Class Chlorophyceae Research Articles

Aktivitas antioksidan, total fenolik, flavonoid dan saponin anggur laut (Caulerpa lentillifera) diekstrak dengan pelarut yang berbeda polaritas

Caulerpa lentillfera is a species of seaweed that belongs to the class Chlorophyceae (green seaweed). Caulerpa lentillifera contains secondary metabolites consisting of alkaloids, flavonoids, steroids, terpenoids, saponins and phenols that can be used as antioxidants, antimicrobials, anticancer and others. This study was aimed to determine the total phenolic flavonoid compounds, saponins, and antioxidant activity of Caulerpa lentillifera extract. The research method used is an experiment by conducting a series of experiments, namely the extraction of Caulerpa lentillifera using the maceration method in stages with solvents of different polarity. The solvents used consisted of non-polar (n-hexane), semi-polar (ethyl acetate) and polar (methanol). The analysis parameters consisted of yield analysis, total phenol, flavonoid, saponin, and antioxidant activity. The yield of Caulerpa lentillifera extract extracted with n-hexane, ethyl acetate, and methanol was 0.36; 0.39; and 0.42%. The content of saponins produced from hexane, ethyl acetate and methanol extracts were 0.14%; 0.17%; and 0.20%, respectively, in a 100 g sample. The total phenol produced in the ethyl acetate and methanol extracts were 141,50 mgGAE/100 g and 154,65 mg GAE/100 g, respectively. Flavonoid content was 116,82 mg QE/100 g only found in methanol extract. The antioxidant activity of n-hexane, ethyl acetate, and methanol extracts with IC50 values were 234.28, 203.96, and 124,77 ppm, respectively. Extracts of Caulerpa lentillifera with different polarity solvents were produced different bioactive components. Saponins were produced in all three types of solvents, phenol were found in ethyl acetate and methanol extracts and flavonoids only in methanol extract. The highest antioxidant activity of Caulerpa lentillifera was produced with methanol extract with IC 50 value of 124,77 ppm.

Reconstructing the palaeoecology of a middle Permian alkaline lake using molecular fossils, case study of the Lucaogou Formation in the Junggar Basin, NW China

The lacustrine Lucaogou Formation was deposited during the middle Permian in the Junggar Basin, northwestern China. The depositional environment was an alkaline, brackish to saline lake. The biological diversity of the Lucaogou Formation was reconstructed using biologically informative molecules such as n-alkanes, steranes, and hopanes, and the δ13C composition of organic matter. C30 4α-methyl-24-ethylsterane, C31 lanostane, and abundant C30 − C31 3β-methylhopanes were detected in the organic matter, suggesting the presence of type Ⅰ aerobic methanotrophs including the Methylococcaceae. C30 − C31 2α-methylhopanes and 7- and 8-methylheptadecanes are suggestive of the presence of cyanobacteria. Cyanobacteria and green algae are proposed to have made the dominant contribution to the organic matter. The presence of more 13C-enriched hopanoids in the lower unit compared to the upper unit of the Lucaogou Formation suggest a greater contribution of cyanobacteria to the organic matter in the lower unit. The high abundances of C28 and C29 steranes relative to C27 steranes are likely due to green algae from the Chlorophyta, including the class Chlorophyceae. Dinosteranes that are diagnostic for dinoflagellates were not detected. The low concentrations of C40 isorenieratane, renieratane, β-isorenieratane, renierapurpurane, and β-renierapurpurane that are indicative of photosynthetic green and purple sulfur bacteria indicate a minor contribution from Chlorobiaceae and Chromatiaceae to the organic matter. It is inferred that low to moderate amounts of ciliates grew at or below the relatively unstable chemocline in the lake. The presence of C19-norisopimarane, 8β(H)-labdane, and 4β(H)-19-norisopimarane suggests the presence of coniferous plants growing around the lake, probably including Pinaceae, Araucariaceae, Cupressaceae.

