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Microalgae are important microorganisms which produce potentially valuable compounds. Astaxanthin, a group of xanthophyll carotenoids, is one of the most powerful antioxidants mainly found in microalgae, yeasts, and crustaceans. Environmental stresses such as intense light, drought, high salinity, nutrient depletion, and high temperature can induce the accumulation of astaxanthin. Thus, this research aims to investigate the effect of black light, also known as long-wave ultraviolet radiation or UV-A, as a stressor on the accumulation of astaxanthin as well as to screen the antioxidant property in two tropical green algal strains isolated from Malaysia, Coelastrum sp. and Monoraphidium sp. SP03. Monoraphidium sp. SP03 showed a higher growth rate (0.66 day−1) compared to that of Coelastrum sp. (0.22 day−1). Coelastrum sp. showed significantly higher accumulation of astaxanthin in black light (0.999 g mL culture−1) compared to that in control condition (0.185 g mL−1). Similarly, Monoraphidium sp. SP03 showed higher astaxanthin content in black light (0.476 g mL culture−1) compared to that in control condition (0.363 g mL culture−1). Coelastrum sp. showed higher scavenging activity (30.19%) when cultured in black light condition, indicating a correlation between the antioxidant activity and accumulation of astaxanthin. In this study, black light was shown to possess great potential to enhance the production of astaxanthin in microalgae.

The Pandanduri Dam has a function as a support for agricultural irrigation water and also supports community activities so that it will affect the quality of its waters. The quality of the water needs to be analyzed because it can affect the aquatic ecosystem. This study aims to determine the level of water pollution in the Pandanduri Dam based on the phytoplankton community from the Chlorophyta Division. This type of research is descriptive exploratory. Sampling was carried out at 5 stations that were haphazardly selected with ecological representativeness consideration. Phytoplankton data were analyzed using the abundance formula, Shannon-Wiener diversity index, PIELOU uniformity index, and Simpson dominance index. The phytoplankton from the Chlorophyta Division found in the Pandanduri Dam were 14 species that are Pediastrum duplex var. Gracillimum, Gonium sp. 1, Gonium sp. 2, Coelastrum reticulatum, Scenedesmus acuminatus, Cosmarium sp., Chlamydomonas nasuta, Chlamydomonas sp., Selenastrum capricornutum, Monoraphidium dybowskii, Monoraphidium contortum, Monoraphidium irregular, Westella botryoides, and Kirchneriella lunaris consisting of 4 orders (Sphaeropleales, Chlorococcales, Chlamydomonadales and Desmidiales) and 10 genera (Pediastrum, Coelastrum, Scenedesmus, Gonium, Cosmarium, Chlamydomonas, Selenastrum, Monoraphidium, Westella, and Kirchneriella). The species diversity index of 2.21 is classified as moderate diversity, the species uniformity index is 0.83 which indicates even species growth, and the species dominance index indicates that no species dominates with a value of 0.12. The level of water pollution in the Pandanduri Dam was found in the moderate pollution category (oligotrophic).

Tilapia fish (Oreochromis mossambicus) is a type of freshwater consumption fish, flat body shape with grey, brown or black colour. The purpose of this study was to describe the types of food found in the stomach of tilapia fish (Oreochromis mossambicus) in Talaga Lake, Donggala Regency. This research was conducted in April 2019. The method used in this study was a volumetric occurrence frequency method by a surgical sampling of fish to extract the stomach and analyze it. Based on the results of the analysis of the stomach contents of the Mujair fish (Oreochromis mossambicus), two groups of feed were obtained, namely Vegetable food (Fitoplaknton) in the form of Navicula placentula, Schroederia segitera, Schoroederia anchora, Zignemopsis circumcaniratum, Anabaena sp, Oscillatoria princeps, Spirogyra protifica, Bacillaria sp, Nitzschia aetinastroides, Oedogonium sp, Coelastrum chodati, and animal feed (Zooplankton) in the form of Tubipex sp, Brachionus havanaensis, Cyclops sp, Carcinus sp, Arcella sp, Acetes sp.

The development of biofuels as an alternative to the use of fossil fuels is growing worldwide due to environmental concerns and energy independence; thus, considerable technical progress has been achieved in biofuel production. Microalgae have been widely used for nutrient removal during wastewater treatment and produce compounds that can be used as feedstock for biofuel synthesis. In this work, the green microalga Coelastrum sp. was cultivated using industrial wastes: molasses as the carbon source and synthetic wastewater as the culture medium to determine the potential of its use for biofuel production. The use of synthetic wastewater (SWW) and molasses improved biomass production when compared with cultures carried out in a standard laboratory culture medium, such as tris-acetate-phosphate (TAP). Growth rates of 0.31 and 1.4 day−1 were attained during exponential growth rate with SWW and molasses and TAP media, respectively. The best results in biomass and lipid content, 2.29 ± 0.05 and 0.71 ± 0.03 g L−1, were obtained after 15 days of culture in SWW with molasses. The analysis of the lipid profile, produced by Coelastrum sp. cultured under these conditions, determined that the microalga can be considered as a high-quality feedstock for producing green diesel, bio-jet fuel, or biodiesel.

