Chlorella Sorokiniana Research Articles

Carbon-Storing Structural Material Based on Wastewater-Cultivated Chlorella Sorokiniana

Microalgae cultivation is a promising technology for carbon sequestration and wastewater remediation. It is economically and logistically critical to find viable applications for the large quantities of produced biomass. In current research, a structural material is developed by using nearly 100% Chlorella sorokiniana. The otherwise non-cohesive microalgae cells are first surface-activated and then compacted under a relatively high pressure. The resulting material is a dense solid, stronger than typical steel-reinforced concrete in flexural tests. The processing procedure is simple and fast, and the setup is scalable. This technique may be useful for next-generation green construction and provide a use-case for sustainable microalgae biomass.

P15-16 Deoxynivalenol detoxification by Chlorella sorokiniana leads to inhibitory effects on the Deoxynivalenol induced allergic contact dermatitis symptoms in a mouse model

P15-16 Deoxynivalenol detoxification by Chlorella sorokiniana leads to inhibitory effects on the Deoxynivalenol induced allergic contact dermatitis symptoms in a mouse model

Utilization of recombinant Chlorella expressing dsRNA for protection against grouper nervous necrosis virus

In mammals and fish, dsRNA can induce the type I interferon (IFN-I), leading to the expression of antiviral and immune-related genes. The use of microalgae expressing dsRNA as an oral delivery system to activate innate immunity in fish has not been documented. In this study, wild Chlorella sorokiniana was transformed with NNV (nervous necrosis virus) RdRp and GIV (grouper iridovirus) ORF086R dsRNA expression vectors. The recombinant Chlorella strains effectively protected pearl gentian groupers (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂) against NNV and reduced viral titers. The survival rates of the NNV RdRp and GIV ORF086R dsRNA treatment groups increased by 32 % and 38 %, respectively, compared with that of the control group. These findings indicate that recombinant Chlorella has the potential to be used as an oral delivery strategy for protection against NNV disease in groupers.

Effect of iron oxide nanoparticles on mixotrophic cultivation of Chlorella spp. for biofuel production

The current study investigated the effect of iron oxide nanoparticles (IONPs) on mixotrophic microalgae cultivation in wastewater for biofuel production. Optimal IONPs doses of 10 and 20 mg L−1 increased Chlorella pyrenoidosa growth by 16% and lipid accumulation by 53 %, respectively, compared with the control group. Conversely, the protein content declined drastically, while carbohydrates remained relatively unchanged. A maximum of 15% rise in biomass growth was observed for Chlorella sorokiniana IITRF at an IONPs dose of 20 mg L−1, with no significant variation in biochemical composition. Microalgae grown under mixotrophic conditions with IONPs in a biofilm reactor were more suitable for biogas production than biodiesel, increasing biogas and methane content by 38 and 48%, respectively. The findings suggest that low doses of IONPs can enhance microalgal biomass, biogas production and methane content. Further, metabolomics studies are warranted to investigate the interaction between microalgae and nanoparticles to achieve high-quality biodiesel.

Assessing ecotoxicity, removal efficiency, and molecular response of freshwater microalgae to bisphenol AP