Relationship Between Abundance of Clamydomonas spp and Chlorella spp on Clinical Performance of Red Tilapia Oreochromis niloticus in Silvofishery Ponds

Abstract Chlamydomonas spp. and Chlorella spp. are plankton genera that can be used to determine the level of balance in the aquatic environment. The purpose of this study is to determine the abundance of plankton Chlamydomonas spp. and Chlorella spp. and its relation to the clinical performance of red tilapia in silvofishery ponds. The research method used is an ex post facto causal design with random sampling. The results showed that the water quality in the silvofishery ponds was very good, except for the nitrate parameters of 0.00-1.50 mg/L and salinity of 2-11 gr/L, which exceeded the quality standards. In the silvofishery ponds, 5 plankton classes were found, namely Chlorophyceae, Cyanophyceae, Chrysophyceae, Protozoa, and Dinophysis, consisting of 15 genera. The dominant class Chlorophyceae had an abundance of 2.88E+06 cells/ml. The class Chlorophyceae is dominated by Chlorella spp. (2.63E+06 cells/ml) and Chlamydomonas spp. (2.20E+05 cells/ml). The abundance of Chlamydomonas spp. in silvofishery ponds is closely related to phosphate solubility (0.988). Based on observations of clinical symptoms on the eyes, gills, and fins of fish, no disease infections or physical abnormalities were found in the fish cultured in silvofishery ponds. Fish tend to live well with a growth rate of 0.44 g/day. The aquatic ecosystem of the silvofishery pond, which is dominated by the plankton Chlorella spp. and Chlamydomonas spp., had a good effect on the performance and condition of the farmed fish. This study concludes that the abundance of Chlamydomonas spp. and Chlorella spp. was very dominant compared to other plankton genera. The presence of Chlamydomonas spp. and Chlorella spp. illustrates good and stable environmental conditions in silvofishery ponds, followed by no clinical signs of disease infection in the fish reared during the study period.

Perikphyton Growth on Two Different Bamboo Substrate Models for Its Use in Aquaculture

Periphyton-based fish farming practices are considered low-cost technologies as they help in sustainable aquaculture production. The present study was designed to determine the efficiency of two different substrate models (viz. roof hut model and prism model) made from the bamboo sticks. The small-sized substrate models were constructed for invitro studies. The growth of periphyton was investigated on the 30th day of the experimental setup. This is the first time experimenting with bamboo substrate models. From the result it was found that the biomass of periphyton in terms of dry weight 0.03±0.01 g/cm2 was observed on both substrate models. There is no biomass difference and taxonomic difference between these two models. It may be due to the material used for the construction of the model being the same i.e. bamboo sticks and cotton thread. The taxonomic identification of the periphyton community showed the different genera of class Chlorophyceae and Bacillariophyceae. These models are efficient for periphyton growth and they also increase the productivity of periphyton due to increased surface area of substrate models. These models can be used for low-cost aquaculture.

Diversity and distribution of phytoplanktons in two chours of Madhepura District

Diversity and distribution of Phytoplanktons was studied in Dourachour of Madhepura district. Collected Phytoplanktons belonged to class Chlorophyceae, Cyanophyceae, Bacillariophyceae and Euglinophyceae. Altogether 50 species of Phytoplanktons were identified, 20 from Chlorophyceae, 16 from Cyanophyceae, 9 from Bacillariophyceae and 5 from Euglinophyceae. Chlorophyceae contributed 40% of the total phytoplanktons, Cyanophyceae 32%, Bacillariophyceae 18% and Euglinophyceae 10%. Maximum number of Phytoplanktons was recorded in the month of August and minimum in the month of June, Chlorophyceae showed maximum number in the month of August, Cyanophyceae in the month of May, Bacillariophyceae in the month of January and Euglinophyceae in the month of October. Boyd's diversity index was greater than 4 in every month which show that water of chour is clean. . KEYWORDS :Dourachour, Phytoplankton, Diversity and distribution, Chlorophyceae, Cyanophyceae, Bacillariophyceae and Euglinophyceae.

