Neochloris Oleoabundans Research Articles

Tree-based machine learning for predicting Neochloris oleoabundans biomass growth and biological nutrient removal from tertiary municipal wastewater

Recently, computational models have been increasingly recognized as valuable tools for addressing key challenges in the operational performance of biological wastewater treatment facilities. In this study, tree-based machine learning approaches, such as decision tree regressor (DTR) and extra tree regressor (ETR), were developed to predict microalgae (Neochloris oleoabundans) biomass growth, culture pH, and nutrient removal efficacy (total nitrogen, TN and total phosphorus, TP) for the first time. The experimental data was obtained through a central composite design (CCD) matrix, and Bayesian optimization was applied to fine-tune the models’ hyperparameters. Model performance was evaluated using indicators such as the coefficient of determination (R²), mean absolute error (MAE), and mean-squared error (MSE). The results showed comparable performance between the DTR and ETR models. For TN removal during testing, the R² values for DTR and ETR were 0.9262 and 0.9789, respectively, with DTR (MSE: 0.00895, MAE: 0.0615) and ETR (MSE: 0.00255, MAE: 0.0352) demonstrating reliable predictions. Overall, the ETR model outperformed DTR in predicting responses. The models' generalization capabilities were also assessed by introducing variations in environmental factors.

High cell density culture of microalgae in horizontal thin-layer algal reactor: Modeling of light attenuation and cell growth kinetics

This study delved into the light intensity effects and light attenuation modeling in high cell density culture (HCDC) of green alga Neochloris oleoabundans. The research primarily focused on how different light intensities influence cell growth in terms of cell division and cell mass, and the biochemical composition within the cells. Recognizing the need to avoid overestimating light path by excluding data point in the data zone where the light intensity was zero, we proposed and verified a novel modified Beer-Lambert model, which was superb in fitting experimental data and predicting light attenuation in both low and high cell density cultures. Taking advantage of the prediction power of the modified Beer-Lambert model, we devised an approach to maintain constant mean light intensity (Imean) and by adjusting the incident light intensity (I0). The results indicate that at an Imean of approximately 66.67 μmol/m2/s and 6 mm culture thickness, maximum volumetric and areal biomass productivities of 2.72 g/L/day and 16.32 g/m2/day, respectively, were achieved. Whereas the highest biomass concentration of 28.20 g/L was produced in 20 days at Imean 50 μmol/m2/s. Photoinhibition to cell division become evident at I0 750 μmol/m2/s and above. Using the data generated at constant Imean in the constant specific growth rate range, superb fitting to the Monod model with a R2 of 0.9910 was demonstrated, highlighting the importance of generating reliable data for the modelling of the kinetics of photoautotrophic growth of microalgae, which had considered to be challenging.

Cultivation modes affect the morphology, biochemical composition, and antioxidant and anti-inflammatory properties of the green microalga Neochloris oleoabundans

Microalgae are considered promising sustainable sources of natural bioactive compounds to be used in biotechnological sectors. In recent years, attention is increasingly given to the search of microalgae-derived compounds with antioxidant and anti-inflammatory properties for nutraceutical or pharmacological issues. In this context, attention is usually focused on the composition and bioactivity of algae or their extracts, while less interest is driven to their biological features, for example, those related to morphology and cultivation conditions. In addition, specific studies on the antioxidant and anti-inflammatory properties of microalgae mainly concern Chlorella or Spirulina. The present work was focused on the characterization of the Chlorophyta Neochloris oleoabundans under two combinations of cultivation modes: autotrophy and glucose-induced mixotrophy, each followed by starvation. Biomass for morphological and biochemical characterization, as well as for extract preparation, was harvested at the end of each cultivation phase. Analyses indicated a different content of the most important classes of bioactive compounds with antioxidant/anti-inflammatory properties (lipids, exo-polysaccharides, pigments, total phenolics, and proteins). In particular, the most promising condition able to prompt the production of antioxidant algal biomass with anti-inflammatory properties was the mixotrophic one. Under mixotrophy, beside an elevated algal biomass production, a strong photosynthetic metabolism with high appression of thylakoid membranes and characteristics of high photo-protection from oxidative damage was observed and linked to the overproduction of exo-polysaccharides and lipids rather than pigments. Overall, mixotrophy appears a good choice to produce natural bioactive extracts, potentially well tolerated by human metabolism and environmentally sustainable.