Bisphenol AP (BPAP), an analog of BPA and endocrine disrupter, is increasingly being detected in water, signaling its rise as an environmental contaminant similar to BPA, which is known for its health implications. This study investigated the ecotoxicity of BPAP in four freshwater microalgae (Chlorella sorokiniana, Chlamydomonas mexicana, Scenedesmus obliquus, and Chlorella vulgaris), along with their removal potential and biotransformation. This was followed by de novo transcriptomic analysis to elucidate the molecular response after BPAP exposure. The toxicity (120 h-EC50) of BPAP for microalgal species ranged from 1.509 mg L−1 to 6.509 mg L−1. C. mexicana exhibited the highest removal efficiency of 86.5 % after 12 days, followed by C. vulgaris (86.0 %), S. obliquus (78.9 %), and C. Sorokiniana (56.5 %) at 1 mg L−1. Eight biotransformed BPAP products were analyzed, and their toxicity was predicted to be lower than that of BPAP using the Ecological Structure Activity Relationships software. Transcriptomic analysis of C. mexicana revealed the differential expression of 4611 genes in processes related to metabolism, cellular activities, and stress responses. Genes encoding methyltransferases, glycosyltransferases, and various oxidoreductases, including electron-transferring flavoprotein dehydrogenase and glutaredoxin, were significantly upregulated in algal cells exposed to BPAP, suggesting the potential of C. mexicana for BPAP detoxification via glycosylation and transmethylation. These results offer novel insights into the ecotoxicity, removal potential, and biotransformation of BPAP in freshwater microalgae, with transcriptomic analysis, elucidating the molecular mechanisms of BPAP detoxification for effective environmental remediation.

Green solutions: evaluating the impact of Chlorella sorokiniana and Anabaena laxa on captan phycoremediation

This study explores the use of algae for phycoremediation, focusing on how Chlorella sorokiniana and Anabaena laxa detoxify water contaminated with captan, a common fungicide. The efficiency of these species in absorbing captan and the associated biochemical changes were evaluated to assess their potential for environmental protection. Microalgae were exposed to captan concentrations of 15 and 30 mg/L, and various parameters, including captan uptake, chlorophyll (Chl) a, carotenoid levels, and changes in metabolic profiles (soluble carbohydrates, organic acids, amino acids, and fatty acids), were measured. Results showed Anabaena had a higher captan absorption capacity (141.7 µg/g at 15 mg/L and 239.3 µg/g at 30 mg/L) compared to Chlorella (74.43 µg/g and 162 µg/g). Increased captan uptake reduced the growth of both species, as indicated by lower Chl a levels. Both species accumulated osmo-protectants and antioxidants as defense mechanisms, with soluble sugars increasing by 83.49% in Chlorella and 68.87% in Anabaena, and carotenoids increasing by 60.42% and 46.24%, respectively. Principal component analysis revealed distinct species-level responses, with Anabaena showing greater tolerance. The study concludes that both species can effectively remediate captan, with Anabaena being more efficient, indicating their potential for mitigating agrochemical impacts in aquatic environments and promoting sustainable agriculture and water management.

Nitrogen starvation leads to TOR kinase-mediated downregulation of fatty acid synthesis in the algae Chlorella sorokiniana and Chlamydomonas reinhardtii

BackgroundWhen subject to stress conditions such as nutrient limitation microalgae accumulate triacylglycerol (TAG). Fatty acid, a substrate for TAG synthesis is derived from de novo synthesis or by membrane remodeling. The model industrial alga Chlorellasorokiniana accumulates TAG and other storage compounds under nitrogen (N)-limited growth. Molecular mechanisms underlying these processes are still to be elucidated.ResultPreviously we used transcriptomics to explore the regulation of TAG synthesis in C. sorokiniana. Surprisingly, our analysis showed that the expression of several key genes encoding enzymes involved in plastidic fatty acid synthesis are significantly repressed. Metabolic labeling with radiolabeled acetate showed that de novo fatty acid synthesis is indeed downregulated under N-limitation. Likewise, inhibition of the Target of Rapamycin kinase (TOR), a key regulator of metabolism and growth, decreased fatty acid synthesis. We compared the changes in proteins and phosphoprotein abundance using a proteomics and phosphoproteomics approach in C. sorokiniana cells under N-limitation or TOR inhibition and found extensive overlap between the N-limited and TOR-inhibited conditions. We also identified changes in the phosphorylation status of TOR complex proteins, TOR-kinase, and RAPTOR, under N-limitation. This indicates that TOR signaling is altered in a nitrogen-dependent manner. We find that TOR-mediated metabolic remodeling of fatty acid synthesis under N-limitation is conserved in the chlorophyte algae Chlorella sorokiniana and Chlamydomonas reinhardtii.ConclusionOur results indicate that under N-limitation there is significant metabolic remodeling, including fatty acid synthesis, mediated by TOR signaling. This process is conserved across chlorophyte algae. Using proteomic and phosphoproteomic analysis, we show that N-limitation affects TOR signaling and this in-turn affects the metabolic status of the cells. This study presents a link between N-limitation, TOR signaling and fatty acid synthesis in green-lineage.

