Determination of Microalgal Lipid Content and Fatty Acid for Biofuel Production

Bioremediation of Synthetic Wastewater with Contaminants of Emerging Concern by Nannochloropsis sp. and Lipid Production: A Circular Approach

Contaminants of emerging concern (CECs) pose a potential risk to human and environmental health. Microalgae bioremediation is a promising approach for transforming or removing contaminants from the environment, while contributing to the circular economy. In this study, Nannochloropsis sp. was effectively used for the simultaneous removal of six CECs: paracetamol, ibuprofen, imidacloprid, methylparaben and bisphenol A at 10 µg mL-1 and triclosan at 0.5 µg mL-1 from synthetic wastewater, which were able to survive under such concentrations, higher than those commonly found in the environment (up to 2.82 µg mL-1 of methylparaben). High removal efficiencies were reached for methylparaben (100%) and bisphenol A (93 ± 2%), while for imidacloprid, paracetamol and ibuprofen, 30 ± 1%, 64 ± 2% and 49 ± 5% were removed, respectively. Subsequently, lipids were extracted, and the FAME profile was characterised using GS-MS. The main fatty acids identified after bioremediation were hexadecadienoic acid isomers (C16:2), palmitic acid (C16), linoleic acid (C18:2) and γ-linolenic acid (C18:3). The absence of oleic acid and stearic acid was noticed, suggesting an alteration in the lipidic profile due to contaminant exposure. By exploring the quantification of fatty acids in future work, potential applications for the extracted lipids can be explored, further demonstrating the feasibility of this circular process.

Biphasic lipid extraction from microalgae after PEF-treatment reduces the energy demand of the downstream process

BACKGROUND

The gradual extrusion of water-soluble intracellular components (such as proteins) from microalgae after pulsed electric field (PEF) treatment is a well-documented phenomenon. This could be utilized in biorefinery applications with lipid extraction taking place after such an 'incubation' period, i.e., a post-PEF-treatment step during which the biomass is left undisturbed before any further processing. The goal of this work was to further explore how this incubation could improve lipid extraction.

RESULTS

Experiments were conducted on wet, freshly harvested Auxenochlorella protothecoides, treated with 0.25 or 1.5 MJ/kgDW and incubated for 24 h. Lipid extraction took place with a monophasic ethanol:hexane:water, 1:0.41:0.04 vol/vol/vol mixture with a 75.6 mL solvent per 1 g of dry biomass ratio. The kinetics of the extraction were studied with samples taken between 10 and 1080 min from fresh and incubated biomass. The yields at 10 min were significantly increased with incubation compared to without (31.2% dry weight compared to 1.81%, respectively). The experimental data were fitted with the Patricelli model where extraction occurs in two steps, a rapid washing of immediate available lipids and a slower diffusion one. During Nile-Red staining of microalgae and microscopy imaging, a shift of emission from both GFP and RFP channels to mostly RFP was observed indicating an increase in the polarity of the environment of Nile-Red. These led to an adaption of a biphasic ethanol:hexane:water 1:6:0.4 vol/vol/vol solvent with 37 mL solvent per 1 g of dry biomass ratio which while ineffective on fresh biomass, achieved a 27% dry weight yield from incubated microalgae. The extraction efficiency in the biphasic route was lower compared to the monophasic (i.e., 69% and 95%, respectively). It was compensated however, by the significant solvent reduction (37 mL to 75.6 mL respectively), in particular the ethanol minimization. For the extraction of 1 L lipids, it was estimated that the energy consumption ratio for the biphasic process was 1.6 compared to 9.9 for monophasic, making clearly the most preferential one.

CONCLUSIONS

This biphasic approach significantly reduces solvent consumption and the respective energy requirement for solvent recovery. Incubation thus could majorly improve the commercialization prospects of the process.

