved yield was 1.25 mg/g fresh biomass (6 mg/L of culture, which was attained 3 days after transformation. The Algevir system allows for a fast and efficient production of recombinant proteins, overcoming the difficulties imposed by the low yields and unstable expression patterns frequently observed in stably transformed microalgae at the nuclear level; as well as the toxicity of some target proteins.

  10. Microalgae dewatering based on forward osmosis employing proton exchange membrane.

    Son, Jieun; Sung, Mina; Ryu, Hoyoung; Oh, You-Kwan; Han, Jong-In

    2017-11-01

    In this study, electrically-facilitated forward osmosis (FO) employing proton exchange membrane (PEM) was established for the purpose of microalgae dewatering. An increase in water flux was observed when an external voltage was applied to the FO equipped with the PEM; as expected, the trend became more dramatic with both concentration of draw solution and applied voltage raised. With this FO used for microalgae dewatering, 247% of increase in flux and 86% in final biomass concentration were observed. In addition to the effect on flux improvement, the electrically-facilitated FO exhibited the ability to remove chlorophyll from the dewatered biomass, down to 0.021±0015mg/g cell. All these suggest that the newly suggested electrically-facilitated FO, one particularly employed PEM, can indeed offer a workable way of dewatering of microalgae; it appeared to be so because it can also remove the ever-problematic chlorophyll from extracted lipids in a simultaneous fashion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Prospects of biodiesel production from microalgae in India

    Khan, Shakeel A.; Hussain, Mir Z.; Prasad, S. [Division of Environmental Sciences, Indian Agricultural Research Institute, New Delhi 110012 (India); Rashmi; Banerjee, U.C. [Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical and Education Research (NIPER), Sector 67, Phase X, S.A.S. Nagar, Mohali 160062, Punjab (India)

    2009-12-15

    Energy is essential and vital for development, and the global economy literally runs on energy. The use of fossil fuels as energy is now widely accepted as unsustainable due to depleting resources and also due to the accumulation of greenhouse gases in the environment. Renewable and carbon neutral biodiesel are necessary for environmental and economic sustainability. Biodiesel demand is constantly increasing as the reservoir of fossil fuel are depleting. Unfortunately biodiesel produced from oil crop, waste cooking oil and animal fats are not able to replace fossil fuel. The viability of the first generation biofuels production is however questionable because of the conflict with food supply. Production of biodiesel using microalgae biomass appears to be a viable alternative. The oil productivity of many microalgae exceeds the best producing oil crops. Microalgae are photosynthetic microorganisms which convert sunlight, water and CO{sub 2} to sugars, from which macromolecules, such as lipids and triacylglycerols (TAGs) can be obtained. These TAGs are the promising and sustainable feedstock for biodiesel production. Microalgal biorefinery approach can be used to reduce the cost of making microalgal biodiesel. Microalgal-based carbon sequestration technologies cover the cost of carbon capture and sequestration. The present paper is an attempt to review the potential of microalgal biodiesel in comparison to the agricultural crops and its prospects in India. (author)

  12. Enzymatic cell disruption of microalgae biomass in biorefinery processes.

    Demuez, Marie; Mahdy, Ahmed; Tomás-Pejó, Elia; González-Fernández, Cristina; Ballesteros, Mercedes

    2015-10-01

    When employing biotechnological processes for the procurement of biofuels and bio-products from microalgae, one of the most critical steps affecting economy and yields is the "cell disruption" stage. Currently, enzymatic cell disruption has delivered effective and cost competitive results when compared to mechanical and chemical cell disruption methods. However, the introduction of enzymes implies additional associated cost within the overall process. In order to reduce this cost, autolysis of microalgae is proposed as alternative enzymatic cell disruption method. This review aims to provide the state of the art of enzymatic cell disruption treatments employed in biorefinery processes and highlights the use of endopeptidases. During the enzymatic processes of microalgae life cycle, some lytic enzymes involved in cell division and programmed cell death have been proven useful in performing cell lysis. In this context, the role of endopeptidases is emphasized. Mirroring these natural events, an alternative cell disruption approach is proposed and described with the potential to induce the autolysis process using intrinsic cell enzymes. Integrating induced autolysis within biofuel production processes offers a promising approach to reduce overall global costs and energetic input associated with those of current cell disruption methods. A number of options for further inquiry are also discussed. © 2015 Wiley Periodicals, Inc.

