Search Results (54)

Microbial protein production from acetate represents a promising route for sustainable protein supply, yet its efficiency is constrained by limited understanding of carbon–nitrogen metabolic coordination. In this study, nitrogen availability was systematically varied to investigate its role in regulating biomass composition and protein biosynthesis in Yarrowia lipolytica. Nitrogen limitation markedly reduced cell growth and protein accumulation (19.56% of dry cell weight) while increasing lipid content (up to 34.16%), indicating a altered protein and lipid accumulation under different nitrogen conditions. Transcriptomic analysis revealed a global downregulation of anabolic pathways under nitrogen limitation, accompanied by a shift in nitrogen assimilation from the glutamate dehydrogenase (GDH) pathway to the glutamine synthetase/glutamate synthase (GS–GOGAT) pathway, as well as significant upregulation of genes related to ammonium and amino acid transport. Guided by these findings, metabolic engineering of key nitrogen assimilation pathways was performed. Strains harboring additional copies of GDH and GS expression cassettes showed increased protein content from 48.52% to 55.77% and improved amino acid composition, whereas strains with an additional copy of the GOGAT gene exhibited reduced growth and protein accumulation. These results demonstrate that nitrogen availability regulates biomass composition through coordinated control of nitrogen transport and assimilation, and that balanced upregulation of GDH and GS genes is an effective strategy to improve microbial protein production from acetate, supporting the development of efficient fermentation processes using low-cost carbon sources. Full article

Olive mill wastewater (OMW), due to its high organic load and phenolic content, represents both a major environmental challenge and a promising low-cost substrate for microbial bioprocesses. In this study, lipid production by Yarrowia lipolytica using OMW was optimized through a mixed-level Taguchi experimental design. The effects of OMW dilution (%), nitrogen supplementation, NaCl concentration, sterilization, and carbon source (glucose or glycerol) were evaluated in terms of biomass production, lipid accumulation, and fatty acid composition. The results demonstrated a clear inverse relationship between biomass formation and lipid accumulation. The highest lipid content (33.49%) was achieved under nitrogen-limited conditions combined with a high OMW dilution. After 168 h of fermentation, the calculated lipid yield was 0.51 g/L. Biomass and lipid productivities were calculated as 0.22 g/L/day and 0.073 g/L/day, respectively. ANOVA analysis revealed that nitrogen concentration was the dominant factor affecting lipid production (67.71%), followed by NaCl concentration (18.83%). In contrast, OMW dilution, sterilization, and carbon source type were not statistically significant (p > 0.05), indicating that lipid production can be effectively performed under non-sterile conditions with flexible substrate utilization. Fatty acid analysis revealed that the produced lipids were rich in oleic acid (C18:1n9c), reaching up to 57.97%, with unsaturated fatty acids generally accounting for the majority of the total fatty acid composition. Although the carbon source had a limited effect on lipid yield, it contributed to variations in fatty acid composition, suggesting the possibility of tailoring lipid quality through substrate selection. Full article

This focused review examines fermentation and fermentation-integrated microbial platforms that convert two regionally relevant substrate classes, Latin American agro-industrial residues and concentrated CO₂ streams, into high-value bioproducts. The review is not intended as a complete survey of all biomass valorization routes in Latin America. Instead, it evaluates platform–feedstock–product combinations with clear translational relevance for regional biorefineries, with emphasis on literature from 2020–2025 and on earlier benchmark studies only when they define current technical performance limits. Latin America and the Caribbean combine high-volume sugarcane, agave, coffee, citrus, banana, cacao, and tuber-processing residues with biogenic CO₂ from ethanol fermentation and industrial point sources from cement, lime, and oil-and-gas operations. The technical opportunity is therefore not residue abundance alone, but the rational coupling of residue chemistry, CO₂-source quality, locally isolated microbial strains, and process architectures that can be scaled under regional constraints. We compare phototrophic CO₂-fixing modules based on cyanobacteria and microalgae, chemoautotrophic gas fermentation using Cupriavidus necator and related systems, heterotrophic yeast platforms including Rhodotorula spp. and Yarrowia lipolytica, and bacterial platforms for PHAs, bacterial cellulose, and organic acids. The core technical analysis focuses on substrate conditioning, hydrolysate inhibition, oxygen- and gas-transfer constraints, light delivery, C/N control, mixed-sugar utilization, metabolic engineering, reactor configuration, downstream processing, and quantitative reporting metrics. One fermentation-integrated laboratory case study—the Synechocystis sp. PCC 6803–Rhodotorula mucilaginosa UANL-001L CO₂-to-carotenoid relay—and one explicitly defined non-fermentative boundary case on peel-extract-derived coating films are used to illustrate two different aspects of regional biorefinery design: dual-feedstock microbial conversion and low-CapEx product-fit decisions for agro-industrial residues. We conclude that Latin America’s strongest near-term position is in technically disciplined, product-specific biorefineries that integrate local feedstock chemistry with engineered or locally adapted chassis, rather than in generic biomass-to-product claims. Full article