Application of Aqueous Two-Phase Systems with Thermoseparating Polymers (EOPO) as a Method for Extractive Fermentation with Neochloris oleoabundans

Extractive fermentation is an in situ method for the production and recovery of biomolecules of interest. Aqueous two-phase systems (ATPS) allow the product to be recovered in one phase of the system, reducing unit operations in the bioprocess. Thermosensitive polymers such as EOPOs are an interesting alternative to be applied in ATPS. In this work, different EOPOs were tested in an extractive fermentation strategy with the green microalgae Neochloris oleoabundans to provide a basis for future implementations of these systems in microalgae bioprocesses. Extractive fermentations were carried out with two EOPOs of different molecular weights (3900 and 12,000 g/mol) at concentrations of 10% and 15% (w/v). The microalga was incubated axenically under two different sets of conditions for 21 and 45 days, respectively. Cell counts were performed, and cell growth curves were obtained. Additionally, a semi-continuous and batch extractive fermentation assay was performed. The extractive fermentation with EOPO showed lower cell growth and a longer adaptation time of the microalgae in the fermentation, and EPS production yields of up to 8–23 g/L were obtained. Extractive fermentation is an interesting method to be implemented in microalgae cultures; however, further conditions need to be explored to achieve an appropriate bioprocess.

Two-step cultivation of Neochloris oleoabundans in a novel horizontal thin-layer algal reactor: Interplay of pH and dissolved inorganic carbon

This study explored the impacts of culture pH and addition of NaHCO3 on the growth of an oil-rich green alga Neochloris oleoabundans. It was observed that in the absence of aeration, the culture pH fluctuated over wide ranges during the day/night cycles without additional DIC, which was flatted significantly by adding DIC in culture, demonstrating the effectiveness of DIC as a pH buffer. Addition of DIC in the range of 80–320 mM led to an increase in cell size and inhibition of cell division, which became more severe with the increase of DIC concentration in the tested range. Under 160 mM DIC, pH's effects on algal growth were studied at constant levels (7.5, 8.5, and 9.5). Lower pH increased cell division inhibition, linked to rising dissolved CO2. Based on these findings, a two-step cultivation strategy was devised and explored. By growing algae in the first stage in cultures without additional DIC and with culture pH controlled at 7.5, followed by cessation of aeration and addition of 160 mM NaHCO3 on the fourth day of cultivation, similar cell growth rate and lipid productivity were obtained as that in cultures with continuous aeration throughout the 8-day cultivation, with lower cell density but larger cell size. By discontinuing aeration, a reduction of 76.73% in aeration CO2 and 50% of aeration energy were achieved.

Neochloris oleoabundans cell wall rupture through melittin peptide: a new approach to increase lipid recovery.

Microalgae cell wall affects the recovery of lipids, representing one of the main difficulties in the development of biofuel production. This work aimed to test a new method based on melittin peptide to induce a cellular disruption in N. oleoabundans. Neochloris oleoabundans cells were grown at 32°C in the presence of a high concentration of nitrate-phosphate, causing a cell disruption extent of 83.6%. Further, a two-fold increase in lipid recovery following melittin treatment and solvent extraction was observed. Additionally, it was possible to verify the effects of melittin, both before and after treatment on the morphology of the cells. Scanning electron microscopy (SEM) and confocal images of the melittin-treated microalgae revealed extensive cell damage with degradation of the cell wall and release of intracellular material. Melittin produced a selective cell wall rupture effect in N. oleoabundans under some culture conditions. These results represent the first report on the effect of melittin on lipid recovery from microalgae.

Metabolic Responses of the Microalga Neochloris oleoabundans to Extracellular Self- and Nonself-DNA.

Stressed organisms identify intracellular molecules released from damaged cells due to trauma or pathogen infection as components of the innate immune response. These molecules called DAMPs (Damage-Associated Molecular Patterns) are extracellular ATP, sugars, and extracellular DNA, among others. Animals and plants can recognize their own DNA applied externally (self-exDNA) as a DAMP with a high degree of specificity. However, little is known about the microalgae responses to damage when exposed to DAMPs and specifically to self-exDNAs. Here we compared the response of the oilseed microalgae Neochloris oleoabundans to self-exDNA, with the stress responses elicited by nonself-exDNA, methyl jasmonate (MeJA) and sodium bicarbonate (NaHCO3). We analyzed the peroxidase enzyme activity related to the production of reactive oxygen species (ROS), as well as the production of polyphenols, lipids, triacylglycerols, and phytohormones. After 5 min of addition, self-exDNA induced peroxidase enzyme activity higher than the other elicitors. Polyphenols and lipids were increased by self-exDNA at 48 and 24 h, respectively. Triacylglycerols were increased with all elicitors from addition and up to 48 h, except with nonself-exDNA. Regarding phytohormones, self-exDNA and MeJA increased gibberellic acid, isopentenyladenine, and benzylaminopurine at 24 h. Results show that Neochloris oleoabundans have self-exDNA specific responses.

