Search Results (28)

The use of phytobiotics in aquafeeds is a promising strategy to enhance performance and resilience to disease. This study evaluated the protective role of Morus alba (MA) extract against Vibrio cholerae, integrating in vivo responses in Dormitator latifrons (growth, biochemical and enzymatic responses, haemato-immunology and tissue histopathology) with in vitro assessment of V. cholerae growth, virulence-associated gene expression and cellular morphology. D. latifrons juveniles were fed five diets (0, 5, 10, 15 and 20 g/kg feed; three tanks per treatment, 15 fish per tank) for eight weeks, followed by a 7-day challenge with V. cholerae. MA increased growth and feed utilisation (p < 0.05); the 20 g/kg group reached 27.57 g final weight with a feed conversion ratio of 1.24, and whole-body protein and lipid contents rose at higher doses. MA modulated plasma biochemistry and key digestive (amylase, lipase), metabolic (ALT, AST) and antioxidant (SOD, CAT, GPx) enzymes, and improved haematological profiles. Histology of the intestine, liver and spleen showed preserved architecture and reinforced mucosal features in supplemented fish, particularly at 15–20 g/kg. Post-challenge, supplemented groups exhibited higher survival/relative protection than controls, alongside lower transaminases and stronger antioxidant responses. In vitro, MA extract inhibited V. cholerae growth, attenuated virulence-associated gene (toxR, ompU) expression and induced marked morphological damage in planktonic cells. Multivariate analyses (Z-score heatmaps and PCA) linked immune–enzymatic improvements with growth and protection. Overall, 15–20 g/kg MA optimised immunophysiological status and disease resistance, supporting MA as a functional feed additive for sustainable aquaculture of D. latifrons. Full article

Propionylated derivatives of gastrodin are valuable due to their enhanced lipophilicity and bioavailability. This study investigated the molecular basis for the differential catalytic efficiency of Aspergillus oryzae whole cells in gastrodin propionylation. A high conversion rate of 96.84% was achieved with soybean oil induction, compared to only 8.23% under glucose induction. Comparative transcriptomic analysis identified 20,342 differentially expressed genes (DEGs), which were significantly enriched in lipid metabolism and signal transduction pathways. From 26 upregulated lipase-related DEGs, a candidate triacylglycerol lipase gene (CL24.Contig40_All) was prioritized. Homology modeling and molecular docking supported its potential role by demonstrating that the encoded enzyme possesses a typical α/β hydrolase fold with a catalytic triad and favorable binding with both gastrodin and vinyl propionate. These findings indicate that soybean oil may enhance lipase expression by activating lipid metabolic and phosphatidylinositol signaling pathways, providing crucial transcriptional-level insights and genetic targets for the rational design of efficient whole-cell biocatalysts. Full article

This study was performed to investigate the effects of dietary yeast culture (YC) supplementation on growth performance, digestive function, intestinal inflammatory response, and microbiota composition of largemouth bass Micropterus salmoides (LMB). Six diets were formulated with graded levels of YC (0, 5, 10, 15, 20, and 30 g/kg), referred to as CON, YC5, YC10, YC15, YC20, and YC30, respectively. Each diet was assigned to four replicate tanks of LMB juveniles (initial body weight 8.11 ± 0.05 g) with twenty fish per tank. After an 8-week feeding trial, final body weight and specific growth rate showed an increasing trend with 5~20 g/kg YC and reached a maximum at 15 g/kg YC. Feeding ratio decreased, but feed efficiency ratio (FER) improved in response to dietary YC inclusion, and FER was higher in the YC10 fish than in the YC5, YC20, and YC30 fish. Proximate composition (moisture, protein, and lipid) of the whole fish was not affected by dietary YC levels. The activities of intestinal lipase and trypsin were higher in the YC10 fish, while the relative expression of interleukin-8 (il-8) and il-1β was downregulated in the hindgut of the YC15 fish compared with the CON fish. Histological examination showed that the villus height of the midgut, together with goblet cell density of the foregut and midgut, was higher in the YC10 and YC30 fish than in the CON fish. 16S rRNA sequencing showed that Proteobacteria, Fusobacteria, and Firmicutes dominated the intestinal microbiota in LMB. The decrease in harmful Mycoplasma accounted for the dramatic change in Firmicutes abundance, while the increase in Cetobacterium (specifically C. somerae) accounted for the change in Fusobacteria abundance in the gut of the YC10 and YC30 fish compared with the CON fish. The increase in the beneficial Endozoicomonas was the main reason for the change in Proteobacteria abundance in the intestine of the YC30 fish as compared with the CON fish. Taken together, the alteration of intestinal microbiota composition contributed to the improved digestive function and feed utilization in LMB fed YC-supplemented diets. Based on growth performance, the optimal YC level in the diet for LMB was 15 g/kg. Full article