  13. Polishing of municipal secondary effluent using native microalgae consortia.

    Beltrán-Rocha, Julio César; Barceló-Quintal, Icela Dagmar; García-Martínez, Magdalena; Osornio-Berthet, Luis; Saavedra-Villarreal, Nidia; Villarreal-Chiu, Juan; López-Chuken, Ulrico Javier

    2017-04-01

    This work evaluates the use of native microalgae consortia for a dual role: polishing treatment of municipal wastewater effluents and microalgae biomass feedstock potential for biodiesel or biofertilizer production. An initial screening was undertaken to test N and P removal from secondary effluents and biomass production by 12 consortia. A subsequent treatment was performed by selected consortia (01 and 12) under three operational conditions: stirring (S), S + 12 h of daily aeration (S + A) and S + A enriched with CO 2 (S + AC). All treatments resulted in compliance with environmental regulations (e.g. Directive 91/271/EEC) and high removal efficiency of nutrients: 64-79% and 80-94% of total N and PO 4 3- -P respectively. During the experiments it was shown that pH alkalinization due to microalgae growth benefits the chemical removal of ammonia and phosphorus. Moreover, advantages of pH increase could be accomplished by intermittent CO 2 addition which in this research (treatment S + AC) promoted higher yield and lipid concentration. The resulting dry biomass analysis showed a low lipid content (0.5-4.3%) not ideal for biodiesel production. Moreover, the high rate of ash (29.3-53.0%) suggests that biomass could be readily recycled as a biofertilizer due to mineral supply and organic constituents formed by C, N and P (e.g. carbohydrate, protein, and lipids).

  14. Algevir: An Expression System for Microalgae Based on Viral Vectors

    Bañuelos-Hernández, Bernardo; Monreal-Escalante, Elizabeth; González-Ortega, Omar; Angulo, Carlos; Rosales-Mendoza, Sergio

    2017-01-01

    The use of recombinant algae for the production of valuable compounds is opening promising biotechnological applications. However, the development of efficient expression approaches is still needed to expand the exploitation of microalgae in biotechnology. Herein, the concept of using viral expression vectors in microalgae was explored for the first time. An inducible geminiviral vector leading to Rep-mediated replication of the expression cassette allowed the production of antigenic proteins at high levels. This system, called Algevir, allows the production of complex viral proteins (GP1 from Zaire ebolavirus) and bacterial toxin subunits (B subunit of the heat-labile Escherichia coli enterotoxin), which retained their antigenic activity. The highest achieved yield was 1.25 mg/g fresh biomass (6 mg/L of culture), which was attained 3 days after transformation. The Algevir system allows for a fast and efficient production of recombinant proteins, overcoming the difficulties imposed by the low yields and unstable expression patterns frequently observed in stably transformed microalgae at the nuclear level; as well as the toxicity of some target proteins. PMID:28713333

  15. Biodiesel production from microalgae: cultivation parameters that affect lipid production

    Arias Penaranda, Martha Trinidad; Martinez Roldan, Alfredo de Jesus; Canizares Villanueva, Rosa Olivia

    2013-01-01

    The microalgae have the capacity to mitigate CO 2 emissions and to produce lipids, which are considered with potential to obtain third-generation biofuel. This review provides updated information of the influence of culture conditions on the lipids production with high productivity and profile suitable for the biodiesel production. This document presents a compilation of research conclusions over the last 13 years around the world. in the literature consulted, the authors conclude that although the behavior of microalgae at physiological stress conditions, varies between species; the nutrients limitation, especially nitrogen and phosphorus, associated with heterotrophic growth or high irradiances in phototrophy are considered the most efficient strategies to increase the lipid content in microalgae, particularly triglycerides (consisting of saturated and monounsaturated fatty acids), which are excellent for the production of biodiesel. Also, it is reported that the lipid content increase and the number of unsaturated fatty acids decrease with the addition of small amounts of CO 2 and harvesting the biomass it the stationary phase of growth.