Winery wastewater treatment by microalgae Chlorella sorokiniana and characterization of the produced biomass for value-added products.

The microalgae Chlorella sorokiniana was used for the treatment of winery wastewater (WWW). Batch experiments were initially conducted to investigate how biomass acclimatization in different media, dilution of wastewater, and addition of ammonium nitrogen (NH4-N) affect the growth of microalgae and the removal of major pollutants. Afterwards, two sequencing batch reactor (SBR) systems were tested applying different configurations and hydraulic retention times. The biomass collected at the end of the experiments was characterized for proteins, lipids, carbohydrates, amino acid profile, and the existence of lutein, β-carotene, chlorophyll a, and tocopherols. Batch experiments showed that Chlorella sorokiniana acclimatization to urban wastewater enhanced the removal of NH4-N and total phosphorus (TP). The operation of a two-stage SBR system achieved COD and NH4-N removal equal to 85 ± 9% and 91 ± 20%, respectively, while the use of a single-stage system feeding with anaerobically pretreated WWW resulted to COD and NH4-N removal of 78 ± 9% and 95 ± 9%, respectively. Analyses of biomass showed higher protein content (up to 58.8%) in batch experiments with NH4-N addition as well as in SBR experiments. The cultivation of microalgae under SBR conditions enhanced the production of pigments and tocopherols. The maximum concentrations of 1075mgkg-1, 45.5mgkg-1, and 131.2mgkg-1 were achieved for lutein, β-carotene, and tocopherols, respectively, in the one-stage system. Our findings suggested that Chlorella sorokiniana cultivation in WWW not only removed nutrients from WWW but also could potentially serve for the production of value-added ingredients used in food industry, cosmetics, and animal feedstock.

Ionic liquid and ultrasound as a fast and innovative combination for improved extraction of Chlorella sorokiniana-derived carotenoids

Chlorella sorokiniana is a microalgae with high amounts of carotenoids, but the extraction methods need to be improved. This work hypothesized that the combination of ionic liquids (ILs) and ultrasound would provide a fast and efficient process for carotenoid extraction, allowing for the reuse of ILs in several extractive cycles. This study aimed to develop an improved ILs/ultrasound-based method for extracting carotenoids from C. sorokiniana. The potential reuse of ILs in five consecutive extraction cycles and the recovery of carotenoids was also examined. Moreover, the antioxidant activity of the carotenoid extracts and their effects on metabolic cell viability and cell death were investigated using HT22 neuronal cells. Initial tests with four ILs and acetone as a control were carried out in an ultrasonic probe. The ILs (1-butyl-3-methylimidazolium chloride [BMIM][Cl]; 1-hexyl-3-methylimidazolium chloride [HMIM][Cl]) were selected for the 25−1 fractional experimental design. The maximized parameters obtained in the experimental design were the following: IL ([HMIM][Cl]), a 1:10 solid-liquid ratio, a 1:4 IL-cosolvent ratio, and two repetitions of extraction with 7.5 min (with an extraction yield of 1.29 mg·g‐1 of dry matter). A total of 11 carotenoids were separated, and nine were identified, the major ones being lutein and β-carotene. [HMIM][Cl] recyclability using resin Amberlite XAD-7HP was efficient for at least five cycles. On average, 91 % of the IL was recovered, and the pigment yield increased by 40 %. The antioxidant activities of the extracts obtained using [HMIM][Cl] and acetone were 1.65 μmol and 2.32 μmol of α-tocopherol, respectively. Both extracts (≤ 4.0 μg·mL‐1) exhibited no significant toxicity to HT22 cells. The proposed method is an innovative and improved approach for carotenoid extraction from C. sorokiniana due to its short extraction times and high process yield. [HMIM][Cl] demonstrated stability in reuse cycles and proved to have the potential for obtaining carotenoids from C. sorokiniana.