Natural astaxanthin is known to be produced by green microalgae, a potent producer of the most powerful antioxidant. To increase the productivity of astaxanthin in microalgae, random mutagenesis has been extensively used to improve the yield of valuable substances. In the presented work, a newly isolated Coelastrum sp. was randomly mutagenized by exposure to ethyl methane sulfonate and further screened using two approaches; an approach for high growth mutant and an approach for high astaxanthin producing mutant with a high-throughput screening method using glufosinate. Among these, mutant G1-C1 that was selected using glufosinate showed the highest of total carotenoids (45.48±1.5 mg/L) and astaxanthin (28.32±2.5 mg/L) production, which was almost 2-fold higher than that of wild type. This study indicates that random mutagenesis via chemical mutation strategy and screening using glufosinate successfully expedited astaxanthin production in a mutated strain of a Coelastrum sp.

A novel bioenergy-producing green alga (lab ID.: XNY8011) was isolated from a local mountain in Beijing, China, and was identified as a strain belonging to the genus of Coelastrum on the basis of morphological and molecular characterization. Physiological analyses of photobiological H 2 and lipid production suggested that XNY8011 could be a candidate for biofuels production. This strain could accumulate considerable biomass and produce massive chlorophylls in water diluted waste molasses. Three concentrations of molasses (0.1, 0.2 and 0.5%, w/v) were studied to optimize the cell growth and chlorophylls synthesis of XNY8011, and 0.2% was proved to be the optimum, in which XNY8011 could reach A600 of 1.55 ± 0.06 and produce 11.35 ± 0.93 μg/mL of chlorophylls. It was found that 25 °C is the most preferable temperature for the cell growth of XNY8011 in molasses. Interestingly, the strain XNY8011 exhibited significant low temperature adaptability when growing in waste molasses compared to typical bioenergy green algae. It produced 5.73 and 3.05 folds of cell densities in molasses than that Chlamydomonas reinhardtii CC503 and Chlorella vulgaris did under 20 °C, respectively, and even obtained 13.51 and 2.72 folds of cell densities under 15 °C, respectively. The dynamic analysis suggested that the sugar in waste molasses was utilized as carbon source for cell growth and biomass accumulation. The present study isolated a novel bioenergy-producing green alga from the native environment which could convert waste molasses to biomass and bioenergy with significant temperature adaptability.

Microalgae are photosynthetic microorganisms that are studied due to the variety of metabolites that they produce. However, if cultivated in photobioreactors, these devices should be easy to scale up. Also, harvesting and drying the microalgal biomass should be economically viable at industrial scales. Based on this point of view, in this work a 1.5 L cylindrical-conical photobioreactor was designed to cultivate and harvest the microalga Coelastrum sp. under nitrogen limitation. Maximum cell density was 23.47 × 106 cells mL-1. Biomass and lipid productivities after 5 days of nitrogen limitation were 266.24 mg L-1 d-1 and 137.51 mg L-1 d-1 respectively. A lipid content of 45.6% (w/w dry biomass) was attained. A sludge drying bed was also designed to dry the microalgal biomass. The retention filter used in the sludge drying bed allowed a cell retention efficiency of 86.8% and the final water content of the dried biomass was 7.82 % ± 1.99 which allowed the lipid extraction without further drying. The lipid profile after transesterification of triacylglycerides was [C14:0 (3.04%), C16:0 (35.52%), C18:0 (42.50%), C18:1 (14.30%), C18:2 (4.63%)] which indicates that the lipid extract is more suitable for green diesel than biodiesel production.

A newly isolated green microalga, Coelastrum sp. has the capability to produce and accumulate astaxanthin under various stress conditions. At present, a mutant G1-C1 of Coelastrum sp. obtained through chemical mutagenesis using ethyl methane sulfonate displayed an improvement in astaxanthin accumulation, which was 2-fold higher than that of the wild-type. However, lack of genomic information limits the understanding of the molecular mechanism that leads to a high level of astaxanthin in the mutant G1-C1. In this study, transcriptome sequencing was performed to compare the transcriptome of astaxanthin hyper-producing mutant G1-C1 and wild-type of Coelastrum sp. with respect to astaxanthin biosynthesis. This is to clarify why the mutant produced higher astaxanthin yield compared to the wild-type strain. Based on the transcriptomic analysis, the differentially expressed genes involved in astaxanthin biosynthesis were significantly upregulated in the mutant G1-C1 of Coelastrum sp. Genes coding phytoene synthase, phytoene desaturase, ζ-carotene desaturase, and lycopene β-cyclase involved in β-carotene biosynthesis in the mutant cells were upregulated by 10-, 9.2-, 8.4-, and 8.7-fold, respectively. Genes coding beta-carotene ketolase and beta-carotene 3-hydroxylase involved in converting β-carotene into astaxanthin were upregulated by 7.8- and 8.0-fold, respectively. In contrast, the lycopene ε-cyclase gene was downregulated by 9.7-fold in mutant G1-C1. Together, these results contribute to higher astaxanthin accumulation in mutant G1-C1. Overall, the data in this study provided molecular insight for a better understanding of the differences in astaxanthin biosynthesis between the wild-type and mutant G1-C1 strains.