  16. Utilization of organic residues using heterotrophic microalgae and insects.

    Pleissner, Daniel; Rumpold, Birgit A

    2018-02-01

    Various organic residues occur globally in the form of straw, wood, green biomass, food waste, feces, manure etc. Other utilization strategies apart from anaerobic digestion, composting and incineration are needed to make use of the whole potential of organic residues as sources of various value added compounds. This review compares the cultivation of heterotrophic microalgae and insects using organic residues as nutrient sources and illuminates their potential with regard to biomass production, productivity and yield, and utilization strategies of produced biomasses. Furthermore, cultivation processes as well as advantages and disadvantages of utilization processes are identified and discussed. It was shown that both heterotrophic algae and insects are able to reduce a sufficient amount of organic residues by converting it into biomass. The biomass composition of both organisms is similar which allows similar utilization strategies in food and feed, chemicals and materials productions. Even though insect is the more complex organism, biomass production can be carried out using simple equipment without sterilization and hydrolysis of organic residues. Contrarily, heterotrophic microalgae require a pretreatment of organic residues in form of sterilization and in most cases hydrolysis. Interestingly, the volumetric productivity of insect biomass exceeds the productivity of algal biomass. Despite legal restrictions, it is expected that microalgae and insects will find application as alternative food and feed sources in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

    Poojary, Mahesha M.; Barba, Francisco J.; Aliakbarian, Bahar; Donsì, Francesco; Pataro, Gianpiero; Dias, Daniel A.; Juliano, Pablo

    2016-01-01

    Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability. PMID:27879659

  18. Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

    Mahesha M. Poojary

    2016-11-01

    Full Text Available Marine microalgae and seaweeds (microalgae represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield, selectivity (purity, high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.

  19. Engineering the Chloroplast Genome of Oleaginous Marine Microalga Nannochloropsis oceanica

    Qinhua Gan

    2018-04-01

    Full Text Available Plastid engineering offers an important tool to fill the gap between the technical and the enormous potential of microalgal photosynthetic cell factory. However, to date, few reports on plastid engineering in industrial microalgae have been documented. This is largely due to the small cell sizes and complex cell-wall structures which make these species intractable to current plastid transformation methods (i.e., biolistic transformation and polyethylene glycol-mediated transformation. Here, employing the industrial oleaginous microalga Nannochloropsis oceanica as a model, an electroporation-mediated chloroplast transformation approach was established. Fluorescent microscopy and laser confocal scanning microscopy confirmed the expression of the green fluorescence protein, driven by the endogenous plastid promoter and terminator. Zeocin-resistance selection led to an acquisition of homoplasmic strains of which a stable and site-specific recombination within the chloroplast genome was revealed by sequencing and DNA gel blotting. This demonstration of electroporation-mediated chloroplast transformation opens many doors for plastid genome editing in industrial microalgae, particularly species of which the chloroplasts are recalcitrant to chemical and microparticle bombardment transformation.

  20. Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds.

    Poojary, Mahesha M; Barba, Francisco J; Aliakbarian, Bahar; Donsì, Francesco; Pataro, Gianpiero; Dias, Daniel A; Juliano, Pablo

    2016-11-22

    Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.

  1. Stabilisation of microalgae: Iodine mobilisation under aerobic and anaerobic conditions.

    Han, Wei; Clarke, William; Pratt, Steven

    2015-10-01

    Mobilisation of iodine during microalgae stabilisation was investigated, with the view of assessing the potential of stabilised microalgae as an iodine-rich fertiliser. An iodine-rich waste microalgae (0.35 ± 0.05 mg I g(-1) VS(added)) was stabilised under aerobic and anaerobic conditions. Iodine mobilisation was linearly correlated with carbon emission, indicating iodine was in the form of organoiodine. Comparison between iodine and nitrogen mobilisation relative to carbon emission indicated that these elements were, at least in part, housed separately within the cells. After stabilisation, there were 0.22 ± 0.05 and 0.19 ± 0.01 mg g(-1) VS(added) iodine remaining in the solid in the aerobic and anaerobic processed material respectively, meaning 38 ± 5.0% (aerobic) and 50 ± 8.6% (anaerobic) of the iodine were mobilised, and consequently lost from the material. The iodine content of the stabilised material is comparable to the iodine content of some seaweed fertilisers, and potentially satisfies an efficient I-fertilisation dose. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Biodiesel renovável derivado de microalgas: avanços e perspectivas tecnológicas