Phytoene and Phytoene-Rich Microalgae Extracts Extend Lifespan in C. elegans and Protect against Amyloid-β Toxicity in an Alzheimer's Disease Model.

Phytoene is a colourless carotenoid widely available from dietary sources and a precursor for the synthesis of other carotenoids. Although present at high concentrations across different tissues, phytoene is largely viewed as not having physiological activity. Here, we utilize the model organism C. elegans to show that phytoene is bioactive and has anti-ageing properties. Supplementation with phytoene protects against oxidative damage and amyloid-β42 proteotoxicity (a major pathology of Alzheimer's disease), and extends lifespan. We also examine extracts from two microalgae, Chlorella sorokiniana and Dunaliella bardawil. We show that the extracts contain high levels of phytoene, and find that these phytoene-rich extracts have protective effects similar to pure phytoene. Our findings show that phytoene is a bioactive molecule with positive effects on ageing and longevity. Our work also suggests that phytoene-rich microalgae extracts can utilized to produce foods or supplements that promote healthy ageing and prevent the development of chronic age-related diseases.

PRODUCTION OF BIODIESEL FROM MICROALGAE CULTIVATED WITH VINASSE

Purpose: The objective of this work was to carry out the cultivation of the microalgae Chlorella sorokiniana with diluted vinasse, verifying its potential for remediation of nutrients and increase of its lipid fraction, to produce biodiesel according to the current regulation. Theoretical Framework: The quest to reduce fossil fuels, which are responsible for negative environmental impacts, has boosted the demand for biofuels in recent years. Biodiesel has been gaining prominence as a promising alternative to replace petroleum derivatives since it can be produced from various raw materials, such as microalgae. Design/Methodology/Approach: Different vinasse dilutions were studied for the cultivation of Chlorella sorokiniana CTT 7727, being 5, 10 and 15% (v v-1) and N:P:K (20:5:20) 1% (v v-1) medium as a comparative standard. Biodiesel was produced by direct transesterification and analyzed by gas chromatography coupled to a flame ionization detector, enabling the identification and quantification of the fatty acid profile. Findings: The results obtained indicated that vinasse 10% (v v-1) proved to be promising for application as a culture medium for this microalgae species, as it guaranteed a good cell growth rate, high biomass productivity and lipid yield. Considering the biodiesel produced, it fits the regulatory standards analyzed by the National Agency of Petroleum, Natural Gas and Biofuels (ANP). Research, Practical & Social Implications: The research demonstrates the feasibility of cultivating the microalga Chlorella sorokiniana with diluted vinasse, highlighting the 10% concentration as promising for optimizing cell growth and lipid yield. The results ensure compliance with ANP regulations for biodiesel production, indicating immediate and sustainable applicability on an industrial scale. Socially, it contributes to the pursuit of biofuels, reducing dependence on fossil sources and promoting more sustainable practices in the bioenergy industry. Originality/Value: The study's originality lies in the unique combination of Chlorella sorokiniana CTT 7727, diluted vinasse, and biodiesel production in accordance with ANP regulations. It stands out for identifying the optimal vinasse concentration (10%) for cultivation, presenting an economical and effective approach. The strategic value is in the use of an alternative raw material cultivated with an industrial residue, promoting the diversification of the energy matrix and mitigating environmental impacts associated with conventional fuels.