Effects of culture pH on cell surface properties and biosorption of Pb(II), Cd(II), Zn(II) of green alga Neochloris oleoabundans

Microalgal biomass has been established as a promising biosorbent for heavy metal ion (HMI) removal from contaminated waters. In this study, the cell surface properties of green alga Neochloris oleoabundans grown at different culture pH, i.e., 7.5, 8.5, and 9.5, which are referred to as B-7.5, B-8.5, and B-9.5, respectively, were investigated. The biosorption of three HMIs, i.e., Pb(II), Cd(II) and Zn(II), were studied systematically by these three types of biomasses. The results of isothermal analysis indicate that the biosorption was monolayer surface adsorption. Based on the Sips model, which best fits the experimental data among the three tested isotherm models, the biosorption capacities of all the three tested HMI on different biomasses followed the order B-9.5 > B-8.5 > B-7.5. The algal biomass obtained at culture pH 9.5, i.e., B-9.5, exhibited the highest biosorption capacities of Pb(II), Cd(II), and Zn(II) at biosorption pH 6.0, which were 100.01, 43.92, and 32.43 mg/g, respectively, corresponding to 3.0, 3.3, and 2.3 folds of that exhibited by B-7.5. FTIR, SEM, EDS and XPS were employed for characterization of cell surface. The XPS analysis revealed higher content of carboxyl (COOH) group on the B-9.5 cell surface than B-7.5 and B-8.5, which might be responsible for the much higher biosorption capacity of HMI by B-9.5.

Fine resolution analysis of bacterial communities associated with Neochloris oleoabundans culture and insights into terpenes as contamination control agents

Biological contamination is one of the main bottlenecks in microalgae production, reducing quality and productivity and sometimes leading to the complete loss of the cultures. Selecting terpenes can be a pathway toward eco-friendly contamination control in microalgae cultures. This work evaluated the presence of bacterial contaminants in N. oleoabundans cultures through HTS and 16S analysis and their susceptibility to six natural terpenes (α-pinene, β-pinene, limonene, trans-cinnamaldehyde, linalool, and eugenol). The principal phyla identified were Proteobacteria, Bacteroidetes, and Actinobacteria, and based on these data, 89 bacterial isolates of seven genera were obtained (36 Aureimonas sp., 27 Microbacterium sp., 5 Pseudomonas sp., 9 Bacillus sp., 14 Shinella sp., 1 Brevundimonas sp., and 1 Exiguobacterium sp.) at 25ºC in the presence of light. It was possible to observe that Beta-pinene 50mg L- 1 only inhibited Bacillus sp. In contrast, Alpha-pinene, Linalool, and Trans-cinnamaldehyde, at a concentration of 6.25mg L- 1 efficiently inhibited most isolates. The inhibition percentages found were 79-99%.

Optimization of cavitation-assisted biodiesel production and fuel properties from Neochloris oleoabundans microalgae oil using genetic algorithm and response surface methodology

Biodiesel is a promising alternative fuel for diesel engines that provides energy security and significant environmental benefits. But its commercialization is restricted due to the cost and quality as compared to diesel fuel. To address the above, Neochloris oleoabundans microalgae oil, a non-edible, cost-effective, and underutilized third-generation feedstock, is used to produce superior biodiesel by the transesterification reaction using a hydrodynamic cavitation (HC) approach. In this research work, the transesterification model for microalgae biodiesel production is optimized through genetic algorithm (GA) and response surface methodology (RSM) using MATLAB R2020a and Design Expert 8.0.7.1, respectively. Four process input variables (operating pressure (0.5–2.5 bar), catalyst concentration (0.5–1.5 wt.%), reaction time (5–25 minutes), and molar ratio (3:1 to 7:1)) and a five-level L30 array were developed to construct a statistical model. Biodiesel yield and major properties like density, kinematic viscosity, calorific value, and flash point are the model responses. The optimum conditions for microalgae biodiesel production were operating pressure of 2.43 bar, KOH catalyst concentrations of 1.22 wt. %, reaction time of 15.54 minutes, molar ratio of 5.61:1 and at 60°C fixed reaction temperature. The optimum value of response, such as biodiesel yield, was 99.80%, the density was 0.882 g/cc, the kinematic viscosity was 4.06 cst, the calorific value was 41.72 MJ/kg, and the flash point was 146.64 °C. RSM and GA predicted results were validated experimentally. The reaction time for biodiesel produced by HC in the same settings as the conventional method was reduced by 85%. Due to its faster processing time, the HC approach is preferred to the conventional method.

