Freshwater Green Microalgae Research Articles

The impact of printing industry effluent on the growth and antioxidant response of the freshwater green microalga Chlorella sorokiniana

Contamination of aquatic ecosystems with printing industry wastewater is a serious concern because of the toxicity associated with the effluent components and a tendency to create cascading ecological effects. The influence of printing-press effluent on the freshwater microalga Chlorella sorokiniana strain UTEX2714 was studied under controlled laboratory conditions. The microalga was subjected to various effluent concentrations prepared by diluting printing-press effluent with bold basal medium (BBM) in the following ratios (effluent:medium): 1:149, 1:119, 1:99, 5:95 and 10:90, reflecting greater concentrations of the effluent. The control BBM had no effluent added. Higher effluent concentrations had a negative impact on the cell density of C. sorokiniana; at low effluent concentrations the algae displayed a high growth rate and high chlorophyll a production (p < 0.05), although total chlorophyll content did not differ significantly among treatments (p ≥ 0.05). This study also discovered an increase in peroxidase activity in this microalga in response to higher concentrations of printing-press effluent, which indicated an increase in oxidative stress that prompted antioxidant defence mechanisms. We conclude that printing-press effluent adversely affects the physiology of C. sorokiniana, indicating the potential of printing wastewater to harm phytoplankton in freshwater environments.

Rapid photocatalytic disruption of Chlorella vulgaris cells for extraction of triacylgricides using Ag3PO4–TiO2 nanocomposite

Freshwater green microalgae are a source of valuable industrial products. Owing to the lipid accumulating nature of these organisms, it is among the most promising solutions to meet carbon neutral hydrocarbon fuel needs for future transportation. However, there are many technical hurdles that need to be overcome before their commercial viability. One of the challenges is getting cellular lipids out from the cell because of the sturdy algal cell wall. Several chemical, physical, thermal, and biological techniques have been tested and reported so far, but all the methods are either energy intensive, not scalable, product damaging, slow or less effective. Photocatalysis is a promising field with emerging green solutions to many environmental problems and has only scarcely been studied so far for algal cell disruption. In this study Ag3PO4–TiO2 photocatalyst was used for pre-treatment of Chlorella vulgaris (UTEX-26) cells in the presence of UV and visible light. Results showed an increase of ∼8% in lipid quantity compared to raw cells with 5 and 30 min of UV and visible light pre-treatment, respectively at a catalyst dose of 500 mg L−1 at pH 3. The Attenuated Total Reflection - Infra Red (ATR-IR) analysis of bio-oil revealed that no significant change in lipid quality occurred due to photocatalytic pre-treatment. The pre-treatment experiments also resulted in simultaneous harvesting of the cells, thus further reducing the energy needs of the process. The technique for algal cell wall disruption using Ag3PO4–Titania composites for lipid yield enhancement has not been reported to date.

Antibacterial activity of freshwater green microalgae from Almaty region

The urgent search for new natural bioactive compounds has led to the investigation of freshwater microalgae in the Almaty region for their antibacterial properties. For this purpose, a study was carried out to investigate microalgae cultures from the division of Clorophyta for their potential to produce biologically active compounds (Parachlorella kessleri, Monoraphidium griffithii, Ankistrodesmus falcatus, Nephrochlamys subsolitaria), which also have the potential for wide use in other biotechnological applications. Methanol extracts of 4 strains of microalgae cultures against 11 strains of bacteria were used to evaluate the biological antibacterial activity. Significant antibacterial effects were observed, in particular the methanol extract of P. kessleri showed high activity against B. subtilis, S. aureus and K. pneumoniae; N. subsolitaria showed strong activity against B. subtilis, P. aeruginosa and E. coli. The results of GC/MS analysis confirmed the presence of important bioactive compounds (decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane) in the microalgae extracts. The data obtained play an important role in the development of microalgae-based antibacterial drugs.