Coelastrum is a genus of green algae that belongs to the Scenedesmaceae family. There is little information available about this genus. A phylogenetic analysis of the ITS2 sequences showed that Coelastrum is a paraphyletic group. To better explore the phylogenetic status of this genus, we report the mitochondrial genome sequence of Coelastrum sp. F187 using next-generation sequencing technology. The complete mitochondrial genome is 52,888 bp in size and encodes 43 conventional mitochondrial genes, including 14 protein-coding genes (PCGs), 24 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Most of the PCGs (12/14) and all tRNAs were located in the heavy chain and the light chain, respectively. The phylogenetic analysis based on the complete mitochondrial genome sequences indicated that Coelastrum is closely related to Pectinodesmus pectinatus. The sequenced complete mitochondrial genome of Coelastrum sp. F187 provides fundamental molecular data that will be useful for species identification, population genetics, and evolutionary relationships.

Enhanced biofuel production strategies from microalgae by employing affordable bio-waste usage are fetching significance, nowadays. This study examines the effect of VWE for enhanced biomass from new indigenous microalgal isolates, Asterarcys sp. SPC, Scenedesmus sp. KT-U, Scenedesmus sp. KTWL-A, Coelastrum sp. T–E, and Chlorella sp. TWL-B. The growth of microalgae in VWE-treated growth media showed considerable increase (1.14–2.3 folds) than control medium (without VWE). Further, two effective native microalgae were selected based on growth in VWE treatment, biomass productivity, and TAG accumulation through statistical clustering analysis. Mixotrophic batch cultivation of Scenedesmus sp. KT-U and Asterarcys sp. SPC cultivated using VWE treatment in the optimum concentration had produced significant average increase in BP (1.8 and 1.4 folds, respectively) than control (without VWE). Whereas in the lipid production phase, there was a noticeable increase in lipid yield in VWE-treated cells of lipid phase (231.8 ± 17.9 mg/L and 243.5 ± 25 mg/L) in Scenedesmus sp. KT-U and Asterarcys sp. SPC, respectively, than in control (140.5 ± 28 mg/L and 166.4 ± 23 mg/L) with considerable TAG accumulation. Thus, this study imparts strain selection process of native microalgae based on vegetable waste usage for improved yield of biomass and lipid amenable for cost-effective biodiesel production.

Microalgae cultivation is a promising approach to remove ambient CO2 via photosynthesis process. This paper investigates the impact of high CO2 concentrations (6, 12, and 16%) on algae growth, CO2 biofixation, lipid and carbohydrate contents, and nutrient removal of newly isolated microalgae, Coelastrum sp. SM. In addition, the ability of microalgae to produce biodiesel at optimal condition was studied. The microalgae were cultivated in wastewater using an airlift photobioreactor. Under 12% CO2, the maximum biomass productivity and CO2 fixation rate were 0.267 g L−1 day−1 and 0.302 g L−1 h−1, respectively. Total Kjeldahl nitrogen (TKN), total phosphorous (TP), nitrate, and sCOD removal efficiency were 84.01, 100, 86.811, and 73.084%, respectively. Under 12% CO2 and at the same condition for cell growth, the highest lipid and carbohydrate contents were 3 7.91 and 58.45%, respectively. The composition of fatty acids methyl ester (FAME) of the microalga lipid was defined. Based on the obtained results and FAME profile, Coelastrum sp. SM was a suitable feedstock for biodiesel production and also, the organism had a great potential for CO2 biofixation, which is also more suitable than any other reported strains in other related studies.

