Lipid Yield Research Articles

Enhanced microalgal biomass and lipid production with simultaneous effective removal of Cd using algae-bacteria-activated carbon consortium added with organic carbon source

Recently, using microalgae to remediate heavy metal polluted water has been attained a huge attention. However, heavy metals are generally toxic to microalgae and consequently decrease biomass accumulation. To address this issue, the feasibility of adding exogenous glucose, employing algae-bacteria system and algae-bacteria-activated carbon consortium to enhance microalgae growth were evaluated. The result showed that Cd2+ removal efficiency was negatively correlated with microalgal specific growth rate. The exogenous glucose alleviated the heavy metal toxicity to algal cells and thus increased the microalgae growth rate. Among the different treatments, the algae-bacteria-activated carbon combination had the highest biomass concentration (1.15 g L−1) and lipid yield (334.97 mg L−1), which were respectively 3.03 times of biomass (0.38 g L−1) and 4.92 times of lipid yield (68.08 mg L−1) in the single microalgae treatment system. Additionally, this algae-bacteria-activated carbon consortium remained a high Cd2+ removal efficiency (91.61%). In all, the present study developed an approach that had a great potential in simultaneous heavy metal wastewater treatment and microalgal lipid production.

Recovery of lipophilic compounds of Vincetoxicum species by supercritical carbon dioxide extraction

In this study, the dried herb of three Vincetoxicum species was subjected to supercritical carbon dioxide (SC-CO2) extraction for the recovery and characterisation of lipophilic compounds. The differences in extraction yield were not remarkable for the analyzed species; however, the effect of herb harvesting time at different year was quite significant. Two times higher yields of lipids were obtained from the plants collected in September 2020 compared to those collected in June 2022, e.g., from 1.39 to 3.01%. Linoleic, linolenic, oleic and palmitic acids were the major fatty acids in the extracted oils. β-sitosterol was the major phytosterol (from 4.84 to 10.74 mg/g), followed by stigmasterol, while vitamin E (α-tocopherol) was the dominant tocopherol in Vincetoxicum species extracts.CO2 extracts had similar antioxidant capacity and total phenolic content determined by different methods. Isovaleric acid, butyrolactone, hexanoic acid were the major volatile components identified in almost all plants extracts, however based on the integrated peak area significant quantitative variations were observed for different species and harvesting period (year). In conclusion, this study is the first report on lipophilic fraction of Vincetoxicum species recovered by SC-CO2, which demonstrates the presence of various bioactive components in the studied botanicals.

Nutrient sequestration and lipid production potential of Chlorella vulgaris under pharmaceutical wastewater treatment: experimental, optimization, and prediction modeling studies.

The efficient management and treatment of pharmaceutical industry wastewater (PIWW) have become a serious environmental issue due to its high toxicity. To overcome this problem, the present study deals with the phycoremediation of PIWW using Chlorella vulgaris microalga isolated from the Ganga River at Haridwar, India. For this, response surface methodology (RSM) and artificial neural network (ANN) tools were used to identify the best reduction of total phosphorus (TP) and total Kjeldahl's nitrogen (TKN) based pollutants along with the lipid production efficiency of C. vulgaris. Three different concentrations of pharmaceutical wastewater (0, 50, and 100%), operating temperatures (20, 25, and 30 °C), and light intensity (2000, 3000, and 4000 lx) were used to design the phycoremediation experiments having 6:18 h of dark/light period and reactor functional volume of 15L. Findings revealed that C. vulgaris was good enough to remove maximum TP (90.35%), TKN (83.55%) along 20.88% of lipid yield at 25.62 °C temperature, 60.73% PIWW concentration, and 4000 lx of light intensity, respectively. Based on the model performance and validation results, ANN showed more accuracy as compared to the RSM tool. Therefore, the findings of this study showed that C. vulgaris is capable of treating PIWW efficiently along with significant production of lipid content which can further be used in various applications including biofuel production.