Hydrocytium expands the phylogenetic, morphological, and genomic diversity of the poorly known green algal order Chaetopeltidales.

Chaetopeltidales is a small, understudied order of the green algal class Chlorophyceae, that is slowly expanding with the occasional discoveries of novel algae. Here we demonstrate that hitherto unrecognized chaetopeltidaleans also exist among previously described but neglected and misclassified species. Strain SAG 40.91 of Characium acuminatum, shown by previous preliminary evidence to have affinities with the orders Oedogoniales, Chaetophorales, and Chaetopeltidales (together constituting the OCC clade), was investigated with light and electron microscopy to characterize its morphology and ultrastructure. Sequence assemblies of the organellar and nuclear genomes were obtained and utilized in bioinformatic and phylogenetic analyses to address the phylogenetic position of the alga and its salient genomic features. The characterization of strain SAG 40.91 and a critical literature review led us to reinstate the forgotten genus Hydrocytium A.Braun 1855, with SAG 40.91 representing its type species, Hydrocytium acuminatum. Independent molecular markers converged on placing H. acuminatum as a deeply diverged lineage of the order Chaetopeltidales, formalized as the new family Hydrocytiaceae. Both chloroplast and mitochondrial genomes shared characteristics with other members of Chaetopeltidales and were bloated by repetitive sequences. Notably, the mitochondrial cox2a gene was transferred into the nuclear genome in the H. acuminatum lineage, independently of the same event in Volvocales. The nuclear genome data from H. acuminatum and from another chaetopeltidalean that was reported by others revealed endogenized viral sequences corresponding to novel members of the phylum Nucleocytoviricota. The resurrected genus Hydrocytium expands the known diversity of chaetopeltidalean algae and provides the first glimpse into their virosphere.

Johansenicoccus eremophilus gen. et sp. nov., a novel evolutionary lineage in Chlorophyceae with unusual genomic features

Background – Green algae are a diverse group of photosynthetic eukaryotes, yet are still vastly understudied compared to land plants. For many years, green algae were characterized based on their morphology and life cycles. More recently, phylogenetic and genomic analyses have been added to the phycological toolkit for a better understanding of algal biodiversity and evolutionary history. Material and methods – A desert strain of green algae was isolated from Joshua Tree National Park (JTNP) in southern California as part of a larger biodiversity survey. The alga’s nuclear rRNA genes as well as the chloroplast genome were sequenced, annotated, and analysed in addition to a morphological assessment. Results – Morphologically this strain is especially similar to Pseudomuriella and Rotundella, and its lipid profile resembles that of other soil algae, but phylogenomic analyses demonstrate that it is a distinct evolutionary lineage in Chlorophyceae. The alga exhibits several unusual genomic features, the most remarkable being its highly derived yet apparently functional nuclear rRNA genes, 18S and 28S. Both genes are GC-rich and bear many compensatory base changes to maintain a similar secondary structure to that of other green algae. The chloroplast genome has a distinct gene order and repeat arrangement from other published green algal plastomes, but contains the expected genes and also provides phylogenetically informative data. Conclusion – We conclude that the strain be placed into a new species and genus in the class Chlorophyceae, and propose the name Johansenicoccus eremophilus for this new taxon. Johansenicoccus eremophilus exemplifies science’s insufficient understanding of the range of genomic variations among inconspicuous soil algae.

Heterochlamydomonas uralensis sp. nov. (Chlorophyta, Chlamydomonadaceae), New Species Described from the Mountain Tundra Community in the Subpolar Urals (Russia)

This paper describes a new species from the class Chlorophyceae, Heterochlamydomonas uralensis sp. nov., isolated from the soil of the carex-moss-lichen tundra in the Subpolar Urals Mountains, Russia. The taxon is studied using morphological methods and DNA identification. Heterochlamydomonas uralensis differs from other Heterochlamydomonas spp. by cellular morphology, detected on light and ultrastructural levels, and 18S and ITS2 rDNA sequences. These results support the separation of the species Heterochlamydomonas uralensis sp. nov. This study is important for connecting data from DNA metabarcoding with species described on the basis of morphological characteristics.

