Search Results (24)

The increasing demand for sustainable, economical, and environmentally friendly solutions has positioned microalgae as promising candidates in biotechnology, particularly in food, feed, nutraceutical, pharmaceutical, biofuel, and bioremediation applications. This review explores the role of the Nannochloropsis genus and other marine oleaginous microalgae in co-cultivation systems, highlighting their mechanisms of interaction with various microorganisms and their potential for various biotechnological purposes. Case studies of Nannochloropsis sp. co-cultures with other microalgae, bacteria, and fungi are presented. The different types of associations are described as alternative strategies to enhance biomass productivity, lipid accumulation, and nutrient recycling. A key focus of this review is the potential of Nannochloropsis microalgae co-cultivation in food, as it is part of the list of microalgae to be approved for consumption in the European Union, discussing their rich nutritional value, safety, and regulatory status. Additionally, the role of microalgae in the alternative protein sector is explored, with particular emphasis on their integration in cultivated meat products as nutrient suppliers and metabolic partners for animal cells. Despite their potential, several challenges, such as scale-up, contamination risk, and strain selection, remain key obstacles to the widespread adoption of microalgal biotechnology. Future research should focus on optimizing microalgae-based co-cultures for food applications, addressing safety concerns, and further investigating their integration into functional foods and cellular agriculture products. Full article

Antarctic soil represents an important reservoir of filamentous fungi (FF) species with the ability to produce novel bioactive lipids. However, the lipid extraction method is still a bottleneck. The objective of the present work was to isolate and identify cultivable FF from Antarctic soils, to assess the most effective methods for fatty acid (FA) extraction, and to characterise the obtained lipids. A total of 18 fungal strains belonging to the Botrytis, Cladosporium, Cylindrobasidium, Mortierella, Penicillium, Pseudogymnoascus, and Talaromyces genera and the Melanommataceae family were isolated and identified. The Folch, Bligh and Dyer, and Lewis extraction methods were assessed, and methyl esters of FA (FAMEs) were obtained. The Lewis method was the best in recovering FAMEs from fungal biomass. A total of 17 FAs were identified, and their chemical compositions varied depending on fungal species and strain. Oleic, linoleic, stearic, and palmitic acids were predominant for all fungal strains in the three assessed methods. Among the analysed strains, Cylindrobasidium eucalypti, Penicillium miczynskii, P. virgatum, and Pseudogymnoascus pannorum produced high amounts of FA. This suggests that the soils of Antarctica Bay, as well as harbouring known oleaginous fungi, are also an important source of oleaginous filamentous fungi that remain poorly analysed. Full article

This paper examines the role of filamentous fungi in enhancing the sustainable extraction of vegetable oils from oilseeds. Fungi such as Aspergillus, Penicillium, Fusarium, Trichoderma, and Rhizopus are highlighted for their ability to produce hydrolytic enzymes, including lipases, cellulases, and hemicellulases, which break down plant cell walls and facilitate oil release. This biotechnological approach not only improves oil yield but also reduces operational costs and environmental impacts, contributing to sustainable development goals. The integration of oleaginous fungi, capable of accumulating lipids, is also discussed as a promising avenue for boosting oil production efficiency. Furthermore, this paper underscores the importance of combining traditional knowledge with modern biotechnological advancements. This integration respects local cultural practices while optimizing extraction processes, ensuring minimal ecological disruption. The use of fungi in oilseed degradation represents a significant step towards more eco-friendly and cost-effective vegetable oil production, making it a valuable contribution to sustainable agricultural and industrial practices. Full article

Thamnidium elegans and Mortierella alpina are two oleaginous fungi that belong to Mucoromycota that synthesize polyunsaturated fatty acids, which are credited with multiple health benefits and possible anticancer properties. These fungi were cultivated on culture media, with glucose or glycerol as a carbon source. After extracting the lipids, we transformed them into fatty acid lithium salts (FALSs), which are water-soluble and absorbable mammalian cells, including DU-145 and PC-3 cancer cells. The two cell lines, both long-established prostate cancer models, were treated with FALSs and indicated increased susceptibility to the lipid derivatives. The viability and proliferation rates were significantly reduced, as well as their migratory capabilities, which were significantly impaired compared to olive oil-derived FALS, which was used as a control substance. We conclude that the FALS derivatives of microbial lipids from these organisms exhibit anticancer effects, by suppressing the proliferation and migration of human prostate cancer cell lines. Full article