A critical review on hydrothermal liquefaction screening using Microalgae as a two-way approach to sewage water treatment and biofuel production

<p>Hydrothermal liquefaction (HTL) is involved in concurrently treating both sewage water and generating biofuels. It involves the analysis of various operating parameters, such as pressure, catalyst temperature, and reaction time, to determine the productivity and physiochemical properties of the resulting bio-oil. The critical assessment of over 100 algal strains, compared on the basis of their growth kinetics in different wastewater environments and their HTL-based yields, identified Auxenochlorella pyrenoidosa and Microchaete spirulina strains as the most suitable ones for optimised municipal wastewater treatment. Additionally, other strains like Chlorella sorokiniana, Tetradesmus obliquus, and Desmodesmus abundance are found to be effective for heavy metal remediation in municipal wastewater due to their high biosorption capacities. Furthermore, certain microalgal strains, namely Auxenochlorella pyrenoidosa, Botryococcus braunii, Microchloropsis gaditana, and Microchaete spirulina, were described as promising microalgae in the production of high crude oil yields through the HTL technique. The current review highlights the integrated approach of sustainable and economical HTL techniques using the best microalgal strains as a technologically and environmentally feasible solution selected through a systematic protocol for sewage water treatment and biofuel production.</p>

Comprehensive Analysis of Biomass from Chlorella sorokiniana Cultivated with Industrial Flue Gas as the Carbon Source.

Chlorella sorokiniana, isolated from a pond adjacent to a cement plant, was cultured using flue gas collected directly from kiln emissions using 20 L and 25000 L photobioreactors. Lipids, proteins, and polysaccharides were analyzed to understand their overall composition for potential applications. The lipid content ranged from 17.97% to 21.54% of the dry biomass, with carotenoid concentrations between 8.4 and 9.2 mg/g. Lutein accounted for 55% of the total carotenoids. LC/MS analysis led to the identification of 71 intact triacylglycerols, 8 lysophosphatidylcholines, 10 phosphatidylcholines, 9 monogalactosyldiacylglycerols, 12 digalactosyldiacylglycerols, and 1 sulfoquinovosyl diacylglycerol. Palmitic acid, oleic acid, linoleic acid, and α-linolenic acid were the main fatty acids. Polyunsaturated fatty acid covers ≥ 56% of total fatty acids. Protein isolates and polysaccharides were also extracted. Protein purity was determined to be ≥75% by amino acid analysis, with all essential amino acids present. Monomer analysis of polysaccharides suggested that they are composed of mainly D-(+)-mannose, D-(+)-galactose, and D-(+)-glucose. The results demonstrate that there is no adverse effect on the metabolite profile of C. sorokiniana biomass cultured using flue gas as the primary carbon source, revealing the possibility of utilizing such algal biomass in industrial applications such as animal feed, sources of cosmeceuticals, and as biofuel.

Developing Strain-Specific Simple Sequence Repeat (SSR) Markers for Chlorella sorokiniana.

Chlorella sorokiniana green microalga offers many environmentally friendly applications, including wastewater treatment, biofertilizers, animal feed, and biofuel production. Different strains of C. sorokiniana have unique properties that may suit one application but not another. There is a need to distinguish between the many available strains of C. sorokiniana to choose the one that best fits the application. Consequently, our research goal was to develop strain-specific simple sequence repeat (SSR) markers to differentiate between the different strains. Seventeen markers spanning ten out of the twelve chromosomes of the C. sorokiniana genome were developed and validated on eight different strains from culture collections and our lab, and were then analyzed by fragment analysis. The results demonstrate the potential of these polymorphic markers to detect the genetic differences between the strains of C. sorokiniana, and to serve as useful tools for the intra-species population genetic analysis and conservation genetics studies of C. sorokiniana.

Effects of Chlorich®EnergyBoost on Enhancing Physical Performance and Anti-Fatigue Properties in Mice.