Direct enzymatic hydrolysis of alkaline storage pretreated corn stover for lipid production by Rhodosporidium toruloides

Lignocellulosic biomass (LCB) conversion often requires chemical and energy-intensive pretreatment, which produces toxic by-products that impede microbial cell growth and downstream processes. Thus, pretreatment under mild conditions remains to be developed to improve enzymatic digestibility and reduce degradation products. Here, we investigated the direct enzymatic hydrolysis of alkaline storage pretreated corn stover (AS-CS) that was treated with different concentrations of sodium hydroxide (NaOH) under various temperatures for different storage duration. Results revealed that AS-CS was suitable for direct enzymatic hydrolysis for high sugar recovery. The total reducing sugar (TRS) recovery reached 88% for the CS sample treated with 6% NaOH for 60 days at 15 °C, and the corresponding hydrolysates were successfully used by Rhodosporidium toruloides for lipid production at a lipid yield of 0.20 g/g consumed TRS. Storage temperatures ranged from 15 to 35 °C had no differential impacts on enzymatic digestibility, however at 25 °C, the control and those CS samples treated with 2% NaOH were found with relatively high microbial contamination. This method offers an energy-efficient LCB conversion for high TRS recovery and supports microbial lipid technology. Future studies should focus on scalability and techno-economic analysis to validate its applicability on a larger scale.

Biorefinery-centric ethanol and oleochemical production employing Yarrowia lipolytica and Pichia farinosa

The research examined the capabilities of Yarrowia lipolytica (YL) and Pichia farinosa (PF) in converting sugars to ethanol and oleochemicals. Lipid, ethanol, protein yield and gene-expressions were analysed at different substrate concentrations (3 to 30 g/L) with glucose, food waste, and fermentation-effluent. Optimal results were obtained at 20 g/L using both synthetic carbon with 4.6 % of total lipid yield. Lauric and Caprylic acid dominance was noted in total lipid fractions. Protein accumulation (6 g/L) was observed in glucose system (20 g/L) indicating yeast strains potential as single-cell proteins (SCP). Fatty-acid desaturase (FAD12) and alcohol dehydrogenase (ADH) expressions were higher at optimum condition of YL (1.15 × 10−1, 3.8 × 10−2) and PF (5.8 × 10−2, 3.8 × 10−2) respectively. Maximum carbon reduction of 87 % depicted at best condition, aligning with metabolic yield. These findings highlights promising role of yeast as biorefinery biocatalyst.

Extraction of neutral lipids and phospholipids from marine biomasses using subcritical and supercritical fluids

Supercritical carbon dioxide (scCO2) and subcritical dimethylether (DME) were used to extract lipids from partially to fully dry marine biomass - whole jack mackerel (WJM), Hoki frames and heads (HFH), and Greenshell mussel meat (GSM). scCO2 gave a lower extraction yield of total lipids from GSM (42%) compared to WFH and HFH (86 - 88% yield) due to the higher concentration of phospholipids present in GSM. DME gave a higher extraction yield of total lipids and phospholipids than scCO2 for all marine biomass types. Phospholipid yield from GSM using DME was dependent on moisture content of the feed marine biomass and decreased with decreasing moisture content. Our results suggested that phospholipid extraction yield can be optimised by partly drying biomass to 30 - 50% moisture prior to extraction. DME extracts contained good levels of omega-3 fatty acids with minimal hydrolytic phospholipid degradation, thus providing a potential processing technology option to recover them from marine biomass.

Fine-tuning of key parameters to enhance biomass and nutritional polyunsaturated fatty acids production from Thraustochytrium sp.

The escalating demand for long-chain polyunsaturated fatty acids (PUFAs) due to their vital health effects has deepened the exploration of sustainable sources. Thraustochytrium sp. stands out as a promising platform for omega-3 and 6 PUFA production. This research strategically optimizes key parameters: temperature, salinity, pH, and G:Y:P ratio and the optimized conditions for maximum biomass, total lipid, and DHA enhancement were 28 °C, 50 %, 6, and 10:1:2 respectively. Process optimization enhanced 32.30 and 31.92 % biomass (9.88 g/L) and lipid (6.57 g/L) yield. Notably, DHA concentration experienced a substantial rise of 69.91 % (1.63 g/L), accompanied by notable increases in EPA and DPA by 82.69 % and 31.47 %, respectively. MANOVA analysis underscored the statistical significance of the optimization process (p < 0.01), with all environmental factors significantly influencing biomass and lipid data (p < 0.05), particularly impacting DHA production. Thraustochytrium sp. can be a potential source of commercial DHA production with the fine-tuning of these key process parameters.