The microbial production of value-added lipids by oleaginous yeasts has attracted considerable interest as a sustainable alternative to conventional lipid sources. In this study, the effects of selected fermentation parameters on biomass production, lipid production, and fatty acid composition of Yarrowia lipolytica YB-423 were investigated using flaxseed and chia seed oils as carbon sources. A Taguchi method was employed to evaluate and optimize the influence of temperature, fermentation time, nitrogen concentration, and oil supplementation. The results showed that nitrogen availability was the dominant factor governing biomass formation. The highest lipid production was achieved at 21 °C after 6 days of fermentation in the absence of an added nitrogen source supplemented with 10 mL/L oil, resulting in lipid contents of 62.53% and 64.61% for flaxseed and chia seed oils, respectively. Lipid content was primarily influenced by nitrogen concentration and oil supplementation, while temperature and fermentation time showed secondary but significant effects. Beyond total lipid production, fatty acid profiling demonstrated that both oil sources supported PUFA-rich lipid production; however, chia seed oil resulted in a broader variation in α-linolenic acid (ALA) content across fermentation conditions. The highest ALA content reached 67.40% at 14 °C after 4 days of fermentation under 30 mL/L chia seed oil supplementation. Additionally, ALA levels reached approximately 62% at 7 °C under higher chia seed oil concentrations (20–30 mL/L). In contrast, flax seed oil yielded relatively stable ALA levels, generally ranging between 45% and 56%, depending on fermentation parameters. Full article

The recycling of fossil-based plastic waste remains a key challenge in reducing environmental pollution and greenhouse gas emissions. An innovative approach is the biotechnological conversion of the n-alkane mixture obtained from thermal pyrolysis of plastic waste. This study focuses on the use of the oleaginous yeast Yarrowia lipolytica for the valorization of polyethylene (PE)-derived pyrolysis oil. From a screening of 50 Y. lipolytica strains, the most promising candidate was selected, and its single-cell phenotype was stabilized by MHY1 deletion. In shake flask experiments, this strain grew similarly on 5–20 vol% of n-hexadecane, revealing no inhibitory effects. Subsequently, a high cell density fermentation was established in a 4 L bioreactor using a pulsed fed-batch approach, resulting in biomass concentrations of up to 145.6 g·L⁻¹, which contained 22.0% triacylglycerols. In addition, cultivation at pH 2.5, compared to pH 4.0, reduced citrate formation from 95.6 to 0.8 g·L⁻¹, while biomass and TAG titers remained similar. Overall, these results highlight the potential of integrating plastic waste-derived pyrolysis oil into future bioprocesses using Y. lipolytica as an effective platform for high cell density production. Full article

In this study, single-cell oil (SCO) production from waste sunflower oil was optimized using Yarrowia lipolytica IFP29 (ATCC 20460). Optimizations were performed via a multi-response approach based on the Taguchi orthogonal array design (L16), targeting maximum biomass concentration and lipid content (based on dry cell weight). A total of 16 experimental conditions were tested with five key parameters: nitrogen concentration (0, 1, 2, and 4 g/L), WCO concentration (20, 40, 60, and 80 g/L), Tween 80 content (0, 0.5, 1, and 2%) as well as the application of sonication and sterilization. Analysis of variance revealed that all tested factors, except Tween 80 and sonication, had statistically significant effects on lipid content (p < 0.05). The highest lipid content (72.86% of dry cell weight) was obtained in a sterilized, sonicated medium containing 80 g/L WCO and 2% Tween 80, under conditions without nitrogen supplementation. In contrast, maximum biomass production (4.18 g/L) was achieved in sterile cultures with high nitrogen (4%) and high WCO (80 g/L) in the absence of Tween 80 and sonication. Palmitic acid (C16:0) content was also successfully optimized, with nitrogen concentration and Tween 80 supplementation exerting a statistically significant effect (p < 0.05). These results highlight the potential of waste sunflower oil as a low-cost feedstock for SCO production and support the development of economically and environmentally sustainable bioprocesses. Full article