Eicosatetraenoic acid (ETA, 20:4, ω-3) is the desaturation product of dihomo-gamma linolenic acid (DGLA, 20:3, ω-6) catalyzed by delta-17 desaturase, which is considered as a healthy product that helps to lower risk of heart diseases. The oleaginous filamentous fungus, Mucor circinelloides, has been used for a long time as a model micro-organism for GLA production at industrial scales. However, M. circinelloides lacks the key enzymes to synthesize C20 polyunsaturated fatty acids (PUFAs). M. circinelloides could produce DGLA by overexpressing the D6E(GLELO) gene, which could be a useful tool to produce ETA due to the availability of established genetic manipulation tools. Therefore, in this study, delta-17 desaturase (PpD17 and PaD17) genes from Phytophthora parasitica and Pythium aphanidermatum, respectively, were introduced into M. circinelloides to construct an ETA-producing cell factory. Our results showed that the PaD17 and PpD17 overexpression strains’ biomass increased by 25.98 and 23.34 g/L (39.98 and 25.75%), respectively, compared with the control strain. Meanwhile, the lipid contents of the recombinant strains also increased and reached up to 28.88% in Mc-PaD17 and 30.95% in Mc-PpD17, respectively, compared with the control strain (23.38% in Mc-2076). The RT-qPCR results showed that overexpression of delta-17 desaturase genes promoted the expression of cme2, fas2, and D6E, thereby contributing to lipid biosynthesis in M. circinelloides. Meanwhile, the content of ETA reached up to 1.95%, and the yield of ETA was up to 114.69 mg/L in PpD17 overexpression mutants at 96 h. This study provided the first report on the construction of an ETA-producing cell factory by heterologous overexpression of the PpD17 gene in M. circinelloides, which established a new scope for further research in the production of ETA in oleaginous fungi. Full article

Due to their low cost and ability to synthesize lipids for sustainable biodiesel production, oleaginous fungus has recently gained more prominence than other microorganisms. The new oleaginous fungus Aspergillus carneus OQ275240’s dry biomass, lipid content, and lipid yield were all optimized in this work, using the response surface methodology-based Box–Behnken design. Analysis of variance (ANOVA) was also used to examine the experimental data, and multiple regression analysis was used to fit the data to a second-order polynomial equation. Three independent variables, such as the concentration of yeast, glucose, and phosphorus, were examined for their mutual impacts. Maximum dry biomass (0.024 g/50 mL), lipid content (36.20%), and lipid yield (8.70 mg/50 mL) were achieved at optimal concentrations of 2.68 g/L of yeast, 20.82 g/L of glucose, and 0.10 g/L of phosphorus, respectively, showing that the actual data and predictions of the models were in good agreement. A. carneus OQ275240 has a favorable fatty acid profile that can be used to successfully create biodiesel, as shown by the presence of palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1) in its fatty acid methyl esters (FAMEs) profile. Furthermore, the qualities of the biodiesel were investigated, and it was found that they fell within the parameters established by the international specifications EN 14214 (Europe) and ASTM D6751-08 (United States). These findings point to the newly evaluated filamentous fungal strain as a potential feedstock for the production of high-quality biodiesel. Full article

Malate transporter proteins (MTPs) play a pivotal role in regulating flux in the citrate/malate/pyruvate shuttle to deliver acetyl-CoA from the mitochondria to the cytosol and thus regulate lipid biosynthesis in oleaginous fungi. Despite the recent successful exploration of the mitochondrial malate transporters in Mucor circinelloides, research with in silico analyses that include molecular docking and their dynamics, in addition to homology modelling of malate transporters, have not been reported. In this study, the physico-chemical properties and nucleotide sequence analysis of two mitochondrial MTPs (MT and SoDIT-a with Gene/protein ID scafold00018.48 and scafold00239.15, respectively), in M. circinelloides WJ11 were performed. The three-dimensional (3D) model of the mitochondrial MTPs was determined and the best-docked complex stabilities were demonstrated with molecular dynamic (MD) simulations. The activity domain was revealed to form hydrogen bonds and piling interactions with citrate and malate upon docking. Our study showed better binding affinities for the MTPs—reaching up to −3.44 and −7.27 kcal/mol with the MT and SoDIT-a proteins, respectively (compared to the target of −2.85 and −6.00 kcal/mol for citric acid-binding). MD simulations illustrated that the protein complexes demonstrated conformational stability throughout the simulation. This study was the first to elucidate the structural characteristics of mitochondrial MTPs in M. circinelloides WJ11, providing direct evidence regarding the transport mechanism of specific substrates. Furthermore, the current results support ongoing efforts to combine functional and structural data to better understand the MTPs (at the molecular and atomic levels) of an oleaginous fungus such as M. circinelloides. Full article