Fatty acid compositions and oil ratio of different species from the Brassicaceae

Crude lipid has become one of the most significant demands of nations in recent years, oil crops and their lipid yield are becoming more and more vital. The composition of fatty acids reveals the caliber of oil crops. This study aims to determine and compare the oil content and fatty acid compositions of S. arvensis, B. nigra, B. napus, S. alba and C. sativa plants. It was determined that the oil ratios of the samples belonging to the B.nigra species varied between 27.132% and 29.350%, and the oil ratios of the samples belonging to the S. arvensis species varied between 27.495% and 28.855%. It was determined that the oil ratios of the samples belonging to the B.nigra species varied between 27.132% and 29.350%, and the oil ratios of the samples belonging to the S. arvensis species varied between 27.495% and 28.855%. Erucic acid value was determined to be highest in S. arvensis species, oleic and linoleic acids in B. napus, and linolenic acid in C. sativa. The data obtained showed that the oil ratios and fatty acid compositions of S. arvensis and B. nigra were very close to the values obtained from B. napus, S. alba and C. sativa, which were used as standards and grown as cultivated plants in this study. This suggests that the wild plants S. arvensis and B. nigra have the potential to be cultivated.

Beneficiation of paper-pulp industrial wastewater for improved outdoor biomass cultivation and biodiesel production using Tetradesmus obliquus (Turpin) Kützing

Algae-based wastewater bioremediation offers a cost-effective method for sustainably treating wastewater while simultaneously addressing global water scarcity and pollution. This study highlights the benefits of treating primary-treated (PTW) and secondary-treated (STW) paper-pulp industrial wastewaters using the microalga Tetradesmus obliquus (Turpin) Kützing. A batch culture study revealed that 50 % secondary treated wastewater can increase the biomass yield 1.8 fold to 2.51 g L−1 in 15 days with a corresponding lipid yield of 390.2 mg L−1. Upscaling this work in 200 L open raceway ponds with 50 % STW as the growth medium showed areal biomass and lipid productivities of 26.80 and 3.90 g m−2 day−1, respectively, in 15 days at 20 cm culture depth. This translates to a projected high annual biomass productivity of approximately 85.0 tons hectare−1 year−1 based on datasets spanning two consecutive years. Bioremediation efficiencies of 80.0 %, 91.51 %, and 92.10 % were achieved for COD, TOC, and NH4+ respectively. Biodiesel produced showed a large percentage of saturated and monounsaturated fatty acids (∼90 %) and its fuel properties complied with the global biodiesel standards. This study thus shows that using paper-pulp industrial wastewater for algal growth offers a sustainable solution for energy generation and wastewater treatment, with significant implications for environmental sustainability.

Influence of super-optimal light intensity on the acetic acid uptake and microalgal growth in mixotrophic culture of Chlorella sorokiniana in bubble-column photobioreactors

This study seeks to determine the influence of super-optimal light intensity on acetic acid uptake and its associated impact on the cellular composition of Chlorella sorokiniana in a semi-batch mixotrophic cultivation setup. Unicellular green microalga Chlorella sorokiniana is grown in a 1L bubble-column photobioreactor at light intensities from 6000 to 14,000 lx (≈81 to 189 µmol.photons.m−2.s−1). We find that microalgal acetic acid utilization reduces as illumination increases from an optimal 10,000 lx (≈135 µmol.photons.m−2.s−1) to a super-optimal zone (>10000 lx). This lowers microalgal growth (2.75 g/L) and acetic acid intake, which peak at 6 mL/L (10000 lx) and drop to 2 and 1 mL/L at 12,000 and 14,000 lx, respectively. Concurrently, the maximum lipid yield decreases from 0.66 g/L (10000 lx) to 0.54 g/L (12000 lx) and 0.42 g/L (14000 lx). Hence, super-optimal illumination not only disturbs phototrophy but also affects the heterotrophic component, creating an imbalance between the two.