Biopreservation using lactic acid bacteria has gained a growing interest as an alternative to chemical preservatives and/or as a complementary tool to prevent fungal spoilage in dairy products. Among the action mechanisms of antifungal LAB, competitionexclusion for trace elements has recently been highlighted. To further investigate this mechanism, two antifungal LAB strains, Lactiplantibacillus plantarum L244 and Lactobacillus rhamnosus CIRM-BIA1759, were studied in a yogurt model. Firstly, the antifungal activity of these strains against four main dairy spoilage fungi (Penicillium biforme, Mucor racemosus, Galactomyces geotrichum and Yarrowia lipolytica) was evaluated with or without trace element (6 metals and 12 vitamins) supplementation. Only manganese supplementation led to a suppression of the antifungal activity of both L. plantarum L244 and L. rhamnosus CIRM-BIA1759 against P. biforme and/or Y. lipolytica. The scavenging of trace elements was then measured using HR-ICP-MS in both cell-free yogurt whey and fungal biomass. HR-ICP-MS results showed a significant scavenging of Mn in L. plantarum L244 and L. rhamnosus CIRM-BIA1759 whey, as well as Cu for L. rhamnosus CIRM-BIA1759. Moreover, element uptake profiles, including metal and non-metal elements, for each of the target fungi were affected by the use of antifungal cultures. Finally, the role of competitionexclusion for manganese in the inhibition of 25 fungal spoilers was evaluated via oCelloScope growth follow-up. Growth inhibition by antifungal LAB strains was suppressed after Mn supplementation in cell-free whey for the 16 (out of 25) fungi initially inhibited without Mn supplementation. The nine other fungi were not inhibited or were poorly inhibited in the different tested conditions. This study confirmed the role of competitionexclusion for Mn in the antifungal activity of L. plantarum L244 and L. rhamnosus CIRM-BIA1759 strains but also revealed that this mechanism is not generic among fungal species, as the growth behavior of several tested species was not impacted by Mn scavenging. Full article

This study evaluated the nutritional, functional, biological, and sensory potential of proteins derived from Yarrowia lipolytica biomass and their enzymatic hydrolysates for food applications. Three strains were cultivated under bioreactor conditions, with strain JII1c selected for its superior biomass yield and protein content. Its amino acid composition was rich in lysine and branched-chain amino acids, with protein quality indices (CS = 37.8%, EAAI = 36.17%) confirming value in plant-based diets. Proteins were isolated and hydrolysed using a non-commercial serine protease from Cucurbita ficifolia, which enhanced solubility (NSI: 19.4 → 49.2%), water and oil absorption, and emulsion stability. Hydrolysates showed notable biological activities, including ACE (71.8%), DPP-IV (52.3%), and α-glucosidase (67.4%) inhibition, indicating potential metabolic benefits. Sensory evaluation of extrudates confirmed improvements in aroma, texture, and flavour when hydrolysates were incorporated. The use of a plant-derived protease demonstrates a sustainable approach to producing bioactive peptides. Y. lipolytica hydrolysates emerge as promising clean-label ingredients that combine nutritional quality with techno-functional performance, supporting their integration into health-oriented and sustainable food products. Full article

The aim of the study was to investigate the effects of different concentrations (0.15, 0.30, and 0.45 mL/L) of essential oils from coriander seeds (Coriandrum sativum), tarragon (Artemisia dracunculus), and orange peels (Citrus sinensis) on biomass, lipid content, and lipid yield of the strains Yarrowia lipolytica Y-1094, Y. lipolytica YB 423, and Y. lipolytica IFP29. The fatty acid composition of the oils produced by the strains was also determined. The highest biomass (5.38 ± 1.80 g/L) and lipid production (0.98 ± 0.42 g/L) were observed in the presence of Y. lipolytica IFP29 and Y. lipolytica YB 423, respectively. The lipid yield showed the highest value at the level of 0.45 mL/L in the presence of the Y. lipolytica Y-1094 strain. The correlation heat map results indicate that 0.45 mL of tarragon affected biomass and lipid content more than the other essential oils used. Y. lipolytica Y-1094 produced higher levels in terms of myristic acid and palmitic acid in all three essential oil sources than the other strains. The highest oleic acid level of all strains was determined in coriander seed essential oil, and the lowest in tarragon essential oil. The oleic acid level of Y. lipolytica Y-1094 was lower than that of the other two strains in all essential oils. Regarding linoleic acid, the oil level did not have a significant effect in the presence of tarragon and orange peel. Full article