Understanding ecotoxicological drivers and responses of freshwater green algae, Raphidocelis subcapitata, to cationic polyquaternium polymers

Cationic polymer (CP) ecotoxicity is important to understand and investigate as they are widely used in industrial and consumer applications and have shown toxic effects in some aquatic organisms. CPs are identified as “polymers of concern” and are to be prioritized in upcoming regulatory reviews, (e.g., REACH). Algae have generally been found to be the most sensitive trophic level to CP. This study aimed at elucidating the magnitude of cationic polyquaternium toxicity towards algae and to understand key toxicological drivers. A suite of polyquaterniums with varying charge density (charged nitrogen moieties) and molecular weight were selected. Highly charged polyquaternium-6 and -16 were toxic towards the freshwater green microalgae Raphidocelis subcapitata with ErC50-values ranging between 0.12 and 0.41 mg/L. Lower charge density polyquaternium-10 materials had much lower toxicity with ErC50 > 200 mg/L, suggesting that charge density is an important driver of algal toxicity. These levels of toxicity were in line with historic CP data in literature. Algal agglomeration was observed in all tests but was not linked with impacts on algal growth rate. However, agglomeration can pose challenges in the technical conduct of tests and can impair interpretation of results. The toxicity mitigation potential of humic acid was also explored. The addition of 2–20 mg/L humic acid completely mitigated PQ6 and PQ16 toxicity at concentrations higher than clean water ErC50-values. CP toxicity mitigation has also been observed in fish and invertebrate tests, suggesting that CP mitigation should be accounted for in all trophic levels within an environmental safety framework.

The ecotoxicity of single-layer molybdenum disulfide nanosheets on freshwater microalgae Selenastrum capricornutum

Molybdenum disulfide (MoS2) nanomaterials have attracted considerable attention due to their unique physicochemical properties and promising applications, and subsequent risks to the environment and human health. However, the toxicological investigations of MoS2 nanosheets in aquatic environments are still limited. Herein, their aquatic toxic effects and involved mechanisms were explored using a freshwater green microalgae model, Selenastrum capricornutum. Several endpoints, including algal growth, photosynthetic pigment and macromolecular substances synthesis, were investigated after exposure to 0.02–50.0 mg/L MoS2 nanosheets. Furthermore, oxidative stress, membrane damage, lipid oxidation, and secretion of extracellular polymeric substances were elucidated as well. The results showed that single-layer MoS2 (SLMoS2) nanosheets at low concentrations (≤ 1.0 mg/L) stimulated the synthesis of chlorophyll and primary macromolecules, and they slightly promoted the growth of S. capricornutum. In contrast, higher concentrations of SLMoS2 (> 1.0 mg/L) inhibited algae growth through ROS-mediated membrane destruction and oxidative damage. Surprisingly, SLMoS2 accelerated extracellular polymeric substances (EPS) secretion and changed their fluorescent components, thus influencing algal growth. Taken together, MoS2 nanomaterials exerted bidirectional effects on S. capricornutum at the cellular, histological and organismal levels. These results provide considerable support regarding the adverse effects of MoS2 nanomaterials on freshwater microalgae.

Structural properties of the extracellular biopolymer (β-D-xylo-α-D-mannan) produced by the green microalga Gloeocystis vesiculosa Nägeli

Many species of microalgae produce a relatively diverse range of metabolites that are interesting for biotechnological applications, and among them exopolysaccharides attract attention due to their structural complexity, biological activities, biodegradability or biocompatibility. An exopolysaccharide of high molecular weight (Mp) of 6.8 × 105 g/mol was obtained by cultivation of the freshwater green coccal microalga Gloeocystis vesiculosa Nägeli 1849 (Chlorophyta). Chemical analyses revealed a dominance of Manp (63.4 wt%), Xylp and its 3-O-Me-derivative (22.4 wt%), and Glcp (11.5 wt%) residues. The results of the chemical and NMR analyses showed an alternating branched 1,2- and 1,3-linked α-D-Manp backbone terminated by a single β-D-Xylp and its 3-O-methyl derivative at O2 of the 1,3-linked α-D-Manp residues. The α-D-Glcp residues were found mainly as 1,4-linked and to a lesser extent as the terminal sugar, indicating partial contamination of β-D-xylo-α-D-mannan with amylose (∼10 wt%) in G. vesiculosa exopolysaccharide.