Cultivation of microalgae in wastewater is a promising and cost-effective approach for both CO2 biofixation and wastewater remediation. In this study, a new strain of Coelastrum sp. was isolated from cattle manure leachate. The isolated microalgae were then cultivated in wastewater. Effects of different sCOD concentrations (600, 750, 900, 1050 mg L−1) and light intensities (1000, 2300, 4600, 6900 and 10000 Lux) on biomass production, CO2 consumption rate and nutrient removal from wastewater were investigated. The results showed that maximum cell growth and CO2 consumption rate were 2.71 g L−1 and 53.12 mg L−1 day−1, respectively, which were obtained in the wastewater with 750 mg L−1 sCOD and under the light intensity of 6900 Lux. The microalgae were able to completely consume all CO2 after incubation period of 4 days. The highest sCOD, total Kjeldahl nitrogen (TKN), nitrate and total phosphorous (TP) removal at such conditions were 53.45, 91.18, 87.51 and 100%, respectively. The lipid content of microalgal biomass was also measured under different light intensities; maximum amount of lipid was determined to be 50.77% under illumination of 2300 Lux. Finally, the CO2 consumption rate and biomass productivity of microalgae in semi-batch culture with continuous gas flow (CO2 6%:N2 94%) were investigated. The rate of CO2 consumption and biomass productivity were 0.528 and 0.281 g L−1 day−1, respectively. The TKN, nitrate, TP and sCOD removal rate of microalgae were 83.51, 80.91, 100, 41.4%, respectively.

Se presenta el estudio sistemático de las esporas y formas algales recuperadas de la Formación Río Turbio, Eoceno medio–tardío de la Cuenca Austral. Se describen algas de agua dulce, briofitas, helechos y licofitas. Closterium sp. cf. C. thailandicum Songtham et al., Botryococcus sp., Coelastrum sp. 1, Catinipollis eiseltalensis Krutzsch, Bryophyta s.l. sp. 1, Kuylisporites waterbolkii Potonié, Matonisporites sp.1, Foveotriletes sp. 1, Polypodiisporites perverrucatus (Couper) Khan y Martin, Klukisporites scaberis (Cookson y Dettmann) Dettmann, Deltoidospora cf. australis, (Couper) Pocock, Verrucosisporites sp. 1, Verrucosisporites sp. 2 son nuevas formas para la Formación Río Turbio. La especie Crassoretitriletes vanraadshooveni Germeraad et al. es un nuevo registro para Argentina y Gleicheniidites circinidites Dettmann lo es para el Eoceno de Argentina. de Argentina.

Coelastrum proboscideum Bohlin, 1896 (Sphaeropleales, Scenedesmaceae, Chlorophyta) is a coenobial species with cosmopolitan distribution in diverse freshwater habitats. Coelastrum spp. are widely tested for biotechnological applications such as carotenoid and lipid production, and in bioremediation of wastewater. Here, we report the draft genome of C. proboscideum var. dilatatum strain SAG 217-2. The final assembly comprised 125,935,854 bp with over 8357 scaffolds. The whole-genome data is publicly available in the Nucleotide Sequence Archive (CNSA) of China National GeneBank (CNGB) (https://db.cngb.org/cnsa/) under the accession number CNA0014153.

The utilization of microalgae as a source of carotenoid productions has gained increasing popularity due to its advantages, such as a relatively fast turnaround time. In this study, a newly discovered Coelastrum sp. TISTR 9501RE was characterized and investigated for its taxonomical identity and carotenoid profile. To the best of our knowledge, this report was the first to fully investigate the carotenoid profiles in a microalga of the genus Coelastrum. Upon use of limited nutrients as a stress condition, the strain was able to produce astaxanthin, canthaxanthin, and lutein, as the major carotenoid components. Additionally, the carotenoid esters were found to be all astaxanthin derivatives, and &beta, carotene was not significantly present under this stress condition. Importantly, we also demonstrated that this practical stress condition could be combined with simple growing factors, such as ambient sunlight and temperature, to achieve even more focused carotenoid profiles, i.e., increased overall amounts of the aforementioned carotenoids with fewer minor components and chlorophylls. In addition, this green microalga was capable of tolerating a wide range of salinity. Therefore, this study paved the way for more investigations and developments on this fascinating strain, which will be reported in due course.

Microalga is one of the main sources of biomasses for the production of biofuels in the 21st century. Many labs and industries around the world are seeking for more productive strains and better cultivation models. The aim of this work was to evaluate the growth and kinetic parameters of six microalgae, and the moisture and lipid contents and fatty acids profiles of the biomasses harvested at the end of each cultivation. The microalgae were isolated in the Mid-Western Region of Brazil cultivated in open pond systems. It was observed that among the six microalgae used in this work, Pseudokirchneriella subcapitata presented the higher maximum specific growth rate (μmax) (0.12 day-1). The microalgae Coelastrum sp. and P. subcapitata were the ones with the highest lipid contents, with approximately 20% of dry mass. The main fatty acid accumulated in these conditions was palmitic acid, with percentages of 59 to 69% for all microalgae evaluated. Other factors that had influenced results from cultivations in open ponds were discussed here.