Application of ANN-MOGA for nutrient sequestration for wastewater remediation and production of polyunsaturated fatty acid (PUFA) by Chlorella sorokiniana MSP1

Chlorella bears excellent potential in removing nutrients from industrial wastewater and lipid production enriched with polyunsaturated fatty acids. However, due to the changing nutrient dynamics of wastewater, growth and metabolic activity of Chlorella are affected. In order to sustain microalgal growth in wastewater with concomitant production of PUFA rich lipids, RSM (Response Surface Methodology) followed by heuristic hybrid computation model ANN-MOGA (Artificial Neural Network- Multi-Objective Genetic Algorithm) were implemented. Preliminary experiments conducted taking one factor at a time and design matrix of RSM with process variables viz. Sodium chloride (1 mM–40 mM), Magnesium sulphate (100 mg–800 mg) and incubation time (4th day to 20th day) were validated by ANN-MOGA. The study reported improved biomass and lipid yield by 54.25% and 12.76%, along with total nitrogen and phosphorus removal by 21.92% and 18.72% respectively using ANN-MOGA. It was evident from FAME results that there was a significantly improved concentration of linoleic acid (19.1%) and γ-linolenic acid (21.1%). Improved PUFA content makes it a potential feedstock with application in cosmeceutical, pharmaceutical and nutraceutical industry. The study further proves that C. sorokiniana MSP1 mediated industrial wastewater treatment with PUFA production is an effective way in providing environmental benefits along with value addition. Moreover, ANN-MOGA is a relevant tool that could control microalgal growth in wastewater.

Environmental assessment of Rhodosporidium toruloides-1588 based oil production using wood hydrolysate and crude glycerol

Rhodosporidium toruloides, an oleaginous yeast, is a potential feedstock for biodiesel production due to its ability to utilize lignocellulosic biomass-derived hydrolysate with a considerably high lipid titer of 50–70 % w/w. Hence, for the first-time environmental assessment of large-scale R. toruloides-based biodiesel production from wood hydrolysate and crude glycerol was conducted. The global warming potential was observed to be 0.67 kg CO2 eq./MJ along with terrestrial ecotoxicity of 1.37 kg 1,4-DCB eq./MJ and fossil depletion of 0.13 kg oil eq./MJ. The highest impacts for global warming (∼45 %) and fossil depletion (∼37 %) are attributed to the use of chloroform for lipid extraction while fuel consumption for transportation contributed more than 50 % to terrestrial ecotoxicity. Further, sensitivity analysis revealed that maximizing biodiesel yield by increasing lipid yield and solid loading could contribute to reduced environmental impacts. In nutshell, this investigation reveals that environmental impact varies with the type of chemical utilized.

Microscopic characterization, TLC fingerprinting and optimization of total lipid content from Euphorbia neriifolia (L.) using response surface methodology.