Triacylglycerol (TG) with high-value long-chain polyunsaturated fatty acids is beneficial to human health; consequently, there is an urgent need to broaden its sources due to the current growing demand. Mortierella alpina, one of the most representative oleaginous fungi, is the only certificated source of dietary arachidonic acid-rich oil supplied in infant formula. This study was conducted to improve TG production in M. alpina by homologous overexpression of diacylglycerol acyltransferase (DGAT) and linseed oil (LSO) supplementation. Our results showed that the homologous overexpression of MaDGAT1B and MaDGAT2A strengthened TG biosynthesis and significantly increased the TG content compared to the wild-type by 12.24% and 14.63%, respectively. The supplementation with an LSO concentration of 0.5 g/L elevated the TG content to 83.74% and total lipid yield to 4.26 ± 0.38 g/L in the M. alpina-MaDGAT2A overexpression strain. Our findings provide an effective strategy for enhancing TG production and highlight the role of DGAT in TG biosynthesis in M. alpina. Full article

Adenosine deaminase (ADA) is an enzyme distributed in a wide variety of organisms that cleaves adenosine into inosine. Since inosine plays an important role in nitrogen metabolism, ADA may have a critical function in the regulation of fatty acid synthesis. However, the role of ADA in oleaginous fungi has not been reported so far. Therefore, in this study, we identified one ada gene encoding ADA (with ID scaffold0027.9) in the high lipid-producing fungus, Mucor circinelloides WJ11, and investigated its role in cell growth, lipid production, and nitrogen metabolism by overexpressing and knockout of this gene. The results showed that knockout of the ada altered the efficiency of nitrogen consumption, which led to a 20% increment in the lipid content (25% of cell dry weight) of the engineered strain, while overexpression of the ada showed no significant differences compared with the control strain at the final growth stage; however, interestingly, it increased lipid accumulation at the early growth stage. Additionally, transcriptional analysis was conducted by RT-qPCR and our findings indicated that the deletion of ada activated the committed steps of lipid biosynthesis involved in acetyl-CoA carboxylase (acc1 gene), cytosolic malic acid enzyme (cme1 gene), and fatty acid synthases (fas1 gene), while it suppressed the expression of AMP-activated protein kinase (ampk α1 and ampk β genes), which plays a role in lipolysis, whereas the ada-overexpressed strain displayed reverse trends. Conclusively, this work unraveled a novel role of ADA in governing lipid biosynthesis and nitrogen metabolism in the oleaginous fungus, M. circinelloides. Full article

Mucor circinelloides, an oleaginous filamentous fungus, is gaining popularity due to its ability to synthesize significant amounts of lipids containing γ-linolenic acid (GLA) that have important health benefits. Malic enzyme (ME), which serves as the main source of NADPH in some fungi, has been found to regulate lipid accumulation in oleaginous fungi. In the present study, the role of two cytosolic ME genes, cmalA and cmalB, in the lipid accumulation of the M. circinelloides high-lipid-producing strain WJ11, was evaluated. Strains overexpressing cmalA and cmalB showed a 9.8- and 6.4-fold rise in specific ME activity, respectively, and an elevation of the lipid content by 23.2% and 5.8%, respectively, suggesting that these genes are involved in lipid biosynthesis. Due to increased lipid accumulation, overall GLA content in biomass was observed to be elevated by 11.42% and 16.85% in cmalA and cmalB overexpressing strains, respectively. Our study gives an important insight into different studies exploring the role of the cmalA gene, while we have for the first time investigated the role of the cmalB gene in the M. circinelloides WJ11 strain. Full article

The oleaginous fungus Mortierella alpina is a safe source of polyunsaturated fatty acids (PUFA) in industrial food and feed production. Besides PUFA production, pharmaceutically relevant surface-active and antimicrobial oligopeptides were isolated from this basal fungus. Both production of fatty acids and oligopeptides rely on the biosynthesis and high turnover of branched-chain-amino acids (BCAA), especially l-leucine. However, the regulation of BCAA biosynthesis in basal fungi is largely unknown. Here, we report on the regulation of the leucine, isoleucine, and valine metabolism in M. alpina. In contrast to higher fungi, the biosynthetic genes for BCAA are hardly transcriptionally regulated, as shown by qRT-PCR analysis, which suggests a constant production of BCAAs. However, the enzymes of the leucine metabolism are tightly metabolically regulated. Three enzymes of the leucine metabolism were heterologously produced in Escherichia coli, one of which is inhibited by allosteric feedback loops: The key regulator is the α-isopropylmalate synthase LeuA1, which is strongly disabled by l-leucine, α-ketoisocaproate, and propionyl-CoA, the precursor of the odd-chain fatty acid catabolism. Its gene is not related to homologs from higher fungi, but it has been inherited from a phototrophic ancestor by horizontal gene transfer. Full article