Development of a high-performance thin-layer chromatography-based method for targeted glycerolipidome profiling of microalgae

The conditionally essential very-long-chain polyunsaturated fatty acids (VLC-PUFAs), such as eicosapentaenoic acid (EPA, C20:5 n-3), play a vital role in human nutrition. Their biological activity is thereby greatly influenced by the distinct glycerolipid molecule that they are esterified to. Here, microalgae differ from the conventional source, fish oil, both in quantity and distribution of VLC-PUFAs among the glycerolipidome. Therefore, the aim of this study was to develop a fast and reliable one-dimensional high-performance thin-layer chromatography (HPTLC)-based method that allows the separation and quantification of the main microalgal glycerolipid classes (e.g., monogalactosyldiacylglycerol (MGDG), sulfoquinovosyl diacylglycerol (SQDG), phosphatidylglycerol (PG)), as well as the subsequent analysis of their respective fatty acid distribution via gas chromatography (GC) coupled to mass spectrometry (MS). Following optimization, method validation was carried out for 13 different lipid classes, based on the International Conference on Harmonization (ICH) guidelines. In HPTLC, linearity was effective between 100 and 2100 ng, with a limit of quantification between 62.99 and 90.09 ng depending on the glycerolipid class, with strong correlation coefficients (R2 > 0.995). The recovery varied between 93.17 and 108.12%, while the inter-day precision measurements showed coefficients of variation of less than 8.85%, close to the limit of detection. Applying this method to crude lipid extracts of four EPA producing microalgae of commercial interest, the content of different glycerolipid classes was assessed together with the respective FA distribution subsequent to band elution. The results showed that the described precise and accurate HPTLC method offers the possibility to be used routinely to follow variations in the glycerolipid class levels throughout strain screening, cultivation, or bioprocessing. Thus, additional quantitative analytical information on the complex lipidome of microalgae can be obtained, especially for n-3 and n-6 enriched lipid fractions.

Microalgal bioactive metabolites as promising implements in nutraceuticals and pharmaceuticals: inspiring therapy for health benefits

The rapid increase in global population and shrinkage of agricultural land necessitates the use of cost-effective renewable sources as alternative to excessive resource-demanding agricultural crops. Microalgae seem to be a potential substitute as it rapidly produces large biomass that can serve as a good source of various functional ingredients that are not produced/synthesized inside the human body and high-value nonessential bioactive compounds. Microalgae-derived bioactive metabolites possess various bioactivities including antioxidant, anti-inflammatory, antimicrobial, anti-carcinogenic, anti-hypertensive, anti-lipidemic, and anti-diabetic activities, thereof rapidly elevating their demand as interesting option in pharmaceuticals, nutraceuticals and functional foods industries for developing new products. However, their utilization in these sectors has been limited. This demands more research to explore the functionality of microalgae derived functional ingredients. Therefore, in this review, we intended to furnish up-to-date knowledge on prospects of bioactive metabolites from microalgae, their bioactivities related to health, the process of microalgae cultivation and harvesting, extraction and purification of bioactive metabolites, role as dietary supplements or functional food, their commercial applications in nutritional and pharmaceutical industries and the challenges in this area of research.

Graphical abstract

Dynamic modeling and parameter estimation of biomethane production from microalgae co-digestion

This work proposes a dynamic modeling procedure applied to biomethane production from microalgae residual co-digestion. A two-stage anaerobic digestion representation is selected, considering acidogenesis and methanogenesis as main reaction pathways. Based on the experimental database generated in the University of Mons Laboratories, several candidate models, assuming the presence or absence of biomass dynamics, are suggested, and parametric structural and local identifiability studies are performed. An original parameter estimation procedure is applied to a data-set partition used for model direct validation. The remaining experiment data are dedicated to cross-validation. The results point out how these dynamic models may serve as advanced monitoring software tools such as digital twins, even in the presence of incomplete process data.

Assessment of Sargassum sp., Spirulina sp., and Gracilaria sp. as Poultry Feed Supplements: Feasibility and Environmental Implications

Eutrophication, coupled with ocean acidification and warming, results in an increased concentration of marine algae, severely impacting some regions. Several algae are a rich source of protein and minerals. Marine algae are rich in bioactive molecules with antioxidants, anti-inflammatory, anti-fungal, and antimicrobial properties. These properties make them attractive for usage in the pharmaceutical industry. This study evaluated Sargassum sp., Spirulina sp., and Gracilaria sp. for use as poultry feed. Chemical analyses show that crude protein (CP) in analyzed algae was 9.07–63.63%, with a fiber content of 0.15–17.20%, and a crude fat range of 0.152–2.11%, suggesting that algae can partially substitute imported protein sources used for poultry feed. A rapid impact assessment matrix (RIAM) was used to assess the environmental footprint of algae usage in poultry feed. The environmental assessment results show promising opportunities to help harvest the algae from the marine area. However, the feasibility of establishing outdoor algal ponds is not environmentally viable in the Middle East.