Euphorbia neriifolia (EN) is a medicinal plant used to treat a variety of ailments in traditional systems. Despite numerous studies on pharmacological activities, no information was available on the microscopic study of this plant. This is the first study that has been attempted to fill this need by performing the light and field emission scanning electron microscopy (FESEM) of leaf, stem, and latex. The powder microscopy of several organs (leaves, stem, and bark) and exudate (latex) of EN was carried out using safranine, fast green, phloroglucinol, and other standard solutions at different magnifications. The chemical fingerprinting of petroleum ether extract was accomplished by using thin layer chromatography. The optimization of total lipid content from the EN leaf under ultrasound-assisted extraction (UAE) and soxhlet extraction (SE) procedure was determined using response surface methodology (RSM). The studied factors that affect the lipid content were: solvent ratio, extraction temperature, and extraction time. Several notable characteristics observed in the leaf of EN are amphistomatic leaves with anticlinical cell walls, anomocytic stomata, spongy mesophyll cells, elongated palisade cells, angular collenchyma, and U-shaped vascular bundle. The plano-convex midrib is covered by polygonal to oval-shaped cuticles and contains anomocytic stomata. The circular petiole has no trichomes and contains laticifers, crystals, and idioblasts. The circular stem was observed with trichomes, hypodermis, collenchyma, parenchymatous cells, central pith, pentagonal stellar region, cambium, and 2-4 times more xylem that of phloem. All of the powdered plant parts and exudate under study contained trichomes, xylem vessels, wood fibers, cork cells, starch grains, calcium oxalate crystals, idioblasts, lignified cork, tannin content, stone cells, and oil globules. The blackish-green colored petroleum ether extract with semi-solid consistency showed the greatest percent (%) yield of 4% in the latex of EN. The thin layer chromatography (TLC) examination of petroleum ether extract of EN leaf produced a maximum 6 spots with Rf values of 0.16, 0.58, 0.62, 0.73, and 0.96 in the mobile phase of petroleum ether-acetone (8:2). In terms of optimization, the dark green colored UAE extract with semi-sticky consistency showed highest % yield of 4.5% whereas the yellowish green colored SE extract of sticky consistency showed the highest % yield of 4.9%. The findings showed that there were not many differences in the total lipid content between UAE (0.16%) and SE (0.11%). However, the best optimum condition for lipid content extraction analysis was obtained as follows: solvent ratio (PE:HE) 50:50, extraction temperature 50°C, extraction time 45 min for UAE, and solvent ratio (PE:HE) 60:40, extraction temperature 45°C, and extraction time of 24 h for SE. Hence, this study signifies the various noteworthy microscopic features along with the presence of different phytocompounds through TLC and best optimized condition for the extraction of lipids from different parts of EN. As no previous study has been reported, the outcomes obtained from the current study prove to be beneficial in the identification of species, quality control, and detection of any adulteration from the laboratory and commercial samples of EN. RESEARCH HIGHLIGHTS: The percent yield was found to be maximum in latex extract (4%). The leaf pet ether extract was separated into 6 bands with different Rf values. The extracted compounds from Euphorbia neriifolia leaves were categorized into non-polar heat tolerant. The highest total lipid yield (0.1119) was obtained at solvent ratios 60:40 of PE:HE (petroleum ether: petroleum hexane).

Cyclic stability evaluation of a novel CO2 absorption-microalgae conversion (CAMC) system

CO2 absorption-microalgae conversion (CAMC) system is a promising alternative to simultaneous CO2 capture and utilization. However, it is necessary to explore the stability of recycled absorption solvent for subsequent culture of CAMC system. In this work, dilution, activated carbon adsorption and H2O2/UV photocatalytic treatment were used to treat the absorption solution that had been run once in CAMC system and then the subsequent culture was performed and its performance was evaluated. It was found that these treatments could restore the performance of circulating absorption solution and H2O2/UV photocatalytic treatment showed the best effect. The biomass concentration, NADPH content and RubisCO enzyme activities increased by 18 %, 92.0 %, and 26.5 % by H2O2/UV photocatalytic treatment. H2O2/UV photocatalytic treatment enhanced carbon fixation rate, which was 7.05 % higher than untreated group. H2O2/UV photocatalytic treatment could improve the yield of lipid and protein. These results showed that H2O2/UV photocatalytic treatment could restore the performance of circulating solution to the level of primary culture and maintain the cyclic stability of CAMC system. Therefore, this study provided a certain guiding significance for the application of CAMC system.

Computational assessment of lipid production in Rhodosporidium toruloidesin two-stage and one-stage batch bioprocesses.

Oleaginous yeasts are promising platforms for microbial lipids production as a renewable and sustainable alternative to vegetable oils in biodiesel production. In this paper, a thorough in silico assessment of lipid production in batch cultivation by Rhodosporidium toruloideswas developed. By means of dynamic flux balance analysis, the traditional two-stage bioprocess (TSB) performed by the native strain was contrasted with one-stage bioprocess (OSB) using four designed strains obtained by gene knockout strategies. Lipid titer, yield, content, and productivity were analyzed at different initial C/N ratios as relevant performance indicators used in bioprocesses. By weighting these indicators, a global lipid efficiency metric(GLEM) was defined to consider different scenarios. Under simulated conditions, designed strains for lipid overproduction in OSB outperformed the TSB in terms of lipid title (up to threefold), lipid yield (up to 2.4-fold), lipid content (up to 2.8-fold, with a maximum of 76%), and productivity (up to 1.3-fold), depending on C/N ratios. Using these efficiency parameters and the proposed GLEM, the process of selecting the most suitable candidates for lipid production could be carried out before experimental assays. This methodology holds the potential to be extended to other oleaginous microorganisms and diverse strain design techniques.