Sustainability represents a significant global challenge, requiring a balance between environmental impact and the use of natural resources. White biotechnology, which uses microorganisms and enzymes for environmentally friendly products and processes, offers promising solutions to support a growing population. Within this context, the yeast Yarrowia lipolytica stands out, so we investigated the generation of biomass from two wild strains (ATCC 9773 and NRRL Y-50997) using different carbon sources. Additionally, protein content and amino acid profiles were assessed via standardized analytical methods to evaluate their potential as nutritional yeasts. Both strains demonstrated potential as nutritional yeasts, with biomass productivities of up to 35.5 g/L and 42 g/L, respectively. The protein content was high, with 58.8% for ATCC 9773 and 58.2% for NRRL Y-50997. Furthermore, the strains presented essential amino acid contents of 62.6% and 41.5%, with lysine being the most abundant amino acid. These findings underscore the versatility and productivity of Y. lipolytica, highlighting its potential for sustainable biotechnological applications such as single-cell protein production. Full article

This study investigated the potential of Yarrowia lipolytica, an oleaginous yeast, for producing lipid-rich biomass and its application in food technology. According to EFSA guidelines, lipid-rich biomass is recognized as a novel food with potential nutritional and technological value. However, cost-effective and scalable production of such biomass remains a challenge. The yeast was cultured in a nitrogen-limited medium using a cost-containment strategy based on the use of waste carbon sources, such as post-frying oil and untreated tap water. The composed batch culture approach studied in the experiments presented an example that reduces the cost of yeast biomass biosynthesis. This research aimed to characterize the biomass to assess its nutritional quality and suitability for food applications. Cultures were conducted in a laboratory bioreactor with a working volume of 4 litres. Key kinetic parameters were determined, including biomass yield (X), maximum lipid concentration (Lmax), lipid yield, protein yield relative to substrate and the specific rate of lipid synthesis or protein content and other cellular components. The biomass of Y. lipolytica demonstrated a high lipid content (39.43–50.53%), with significant levels of protein (24.16–27.03%) and unsaturated fatty acids, including oleic acid (62.73–66.44%) and linoleic acid (19.40–21.40%). Lipid-rich biomass produced in cultures with shorter times (20 h), which ended in the logarithmic growth phase, exhibited lower oxidative stability than longer cultures (65 h), which ended in the stationary growth phase. The results of this study highlighted that waste carbon sources and untreated tap water did not significantly impact the biomass yield or the nutritional profile, but did affect the stability of the produced oil. The biomass of Y. lipolytica, containing over 20% lipids, could serve as a promising raw material for food technology, providing a sustainable alternative to traditional vegetable oils. This work makes an important contribution to the development of alternative lipid sources by integrating waste processing in bioreactor-scale culture and kinetic modelling. Full article

Yeast biomass, a by-product of various industrial processes, is a sustainable source of food ingredients. Despite its nutritional richness, studies on Yarrowia lipolytica W29 biomass for high-value compound production using low-cost substrates like glycerol and glucose remain limited. These substrates enhance productivity and modulate cell wall composition. Extracting these compounds is complex but can be optimized through sequential hydrolysis, including autolysis and acid hydrolysis. In this study, mannoprotein exhibited a 60% emulsification index, 40 mN m⁻¹ surface tension for both substrates, and thermal stability with a mass retention above 30%. Acid hydrolysis yielded bioactive peptides (<1 kDa) with the highest antioxidant activity: 220 µM Trolox (ABTS), 270 µM Trolox (DPPH), and 125 µM ascorbic acid (FRAP). The raw biomass and feed ingredient (dry residue) provided 100% and 90% of the daily protein intake, respectively, with a β-glucan content of 17%. Glycerol and glucose resulted in similar high-value compounds, highlighting glycerol as a cost-effective carbon source. Thus, sequential hydrolysis is an effective strategy for extracting compounds from Y. lipolytica W29 biomass, offering a promising alternative for industrial applications due to its high nutritional value and functional properties. Full article