Um estudo sistemático da diversidade e distribuição de algas verdes da família Selenastraceae do distrito de Chandrapur, Maharashtra, Índia

ABSTRACT The family Selenastraceae belongs to the order Chlorococcales of Class Chlorophyceae. It contains elongated cells, which may be straight or variously warped. The present study was conducted in the Chandrapur district of Maharashtra State, India to find out the algal diversity in the major rivers Wardha, Painganga, and wain ganga. The paper reveals the diversity and distribution of twenty-four taxa of six genera of the family Selenastraceae in these major rivers of the Chandrapur district.

Abundance and biomass of Bdelloid rotifers in the microbial mats from East Antarctica: The ecological relations between microscopic phototrophs and invertebrates

AbstractMicrobial mats in Antarctica are known to harbor microscopic organisms. Recently, comprehensive studies of the diversity of microbial mats have been conducted using genetic analysis of 16 S rRNA and 18 S rRNA genes. However, the quantitative biological contribution of each microorganism constituting the microbial mats remains unknown. We surveyed microscopic phototrophs and invertebrates in mats sampled from five lakes and one ephemeral wetland on the Sôya Coast, East Antarctica. We identified seven taxonomic groups of phototrophs, of which five (Orders Chroococcales, Nostocales, and Oscillatoriales, and Classes Chlorophyceae and Bacillariophyceae) were found at all sites, and three taxonomic groups of invertebrates (Class Bdelloidea, and Phyla Nematoda, Tardigrada). Bdelloidea were the most predominant invertebrate group at all sampling sites. The biomass of the Bdelloidea was 4–10 times higher than the total biomass of the Nematoda and Tardigrada at all sampling sites. The total biomass of all groups identified was higher in the ephemeral wetland than in the lakes. Of the five lakes, Skallen Ôike had the highest total biomass. These findings suggest that higher biomasses exist in eutrophic environments (the marine relict lake, Skallen Ôike, and an ephemeral wetland) where nutritional carryover or higher nutritional flux is expected. In addition, statistical differences in the community structure among the lakes and the ephemeral wetland could be detected based on the biomass compositions of the taxonomic groups. The community structure of each lake and the wetland was statistically dissimilar, indicating the phototrophs and invertebrates had a unique community structure at each study site.

Keragaman Plankton di Sungai

This study aims to determine plankton diversity in the Aek Pala River, Labuhanbatu Regency. The method used is descriptive observative. Sampling was done by filtering 10 L of water using a plankton net. The results showed that there were 15 genera of plankton in Aek Pala waters, including 10 types of phytoplankton and 5 types of zooplankton. The most abundant diversity of phytoplankton species found was in the class Chlorophyceae, which was 75% (7 species). In contrast, the highest diversity of zooplankton species is from the class Crustacea (3 species). In addition, the physical and chemical parameters of the waters show that Aek Pala waters are very good for supporting plankton life. In conclusion, the diversity of plankton species obtained included phytoplankton (classes Chlorophyceae, Bacillariophyceae and Dinophyceae) and zooplankton (classes Crustacea and Rotifera). The abundance of plankton found categorizes that the river waters have moderate fertility. 
 Keywords: Diversity, Plankton, Zooplankton, Phytoplankton and Aek Pala River

Multi-omics profiling of the cold tolerant Monoraphidium minutum 26B-AM in response to abiotic stress