The use of agro-industrial by-products and processing residues, which are rich in carbohydrates, proteins, and lipids, in the production of lipases allows the sustainable use of these residues, reducing environmental impacts. In this study, the immersion water of lentils, soybeans, and textured soy protein was evaluated as carbon and nitrogen sources in the production of whole-cell lipases, and the resulting biomass was used in the hydrolysis of residual soybean oil with conventional heating and ultrasound. The results showed that the best culture medium was the one with 50% textured soybean protein, reaching values of 149.04 U/g of hydrolytic activity, 12.92 g/L of biomass concentration, 144.17 U of total biomass activity, and specific and volumetric productivities of 2.07 U/g·h and 20.02 U/L·h, respectively. The positive effect of adding soybean frying oil to the crop was observed, which increased cell production and hydrolytic activity. The biomass obtained showed potential for the ultrasound-assisted hydrolysis of vegetable oils, reaching approximately 43.36% hydrolysis in 7 h of reaction, with an initial rate of 31.03 mmol/h. It is concluded that soybean protein processing water is a viable candidate to replace traditional nitrogen sources, being an economically attractive alternative due to its wide generation in restaurants. Full article

Lipases are enzymes of great application importance in the food industry, in the cosmetic and detergent industries, in pharmacy and medicine, and in organic chemistry. Among lipases of various origins, those from microorganisms are currently the most commonly used. An excellent producer of lipases seems to be the nonconventional Yarrowia lipolytica yeast, but the biosynthesis of valuable metabolites depends on many factors. This study aimed to investigate the biodiversity of extracellular enzymes produced by four strains of Y. lipolytica, and to determine the optimal conditions of catalysis for the enzymes, according to temperature and pH, in a model hydrolysis reaction. Based on the obtained results, the biodiversity and strain dependence in lipase biosynthesis were observed. Using a Central Composite Design, it was found that temperature is the main factor in determining lipase activity. The enzymes produced by four different strains exhibited other substrate specificity, which was investigated using Latin square design methodology. Only two examined yeast strains, KKP 379 and W29, produced extracellular lipases at a high activity level towards medium- and long-chain fatty acid esters. Moreover, extracellular lipase from wild-type strain KKP 379 was further characterized, followed by exploring the activity of whole-cell biocatalyst and lyophilized enzyme solutions, and it was acknowledged that it was a “true” lipase with the highest affinity to p-nitrophenyl oleate. 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

Developing reusable and easy-to-operate biocatalysts is of significant interest in biodiesel production. Here, magnetic whole-cell catalysts constructed through immobilizing recombinant Escherichia coli cells (containing MAS1 lipase) into Fe₃O₄–chitosan magnetic microspheres (termed MWCC@MAS1) were used for fatty acid methyl ester (FAME) production from waste cooking oil (WCO). During the preparation process of immobilized cells, the effects of chitosan concentration and cell concentration on their activity and activity recovery were investigated. Optimal immobilization was achieved with 3% (w/v) chitosan solution and 10 mg wet cell/mL cell suspension. Magnetic immobilization endowed the whole-cell catalysts with superparamagnetism and improved their methanol tolerance, enhancing the recyclability of the biocatalysts. Additionally, we studied the effects of catalyst loading, water content, methanol content, and reaction temperature on FAME yield, optimizing these parameters using response surface methodology and Box–Behnken design. An experimental FAME yield of 89.19% was gained under the optimized conditions (3.9 wt% catalyst loading, 22.3% (v/w) water content, 23.0% (v/w) methanol content, and 32 °C) for 48 h. MWCC@MAS1 demonstrated superior recyclability compared to its whole-cell form, maintaining about 86% of its initial productivity after 10 cycles, whereas the whole-cell form lost nearly half after just five cycles. These results suggest that MWCC@MAS1 has great potential for the industrial production of biodiesel. Full article

Yarrowia lipolytica is a robust yeast species that has gained significant attention as a biofactory for various biotechnological applications and undoubtedly can be referred to as a hidden treasure trove due to boasting a diverse array of enzymes with wide-ranging applications in multiple industries, including biofuel production, food processing, biotechnology, and pharmaceuticals. As the biotechnology field continues to expand, Y. lipolytica is poised to play a pivotal role in developing eco-friendly and economically viable bioprocesses. Its versatility and potential for large-scale production make it a promising candidate for sustainably addressing various societal and industrial needs. The current review article aimed to highlight the diverse enzymatic capabilities of Y. lipolytica and provide a detailed analysis of its relevance in biocatalysis, including the use of whole-cell catalysts and isolated enzymes. The review focused on wild-type yeast strains and their species-dependant properties and selected relevant examples of Y. lipolytica used as a host organism for overexpressing some enzymes. Furthermore, the application of Y. lipolytica’s potential in enantiomers resolution, lipids processing, and biodiesel synthesis, as well as the synthesis of polymers or esterification of different substrates for upgrading biologically active compounds, was discussed. Full article