Animal waste fats were explored as a fermentation substrate for the production of high-value unsaturated single cell oil (SCO) using oleaginous fungi, Mucor circinelloides and Mortierella alpina. Both strains showed good growth and lipid accumulation when using animal fat as a single carbon source. The biomass concentration of 16.7 ± 2.2 g_DCW/L and lipid content of 54.1%_wt (of dry cell weight) were obtained for Mucor circinelloides in shake flask experiments, surpassing the biomass yield achieved in batch and fed-batch fermentation. In contrast, Mortierella alpina gave the highest biomass concentration (8.3 ± 0.3 g_DCW/L) and lipid content (55.8%_wt) in fed-batch fermentation. Fat grown Mortierella alpina was able to produce arachidonic acid (ARA), and the highest ARA content of 23.8%_wt (of total lipid weight) was in fed-batch fermentation. Gamma-linolenic acid (GLA) was produced by both fungal strains. At the end of fed-batch fermentation, the GLA yields obtained for Mucor circinelloides and Mortierella alpina were 4.51%_wt and 2.77%_wt (of total lipid weight), respectively. This study demonstrates the production of unsaturated SCO-rich fungal biomass from animal fat by fermentation. Full article

Microbial lipid production with cost effectiveness is a prerequisite for the oleochemical sector. In this work, genome-wide transcriptional responses on the utilization of xylose and glucose in oleaginous Aspergillus oryzae were studied with relation to growth and lipid phenotypic traits. Comparative analysis of the active growth (t1) and lipid-accumulating (t2) stages showed that the C5 cultures efficiently consumed carbon sources for biomass and lipid production comparable to the C6 cultures. By pairwise comparison, 599 and 917 differentially expressed genes (DEGs) were identified in the t1 and t2 groups, respectively, in which the consensus DEGs were categorized into polysaccharide-degrading enzymes, membrane transports, and cellular processes. A discrimination in transcriptional responses of DEGs set was also found in various metabolic genes, mostly in carbohydrate, amino acid, lipid, cofactors, and vitamin metabolisms. Although central carbohydrate metabolism was shared among the C5 and C6 cultures, the metabolic functions in acetyl-CoA and NADPH generation, and biosynthesis of terpenoid backbone, fatty acid, sterol, and amino acids were allocated for leveraging biomass and lipid production through at least transcriptional control. This study revealed robust metabolic networks in the oleaginicity of A. oryzae governing glucose/xylose flux toward lipid biosynthesis that provides meaningful hints for further process developments of microbial lipid production using cellulosic sugar feedstocks. Full article

Oleaginous filamentous fungi can accumulate large amount of cellular lipids and biopolymers and pigments and potentially serve as a major source of biochemicals for food, feed, chemical, pharmaceutical, and transport industries. We assessed suitability of Fourier transform (FT) Raman spectroscopy for screening and process monitoring of filamentous fungi in biotechnology. Six Mucoromycota strains were cultivated in microbioreactors under six growth conditions (three phosphate concentrations in the presence and absence of calcium). FT-Raman and FT-infrared (FTIR) spectroscopic data was assessed in respect to reference analyses of lipids, phosphorus, and carotenoids by using principal component analysis (PCA), multiblock or consensus PCA, partial least square regression (PLSR), and analysis of spectral variation due to different design factors by an ANOVA model. All main chemical biomass constituents were detected by FT-Raman spectroscopy, including lipids, proteins, cell wall carbohydrates, and polyphosphates, and carotenoids. FT-Raman spectra clearly show the effect of growth conditions on fungal biomass. PLSR models with high coefficients of determination (0.83–0.94) and low error (approximately 8%) for quantitative determination of total lipids, phosphates, and carotenoids were established. FT-Raman spectroscopy showed great potential for chemical analysis of biomass of oleaginous filamentous fungi. The study demonstrates that FT-Raman and FTIR spectroscopies provide complementary information on main fungal biomass constituents. Full article

Calcium controls important processes in fungal metabolism, such as hyphae growth, cell wall synthesis, and stress tolerance. Recently, it was reported that calcium affects polyphosphate and lipid accumulation in fungi. The purpose of this study was to assess the effect of calcium on the accumulation of lipids and polyphosphate for six oleaginous Mucoromycota fungi grown under different phosphorus/pH conditions. A Duetz microtiter plate system (Duetz MTPS) was used for the cultivation. The compositional profile of the microbial biomass was recorded using Fourier-transform infrared spectroscopy, the high throughput screening extension (FTIR-HTS). Lipid content and fatty acid profiles were determined using gas chromatography (GC). Cellular phosphorus was determined using assay-based UV-Vis spectroscopy, and accumulated phosphates were characterized using solid-state ³¹P nuclear magnetic resonance spectroscopy. Glucose consumption was estimated by FTIR-attenuated total reflection (FTIR-ATR). Overall, the data indicated that calcium availability enhances polyphosphate accumulation in Mucoromycota fungi, while calcium deficiency increases lipid production, especially under acidic conditions (pH 2–3) caused by the phosphorus limitation. In addition, it was observed that under acidic conditions, calcium deficiency leads to increase in carotenoid production. It can be concluded that calcium availability can be used as an optimization parameter in fungal fermentation processes to enhance the production of lipids or polyphosphates. Full article