Production, Processing, and Protection of Microalgal n-3 PUFA-Rich Oil

Microalgae have been increasingly considered as a sustainable “biofactory” with huge potentials to fill up the current and future shortages of food and nutrition. They have become an economically and technologically viable solution to produce a great diversity of high-value bioactive compounds, including n-3 polyunsaturated fatty acids (PUFA). The n-3 PUFA, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), possess an array of biological activities and positively affect a number of diseases, including cardiovascular and neurodegenerative disorders. As such, the global market of n-3 PUFA has been increasing at a fast pace in the past two decades. Nowadays, the supply of n-3 PUFA is facing serious challenges as a result of global warming and maximal/over marine fisheries catches. Although increasing rapidly in recent years, aquaculture as an alternative source of n-3 PUFA appears insufficient to meet the fast increase in consumption and market demand. Therefore, the cultivation of microalgae stands out as a potential solution to meet the shortages of the n-3 PUFA market and provides unique fatty acids for the special groups of the population. This review focuses on the biosynthesis pathways and recombinant engineering approaches that can be used to enhance the production of n-3 PUFA, the impact of environmental conditions in heterotrophic cultivation on n-3 PUFA production, and the technologies that have been applied in the food industry to extract and purify oil in microalgae and protect n-3 PUFA from oxidation.

Could termites be hiding a goldmine of obscure yet promising yeasts for energy crisis solutions based on aromatic wastes? A critical state-of-the-art review

Biodiesel is a renewable fuel that can be produced from a range of organic and renewable feedstock including fresh or vegetable oils, animal fats, and oilseed plants. In recent years, the lignin-based aromatic wastes, such as various aromatic waste polymers from agriculture, or organic dye wastewater from textile industry, have attracted much attention in academia, which can be uniquely selected as a potential renewable feedstock for biodiesel product converted by yeast cell factory technology. This current investigation indicated that the highest percentage of lipid accumulation can be achieved as high as 47.25% by an oleaginous yeast strain, Meyerozyma caribbica SSA1654, isolated from a wood-feeding termite gut system, where its synthetic oil conversion ability can reach up to 0.08 (g/l/h) and the fatty acid composition in yeast cells represents over 95% of total fatty acids that are similar to that of vegetable oils. Clearly, the use of oleaginous yeasts, isolated from wood-feeding termites, for synthesizing lipids from aromatics is a clean, efficient, and competitive path to achieve "a sustainable development" towards biodiesel production. However, the lacking of potent oleaginous yeasts to transform lipids from various aromatics, and an unknown metabolic regulation mechanism presented in the natural oleaginous yeast cells are the fundamental challenge we have to face for a potential cell factory development. Under this scope, this review has proposed a novel concept and approach strategy in utilization of oleaginous yeasts as the cell factory to convert aromatic wastes to lipids as the substrate for biodiesel transformation. Therefore, screening robust oleaginous yeast strain(s) from wood-feeding termite gut system with a set of the desirable specific tolerance characteristics is essential. In addition, to reconstruct a desirable metabolic pathway/network to maximize the lipid transformation and accumulation rate from the aromatic wastes with the applications of various "omics" technologies or a synthetic biology approach, where the work agenda will also include to analyze the genome characteristics, to develop a new base mutation gene editing technology, as well as to clarify the influence of the insertion position of aromatic compounds and other biosynthetic pathways in the industrial chassis genome on the expressional level and genome stability. With these unique designs running with a set of the advanced biotech approaches, a novel metabolic pathway using robust oleaginous yeast developed as a cell factory concept can be potentially constructed, integrated and optimized, suggesting that the hypothesis we proposed in utilizing aromatic wastes as a feedstock towards biodiesel product is technically promising and potentially applicable in the near future.