    Claudio M. P. Pereira

    2012-01-01

    Full Text Available Microalgae are a promising source of raw material for biodiesel production. This review discusses the latest developments related to the application of microalgae biomass for biodiesel production. Characterization of fatty acid of microalgae and comparisons with other sources of raw materials and processes are presented. Furthermore, technological perspectives and approaches for growing microalgae in photobioreactors, microalgal oil extraction techniques, and procedures for synthesizing biodiesel are reviewed.

  3. Loktak Lake, Manipur, northeast India: a Ramsar site with rich rotifer (Rotifera: Eurotatoria diversity and its meta-analysis

    Bhushan Kumar Sharma

    2016-04-01

    Full Text Available A total of 162 species (S of Rotifera belonging to 40 genera and 20 families examined from Loktak Lake, an important floodplain lake of northeast India (NEI that is one of the richest assemblages of the taxon known from the Indian sub-region. It merits biodiversity value as ~40.0% and ~62.0% of species recorded from India and NEI, respectively. One species is new to India, 23 species are new to Manipur and 14 species are new to Loktak basin. Biogeographically interesting elements included three Australasian, five Oriental, ten palaeotropical and one cosmo-subtropical species. Lecanidae > Lepadellidae > Brachionidae > Trichocercidae collectively comprised 65.4% of S; Lecane > Lepadella > Trichocerca are diverse genera; and paucity of Brachionus spp. is distinct. Loktak Rotifera indicated importance of cosmopolitan, the littoral-periphytonic and small-sized species, and ‘tropical character’. ANOVA recorded significant variations of the rotifer richness amongst three sampling sites of Loktak during June 2010–May 2012 survey. The richness followed osscillaring monthly variations and indicated lack of significant influence of any individual abioitic parameter at all three stations.

  4. NMDA receptor expression and C terminus structure in the rotifer Brachionus plicatilis and long-term potentiation across the Metazoa.

    Kenny, Nathan J; Dearden, Peter K

    2013-12-01

    The C termini of N-methyl-D-aspartate (NMDA) receptor NR2 subunits are thought to play a major role in the molecular establishment of memory across the Bilateria, via the phenomenon known as long-term potentiation (LTP). Despite their long history of use as models in the study of memory, the expression and structure of the NR2 subunit in the Lophotrochozoa has remained uncategorized. Here, we report the phylogenic relationships of NR subunits across the Bilateria, and the cloning and in situ analysis of expression of NMDA NR1 and NR2 subunits in the monogont rotifer Brachionus plicatilis. RNA in situ hybridization suggests expression of NMDA receptor subunits in B. plicatilis is neural, consistent with expression observed in other species, and ours is the first report confirming NR2 expression in the lophotrochozoan clade. However, the single NR2 subunit identified in B. plicatilis was found to lack the long C terminal domain found in vertebrates, which is believed to modulate LTP. Further investigation revealed that mollusc and annelid NR2 subunits possess long intracellular C terminal domains. As data from molluscs (and particularly Aplysia californica) are the basis for much of our understanding of LTP, understanding how these diverse lophotrochozoan C termini function in vivo will have many implications for how we consider the evolution of the molecular control of learning and memory across the Metazoa as a whole and interpret the results of experiments into this vital component of cognition.

  5. Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.