Metabolomic response of microalgae towards diclofenac sodium during its removal from water and concomitant recovery of pigments and lipids

The aim of this work was to assess the efficiency of freshwater green microalga, Chlorella sorokiniana for diclofenac sodium (DFS) removal, and metabolic response of alga to comprehend the metabolic pathways involved/affected during DFS decontamination. Results showed 91.51 % removal of DFS could be achieved within 9 days of algal treatment along with recovery of enhanced value-added bioresources i.e. chlorophyll, carotenoids, and lipids from the spent biomass. DFS also had an effect on enzyme activity including superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation (MDA). Furthermore, metabolomics profiling provided an in-depth insight into changes in the metabolic response of C. sorokiniana wherein DFS induced 32 metabolites in microalgae compared to unexposed-control. This study offers microalgae as a green option for DFS removal, and the metabolomics study complemented with DFS could be an approach to understand the stress-induced strategies of C. sorokiniana for concomitant value-added products recovery in presence of DFS.

THE USE OF A SELECTED FAST-SEDIMENTATION GREEN MICROALGAE FOR WASTEWATER TREATMENT

The use of microalgae in biotechnological processes, such as bioenergy production and wastewater treatment have been and continue to be of great interest. However, the commercialization of their potential is hindered due to various technical challenges, with biomass harvesting being the largest and most expensive energy consumer among them. Therefore, a major challenge is in finding an efficient harvesting method with high economic feasibility. In this study, a rapid-sedimentation freshwater green microalga was used for batch treatment of artificial wastewater. This strain, in addition to its ability to efficiently remove and use N, P as a source of nutrients, has the advantage of a fast-sedimentation innate feature that allows for a rapid biomass settling (less than 10 minutes) without the addition of any flocculant. This green microalgal strain grows in the form of macrocolonies that significantly favor harvesting by rapid natural gravitational sedimentation. Thus, as this microalga will not require centrifugal harvesting, which is expensive and energy-consuming, its use at both bench and pilot scale could be a promising, cost-effective, and environmentally friendly approach for biotechnological applications.

Limited Phosphorous Supply Improved Lipid Content of Chlorella vulgaris That Increased Phenol and 2-Chlorophenol Adsorption from Contaminated Water with Acid Treatment

Phenolic compounds are toxic and ominously present in industrial effluents, which can end up in water bodies, causing potential damage to living organisms. This study employed the dried biomass of freshwater green microalgae Chlorella vulgaris to remove phenol and 2-chlorophenol from an aqueous environment. C. vulgaris was grown under different phosphorus- (P) starved conditions, and biomass was treated with sulfuric acid. It was observed that reducing the P level enhanced the lipid content by 7.8 times while decreasing protein by 7.2 times. P-starved C. vulgaris dried biomass removed phenol and 2-chlorophenol by 69 and 57%, respectively, after 180 min from the contaminated water. Acid-treated P-starved C. vulgaris dried biomass removed phenol and 2-chlorophenol by 77 and 75%, respectively, after 180 min. Thus, an economical and eco-friendly P-starved and acid treated C. vulgaris biomass has better potential to remove phenol and 2-chlorophenol from contaminated ground water and industrial wastewater.

A CO2-rich environment-mediated amelioration of nutritional stress effect in an indigenous freshwater green microalga Desmodesmus sp.

A CO2-rich environment-mediated amelioration of nutritional stress effect in an indigenous freshwater green microalga Desmodesmus sp.

Characterisation of bio-oil extracted from microalgae Botryococcus sp. biomass grown in domestic and food processing wastewaters for valuable hydrocarbon production

Microalgae cultivation for biofuels feedstock and value-added chemicals is a sustainable approach to renewable energy generation development. This study aims to establish a detailed hydrocarbon profile for freshwater green microalgae oil extracted from local Botryococcus sp. biomass cultivated using domestic wastewater (DW) and food processing wastewater (FW). The cultivation experiment was conducted using an enclosed photobioreactor in triplicate for 18 days under an outdoor condition. Microalgae bio-oil was extracted by employing the Soxhlet extraction method (EPA 9071B), and the various potential hydrocarbon characterisations were obtained using GC-MS analysis. The extracted microalgae oil content was higher when Botryococcus sp. was cultivated in DW (70.7%) compared to FW (53.1%) as a culture medium. The GC-MS analysis found that Phenol, 2,4-bis(1,1-dimethylethyl) -(C14H22O), contributed the highest peak percentage (29.6%) of the total hydrocarbon compounds when utilised DW as a culture medium. Meanwhile, Hexadecenoic acid, methyl ester (C17H34O2) was found as the major compound revealed from Botryococcus sp. that grew in FW with 41% of peak total hydrocarbon. Both wastewater types show potential for cultivating Botryococcus sp. for hydrocarbon production and may serve as environmentally friendly feedstocks for biofuels and chemical ingredients in many industries.