Biochemical Mapping of Pyrodinium bahamense Unveils Molecular Underpinnings behind Organismal Processes

Proteins, lipids, and carbohydrates from the harmful algal bloom (HAB)-causing organism Pyrodinium bahamense were characterized to obtain insights into the biochemical processes in this environmentally relevant dinoflagellate. Shotgun proteomics using label-free quantitation followed by proteome mapping using the P. bahamense transcriptome and translated protein databases of Marinovum algicola, Alexandrium sp., Cylindrospermopsis raciborskii, and Symbiodinium kawagutii for annotation enabled the characterization of the proteins in P. bahamense. The highest number of annotated hits were obtained from M. algicola and highlighted the contribution of microorganisms associated with P. bahamense. Proteins involved in dimethylsulfoniopropionate (DMSP) degradation such as propionyl CoA synthethase and acryloyl-CoA reductase were identified, suggesting the DMSP cleavage pathway as the preferred route in this dinoflagellate. Most of the annotated proteins were involved in amino acid biosynthesis and carbohydrate degradation and metabolism, indicating the active roles of these molecules in the vegetative stage of P. bahamense. This characterization provides baseline information on the cellular machinery and the molecular basis of the ecophysiology of P. bahamense.

The potential use of Chlamydomonas reinhardtii and Chlorella sorokiniana as biostimulants on maize plants

Nitrogen deficiency and drought stress are among the major stresses faced by plants with negative consequence on crop production. The use of plant biostimulants is a very promising application in agriculture to improve crop yield, but especially to prevent the effect of abiotic stresses. Algae-derived biostimulants represent an efficient tool to stimulate the root development: while macroalgae have already been widely adopted as a source of biostimulants to improve plants growth and resilience, far less information is available for microalgae. The objective of this work is to investigate the stimulant ability on maize roots of two green algae species, Chlamydomonas reinhardtii and Chlorella sorokiniana, being respectively the model organism for Chlorophyta and one of the most promising species for microalgae cultivation at industrial scale. The results obtained demonstrate that both C. reinhardtii and C. sorokiniana cells promoted the development of maize root system compared to the untreated negative control. C. sorokiniana specifically increased the number of secondary roots, while improved micro-nutrients accumulation on roots and shoots was measured in the case of C. reinhardtii treated plants. When these microalgae-derived biostimulants were applied on plants grown in stress conditions as nitrogen deficiency, improved development of the root system was measured in the case of plants treated with C. sorokiniana biomass. Microalgae cultivation for biostimulant production can thus be considered as a bio-based process providing solutions for improving plant resilience toward stress conditions.

Benefits and Drawbacks of Ultrasound-Assisted Extraction for the Recovery of Bioactive Compounds from Marine Algae

The increase in life expectancy has led to the appearance of chronic diseases and interest in healthy aging, in turn promoting a growing interest in bioactive compounds (BCs) and functional ingredients. There are certain foods or products rich in functional ingredients, and algae are one of them. Algae consumption has been nominal in Europe until now. However, in recent years, it has grown significantly, partly due to globalization and the adoption of new food trends. With the aim of obtaining BCs from foods, multiple methods have been proposed, ranging from conventional ones, such as maceration or Soxhlet extraction, to more innovative methods, e.g., ultrasound-assisted extraction (UAE). UAE constitutes a novel method, belonging to so-called green chemistry, that enables the extraction of BCs requiring lower amounts of solvent and energy costs, preserving the integrity of such molecules. In recent years, this method has been often used for the extraction of different BCs from a wide range of algae, especially polysaccharides, such as carrageenans and alginate; pigments, including fucoxanthin, chlorophylls, or β-carotene; and phenolic compounds, among others. In this way, the application of UAE to marine algae is an efficient and sustainable strategy to pursue their deep characterization as a new source of BCs, especially suitable for vegetarian and vegan diets.

Prospects of Microalgae for Biomaterial Production and Environmental Applications at Biorefineries

Microalgae are increasingly viewed as renewable biological resources for a wide range of chemical compounds that can be used as or transformed into biomaterials through biorefining to foster the bioeconomy of the future. Besides the well-established biofuel potential of microalgae, key microalgal bioactive compounds, such as lipids, proteins, polysaccharides, pigments, vitamins, and polyphenols, possess a wide range of biomedical and nutritional attributes. Hence, microalgae can find value-added applications in the nutraceutical, pharmaceutical, cosmetics, personal care, animal food, and agricultural industries. Microalgal biomass can be processed into biomaterials for use in dyes, paints, bioplastics, biopolymers, and nanoparticles, or as hydrochar and biochar in solid fuel cells and soil amendments. Equally important is the use of microalgae in environmental applications, where they can serve in heavy metal bioremediation, wastewater treatment, and carbon sequestration thanks to their nutrient uptake and adsorptive properties. The present article provides a comprehensive review of microalgae specifically focused on biomaterial production and environmental applications in an effort to assess their current status and spur further deployment into the commercial arena.