Microalgae that are of interest for biofuel production must be able to tolerate environmental changes that occur in outdoor cultivation systems. While algal cultures may experience daily temperature fluctuations and seasonal environmental changes, the underlying mechanisms that control and regulate physiological responses and adaptation to environmental pressures are largely unknown. Systems-level characterization enabled by functional genomics can help identify biochemical pathways that promote stability and productivity of algae in various environmental conditions. Monoraphidium minutum 26B-AM, a freshwater green microalga, was identified as a top performer in biomass production in winter season screens. We sequenced the genome of M. minutum 26B-AM and applied our multi-omics pipeline to profile this high potential strain under high salt and cold temperature perturbations. Through comparative analysis, including other green algae in the class Chlorophyceae, we identified gene families unique to the genus Monoraphidium, including a desaturase that has been linked to cold tolerance in plants. We observed that osmolytes, such as trehalose, proline and betaine, accumulate under salt stress, coinciding with upregulation of genes involved in biosynthesis of these metabolites. From the genome annotation, we reconstructed a metabolic model to provide a detailed map of the metabolic pathways and can be used to simulate growth and reaction fluxes. This multi-omics analysis provides a foundation to explore algal strain potential for biofuel applications, guides strain engineering, and expands our understanding of metabolic and regulatory mechanisms of algae in applied systems.

Keanekaragaman Fitoplankton di Padang Lamun Kawasan Pesisir Mandalika Kabupaten Lombok Tengah

Phytoplankton is a source of food for zooplankton, fish larvae, and other organisms that live in seagrass beds. The purpose of this study was to determine the diversity of phytoplankton in seagrass beds in the coastal area of Mandalika, Central Lombok Regency. The location of water sample data collection was determined by purposive sampling by considering the percentage of seagrass cover. The sampling locations included 3 water locations, namely seagrass beds on the coast of Kuta, seagrass beds on the coast of Tanjung Ann, and seagrass beds on the coast of Gerupuk Bay. The research was conducted for three months from July to September 2021. The results of the study in the Mandalika coastal seagrass beds found 6 classes of phytoplankton, 26 orders, 30 families, 42 genera, and 46 phytoplankton species. Twenty one species of phytoplankton are from the Class Bacillariophyceae, 9 species from the Class Dinophyceae, 7 species from the Class Chlorophyceae, 5 species from the Class Cyanophyceae, 3 species from the Class Chrysophyceae, and 1 species from the Class Rhodophyceae. The abundance of phytoplankton at the three sampling locations ranged from 285-445 ind/L. The Phytoplankton Diversity Index in the three locations ranged from 1.35 to 2.75, which means communities with moderate diversity and dominance index ranged from 0.20-2.33.

Vitamin and mineral content of microalgae Phorpyridium and Chlorella and development prospects for food raw materials in Indonesia

Porphyridium cruentum is a product of the division of the genus Rhodophyta. It is a single cell that lives or colonizes freely in mucillago. The cells continuously secrete mucillago compounds, forming a capsule that envelops the cells. Mucillago is a sulfate polysaccharide that is soluble in water [1]. Microalgae Chlorella sp. are marine algae that can grow on fresh water and sea water media. This type of algae has a green pigment included in it class Chlorophyceae of the Chlorellaceae family. The goal of this study was to find out how much vitamin and mineral content there was in Phorpyridium and Chlorella cultivated on Conway media. The findings demonstrate that Phorpyridium has a higher vitamin E content than vitamins B1, B2, and B6. ie. 2,4 mg/100 g. Mineral analysis showed that Phorpyridium contained K minerals (45,7 mg/100g), Ca (201 g/100g), Mg (1090 mg/100g), Fe (38,2 mg/kg), Zn (3,45 mg/kg), Se (0,04 mg/kg), and P (2351 mg/kg).. Vitamin analysis of Chlorella show that vitamin B1 in Chlorella higher than Phorpyridium ie.( 3,71 mg/kg). Mineral analysis showed that Chlorella contained K minerals (714 mg/100g), Ca (331 g/100g), Mg (335 mg/100g), Fe (539 mg/kg), Zn (21,7 mg/kg), Se (0,22 mg/kg), and P (2982 mg/kg).