Development of operating process for continuous production of biomass by Tetradesmus obliquus (MT188616.1) in a hollow fiber membrane photobioreactor

An effective prototype of photobioreactor namely hollow fiber membrane bioreactor is employed to produce algal biomass for biofuel production. The effect of two-stage cultivation system on the biomass productivity and lipid production is studied using freshwater green microalga Tetradesmus obliquus MT188616.1. The hybrid system combines exponential biomass production in hollow fiber membrane photobioreactor (HFMPBr) and a coordinated high-lipid stimulation phase in nitrogen-deprived medium by the shake flask method. This work is proposed to examine the usefulness of HFMPBr module to enhance the microalgal growth rate through the effective mass transfer by standardizing the culture medium re-circulation flow rates (5 – 45 mL min−1) through the hollow fiber membranes. Cultivation is carried out at continuous mode in HFMPBr containing polysulfone fabricated membranes at fixed light intensity of 50 µmol m−2 s−1 and temperature at 28 °C. Biomass productivity and specific growth rate obtained are 0.44 g L−1d−1 and 1.61 µ d−1 with a lipid yield of 0.1 g L− 1. The key operating parameter i.e., liquid flow rate is optimized based on biomass production. The highest biomass concentration is produced at the flow rate of 45 mL min−1. The results showed that HFMPBr module is a better choice for the algal-cultivation to obtain higher biomass yield.

Growth, lipids, proteins, and carotenoid contents of some freshwater green microalgae under simulated day/night temperature fluctuation

Day/night or seasonal temperature fluctuation is a major factor during outdoor cultivation of microalgae. In the present study, we investigated the impact of simulated day/night temperatures (20oC night and 30oC day) on the growth, lipid, protein and carotenoid contents of four local oleaginous microalgae strains under mixotrophic and heterotrophic conditions. The impact of simulated day/night temperatures on the growth and biochemical compositions varied across species and culture conditions (mixotrophic or heterotrophic). The lipid productivity by Dictyosphaerium sp. under heterotrophic condition was twice the value obtained at constant temperature but showed no significant (p &gt; 0.05) impact under mixotrophic condition. Desmodesmus subspicatus elicited higher lipid (15%) and carotenoid (56%) contents under simulated day/night temperature regime than at constant temperature (30oC) (p&lt;0.05). There was a negative impact on the protein content of the microalgal species under mixotrophic and heterotrophic conditions. The above results have shown that these species have high potentials for co-production of lipids, protein and carotenoid under outdoor conditions.

Factors Influencing the Production of Extracellular Polysaccharides by the Green Algae Dictyosphaerium chlorelloides and Their Isolation, Purification, and Composition.

The freshwater green microalgae, Dictyosphaerium chlorelloides (CCALA 330), has the ability to produce extracellular polysaccharides (EPS). Conditions for optimum growth and EPS overproduction were determined in laboratory-scale tubular photobioreactors (PBR) with a working volume of 300 mL. Multiple limitations in nutrient supply were proven to be an effective method for EPS overproduction. Salinity stress was also applied to the culture, but no significant increase in EPS production was observed. The effects of different nitrogen sources were examined and the microalgae exhibited the fastest growth and EPS production in medium containing ammonium nitrate. Under determined optimal conditions, EPS concentration reached 10 g/L (71% of the total biomass) and a total biomass of 14 g/L at the end of 17 days cultivation. Pilot-scale cultivation was also carried out in a column type airlift photobioreactor (PBR) with a working volume of 60 L. A new and efficient methodology was developed for separating cells from the EPS-containing culture broth. Due to the strong attachment between cells and EPS, high-pressure homogenization was carried out before a centrifugation process. The EPS in the supernatant was subsequently purified using ultrafiltration. The green microalgae Dictyosphaerium chlorelloides may therefore be appropriate for the commercial production of EPS.

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.