Topraktan İzole Edilen Bacillus sp. Suşlarının Lipid Üretim Kapasitelerinin Taranması ve Farklı Boyama Teknikleri ile Lipid Boyama

Microbial lipids have been attracting more and more attention in recent years as promising raw &#x0D; materials for the production of biodiesel and value-added compounds. In the current economic and &#x0D; environmental situation, finding new renewable sources of lipids will be crucial. Recent research has &#x0D; necessitated the search for new efficient microbial producers with lipid production efficiency. For this &#x0D; purpose,50 Bacillus sp. strains previously isolated from the soil were screened for their lipid production &#x0D; capacity. As a result of the production using a single-cell oil production medium, only two Bacillus spp. &#x0D; strains showed growth. These bacteria were named as Bacillus sp. E40 and Bacillus sp. E226. Bacteria &#x0D; were then characterized in terms of their biomass, lipid yields, and lipid contents. The biomass of &#x0D; Bacillus sp. E40 and E226 bacterial isolates, were 0,28 and 0,22 g.L-1, respectively. The highest lipid &#x0D; content was reached by E226 with 54.5%. Bacillus sp. E40 lipid content was determined as 46.4%. In &#x0D; addition, both intracellular lipid staining and colony staining demonstrated the presence of lipids. With &#x0D; this study, it was reported for the first time that local Bacillus sp. strains isolated from soil have lipid &#x0D; producing capacity.

Unlocking the potential of microalgae cultivated on wastewater combined with salinity stress to improve biodiesel production

Microalgae have the potential as a source of biofuels due to their high biomass productivity and ability to grow in a wide range of conditions, including wastewater. This study investigated cultivating two microalgae species, Oocystis pusilla and Chlorococcus infusionum, in wastewater for biodiesel production. Compared to Kühl medium, KC medium resulted in a significant fold increase in cellular dry weight production for both O. pusilla and C. infusionum, with an increase of 1.66 and 1.39, respectively. A concentration of 100% wastewater resulted in the highest growth for O. pusilla, with an increase in biomass and lipid content compared to the KC medium. C. infusionum could not survive in these conditions. For further increase in biomass and lipid yield of O. pusilla, different total dissolved solids (TDS) levels were used. Maximum biomass and lipid productivities were achieved at 3000 ppm TDS, resulting in a 28% increase in biomass (2.50 g/L) and a 158% increase in lipid yield (536.88 mg/g) compared to KC medium. The fatty acid profile of O. pusilla cultivated on aerated wastewater at 3000 ppm TDS showed a high proportion of desirable saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) for biodiesel production. Cultivating microalgae in wastewater for biodiesel production can be cost-effective, especially for microalgae adapted to harsh conditions. It could be concluded that O. pusilla is a promising candidate for biodiesel production using wastewater as a growth medium, as it has high biomass productivity and lipid yield, and its fatty acid profile meets the standard values of American and European biodiesel standards. This approach offers a sustainable and environmentally friendly solution for producing biofuels while reducing the environmental impact of wastewater disposal.

Paracetamol biodegradation coupling lipid biosynthesis in acclimated microalgae Coccomyxa subellipsoidea