Present investigation focused on marine microalgae strain Coelastrum sp. for enhanced biodiesel production. Microalgae grow when stressed and produce enhanced lipids despite urea being present. The dry cell weight, chlorophyll (a) content and total biomass yield increased productivity after the addition of urea in the nutrient medium. The chlorophyll (a) concentration and biomass yield obtained was 5.8839 μg/mL and 0.2357 ± 0.14 g. However, Coelastrum sp. obtained 41% of dry lipid under the absence of urea source than other microalgae species. The presence of some FAME components in the Coelastrum sp. provides scientific evidence for major constituent marine microalgae biodiesel. The GCMS revealed that major chemical constituents were hexadecanoic acid, Phthalic acid, di (3,4-dimethyl) ester, 5-(2-Aminopropyl)2-methylphenol and Phenethylamine, p, alpha-dimethyl (please add biodiesel yield or FAME %). The use of marine microalgae stressed by nitrogen source will beneficial to produce commercially viable biodiesel.

The present study deals with phytoplankton population of Navule pond in Shivamogga during September 2014 to August 2015. Blue-greens constituted the major group (41.75%) followed by Chlorococcalas (36.68%), Diatoms (13.36%), euglenoids (7.35%) and Desmids (0.86%). The phytoplankton community was composed of 11 species of Blue-greens, 20 species of Chlorococcales, 18 species of Diatoms, 11 species of Euglenoids and 08 species of Desmids. Each group of phytoplankton showed different peak periods, the summer season produces relatively more phytoplankton than rainy and winter season. The variations in physico-chemical parameters are responsible for the fluctuation of quantity of phytoplankton. The dominant genera recorded on the pond were Anabaenopsis sp., Ocillatoria sp., Euglena sp., and Phacus. Some of the pollution tolerant species identified during the present study are Scenedesmusquadricauda, Coelastrum sp., Tetraedonmuticum, Ocillatoria sp., Phormidium sp., Microcystis sp., Anabaena sp., Navicula sp., Synedra ulna, Cyclotella sp., and Pinnularia sp. In the present study Microcystisaeroginosa was recorded indicates the civic pollution.

Microalgae are known to be a potential resource of high-value metabolites that can be used in the growing field of biotechnology. These metabolites constitute valuable compounds with a wide range of applications that strongly enhance a bio-based economy. Among these metabolites, astaxanthin is considered the most important secondary metabolite, having superior antioxidant properties. For commercial feasibility, microalgae with enhanced astaxanthin production need to be developed. In this study, the tropical green microalgae strain, Coelastrum sp., isolated from the environment in Malaysia, was incubated with methyl viologen, a reactive oxygen species (ROS) reagent that generates superoxide anion radicals (O2-) as an enhancer to improve the accumulation of astaxanthin. The effect of different concentrations of methyl viologen on astaxanthin accumulation was investigated. The results suggested that the supplementation of methyl viologen at low concentration (0.001 mM) was successfully used as a ROS reagent in facilitating and thereby increasing the production of astaxanthin in Coelastrum sp. at a rate 1.3 times higher than in the control.

portuguesEmbora a biodiversidade da comunidade fitoplanctonica no Estado de Sao Paulo seja bastante conhecida, em Guarulhos, o segundo maior municipio do estado, o conhecimento da flora ficologica ainda e incipiente. Assim, este trabalho apresenta uma lista de especies da comunidade fitoplanctonica identificadas em lagos urbanos do municipio de Guarulhos. Foram analisados nove lagos entre 2016 e 2019. As mostras de agua foram coletadas na subsuperficie com rede de plâncton (20 µm) e preservadas em formol a 4%. As analises taxonomicas foram feitas ao microscopio optico com reticulo micrometrado e câmera fotografica acoplada. Foram identificados 88 taxons distribuidos em 9 classes, 11 ordens, 22 familias, 50 generos, 86 especies e duas variedades taxonomicas. Os generos com maior riqueza especifica foram: Desmodesmus Frield & Hegewald (oito especies) e Coelastrum Nageli (cinco especies) ambos pertencentes a Chlorophyceae e, dentre as Cyanobacteria, Aphanocapsa C. Nageli e Microcystis Kutzing, com cinco e quatro especies respectivamente. Em relacao a frequencia de ocorrencia, Microcystis aeruginosa, Aphanocapsa annulata e Radiocystis fernandoi, todas pertencentes a Cyanobacteria, foram classificadas como muito frequente. 49% das especies foram classificadas como raras, sendo 27 especies (30,3%) encontradas apenas no pesqueiro Cabosol, ambiente com a maior riqueza especifica dentre os nove analisados, 10 especies foram exclusivas do Lago dos Patos, cinco do Lago agua Azul e uma exclusiva do lago 2 do Bosque Maia. A listagem de especies fitoplanctonicas realizada no presente estudo permitiu o conhecimento da biodiversidade fitoplanctonica do municipio de Guarulhos e ampliou a distribuicao de especies no estado de Sao Paulo. EnglishAlthough the biodiversity of the phytoplankton community in the State of Sao Paulo is well known, in Guarulhos, the second-largest municipality in the state, the knowledge of the phytological flora is still incipient. Thus, this work presents a list of species of the phytoplankton community identified in urban lakes in the city of Guarulhos. Nine lakes were analyzed between 2016 and 2019. Water samples were collected on the subsurface with a plankton net (20 µm) and preserved in 4% formaldehyde. Taxonomic analyzes were performed using an optical microscope with a micrometer lattice and a camera attached. 88 taxa were identified, distributed in 9 classes, 11 orders, 22 families, 50 genera, 86 species and two taxonomic varieties. The genera with the highest species richness were: Desmodesmus Frield & Hegewald (eight species) and Coelastrum Nageli (five species) both belonging to Chlorophyceae and, among Cyanobacteria, Aphanocapsa C. Nageli and Microcystis Kutzing, with five and four species respectively. Regarding the frequency of occurrence, Microcystis aeruginosa, Aphanocapsa annulata and Radiocystis fernandoi, all belonging to Cyanobacteria, were classified as very common. 49% of the species were classified as rare, with 27 species (30.3%) found only in the Cabosol fishery, an environment with the highest species richness among the nine analyzed, 11 species were exclusive to Lago dos Patos, five to Lago agua Azul and an exclusive of Lake 2 of the Bosque Maia. The list of phytoplankton species carried out in this study allowed the knowledge of phytoplankton biodiversity in the city of Guarulhos and expanded the distribution of species in the state of Sao Paulo.