Biosorption of Uranium from aqueous solution by green microalga Chlorella sorokiniana

Uranium and its compounds are radioactive and toxic, as well as highly polluting and damaging the environment. Novel uranium adsorbents with high biosorption capacity that are both eco-friendly and cost-effective are continuously being researched. The non-living biomass of the fresh water green microalga Chlorella sorokiniana was used to study the biosorption of uranium from aqueous solution. The biosorption of uranium from aqueous solutions onto the biomass of microalga C. sorokiniana was investigated in batch studies. The results showed that the optimal pH for uranium biosorption onto C. sorokiniana was 2.5. Uranium biosorption occurred quickly, with an equilibrium time of 90 min. The kinetics followed a pseudo-second-order rate equation, and the biosorption process fit the Langmuir isotherm model well, with a maximum monolayer adsorption capacity of 188.7 mg/g. The linear plot of the DKR model revealed that the mean free energy E = 14.8 kJ/mol, confirming chemisorption adsorption with ion exchange mode. The morphology of the algal biomass was investigated using a scanning electron microscope and energy dispersive X-ray spectroscopy. The FTIR spectroscopy analysis demonstrated that functional groups (carboxyl, amino, and hydroxyl) on the algal surface could contribute to the uranium biosorption process, which involves ion exchange and uranium absorption, and coordination mechanisms. Thermodynamic simulations indicated that the uranium biosorption process was exothermic (ΔH = −19.5562 kJ/mol) and spontaneous at lower temperatures. The current study revealed that C. sorokiniana non-living biomass could be an efficient, rapid, low-cost, and convenient method of removing uranium from aqueous solution.

Synthesis and evaluation of cationic polyacrylamide and polyacrylate flocculants for harvesting freshwater and marine microalgae

• Cationic PAETAC & PAmPTAC were synthesized by UV-induced radical polymerization. • New polymers showed good flocculation performance of freshwater & marine microalgae. • Optimal doses of PAETAC were 50 and 4.8 mg/g for C. vulgaris & P. purpureum. • PAETAC and PAmPTAC produced stable flocs, supporting simple dewatering step. This study addresses the challenge of microalgae harvesting through the development of flocculants. Two positively charged cationic polymers including poly[2 (acryloyloxy)ethyl]trimethylammonium chloride (PAETAC) and poly(3 acrylamidopropyl)trimethylammonium chloride (PAmPTAC) were synthesized using the UV-induced radical polymerization, for harvesting both freshwater and marine microalgae. The results show that the synthesized polymers have excellent flocculation performance for both freshwater green microalgae ( Chlorella vulgaris) and marine red microalgae ( Porphyridium purpureum). PAETAC outperformed PAmPTAC for both Chlorella vulgaris and Porphyridium purpureum microalgae. The optimal PAETAC doses for Chlorella vulgaris and Porphyridium purpureum microalgae were 50 and 4.8 mg/g of dry biomass while the optimal PAmPTAC doses were 252 and 35 mg/g of dry biomass respectively. Additionally, the floc formation with the PAETAC was more stable than PAmPTAC, which supported the dewatering step via sieving. The superior performance can be attributed to the higher molecular weight of the PAETAC polymer when compared to the PAmPTAC polymer. In comparison to commercially available polydiallyldimethylammonium chloride (PolyDADMAC), the newly synthesised PAETAC and PAmPTAC polymers demonstrated superior flocculation efficiency at a lower dose. The findings of this study established a platform technology for designing and synthesising cationic flocculants for use in microalgae harvesting.

The Algal Polysaccharide Ulvan and Carotenoid Astaxanthin Both Positively Modulate Gut Microbiota in Mice.

The intestinal microbial community (microbiota) is dynamic and variable amongst individuals and plays an essential part in gut health and homeostasis. Dietary components can modulate the structure of the gut microbiota. In recent years, substantial efforts have been made to find novel dietary components with positive effects on the gut microbial community structure. Natural algal polysaccharides and carotenoids have been reported to possess various functions of biological relevance and their impact on the gut microbiota is currently a topic of interest. This study, therefore, reports the effect of the sulfated polysaccharide ulvan and the carotenoid astaxanthin extracted and purified from the aquacultured marine green macroalgae Ulva ohnoi and freshwater green microalgae Haematococcus pluvialis, respectively, on the temporal development of the murine gut microbiota. Significant changes with the increase in the bacterial classes Bacteroidia, Bacilli, Clostridia, and Verrucomicrobia were observed after feeding the mice with ulvan and astaxanthin. Duration of the treatments had a more substantial effect on the bacterial community structure than the type of treatment. Our findings highlight the potential of ulvan and astaxanthin to mediate aspects of host-microbe symbiosis in the gut, and if incorporated into the diet, these could assist positively in improving disease conditions associated with gut health.