PHYTOPLANKTON BIODIVERSITY AND POLLUTION BIOINDICATOR IN BOJONEGARA COASTAL WATERS, BANTEN BAY, INDONESIA

Coastal waters of Bojonegara in Banten Bay has a lot of pressure from the surrounding environment, including industry and sand mining. The high intensity and limited space encourage reclamation in coastal areas which can trigger changes in water quality. Research was conducted from October to December 2019, aims to analyze the phytoplankton biodiversity and pollution bioindicator of the waters. The phytoplankton was obtained through filtering 50 liters of water at a depth of 30 cm or surface waters. Observations were also made on water quality conditions including transparency, depth, color, temperature, pH, salinity, and dissolved oxygen (in-situ) and turbidity, Total Suspended Solid (TSS), nitrate, nitrite, and total phosphate (ex-situ). Data analysis was performed on abundance, diversity index, eveness and dominance, similarity index, and saprobic index. Based on observations, it is known that the phytoplankton found were in the class Bacillariophyceae, Chlorophyceae, Cyanophyceae, Dinophyceae, and Chrysophyceae. The index values of diversity, eveness, and dominance of phytoplankton each ranged from 0.2223-1.0070; 0,1289-0,5664; and 0.1550-0.8181, respectively. According to these values, the Bojonegara waters were classifeied as mild to moderate ecological pressure. The similar conditions are also indicated by the saprobic index values. The result of Main Component Analysis (PCA) shows the first component with 53.726% variance represented by turbidity parameters, TSS, total phosphate, transparency, depth, temperature, pH, and DO. These parameters have the most influence on the presence of phytoplankton.

Evaluation of the effects of input variables on the growth of two microalgae classes during wastewater treatment

Wastewater treatment carried out by microalgae is usually affected by the type of algal strain and the combination of cultivation parameters provided during the process. Every microalga strain has a different tolerance level towards cultivation parameters, including temperature, pH, light intensity, CO2 content, initial inoculum level, pretreatment method, reactor type and nutrient concentration in wastewater. Therefore, it is vital to supply the right combination of cultivation parameters to increase the wastewater treatment efficiency and biomass productivity of different microalgae classes. In the current investigation, the decision tree was used to analyse the dataset of class Trebouxiophyceae and Chlorophyceae. Various combinations of cultivation parameters were determined to enhance their performance in wastewater treatment. Nine combinations of cultivation parameters leading to high biomass production and eleven combinations each for high nitrogen removal efficiency and high phosphorus removal efficiency for class Trebouxiophyceae were detected by decision tree models. Similarly, eleven combinations for high biomass production, nine for high nitrogen removal efficiency, and eight for high phosphorus removal efficiency were detected for class Chlorophyceae. The results obtained through decision tree analysis can provide the optimum conditions of cultivation parameters, saving time in designing new experiments for treating wastewater at a large scale.

Evaluation of growth pattern and biochemical components of Chlamydomonas reinhardtii Dangeard

Chlamydomonas reinhardtii Dangeard is the simplest motile, unicellular fresh water alga of class Chlorophyceae. It also functions as the most efficient model system for converting solar energy to chemical energy in the form of various metabolites. The objective of the present work is to deal with the growth conditions/growth kinetics of Chlamydomonas reinhardtii Dangeard, required for optimal biomass production. The parameter used to study growth of algae was, photosynthetic measurement, biomass, proteins and lipid measurement, which vary with the change in the cultural conditions. Present investigations reveal that change in protein content is positively correlated with the increase in biomass, revealing that the algae can grow rapidly in laboratory/cultural conditions. Lipid content shows a negative correlation with proteins and biomass. Lipids are known to have a role as structural components, in hydration and also in signaling events. Lipids, mainly the triacyl glycerides (TAGs) act as storage compounds enabling the microalgae to survive in adverse environmental conditions. Lipidic content increases in Chlamydomonas reinhardtii increases with optimal light and nutrient system. The increase is in the form of triacyl glycerides which serve as precursors for the production of biodiesel and bioethanol. Conclusion- Further research is required to investigate the interactions of biomolecules and growth of algae.