Paracetamol (PAR) has received increasing concern due to its large usage, ubiquitous detection in environment and high ecotoxicology risk. This study investigated the effect of PAR on the growth and lipid production of Coccomyxa subellipsoidea, removal of PAR by C. subellipsoidea, and the metabolic difference in C. subellipsoidea after exposure to PAR. The PAR promoted C. subellipsoidea growth but the biomass increment reduced with PAR concentration increasing. Acclimation evolution could enhance removal capacity of C. subellipsoidea to PAR. Compared to wild C. subellipsoidea, the removal percentage of PAR by acclimated C. subellipsoidea increased 2.71-fold, the content and yield of lipid as well as the content of unsaturated fatty acid in acclimated C. subellipsoidea significantly increased by 1.06-, 1.13- and 1.12-fold, respectively. The metabolism fate of PAR analysis revealed that p-aminophenol was the first step degradadation product, and the molecular docking simulating suggested p-aminophenol was the most prone to undergo metabolism. Differential metabolites analysis showed that the up-regulating glutathione with 2.20-fold in C. subellipsoidea withstanded oxidative stress from PAR and actuated the PAR degradation, the up-regulating citric acid and fumarate as well as malate used as precursor of lipid biosynthesis actuated lipid accumulation. This work provides new insights for using microalgae for efficient treatment of wastewater containing pharmaceuticals contaminants (PCs) coupling high value-added products production.

Valorisation of organic carbons and organo-solvents by mixotrophic cultivation of methylotrophic Tetraselmis indica for enhanced biomolecules production

Microalgal biomass is a sustainable bioresource for producing a wide range of biomolecules such as lipids and chlorophylls, astaxanthin, and β-carotene. The mixotrophic cultivation using organic carbon (OCs) and traditional organo-solvents (OSs), especially methanol (MeOH), has been shown to improve biomass productivity and biomolecule yield. However, limited studies have explored the utilization of OSs as an external carbon source to produce microalgal biomass and for subsequent biorefinery. Thus, the present study evaluates the effects on the cultivation of industrial important microalgal Tetraselmis indica BDUG001 (T. indica BDUG001) through supplementation of various OCs and OSs at different day-night cycles under sterile mixotrophic conditions. Among all the OCs and OSs, MeOH showed the best growth, biomass, and biomolecule production. Interestingly, MeOH at a varying concentration (0–10 g/L) was an ideal carbon source for enhancing T. indica BDUG001 growth, biomass, and biomolecules productivity. At the 7.5 g/L concentration of MeOH, T. indica BDUG001 showed maximized biomass production (2.45 ± 0.07 g/L), lipid content (42.85 ± 1.20%), total lipid yield (1.05 ± 0.03 g/L), photosynthetic pigments [chl-a (3.27 mg/L), chl-b (2.25 mg/L) and TCs (1.27 mg/L]. While the maximum astaxanthin (0.77 μg/gm) and β-carotene (5.21 μg/mg) were observed at 10 and 5.0 g/L, respectively. The present investigation will aid in the microalgal research pipeline for the selection of novel OSs tolerant microalgae strains and utilization of waste OSs for mass-scale sterile mixotrophic cultivation. Moreover, the proposed cultivation system will help to develop low-cost algal biorefinery systems to attain high-quality industrial important biomolecules.

Advanced strategies for effective treatment of vanadium (III) polluted water by potential microalgae

BackgroundEnvironmental concerns are escalating globally due to rising pollution, with heavy metals like vanadium posing health risks even at 2 ppm. Industries like steel and semiconductors discharge vanadium, presenting environmental hazards. However, there's a lack of sustainable treatment methods for vanadium removal. This study aims to develop an eco-friendly microalgae vanadium treatment while utilizing microalgal biomass for biofuels, offsetting treatment expenses. MethodsPotential microalgae is chosen for vanadium (III) treatment. Over an 18-days period, maximum V(III) removal was aimed with adequate biomass and lipid yields. pH and temperature optimization enhances vanadium removal, guided by zeta potential analysis. FTIR confirms vanadium adsorption via algal cell wall reactive groups. Significant FindingsThe study demonstrates a viable solution for the pressing issue of vanadium pollution. Chlorella sorokiniana TU5 effectively removes V(III), achieving a substantial removal rate of 20.38 mgL−1. Moreover, the generated microalgal biomass showed a biomass yield of 2.3 gL−1 and a lipid yield of 577.3 mgL−1. The strategic optimization of pH and temperature further enhances the vanadium removal capacity. This approach not only addresses vanadium pollution but also provides a sustainable route for biofuel production using microalgal biomass, positioning it as a promising technique for industrial-scale vanadium bioremediation.