Microalgae-Based Fluorimetric Bioassays for Studying Interferences on Photosynthesis Induced by Environmentally Relevant Concentrations of the Herbicide Diuron.

The widespread agricultural use of the phenylurea herbicide Diuron (DCMU) requires the investigation of ecotoxicological risk in freshwater and soil ecosystems in light of potential effects on non-target primary producers and a heavier effect on higher trophic levels. We used microalgae-based fluorimetric bioassays for studying the interferences on the photosynthesis of a freshwater and soil model green microalga (Chlamydomonas reinhardtii) induced by environmentally relevant concentrations of the herbicide DCMU. Measurements of steady-state chlorophyll a (Chl-a) fluorescence emission spectra were performed; as well, the kinetics of the Chl-a fluorescence transient were recorded. Percentage indexes of interference on photosynthesis were calculated after comparison of steady-state and kinetic Chl-a fluorescence measurements of DCMU-exposed and control C. reinhardtii cell suspensions. The results obtained after 30 min exposure to the herbicide DCMU confirmed a significant inhibitory effect of DCMU 2 μg/L, and no significant differences between %ι values for DCMU 0.2 μg/L and 0.02 μg/L exposures. Positive %ε values from kinetic measurements of the Chl-a fluorescence transient confirmed the same interfering effect of 2 μg/L DCMU on PSII photochemistry in the exposed C. reinhardtii cell suspensions. Negative values of %ε observed for 0.2 and 0.02 μg/L DCMU exposures could be attributable to a presumptive ‘stimulatory-like’ effect in the photochemistry of photosynthesis. Short-term exposure to sub-μg/L DCMU concentration (≤0.2 μg/L) affects the photosynthetic process of the model microalga C. reinhardtii. Similar environmental exposures could affect natural communities of unicellular autotrophs, with hardly predictable cascading secondary effects on higher trophic levels.

Effect of different wavelengths of LED light on the growth, chlorophyll, β-carotene content and proximate composition of Chlorella ellipsoidea

Chlorella ellipsoidea is a freshwater green microalga that has great prospect for the sustainable development of aquaculture industry. Microalgae require optimal lighting conditions for efficient photosynthesis. The key to cost-effective algal biomass production is to optimize algae growth conditions. This study aimed to investigate the effects of various wavelengths viz. white (380–750 nm), green (510 nm), blue (475 nm), and red (650 nm) light-emitting diodes (LEDs) on the growth, pigment content (chlorophyll-a, chlorophyll-b, and β-carotene), and proximate composition of C. ellipsoidea with a photoperiod of 12 h:12 h light: dark cycle under indoor environmental conditions. C. ellipsoidea was cultured in Bold's Basal Medium for 18 days. The cell density (125.36×105 cells ml−1), cell dry weight (58.9 ± 4.57 mg L−1), optical density (1.66 ± 0.08 g L−1), chlorophyll-a (7.31 ± 0.04 μg ml−1), chlorophyll-b (2.73 ± 0.13 μg ml−1), and β-carotene (0.39 ± 0.04 μg ml−1) content of C. ellipsoidea were significantly (P < 0.05) higher at 15th-day when cultured under blue LED light exposure. Significantly lower growth and nutritional values were obtained under red LED light exposure compared to the control and other LEDs spectra. In Pearson correlation analysis, the cell density and cell dry weight values showed a strong positive correlation with the values of pigment contents of C. ellipsoidea in all the treatments. The LEDs light spectra showed significant effects on proximate composition of C. ellipsoidea. Protein and lipid contents of C. ellipsoidea were significantly higher in blue LED growth conditions compared to white, green, and red LEDs. C. ellipsoidea cells were 3˗7.04 μm in size and the maximum area of the cell was 38.94 μm2 in blue LED treatment. Results of this study demonstrated that blue LED light spectra was the most suitable condition to induce nutritionally rich biomass production of C. ellipsoidea, which can be used as a potential source of fish feed towards sustainable aquaculture.