    Campillo, Sergi; Serra, Manuel; Carmona, María José; Gómez, Africa

    2011-01-01

    Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1) strong founder effects due to rapidly growing populations and very large population sizes, and (2) the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of sampled ponds in areas where secondary contact is likely and doubling sample sizes. We analyzed partial mitochondrial sequences of 252 individuals. We found two deep mitochondrial DNA lineages differing in both their genetic diversity and the complexity of their phylogeographic structure. Our analyses suggest that several events of secondary contact between clades occurred after their expansion from glacial refugia. We found a pattern of isolation-by-distance, which we interpret as being the result of historical colonization events. We propose the existence of at least one glacial refugium in the SE of the Iberian Peninsula. Our findings challenge predictions of the Monopolization hypothesis, since coexistence (i.e., secondary contact) of divergent lineages in some ponds in the Iberian Peninsula is common. Our results indicate that phylogeographic structures in small organisms can be very complex and that gene flow between diverse lineages after population establishment can indeed occur.

  6. Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.

    Sergi Campillo

    Full Text Available Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1 strong founder effects due to rapidly growing populations and very large population sizes, and (2 the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of sampled ponds in areas where secondary contact is likely and doubling sample sizes. We analyzed partial mitochondrial sequences of 252 individuals. We found two deep mitochondrial DNA lineages differing in both their genetic diversity and the complexity of their phylogeographic structure. Our analyses suggest that several events of secondary contact between clades occurred after their expansion from glacial refugia. We found a pattern of isolation-by-distance, which we interpret as being the result of historical colonization events. We propose the existence of at least one glacial refugium in the SE of the Iberian Peninsula. Our findings challenge predictions of the Monopolization hypothesis, since coexistence (i.e., secondary contact of divergent lineages in some ponds in the Iberian Peninsula is common. Our results indicate that phylogeographic structures in small organisms can be very complex and that gene flow between diverse lineages after population establishment can indeed occur.

  7. Morphological alterations in the freshwater rotifer Brachionus calyciflorus Pallas 1766 (Rotifera: Monogononta) caused by vinclozolin chronic exposure.

    Alvarado-Flores, Jesús; Rico-Martínez, Roberto; Adabache-Ortíz, Araceli; Silva-Briano, Marcelo

    2015-05-01

    Vinclozolin (VZ) is a dicarboximide fungicide widely used on fruits, vegetables and wines, effective against fungi plagues. In this study we characterized the effects of VZ using a 4-day reproductive chronic assay with the freshwater rotifer Brachionus calyciflorus. The assay included observations of several features of asexual and sexual reproduction. Our results indicate that VZ: (a) increased asexual and sexual reproduction, (b) caused severe abnormality in females and (c) these abnormalities were inherited by sexual and asexual reproduction. At 1.2 mg/L three abnormal females were found out of 457 total females (0.66 %). This low percentage is consistent and reproducible according to further analysis, where we increased the number of replicates and total females exposed to 1.2 mg/L of VZ, and found 18 abnormal females out of 2868 total females (0.63 % abnormality). Interestingly, abnormal females found at 5.6 mg/L VZ exposure, were able to show mating behavior. Our results suggest that VZ behaves as a strong endocrine disruptor whose effects show the characteristic inverted-U-shape exposure concentration response curve regarding the intrinsic population increase and the percentage of abnormalities as endpoints.

  8. Effects of selected metal oxide nanoparticles on Artemia salina larvae: evaluation of mortality and behavioural and biochemical responses.

    Gambardella, Chiara; Mesarič, Tina; Milivojević, Tamara; Sepčić, Kristina; Gallus, Lorenzo; Carbone, Serena; Ferrando, Sara; Faimali, Marco

    2014-07-01

    The aim was to investigate the toxicity of selected metal oxide nanoparticles (MO-NPs) on the brine shrimp Artemia salina, by evaluating mortality and behavioural and biochemical responses. Larvae were exposed to tin(IV) oxide (stannic oxide (SnO2)), cerium(IV) oxide (CeO2) and iron(II, III) oxide (Fe3O4) NPs for 48 h in seawater, with MO-NP suspensions from 0.01 to 1.0 mg/mL. Mortality and behavioural responses (swimming speed alteration) and enzymatic activities of cholinesterase, glutathione-S-transferase and catalase were evaluated. Although the MO-NPs did not induce any mortality of the larvae, they caused changes in behavioural and biochemical responses. Swimming speed significantly decreased in larvae exposed to CeO2 NPs. Cholinesterase and glutathione-S-transferase activities were significantly inhibited in larvae exposed to SnO2 NPs, whereas cholinesterase activity significantly increased after CeO2 NP and Fe3O4 NP exposure. Catalase activity significantly increased in larvae exposed to Fe3O4 NPs. In conclusion, swimming alteration and cholinesterase activity represent valid endpoints for MO-NP exposure, while glutathione-S-transferase and catalase activities appear to be NP-specific.