Comparison of the effect of CeO2 and CuO2 nanoparticles on performance and emission of a diesel engine fueled with Neochloris oleoabundans algae biodiesel

Comparison of the effect of CeO2 and CuO2 nanoparticles on performance and emission of a diesel engine fueled with Neochloris oleoabundans algae biodiesel

High cell density culture of Neochloris oleoabundans in novel horizontal thin-layer algal reactor: Effects of localized aeration, nitrate concentration and mixing frequency

A horizontal thin-layer algal reactor was designed, constructed and tested for high cell density culture of an oil-rich green alga, Neochloris oleoabundans, at a thickness of 6 mm. A hollow fiber membrane sparger was used for localized aeration with CO2-enriched air, which allowed control of culture pH at a narrow range of pH 7.0–7.5. The optimal nitrate concentration under the investigated conditions was 345 mg-N/L with a cell density of ∼6.6 × 108 cells/mL and biomass concentration of ∼8 g/L. The volumetric and areal biomass productivities were 1.81 g/L/day and 10.85 g m− 2/day, respectively, and the maximum volumetric and areal productivities 3.57 g/L/day and 21.42 g m− 2/day, respectively. Intermittent mixing at a frequency of once every two hours (five min mixing each time) produced a cell growth profile similar to that of continuous mixing. Such intermittent mixing resulted in 98.38 % saving on mixing energy and 33.9 % reduction in water evaporation. It was observed that metabolic stress such as high pH and high nitrate concentration could inhibit cell division while causing cell size to enlarge abnormally. The results indicate that it is technically feasible to have high cell density culture of photoautotrophic microalgae with intermittent mixing and no culture circulation, opening the door towards the development of open algal farming systems of low capital, operational, and maintenance costs.

Characterization of Neochloris oleoabundans under Different Cultivation Modes and First Results on Bioactivity of Its Extracts against HCoV-229E Virus

Microalgae are proposed in several biotechnological fields because of their ability to produce biomass enriched in high-value compounds according to cultivation conditions. Regarding the health sector, an emerging area focuses on natural products exploitable against viruses. This work deals with the characterization of the green microalga Neochloris oleoabundans cultivated under autotrophic and mixotrophic conditions as a source of whole aqueous extracts, tested as antivirals against HCoV-229E (Coronaviridae family). Glucose was employed for mixotrophic cultures. Growth and maximum quantum yield of photosystem II were monitored for both cultivations. Algae extracts for antiviral tests were prepared using cultures harvested at the early stationary phase of growth. Biochemical and morphological analyses of algae indicated a different content of the most important classes of bioactive compounds with antiviral properties (lipids, exo-polysaccharides, and total phenolics, proteins and pigments). To clarify which phase of HCoV-229E infection on MRC-5 fibroblast cells was affected by N. oleoabundans extracts, four conditions were tested. Extracts gave excellent results, mainly against the first steps of virus infection. Notwithstanding the biochemical profile of algae/extracts deserves further investigation, the antiviral effect may have been mainly promoted by the combination of proteins/pigments/phenolics for the extract derived from autotrophic cultures and of proteins/acidic exo-polysaccharides/lipids in the case of mixotrophic ones.

The effect of different drying methods and microalgae species on the quality parameters of biodiesel obtained by transesterification technique

In the study, seven microalgae species called Nitzschia sp., Nannochloropsis sp., Botryococcus braunii, Neochloris oleoabundans, Schizochytrium sp., Chlorella vulgaris L., and Chlorella variabiilis L. were dried by four drying methods: spray, convective, vacuum, and microwave. Biodiesel was produced from dried microalgae via transesterification.The vegetable oil yield was the maximum in spray and vacuum dried Schizochytrium with 35.50 and %34.53, respectively. Similarly, the highest biodiesel yield with 100% was obtained in Schizochytrium dried by spray technique. However, the cloud point of −1.77 °C was the lowest in Botryococcus braunii samples dehydrated by microwave drying. The highest pour point with −10.13 °C was obtained in microwave dried Chlorella variabilis samples, but the maximum freezing point was found in the microwave and convective dried samples of Chlorella variabilis with −13.60 and −13.70 °C, respectively. The lowest water content was measured in biodiesel samples from Botryococcus braunii, Chlorella vulgaris, and Chlorella variabilis dried by microwave technique. However, the best results regarding calorific value were found in Schizochytrium samples dried by spray and vacuum. The viscosity with 6.08 mm2 s−1 and density with 0.90 g cm−3 of Botryococcus braunii dried by the microwave method were at the maximum.Interestingly, two species commonly used in biodiesel production, Chlorella vulgaris and Chlorella variabilis, could not meet the expectations regarding quality parameters. Also, Schizochytrium and Nitzschia were determined as the most suitable microalgae species for the quality standards for biodiesel production. Compared to the others, the most successful results were obtained in the biodiesel produced from Schizochytrium dried spray drying.