The Mesat River is one of the rivers that cross the City of Lubuklinggau. Community activities around the river Mesat less maintain the river can disrupt the river ecosystem Mesat itself. The purpose of this study is to explore the microalgae in the Mesat River Lubuklinggau City. This research uses survey method, carried out on three stations with three repetitions in the waters of the Mesat River Kecamatan Lubuklinggau Timur II Lubuklinggau Town and identified in the Biology Laboratory STKIP-PGRI Lubuklinggau. Data were analyzed descriptively qualitative. The results of the study found microalgae in the Mesat River of Lubuklinggau City consisting of 4 Divisions, 6 Classes, 15 Orders, 19 Famili, 27 Genus and 32 Species. Mesi Abiotik Factor Measurement Results: mean temperature value 250C, average PH value 7.2, average brightness value 18.2 cm and Average Dissolved Oxygen Value 4.64 mg/L. Based on the results of this study it can be concluded that the type of microalgae found in the Mesat River consists of: Ankistrodesmus sp, Micrasterias radiata , Coelastrum sp, Zygnema sp, Chroococus sp, Xanthidium sp, Dictyosphaerium sp, Chlamydomonas sp, Carteria sp, Lyngbya sp, Rhizoclonium hieroglyphicum , Cylotella sp, Surirella elegans , Spyrogira sp, Eunothia sp, Gonatozygon sp Chlorella sp, Oscillatoria limosa , Oscillatoria sp, Tabellaria sp, Pediastrum singulex , Pediastrum duplex , Closterium sp, Cosmarium sp, Mougeotia sp, Phacus triqueter , Phacus lomgicauda , Euglena viridis , Euglena mutabilis , Scenedesmus sp, Scenedesmus acuminatus , and Scenedesmus opaliensis .

The knowledge on diet composition of the freshwater mussel Diplodon enno (Ortmann) would aid in its culture and propagation allowing, this way, the replacement of natural endangered populations in Brazil. Microalgae are the main food source for captive mussels and unionids have displayed an ability to sort algae based on the cellular characteristics prior to ingestion. The main objective of the present work is to analyze the phytoplankton composition of the water from and of the gastrointestinal contents of the mussel D. enno, as an initial step for development of a suitable rearing diet. Therefore, water samples and bivalve specimens were collected from S. Francisco River, city of Paulo Afonso, Bahia, Brazil. The microalgal composition found in water and stomach/gut content samples was very diverse being represented by the following divisions: Cyanophyta, Chlorophyta, Dinophyta and Heterokontophyta (Diatoms). Concerning the relative abundance of microalgae divisions, it is possible to state, for the water and gastrointestinal contents, that Cyanophyta represents 15% and 14%, Chlorophyta 54% in both, Heterokontophyta 31% and 27% and Dinophyta 0% and 5%, respectively. According to the Brazilian CETESB criteria for phytoplankton species classification, 50% of Cyanophyta and 15% of Chlorophyta species observed in the water samples were classified as “very frequent”, as were 68% of Heterokontophyta and 33% of Chlorophyta species in the gut/stomach tract samples. Focusing at a species level, although in the water only Coelastrum sp. and Chroococcus sp. were observed in 100% and 75% of the samples, respectively, in the gastrointestinal tract the species Staurastrum sp., Aulacoseira sp., Scenedesmus sp. and Fragilaria crotonensis occurred in 80% to 100% of the samples. The present results showed that D. enno feeds not only on small chlorophytes microalgae, due to their convenient size that facilitates higher feeding rates, but also on large size diatoms, due to a possible nutritional advantage for the bivalves. Thus, a diet composed by large diatoms and small chlorophytes microalgae may be considered as the most reasonable for the maintenance of D. enno populations.