Experimental and Techno-Economic Study on the Use of Microalgae for Paper Industry Effluents Remediation

Humanity is facing some major global threats, namely lack of environmental sustainability, the energy crisis associated with the unsustainable reliance on fossil fuels, and water scarcity, which will be exacerbated with the rapid growth of urban areas. Researchers have drawn their attention to microalgae, photosynthetic microorganisms known for their environmental applications, such as wastewater remediation and lipids accumulation, to produce third-generation biofuels to solve some of these major issues. Considering this dual role, this study evaluated the potential of the microalga Chlorella vulgaris on nutrient removal from a paper industry effluent and bioenergy production. Firstly, experiments were performed to assess the potential of this microalga to: (i) successfully grow in different concentrations of a paper industry effluent (20% to 100%); and (ii) treat the industrial effluent, reducing phosphorus concentrations to values below the accepted legal limits. Then, a techno-economic assessment was performed to study the viability of a C. vulgaris biorefinery targeting the remediation of a paper industry effluent and bioenergy production. The results have shown that C. vulgaris was able to successfully grow and treat the paper industry effluent. Under these conditions, average biomass productivities determined for this microalga ranged between 15.5 ± 0.5 and 26 ± 1 mg dry weight (DW) L−1 d−1, with maximum biomass concentrations reaching values between 337 ± 9 and 495 ± 25 mg DW L−1 d−1. Moreover, final phosphorus concentrations ranged between 0.12 ± 0.01 and 0.5 ± 0.3 mg P L−1, values below the legal limits imposed by the Portuguese Environment Agency on the paper industry. Regarding the proposal of a microalgal biorefinery for the bioremediation of paper industry effluents with bioenergy production, the techno-economic study demonstrated that six of the seven studied scenarios resulted in an economically-viable infrastructure. The highest net present value (15.4 million euros) and lowest discounted payback period (13 years) were determined for Scenario 3, which assumed a photosynthetic efficiency of 3%, a lipids extraction efficiency of 75%, and an anaerobic digestion efficiency of 45%. Therefore, it was possible to conclude that besides being economically viable, the proposed biorefinery presents several environmental benefits: (i) the remediation of an industrial effluent; (ii) CO2 uptake for microalgal growth, which contributes to a reduction in greenhouse gases emissions; (iii) production of clean and renewable energy; (iv) soil regeneration; and (v) promotion of a circular economy.

Comprehensive assessment of 2G bioethanol production

The advancements in second-generation bioethanol produced from lignocellulosic biomass, such as crops residues, woody crops or energy grasses are gaining momentum. Though, they are still representing less than 3% of total bioethanol production, the GHG reduction potential is higher than for 1G-bioethanol. The environmental impacts of bioethanol production are totally dependent on feedstock availability and conversion technology. The biochemical conversion route must overcome several technological and economical challenges such as pre-treatment, fermentation, hydrolysis process and separation. A completely mature technology is still to be developed and must adapted to the nature of the feedstock. Nevertheless, using process simulation software, Life Cycle Assessment and integrating the different steps of bioresource harvesting and treatment processes, including the energy balances and the water requirements, it is shown that 2G bioethanol production will reduce environmental impacts provided the evaluation addresses a long-time perspective, including all conversion steps and the regeneration of the bioresource.

Pilot Production of Spirulina Biomass and Obtaining of Novel Biodegradable Surfactants

The research results describe the pilot production of microalgae biomass – Spirulina, especially in wintertime, using the geothermal energy of water to save the costs for heating of the pool photobioreactor and biomass drying box. For carrying out of the process a simplified nutrient medium consisting of geothermal water and salts: sodium bicarbonate, potassium nitrate, diammonium phosphate, and urea was developed. The conditions for the Spirulina biomass cultivation in wintertime were optimized. The technical and economic feasibility and conditions for large-scale production of Spirulina in Kazakhstan for commercial purposes are justified. It has been shown that the Spirulina biomass may serve as a feedstock for the production of biodegradable surfactants.