  9. Reducing Vibrio load in Artemia nauplii using antimicrobial photodynamic therapy: a promising strategy to reduce antibiotic application in shrimp larviculture

    Asok, Aparna; Arshad, Esha; Jasmin, C.; Somnath Pai, S.; Bright Singh, I. S.; Mohandas, A.; Anas, Abdulaziz

    2012-01-01

    Summary We propose antimicrobial photodynamic therapy (aPDT) as an alternative strategy to reduce the use of antibiotics in shrimp larviculture systems. The growth of a multiple antibiotic resistant Vibrio harveyi strain was effectively controlled by treating the cells with Rose Bengal and photosensitizing for 30 min using a halogen lamp. This resulted in the death of > 50% of the cells within the first 10 min of exposure and the 50% reduction in the cell wall integrity after 30 min could be attributed to the destruction of outer membrane protein of V. harveyi by reactive oxygen intermediates produced during the photosensitization. Further, mesocosm experiments with V. harveyi and Artemia nauplii demonstrated that in 30 min, the aPDT could kill 78.9% and 91.2% of heterotrophic bacterial and Vibrio population respectively. In conclusion, the study demonstrated that aPDT with its rapid action and as yet unreported resistance development possibilities could be a propitious strategy to reduce the use of antibiotics in shrimp larviculture systems and thereby, avoid their hazardous effects on human health and the ecosystem at large. PMID:21951316

  10. Does a Change from Whole to Powdered Food (Artemia franciscana eggs Increase Oviposition in the Ladybird Coleomegilla maculata?

    Eric W. Riddick

    2015-09-01

    Full Text Available The limited availability of alternative foods to replace natural prey hinders cost-effective mass production of ladybird beetles for augmentative biological control. We compared the effects of powdered vs. whole Artemia franciscana (A. franciscana (brine shrimp eggs with or without a dietary supplement on development and reproduction of Coleomegilla maculata (C. maculata (Coleoptera: Coccinellidae. We tested the hypotheses that (1 powdered A. franciscana eggs are more suitable than whole eggs; and (2 palmitic acid, a common fatty acid in natural prey, i.e., aphids, is an effective dietary supplement. Development time, pre-imaginal survival, sex ratio, and body weight of adults did not differ significantly amongst individuals fed powdered vs. whole eggs, with or without 5% palmitic acid. Significantly more oviposition occurred when females were fed powdered eggs than whole eggs and powdered eggs with 5% palmitic acid than whole eggs with or without 5% palmitic acid. A weak functional relationship was found between pre-oviposition time and total oviposition by females fed powdered eggs with 5% palmitic acid; pre-oviposition time decreased as oviposition increased. Food treatments had no significant differential effect on progeny (egg hatch rate. In conclusion, a simple change in A. franciscana egg texture and particle size (i.e., blending whole eggs into a dust-like powder increases oviposition in C. maculata. Supplementing powdered eggs with 5% palmitic acid might accelerate oogenesis (egg maturation in some females.

  11. Topography and stoichiometry of acidic proteins in large ribosomal subunits from Artemia salina as determined by crosslinking

    Uchiumi, T.; Wahba, A.J.; Traut, R.R.