Transcriptome analysis requires a large quantity of high-quality DNase-treated RNA for poly(A)+ mRNA isolation and sequencing. This could be problematic in many oleaginous microalgal species that harbor strong cell walls and accumulate high lipid content. Using Scenedesmus obliquus, a microalga with high oil content and potential as a source of algal biofuel, we assessed the efficiency of four RNA isolation methods: direct extraction using TriPure, mechanical breakage using either freeze-thawed with bead beating or grinding in liquid nitrogen followed by TriPure, and grinding in liquid nitrogen before using Qiagen RNeasy Plant Mini Kit. Liquid nitrogen grinding with TriPure method gave the best RNA yields at 15.15 µg mg -1 cell dry weight and ~148.9 µg total RNA from 100 ml culture of S. obliquus. Despite lower yields, RNA isolation of oil accumulating cells (~22% w/w lipid content) provided ~68.1 µg total RNA with the yield of 1.70 µg mg -1 cell dry weight. Transcriptome sequencing and de novo assembly with the average contig length of 824 bp reflected high quality of RNA obtained using this method. The RNA isolation protocol was tested on six other oleaginous microalgae including Chlamydomonas reinhardtii, S. acuminatus, Chorella vulgaris, Chlorococcum humicola, Tetradesmus cumbricus and Coelastrum sp. and yielded 0.86 - 5.42 µg mg -1 cell dry weight. For large scale RNA isolation from microalgae, grinding with liquid nitrogen before TriPure provided the best yield and quality. This finding helps simplify RNA isolation for upcoming transcriptome analyses in microalgae.

The present study investigates the performances and mechanisms of biosorption of cadmium (Cd) ions using a lipid extraction residue from three strains of lipid production microalgae. The adsorption performance was determined by batch biosorption experiments and kinetic modeling. The algae cell in the whole growth period and lipid extraction residue both exhibited desirable adsorption performance. The lipid extraction residue from the strain of Coelastrum sp. PTE-15 had the highest capacity of Cd sorption, which was 32.8 mg g−1. FTIR data suggested that the functional groups acting as binding sites on the microalgae surface which participate in biosorption were carboxylic, hydroxyl, and amino. The biosorption properties and maximum adsorption capacity of the lipid extraction residue from three microalgal strains were determined by equilibrium modeling. The adsorption process followed the Langmuir isotherm model with a high value of correlation coefficients (≥0.99) and biosorption capacity being estimated to be 36.1 mg g−1.

Microalgae biodiesel feedstocks have been investigated by numerous research groups to overcome dependence on fossil fuels. This study describes a detailed characterization of five freshwater microalgae strains of the family Scenedesmaceae, based on cell wall ultrastructure, ITS-2 sequence and secondary structure analysis, as well as the estimation of biodiesel properties from fatty acids produced before and after N-limitation. Characterization permitted the reclassification of SCRE-1 and SCRE-2 strains into the subgenus Scenedesmus; DSRE-1 and DSRE-2 strains into the subgenus Desmodesmus; and CORE-1 strain into the genus Coelastrum. Transesterification of fatty acids of the five strains was performed before and after N-limitation, and seven important biodiesel quality parameters were predicted by applying selected correlations. These parameters were then compared to the corresponding specifications in the American and European biodiesel standards. N-limitation promoted higher yields of biomass (up to 3.5 times) and lipids (up to 4.1 times) in all strains under study. Moreover, it was found that SCRE-2 was the only biodiesel that met all estimated parameters of the more stringent European standard before N-limitation. This was also true for DSRE-1 and DSRE-2 biodiesels after limitation, with the exception of their oxidative stability parameter, whose values met the limit of the American but not the European standard.