Chlorich®EnergyBoost, a water extract obtained from Chlorella sorokiniana, has been proposed to enhance physical performance and provide anti-fatigue effects. This study assessed the impact of Chlorich®EnergyBoost supplementation on physical performance and its anti-fatigue properties. Twenty-four mice were allocated into four groups: (1) the control group receiving only water,;(2) the 1X group (49.2 mg/kg/day); (3) the 2X group (98.4 g/kg/day); and (4) the 5X group (246 g/kg/day). All groups were orally administered the supplements for four consecutive weeks. The evaluation included grip strength, swimming endurance, an exhaustion test, and serum biochemistry analysis. Additionally, the study examined the bioactive peptides through matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) and conducted bacterial reverse mutation and acute oral toxicity tests for safety assessment. The findings indicated that Chlorich®EnergyBoost supplementation led to a significant reduction in serum lactate levels by 14.08% to 22.54% and blood urea nitrogen levels by 12.23% to 16.76%, an increase in the lactate clearance rate by 0.28 to 0.35, an enhancement of muscle glycogen storage by 1.10 to 1.44-fold, and hepatic glycogen storage by 1.41 to 1.47-fold. These results demonstrated dose-dependent effects. MALDI-TOF analysis revealed the expression of dihydrolipoamide dehydrogenase and superoxide dismutase. Both the bacterial reverse mutation and acute oral toxicity tests showed no adverse effects.

Feasibility study on heterotrophic utilization of galactose by Chlorella sorokiniana and promotion of galactose utilization through mixed carbon sources culture

BackgroundThe development of alternative carbon sources is important for reducing the cost of heterotrophic microalgae cultivation. Among cheap feedstocks, galactose is one of the most abundant sugars and can be easily obtained from many natural biomasses. However, it is generally difficult to be utilized by microalgae. In addition, the mechanism of its low utilization efficiency in heterotrophic cultivation is still unknown.ResultsAmong seven tested carbon sources, only glucose and acetate could be efficiently utilized by C. sorokiniana in heterotrophic cultivation while there were no apparent signs of utilization of other carbohydrates, including galactose, in regular heterotrophic cultivation. However, galactose could be utilized in cultures with high inoculation sizes. This confirmed that C. sorokiniana has a complete pathway for transporting and assimilating galactose under dark conditions, but the rate of galactose utilization is quite low. In addition, the galactose utilization was greatly enhanced in mixotrophic cultures, which indicated that galactose utilization could be enhanced by additional pathways that can enhance cell growth. Based on above results, a mixed carbon source culture strategy was proposed to improve the utilization rate of galactose, and a significant synergistic effect on cell growth was achieved in cultures using a mixture of galactose and acetate.ConclusionsThis study indicated that the galactose metabolism pathway may not be inherently deficient in Chlorophyta. However, its utilization rate was too low to be detected in regular heterotrophic cultivation. Mixed carbon source culture strategy was confirmed effective to improve the utilization rate of galactose. This study contributes to a deeper understanding of the utilization ability of difficultly utilized substrates in the heterotrophic cultivation of microalgae, which is of great significance for reducing the cost of heterotrophic cultivation of microalgae.

Molecular Phylogeny of Chlorophyta Species Isolated from a Shallow Lake Ecosystem

Studying the algal diversity of lentic ecosystems is an important issue for identifying the alteration in aquatic ecosystems. Morphological characterization of algae is inadequate to identify different types of microalgae and it is also necessary to depend on molecular evidence which is more crucial and a precise tool. In this study, two Chlorophyta species were identified; Tetradesmus dimorphus (Turpin) M.J.Wynne (Basionym: Scenedesmus dimorphus) and Chlorella sorokiniana Shihira & R.W.Krauss), in a shallow lake. The evolutionary tree was constructed for both species and the results showed that the Iraqi Tetradesmus dimorphus isolate was placed in clade 4, more closely related to the Tetradesmus dimorphus from USA, China, Pakistan, and Sweden with similarity 99 %, 99%, 97 %, and 96 % for all respectively. The Iraqi isolated Chlorella sorokiniana (OP718564.1) is within the clade 2, and composed sister group with Chlorella sorokiniana (KU29188.1) from the USA, with 99 % similarity.