    1987-01-01

    The 60S subunits isolated from Artemia salina ribosomes were treated with the crosslinking reagent 2-iminothiolane under mild conditions. Proteins were extracted and fractions containing crosslinked acidic proteins were obtained by stepwise elution from CM-cellulose. Each fraction was analyzed by diagonal (two-dimensional nonreducing-reducing) NaDodSO 4 /polyacrylamide gel electrophoresis. Crosslinked proteins below the diagonal were radioiodinated and identified by two-dimensional acidic urea-NaDodSO 4 gel electrophoresis. Each of the acidic proteins P1 and P2 was crosslinked individually to the same third protein, PO. The fractions containing acidic proteins were also analyzed by two-dimensional nonequilibrium isoelectric focusing-NaDodSO 4 /polyacrylamide gel electrophoresis. Two crosslinked complexes were observed that coincide in isoelectric positions with monomeric P1 and P2, respectively. Both P1 and P2 appear to form crosslinked homodimers. These results suggest the presence in the 60S subunit of (P1) 2 and (P2) 2 dimers, each of which is anchored to PO. Protein PO appears to play the same role as L10 in Escherichia coli ribosomes and may form a pentameric complex with the two dimers in the 60S subunits

  12. Efficiency of Artemia cysts removal as a model invasive spore using a continuous microwave system with heat recovery.

    Balasubramanian, Sundar; Ortego, Jeffrey; Rusch, Kelly A; Boldor, Dorin

    2008-12-15

    A continuous microwave system to treat ballast water inoculated with Artemia salina cysts as a model invasive spore was tested for its efficacy in inactivating the cysts present. The system was tested at two different flow rates (1 and 2 L x min(-1)) and two different power levels (2.5 and 4.5 kW). Temperature profiles indicate that the system could deliver heating loads in excess of 100 degrees C in a uniform and near-instantaneous manner when using a heat recovery system. Except for a power and flow rate combination of 2.5 kW and 2 L x min(-1), complete inactivation of the cysts was observed at all combinations at holding times below 100 s. The microwave treatment was better or equal to the control treatment in inactivating the cysts. Use of heat exchangers increased the power conversion efficiency and the overall efficiency of the treatment system. Cost economics analysis indicates that in the present form of development microwave treatment costs are higher than the existing ballast water treatment methods. Overall, tests results indicated that microwave treatment of ballast water is a promising method that can be used in conjunction with other methods to form an efficient treatment system that can prevent introduction of potentially invasive spore forming species in non-native waters.

  13. Plâncton, Artemia sp, dieta artificial e suas combinações no desenvolvimento e sobrevivência do quinguio (Carassius auratus durante a larvicultura Plankton, Artemia sp, artificial diet and their combinations on the development and survival of goldfish (Carassius auratus during larviculture phase

    Eliana Maria Galdioli

    2000-05-01

    Full Text Available O objetivo deste estudo foi verificar a influência do uso de diferentes alimentos sobre o desenvolvimento de larvas de quinguio (Carassius auratus, assim como determinar o melhor manejo alimentar. O delineamento experimental utilizado foi o inteiramente casualizado com cinco tratamentos e quatro repetições. Para análise estatística utilizou-se o teste de Tukey. Utilizaram-se 20 aquários com capacidade para 10 L, sendo estocadas 20 larvas com 5,20 mm de comprimento por aquário. Os tratamentos utilizados foram: somente ração com 56,00% de proteína bruta (R; plâncton (PL; náuplios de Artemia sp (NA, ração + plâncton (R+PL e ração + náuplios de Artemia sp (R+NA, sendo seu fornecimento à vontade duas vezes ao dia. Houve mortalidade de todos os indivíduos submetidos ao tratamento R. O uso de NA e R+NA proporcionou taxas de sobrevivência superiores (p 0,05. Conclui-se que as diferentes fontes de alimento interferem no desempenho das larvas, sendo o manejo alimentar com o fornecimento de ração + náuplios de Artemia sp o mais adequado para a larvicultura do quinguioThe aim of this study was to verify the influence of different diets on the development of goldfish (Carassius auratus larvae and determine the best diet management during its larviculture phase. The experimental design was totally randomized with five treatments and four replicatess, using Tukey test for statistical analysis. Twenty 10L-aquariums were used, where twenty larvae with 5.20 mm length were stocked per aquarium. Quinguio larvae were fed daily ration of different diets: ration alone including 56.00% crude protein (R, plankton (PL, Artemia sp nauplii (AN, ration + plankton (R+PL and ration + Artemia sp nauplii (R+AN, ad libitum twice a day. Treatment R caused the death of all individuals. AN and R+AN diets provided a higher survival rate (p 0.05 was observed between the different treatments. Under the conditions of the present experiment, the results led to

  14. Distribution of metals during digestion by cutthroat trout fed benthic invertebrates contaminated in the Clark Fork River, Montana and the Coeur d'Alene River, Idaho, U.S.A., and fed artificially contaminated Artemia

    Farag, A.M.; Suedkamp, M.J.; Meyer, J.S.; Barrows, R.; Woodward, D.F.