We investigated the seasonal dynamics of phytoplankton functional groups and the relevant environmental factors (water temperature, total nitrogen content, total phosphorous content and water transparency) in Dianchi Lake, China. We also examined the growth rates and physiological characteristics of representative species in laboratory cultures. In the field experiment, five dominant functional groups, including M (mainly consisted of Microcystis aeruginosa; Microcystis wesenbergii and Microcystis flos-aquae), H1(mainly consisted of Aphanizomenon flos-aquae), J (mainly consisted of Scenedesmus; Pediastrum and Coelastrum), F (mainly consisted of Oocystis and Kirchneriella) and P (mainly consisted of Melosira), were determined. Groups M and J were prevalent throughout the year and comprised more than 90% of the total biomass. Group M was prevalent at a relatively high temperature in summer and autumn; by contrast, group J was dominant at low temperature in winter and early spring. Co-cultivation laboratory experiments revealed that the biomass and the density of Microcystis sp., which is the representative species of the functional group M, were higher at 18 degrees C than at 13 degrees C. Conversely, the density and the biomass of the representative species of the functional group J (consisted of Pediastrum duplex, Coelastrum microporum and Scenedesmus obliquus) were higher at 13 degrees C than at 18 degrees C. At low temperatures, group M (Microcystis spp.) cannot successfully survive and grow at low temperatures, exhibiting various stress responses, such as inhibited photosynthetic activities and reduced phosphorous utilization. However, low temperature increased soluble carbohydrate contents of Microcystis, which favored the fast development of Microcystis, once the temperature warmed. Currently, climate warming is occurring in the Dianchi Lake basin; thus, future climate warming in winter (+/- 5 degrees C) may compromise the advantages of group J and promote the abundance of group M. The water transparency, dissolved oxygen and biodiversity in the lake would be further reduced. Furthermore, the increased microcystin and odor produced by Microcystis would considerably threaten the food web structure and lake ecosystem functions.

In this publication the trophy level of Wapienica dam reservoir, based on the composition species of planktonic algae and their biomass, and concentrations of chlorophyll a, was defined. The research was conducted during the vegetative season in 2013 year; the samples were taken from two research points (W1 – the part of river Wapienica inflow to reservoir and W2 – the part of the reservoir dam) by using bathometer. The whole biomass of planktonic algae and concentration of chlorophyll a from two research areas were low and it allowed to classify water of this reservoir to oligo-/ mesotrophic. Only in the part of the reservoir dam, in summer season, an increased trophy level was observed (Heinonen 1980). A similar trophic character (oligo-/ mesotrophic) of the water reservoir was also indicated by algae species: Achnanthes lanceolata (Bréb.) Grun. in Cl. and Grun., Chrysoccoccus minutus (Fritsch) Nygaard. For a temporary increase of the trophy level, the diatom Nitzschia acicularis (Kütz.) W. Sm. could indicate, because it is a typical species in poorly eutrophic water. The green algae (Pediastrum and Coelastrum, which were observed in summer season) could also indicate for a rise of the trophic state, because they are typical for eutrophic water.

Most natural astaxanthin is fatty acid-esterified in microalgae to prevent oxidation. However, the factors influencing astaxanthin esterification (AE) are poorly understood. In this study, obstacles to AE in Coelastrum sp. HA-1 were investigated. Only half of the astaxanthin molecules in HA-1 were esterified, but AE was stimulated with exogenous linoleic acid (LA) and ethanol treatment. Astaxanthin esters and total astaxanthin (TA) with exogenous LA were elevated to 3.82-fold and 2.18-fold of control levels, respectively. Treatment with 3% (v/v) ethanol enhanced transcription of the Δ12 fatty acid desaturase gene, which caused more oleic acid (OA) to be converted to LA. Furthermore, the contents of astaxanthin esters and TA were 2.42-fold and 1.61-fold control levels, respectively. These findings confirmed that AE was upregulated by increasing LA content. Thus, a large concentration of OA alone does not increase astaxanthin accumulation in HA-1, and a certain amount of LA was necessary for AE.

Microalgae have high photosynthetic efficiency that can fix CO2 from the flue gas directly without any upstream CO2 separation, and concomitantly produce biomass for biofuel applications. These gases, both untreated and treated into current discharge standards, contain CO2, N2, H2O, O2, NOx, SOx, CxHy, CO, particulate matter, halogen acids and heavy metals. Microalgae population studies were conducted in a batch mode experiments at Power plant site of Chamois, Missouri. The experiments were conducted in different period (June to December 2011) of time. This study evaluated the effect of several heavy metals that are present in flue gases on the algae, focusing on the growth and accumulation of lipids in the algae that can be converted to biodiesel. The genus Scenedesmus presented the greatest richness of species and number of counted individuals in the flue gas ponds compare than non flue gas treatment ponds. Among the diatomaceae the genus Navicula sp, Nitizchia sp and Synedra sp. presented the next subdominant richness in the ponds. The last results of counted green algae Ulothrix sp and Coelastrum sp were least number of cells reported in these ponds. The heavy metal-contaminated in flue gas and also enter into the microalgae biomass population. Comparative studies were carried out by flue gas and control system of open ponds. Control system of microalgae population was represented in less amount of heavy metals compare than flue gas ponds.DOI: http://dx.doi.org/10.3126/ijasbt.v2i2.10247 Int J Appl Sci Biotechnol, Vol. 2(2): 114-120