Production of Mannosylerythritol Lipids Using Oils from Oleaginous Microalgae: Two Sequential Microorganism Culture Approach.

Mannosylerythritol lipids (MELs) are biosurfactants with excellent biochemical properties and a wide range of potential applications. However, most of the studies focusing on MELs high titre production have been relying in the use of vegetable oils with impact on the sustainability and process economy. Herein, we report for the first time MELs production using oils produced from microalgae. The bio-oil was extracted from Neochloris oleoabundans and evaluated for their use as sole carbon source or in a co-substrate strategy, using as an additional carbon source D-glucose, on Moesziomyces spp. cultures to support cell growth and induce the production of MELs. Both Moesziomyces antarcticus and M. aphidis were able to grow and produce MELs using algae-derived bio-oils as a carbon source. Using a medium containing as carbon sources 40 g/L of D-glucose and 20 g/L of bio-oils, Moesziomyces antarcticus and M. aphidis produced 12.47 ± 0.28 and 5.72 ± 2.32 g/L of MELs, respectively. Interestingly, there are no significant differences in productivity when using oils from microalgae or vegetable oils as carbon sources. The MELs productivities achieved were 1.78 ± 0.04 and 1.99 ± 0.12 g/L/h, respectively, for M. antarcticus fed with algae-derived or vegetable oils. These results open new perspectives for the production of MELs in systems combining different microorganisms.

Experimental studies on utilization of Neochloris oleoabundans microalgae biodiesel as an alternative fuel for diesel engine

In the present study, biodiesel produced from a third generation feedstock, Neochloris oleoabundans microalgae was tested as green fuel in single cylinder diesel engine. Produced biodiesel and its blends had their properties assessed and compared to petroleum diesel. The microalgae biodiesel blended with diesel as B10, B20 and B30 on volume basis were used as fuel for conducting the combustion, performance and emission analysis of diesel engine. The B20 blend led to a slight reduction in brake thermal efficiency (0.92%) while increasing BSFC as compared to diesel fuel. The highest reductions in CO, HC, and smoke were 23%, 14.34%, and 18.78%, respectively, were obtained as compared to diesel fuel. In comparison to diesel, the combustion parameters showed a maximum reduction in peak pressure and HRR of 1.3% and 3.14%, respectively, for B20, as well as a 1.3°CA reduction in ignition delay.

Effect of phosphate in medium on cell growth and Cu(II) biosorption by green alga Neochloris oleoabundans

Green alga Neochloris oleoabundans cultivated in medium of varied phosphate (K2HPO4) concentration was investigated as the biosorbent for Cu(II) removal from aqueous solutions. The highest biosorption capacity of 180.19 mg-Cu/g-biomass was achieved with biomass grown in medium containing 300 mg/L K2HPO4, which was 2.4 and 2.3 times of that of the biomasses grown in media containing 100 and 500 mg/L K2HPO4, respectively. The Cu(II) biosorption was fast with equilibrium established within 10 min of contact time and the kinetics was characterized as pseudo-second order. A modified Langmuir isotherm model is proposed to account for the inhibition of Cu(II) biosorption by the cell aggregation induced by Cu(II). Furthermore, it was shown that the Cu(II)-induced cell aggregation could be explored to enhance the sedimentation of biomasses to facilitate biomass recovery after Cu(II) adsorption.