Occurrence of Genus Cosmarium in Machagora Dam, Chhindwara District Madhya Pradesh, India

This paper presents a pioneer investigation of (Desmid) Cosmarium species with the aim of documenting, description and exploring of freshwater habitats from Machagora Dam, Chhindwara. The result of the present study reveals the presence of 11 taxa belonging to family Desmidiaceae of the class Chlorophyceae. The study area showed rich algal (Desmid) Diversity. Genus Cosmarium includes Cosmarium angulatum, Cosmarium contractum,Cosmarium crenulatum, Cosmarium cucumis, Cosmarium granatum, Cosmarium maculatiforme, Cosmarium moniliforme, Cosmarium quadratulum, Cosmariumquadratum, Cosmarium quadrum,Cosmarium trilobulatum. All of these are indicators of oligotrophic water.

Comprehensive checklist of algal class Chlorophyceae (sensu Fritsch, 1935) for Uttar Pradesh, India, with updated taxonomic status

Uttar Pradesh is an active center for algal research in India, but regional checklists are not available. Checklists of algae reported from class Chlorophyceae (sensu Fritsch, 1935) are presented here, with taxonomic status updated per AlgaeBase. The checklist covers algae from 17 types of habitats and includes 749 species, 166 varities and six forma, belonging to four phyla, 11 classes, 26 orders, 64 families and 161 genera. Charophyta is the dominant phylum with 519 infrageneric taxa (species, varities, forma), while Chlorophyta is represented by 389 taxa. Zygnematophyceae is the dominant class with 465 infrageneric taxa under two orders, six families and 29 genera. Chlorophyceae has 305 infrageneric taxa under five orders, 33 families, and 76 genera. Cosmarium is the most speciose genus with 163 taxa, followed by Oedogonium (79), Spirogyra (72), and Closterium (54). Our study revealed that of 75 districts in Uttar Pradesh only 40 are explored for algae, with Prayagraj and Lucknow recording 266 and 144 taxa respectively.

Working collection of carotenogenic microalgae living cultures of A. O. Kovalevsky Institute of Biology of the Southern Seas

The article contains information on the specialized working collection of carotenogenic microalgae maintained by the staff of the animal physiology and biochemistry department of A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS (IBSS). The collection was established within the framework of IBSS scientific and applied research to study the mechanisms of stress tolerance in eurybiontic and extremophilic single-celled phototrophs and to identify commercially significant sources of highly valuable ketocarotenoids of astaxanthin group used for medicine and food production. The collection contains 44 microalgal strains of various taxonomic and ecological specialization with a pronounced ability to hypersynthesize secondary carotenoids and lipids under extreme conditions (drying, nutrient starvation, high-intensity illumination, extreme temperature and salinity, effect of toxicants, etc.). The main ways to replenish the fund are direct exchange of carotenogenic species with leading Russian and foreign collections of microalgae and own field sampling in the Black Sea areas of Crimea and Caucasus. The majority of strains in the collection represent two orders of the class Chlorophyceae: Chlamydomonadales (25 strains) and Sphaeropleales (15 strains), since the phenomenon of secondary carotenogenesis is widespread in these orders. Out of them, inhabitants of ephemeral freshwater ponds predominate, as well as aerophilic and soil microalgae. All strains are maintained under controlled conditions on agarized mineral media as pure cultures. Description of the collection accession includes the following data: a) current taxonomic status of the species verified according to updated information from corresponding collections and algological databases, namely AlgaeBase and NCBI Taxonomy Browser; b) species basionym and known synonyms; c) date and source of the strain deposition; d) author’s surname, geographic location, and biotope, from which the strain was isolated; e) accession number of sequences associated with the strain in NCBI (if any); and f) nutrient medium, on which the strain is maintained in the IBSS collection. The significance of the collection for morphological, biological, physiological, and biochemical studies of growth, secondary carotenogenesis, and biotechnological potential in green microalgae is discussed.