ROS-mediated thylakoid membrane remodeling and triacylglycerol biosynthesis under nitrogen starvation in the alga Chlorella sorokiniana.

Many microbes accumulate energy storage molecules such as triglycerides (TAG) and starch during nutrient limitation. In eukaryotic green algae grown under nitrogen-limiting conditions, triglyceride accumulation is coupled with chlorosis and growth arrest. In this study, we show that reactive oxygen species (ROS) actively accumulate during nitrogen limitation in the microalga Chlorella sorokiniana. Accumulation of ROS is mediated by the downregulation of genes encoding ROS-quenching enzymes, such as superoxide dismutases, catalase, peroxiredoxin, and glutathione peroxidase-like, and by the upregulation of enzymes involved in generating ROS, such as NADPH oxidase, xanthine oxidase, and amine oxidases. The expression of genes involved in ascorbate and glutathione metabolism is also affected under this condition. ROS accumulation contributes to the degradation of monogalactosyl diacylglycerol (MGDG) and thylakoid membrane remodeling, leading to chlorosis. Quenching ROS under nitrogen limitation reduces the degradation of MGDG and the accumulation of TAG. This work shows that ROS accumulation, membrane remodeling, and TAG accumulation under nitrogen limitation are intricately linked in the microalga C. sorokiniana.

Low-dose ionizing radiation generates a hormetic response to modify lipid metabolism in Chlorella sorokiniana

Algal biomass is a viable source of chemicals and metabolites for various energy, nutritional, medicinal and agricultural uses. While stresses have commonly been used to induce metabolite accumulation in microalgae in attempts to enhance high-value product yields, this is often very detrimental to growth. Therefore, understanding how to modify metabolism without deleterious consequences is highly beneficial. We demonstrate that low-doses (1–5 Gy) of ionizing radiation in the X-ray range induces a non-toxic, hormetic response in microalgae to promote metabolic activation. We identify specific radiation exposure parameters that give reproducible metabolic responses in Chlorella sorokiniana caused by transcriptional changes. This includes up-regulation of >30 lipid metabolism genes, such as genes encoding an acetyl-CoA carboxylase subunit, phosphatidic acid phosphatase, lysophosphatidic acid acyltransferase, and diacylglycerol acyltransferase. The outcome is an increased lipid yield in stationary phase cultures by 25% in just 24 hours, without any negative effects on cell viability or biomass.

Assessing the Efficiency of Microalgae in the Removal of Salicylic Acid from Contaminated Water: Insights from Zebrafish Embryo Toxicity Tests

Microalgae-based water treatments for the removal of different types of pollution have been gaining considerable attention during the last few decades. However, information about microalgae potential in the removal of pharmaceuticals and personal care products (PPCPs) and the ecotoxicological outcomes is still limited. Therefore, in this work, we aimed at investigating salicylic acid removal from water by three different microalgae strains, namely Chlorella sorokiniana, Chlorella vulgaris and Scenedesmus obliquus. For such a purpose, photobioreactors were operated under batch and semi-continuous mode. Apart from determining the reduction in the concentration of salicylic acid attained by each strain, we used zebrafish embryo bioassays to assess the efficiency of microalgae to reduce its toxicity effects. S. obliquus was the strain that achieved the most significant decrease in the concentration and toxic effects of salicylic acid. Indeed, S. obliquus was able to rescue mortality and reduce abnormalities at practically 100%. The efficiency of C. sorokiniana and, especially, that of C. vulgaris were not so remarkable, indicating that the removal of SA and its toxic effects from water by microalgae is markedly strain dependent. The obtained results proved the importance of considering toxic effects for a more comprehensive evaluation of microalgae efficiency in the removal of PPCPs in view of an adequate selection for water treatment.