Effects of Nitrogen Supplementation Status on CO2 Biofixation and Biofuel Production of the Promising Microalga Chlorella sp. ABC-001

The use of microalgal biomass as feedstock for biofuels has been discussed for decades as it provides a sustainable approach to producing fuels for the future. Nonetheless, its feasibility has not been established yet and various aspects of biomass applications such as CO₂ biofixation should also be explored. Therefore, in this study, the CO₂ biofixation and lipid/carbohydrate production potential of Chlorella sp. ABC-001 were examined under various nitrogen concentrations. The highest biomass productivity and CO₂ biofixation rate of 0.422 g/l/d and 0.683 g/l/d, respectively, were achieved under a nitrogen-rich condition (15 mM nitrate). Carbohydrate content was generally proportional to initial nitrate concentration and showed the highest value of 41.5% with 15 mM. However, lipid content showed an inverse relationship with nitrogen supplementation and showed the highest value of 47.4% with 2.5 mM. In consideration as feedstock for biofuels (bioethanol, biodiesel, and biogas), the sum of carbohydrate and lipid contents were examined and the highest value of 79.6% was achieved under low nitrogen condition (2.5 mM). For lipid-based biofuel production, low nitrogen supplementation should be pursued. However, considering the lower feasibility of biodiesel, pursuing CO₂ biofixation and the production of carbohydrate-based fuels under nitrogenrich condition might be more rational. Thus, nitrogen status as a cultivation strategy must be optimized according to the objective, and this was confirmed with the promising alga Chlorella sp. ABC-001.

Extracción e identificación de lípidos polares de las microalgas Nannochloropsis oceanica y Desmodesmus asymmetricus

Los lípidos polares de las microalgas son de gran interés debido a su aplicación como ingredientes naturales novedosos para las industrias cosmética, nutricional y farmacéutica. Por ello, el presente trabajo buscó determinar el efecto de los principales factores en la extracción e identificación de los lípidos polares de las microalgas Nannochloropsis oceanica y Desmodesmus asymmetricus, mediante el diseño de superficie de respuesta de Box-Behnken y el diseño factorial completo, respectivamente. Estas cepas del Banco de Germoplasma de Organismos Acuáticos (BGOA – IMARPE) fueron cultivadas en un invernadero, en biorreactores de 30 litros, centrifugadas y liofilizadas. Los lípidos fueron extraídos con cloroformo-metanol, fraccionados y analizados con un espectrómetro de masas Waters Xevo G2-XS QTOF. La maximización de la extracción de los lípidos totales determinó un valor óptimo de la relación masa-solvente de 25 mg/3 mL, una proporción 1:1 de cloroformo-metanol, aproximadamente, y un tiempo del baño de ultrasonido entre 10 y 30 min. Los principales lípidos polares identificados para N. oceanica fueron lisofosfatidilcolina (LPC), diacilgliceril-N,N,N-trimetilhomoserina (DGTS), digalactosil diacilglicerol (DGDG) y monogalactosil diacilglicerol (MGDG) y para D. asymmetricus fueron sulfoquinovosil diacilglicerol (SQDG), LDGTS, DGTS, DGDG y MGDG.

Nutritional Potential and Toxicological Evaluation of Tetraselmis sp. CTP4 Microalgal Biomass Produced in Industrial Photobioreactors

Commercial production of microalgal biomass for food and feed is a recent worldwide trend. Although it is common to publish nutritional data for microalgae grown at the lab-scale, data about industrial strains cultivated in an industrial setting are scarce in the literature. Thus, here we present the nutritional composition and a microbiological and toxicological evaluation of Tetraselmis sp. CTP4 biomass, cultivated in 100-m3 photobioreactors at an industrial production facility (AlgaFarm). This microalga contained high amounts of protein (31.2 g/100 g), dietary fibres (24.6 g/100 g), digestible carbohydrates (18.1 g/100 g) and ashes (15.2 g/100 g), but low lipid content (7.04 g/100 g). The biomass displayed a balanced amount of essential amino acids, n-3 polyunsaturated fatty acids, and starch-like polysaccharides. Significant levels of chlorophyll (3.5 g/100 g), carotenoids (0.61 g/100 g), and vitamins (e.g., 79.2 mg ascorbic acid /100 g) were also found in the biomass. Conversely, pathogenic bacteria, heavy metals, cyanotoxins, mycotoxins, polycyclic aromatic hydrocarbons, and pesticides were absent. The biomass showed moderate antioxidant activity in several in vitro assays. Taken together, as the biomass produced has a balanced biochemical composition of macronutrients and (pro-)vitamins, lacking any toxic contaminants, these results suggest that this strain can be used for nutritional applications.