Chlorophyta microalgae as dietary protein supplement: a comparative analysis of productivity related to photosynthesis

Microalgae are studied as innovative sources of a wide range of highly valuable products, including proteins for the food/feed sectors. However, protein content varies depending on algal species, culture conditions and harvesting period. The Phylum Chlorophyta includes most of the described species of green algae. Due to their remarkable peculiarities, four Chlorophyta species belonging to two distinct classes were selected for the research: Chlorella vulgaris and Chlorella protothecoides as Trebouxiophyceae, and Neochloris oleoabundans and Scenedesmus acutus as Chlorophyceae. The algae were studied to obtain comparative results about their growth performance, and total protein content and profile under the same culture conditions. Since photosynthetic process directly influences biomass production, photosynthetic pigment, PSII maximum quantum yield and thylakoid protein content and profile were analysed. SDS-PAGE and 2D BN/SDS-PAGE were performed to expand information on the organization and assembly of the resolved thylakoid complexes of samples. Despite the algal species showed similar growth rates and photosynthetic efficiency, S. acutus showed the highest capability to accumulate proteins and photosynthetic pigments. Regarding the thylakoid protein profile, the two Trebouxiophyceae showed very similar pattern, whereas different amounts of LHCII occurred within the two Chlorophyceae. Finally, the separation of thylakoid protein complexes in 2D BN/SDS-PAGE revealed a more complex pattern in S. acutus as compared to the other species. Overall, it is suggested that a higher stability of the photosynthetic membranes can result in higher biomass and protein production. Altogether, results have highlighted the metabolic uniqueness of each strain, resulting in a non-obvious comparison with the other species.

Growth parameter estimation and model simulation for three industrially relevant microalgae: Picochlorum, Nannochloropsis, and Neochloris.

Multiple models have been developed in the field to simulate growth and product accumulation of microalgal cultures. These models heavily depend on the accurate estimation of growth parameters. In this paper growth parameters are presented for three industrially relevant microalgae species: Nannochloropsis sp., Neochloris oleoabundans, and Picochlorum sp. (BPE23). Dedicated growth experiments were done in photobioreactors to determine the maximal biomass yield on light and maintenance rate, while oxygen evolution experiments were performed to estimate the maximal specific growth rate. Picochlorum sp. exhibited the highest specific growth rate of 4.98 ± 0.24 day−1 and the lowest specific maintenance rate of 0.079 day−1, whereas N. oleoabundans showed the highest biomass yield on light of 1.78 gx·molph −1. The measured growth parameters were used in a simple kinetic growth model for verification. When simulating growth under light conditions as found at Bonaire (12 °N, 68° W), Picochlorum sp. displayed the highest areal biomass productivity of 32.2 g.m−2·day−1 and photosynthetic efficiency of 2.8%. The presented growth parameters show to be accurate compared to experimental data and can be used for model calibration by scientists and industrial communities in the field.

The cultivation of five microalgae species and their potential for biodiesel production

BackgroundDue to the problems we face today, such as wastewater pollution of aquifers and climate change, it is necessary to search for environmental solutions that help us minimize this problem. An alternative solution might be the cultivation of microalgae that are efficient in the purification of wastewater, removal of greenhouse gases and production of biomass that can be used for the production of biofuels such as biodiesel, methane, bioethanol, among others. The aim of this work is to cultivate five strains of microalgae native in Mexico: Chlorella miniata, Coelastrella sp., Desmodesmus quadricauda, Neochloris oleoabundans and Verrucodesmus verrucosus. The cultivations were performed using municipal wastewater and a foliar fertilizer with the further purpose of assessing their capacity to produce various types of biomass, in particular lipids.MethodsThe experiments were carried out using triplicate 16-L glass bioreactors assays with a 12:12 light–darkness cycle at 25 °C ± 1 under constant aeration. Every 3rd day, a 1-mL sample was taken to determine cell density. In the stationary growth phase, each culture was harvested by sedimentation and lipid content analysis was performed. The biomass with the highest concentration of total lipids was subjected to an analysis of the methyl esters of fatty acids.ResultsAn ANOVA test showed significant differences between the growth rates (F = 6.8, p = 0.0001). The species that were able to produce biomass with the highest concentrations of total lipids were Coelastrella sp. with 44–46%; Verrucodesmus verrucosus with 43–44% and Neochloris oleoabundans 35–37%. As the analysis of the methyl esters of fatty acids showed, the species Coelastrella sp. and V. verrucosus produced lipids composed of 82.9% and 91.28% of fatty acids, respectively, containing C16–C18 carbon chains.ConclusionsAll the species used in the present study were able to grow on wastewater and produce high concentrations of lipids. Therefore, the demands for biodiesel production could be met in the immediate future after continuing working with different microalgae species. Therefore, it is necessary to determine their adaptation potential to grow on contaminated effluents and produce lipids that can be used for the benefit of people and environment.