This study investigated the capabilities of Yarrowia lipolytica strains to grow in media with different hydrophobic wastes from the meat industry. The yeast growth, cellular lipid accumulation, production of lipases, and degree of utilization of liquid and solid lipid wastes were studied in shaken cultures in media with organic and inorganic nitrogen sources. The effects of the type of waste, initial concentration of carbon source, Yarrowia strain, and inoculum size were investigated in two experimental sets using the Latin Square 5 × 5 design method. Post-frying rapeseed oil from chicken frying was selected as the carbon source to promote biomass growth. In contrast, the solid lipid fraction from meat broths promoted efficient lipid accumulation and yeast lipolytic activity. An initial concentration of the carbon source at 8% m/v stimulated efficient lipid biosynthesis and lipase production, while 2.5% v/v inoculum provided optimal conditions for the growth and utilization of hydrophobic substrates. No significant differences were observed in the particle dispersion of the liquid and solid wastes in the culture media (span = 2.51–3.23). The maximum emulsification index (62%) was observed in the culture of the Y. lipolytica KKP 323 strain in the medium with post-frying rapeseed oil from chicken frying, which was correlated with biosurfactant synthesis. It was concluded that the type of waste, its structure, and its composition affected various physiological yeast responses. Full article

A novel approach for converting non-edible plant biomass into single-cell protein and oil (SCPO) via consolidated bioprocessing has been established, leveraging aerotolerant thermophilic cellulolytic consortia consisting mainly of Thermoanaerobacterium thermosaccharolyticum, Sporolactobacillus spp. and Clostridium sensu stricto to achieve the rapid and complete conversion of crystalline cellulose into a consistent cocktail of lactate, acetate and ethanol. This cocktail is an excellent substrate for cultivating organisms for SCPO production and food and feed applications, including Cyberlindnera jadinii, Yarrowia lipolytica and Corynebacterium glutamicum. Cultivation on this cocktail resulted in yields (Y_X/S) of up to 0.43 ± 0.012 g/g, indicating a yield from cellulose (Y_X/Cellulose) of up to 0.27 ± 0.007 g/g (dwb). The resulting SCPO was rich in protein (42.5% to 57.9%), essential amino acids (27.8% to 43.2%) and lipids (7.9% to 8.4%), with unsaturated fatty acid fractions of up to 89%. Unlike fermentation feedstocks derived from easily digested feedstocks (i.e., food waste), this approach has been applied to cellulosic biomass, and this mixed-culture bioconversion can be carried out without adding expensive enzymes. This two-stage cellulosic bioconversion can unlock non-edible plant biomass as an untapped feedstock for food and feed production, with the potential to strengthen resiliency and circularity in food systems. Full article

Enzyme immobilization is a crucial method in biotechnology and organic chemistry that significantly improves the stability, reusability, and overall effectiveness of enzymes across various applications. Lipases are one of the most frequently applied enzymes in food. The current study investigated the potential of utilizing selected agri-food and waste materials—buckwheat husks, pea hulls, loofah sponges, and yerba mate waste—as carriers for the immobilization of Sustine^® 121 lipase and Yarrowia lipolytica yeast biomass as whole-cell biocatalyst and lipase sources. Various lignocellulosic materials were pretreated through extraction processes, including Soxhlet extraction with hexane and ethanol, as well as alkaline and acid treatments for loofah sponges. The immobilization process involved adsorbing lipases or yeast cells onto the carriers and then evaluating their hydrolytic and synthetic activities. Preparations’ activities evaluation revealed that alkaline-pretreated loofah sponge yielded the highest hydrolytic activity (0.022 U/mg), while yerba mate leaves under brewing conditions demonstrated superior synthetic activity (0.51 U/mg). The findings underscore the potential of lignocellulosic materials from the agri-food industry as effective supports for enzyme immobilization, emphasizing the importance of material selection and pretreatment methods in optimizing enzymatic performance through giving an example of circular economy application in food processing and waste management. Full article