    2000-01-01

    The concentrations of essential amino acids in three, undigested invertebrate diets collected from the Clark Fork River (CFR) for cutthroat trout were similar to each other, but were c. 25–75% less than Artemia that were exposed to a mixture of arsenic, copper, cadmium, lead and zinc in the laboratory. The Artemia diet appeared less palatable and the texture, quantity and appearance of the intestinal contents differed between fish fed the Artemia and CFR diets. The Pb% in the fluid fraction of the intestinal contents was greater for the Artemia (29%) than for the CFR diets (10–17%), and the Cu% in the amino acid plus metal fraction of the intestinal contents was greater for the Artemia (78%) than for two of the three CFR diets (67% and 70%). Intestinal contents of fish fed invertebrate diets collected from various sites on the Coeur d'Alene River (CDA), Idaho, were similar in texture, quantity, and appearance. For fish fed the CDA diets, differences in the distribution of metals among fractions of the digestive fluids appeared to be related to concentrations of metals in the invertebrate diets. Pb% was lowest of all metals in the fluid portion of the intestinal contents. However, >80% of all metals in the hind gut were associated with the particulate fraction where they may still be available for uptake through pinocytosis.

  15. Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

    Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

    2016-03-01

    Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effective harvesting of the microalgae Chlorella protothecoides via bioflocculation with cationic starch

    Letelier Gordo, Carlos Octavio; Holdt, Susan Løvstad; De Francisci, Davide

    2014-01-01

    In the present work, the flocculation efficiency of cationic starch (Greenfloc 120) was tested on the fresh water microalga Chlorella protothecoides under different conditions (pH and flocculant concentrations). Different concentrations of Greenfloc 120 (0, 2.5, 5, 10, 20, 40mgL-1) were screened...... to use, efficient and cost-effective flocculant for harvesting of microalgae....

  17. Techno-economic assessment of micro-algae as feedstock for renewable bio-energy production

    Jonker, J.G.G.; Faaij, A.P.C.|info:eu-repo/dai/nl/10685903X

    2013-01-01

    This paper determines the energy consumption ratio and overall bio-energy production costs of microalgae cultivation, harvesting and conversion to secondary energy carriers, thus helping to clarify future perspectives of micro-algae production for energy purposes. A limitation growth model is

  18. Sorting cells of the microalga Chlorococcum littorale with increased triacylglycerol productivity

    Dominguez Teles, I.; Zwart, van der Mathijs; Kleinegris, D.M.M.; Wijffels, R.H.; Barbosa, M.J.

    2016-01-01

    Despite extensive research in the last decades, microalgae are still only economically feasible for high valued markets. Strain improvement is a strategy to increase productivities, hence reducing costs. In this work, we focus on microalgae selection: taking advantage of the natural biological

  19. Mild disintegration of the green microalgae Chlorella vulgaris using bead milling

    Postma, P.R.; Miron, T.L.; Olivieri, G.; Barbosa, M.J.; Wijffels, R.H.; Eppink, M.H.M.

    2015-01-01

    In this work, the mild disintegration of the microalgae Chlorella vulgaris for the release of intracellular products has been studied. By means of bead milling the microalgae suspensions were successfully disintegrated at different biomass concentrations (25–145 gDW kg-1) over a range of agitator

  20. Lipid-based liquid biofuels from autotrophic microalgae: energetic and environmental performance

    Reijnders, L.

    2013-01-01

    Commercial cultivation of autotrophic microalgae for food production dates back to the 1950s. Autotrophic microalgae have also been proposed as a source for lipid-based liquid biofuels. As yet, there is no commercial production of such biofuels and estimated near-term prices are far in excess of