Yeast culture is a complex fermentation product consisting of fermentation substrate, yeast cells and their metabolites. This study investigated the potential of yeast culture in replacing fishmeal in the diet of yellow catfish (Pelteobagrus fulvidraco). First, a basal diet was formulated to contain 160 g/kg fishmeal (CON), and then the dietary fishmeal was decreased to 120, 80, 40 and 0 g/kg via yeast culture inclusion, respectively, to form another four isonitrogenous and isolipidic diets (YC-12, YC-8, YC-4 and YC-0). Yellow catfish (3.00 ± 0.10 g) were fed with the above five diets with triplicates per treatment and 40 fish per replicate. After 8 weeks of feeding, the weight gain (WG), protein efficiency rate and protein retention in the YC-12 group and the feed conversion ratio (FCR) in the YC-12 and YC-8 groups showed no significant differences to the CON group (p > 0.05), but the WG in the YC-8, YC-4 and YC-0 groups was significantly lower, and the FCR in the YC-4 and YC-0 groups was significantly higher than in the CON group (p < 0.05). In terms of the whole-body composition, only the crude lipid content in the YC-0 group decreased significantly (p < 0.05). Compared with the CON group, the aspartate aminotransferase and alanine aminotransferase activities and D-lactic acid content in the YC-0 group were significantly increased, and the total cholesterol content was significantly reduced (p < 0.05). The activities of catalase, superoxide dismutase, and alkaline phosphatase, as well as the content of complement C3 and immunoglobulin M, were significantly increased, while the MDA content was significantly reduced in the YC-12 and YC-8 groups (p < 0.05). There were no significant differences in the intestinal amylase and lipase activity among all the groups (p > 0.05), while the trypsin activity in the YC-12 and YC-8 groups, as well as the diamine oxidase in the YC-4 and YC-0 groups, were significantly higher than those in the CON group (p < 0.05). In the intestine histology, there was a significant decrease in the intestinal villus height in the YC-4 and YC-0 groups as well as in the villus width in the YC-0 group (p < 0.05). In the hepatopancreas histology, lipid droplets appeared in the YC-4 and YC-0 groups, and severe cell vacuolation was observed in the YC-0 group. As a summary, in a practical diet containing 160 g/kg fishmeal, yeast culture can effectively replace 40 g/kg fishmeal without negatively affecting the growth performance, nutrient utilization, serum immune and antioxidant, intestinal and hepatopancreas histology of yellow catfish. Full article

This study assessed the application of whole lipolytic cells in the pretreatment of slaughterhouse wastewater to reduce its lipid content. The fungal biomass of Rhizopus oryzae was evaluated in the hydrolysis of slaughterhouse wastewater containing high lipid concentrations, focusing on the biomass’s concentration and the effect of using an emulsifier and surfactant. The use of the whole-cells lipase of Rhizopus oryzae grown in a residual vegetable oil medium proved effective in the hydrolysis of slaughterhouse wastewater, generating concentrations of free fatty acids (FFA) ranging from 40.36 to 90.14 mM. The action of lipase in the hydrolysis of slaughterhouse residues indicated its effectiveness in pretreating lipid-rich liquid residues, potentially boosting the microbiota of this anaerobic treatment. The results showed that lipase activity without surfactant exhibited a similar performance to that of Triton X-100 in the hydrolysis of liquid residues. However, the combination of lipase and surfactant could represent a promising strategy to optimize free fatty acid production from slaughterhouse residues, strengthening anaerobic treatment processes and potentially enhancing the overall efficiency of waste management systems. Full article

Oxidative stress (OS) has been linked to cell damage and chronic disease development; however, the study of psychological factors related with OS has been limited, as has its relationship with biochemical and personal variables. Therefore, the aim of this study was to evaluate the association between a wide variety of personal, psychological, and biochemical factors with OS in a sample of healthy Mexican people. A total of 134 participants, from which 70 (52%) were women, without known chronic conditions were included in the study, and the molecule 8-hydroxy-2′-deoxyguanosine (8-OHdG) was also measured as a marker of OS. We observed in the multivariate analysis of the whole sample that depressive symptoms (measured with CES-D scale) were the only psychological variable significantly associated (positively) with 8-OHdG. In addition, the following sociodemographic variables were associated with 8-OHdG: age, schooling (positively correlated), and the frequency of vitamins/antioxidant consumption (negatively correlated). The biochemical variables of erythrocytes in urine and amylase were positively correlated with 8-OHdG, while glucose was negatively correlated with it. Additional biochemical variables were associated in the multivariate analysis of each sex, including the positive correlation of LDL-cholesterol, LDH enzyme, lymphocytes, and the negative correlation of phosphorus and eosinophils in women’s samples, as well as the positive correlation of potassium, uric acid, and leucocytes in urine and the negative correlation of erythrocytes and lipase in the men’s samples. In conclusion, depression was the only psychological variable positively correlated with 8-OHdG after adjusting for confounders, and new associations with biochemical variables were found with some differences between sexes. Full article

The discovery of novel probiotic bacteria from free-ranging animals for the treatment of inflammatory bowel disease in domestic pets is a unique approach. The chloroform extraction of gastrointestinal (GI) tract material was used to inactivate vegetative cells and select for spore-forming bacteria. A bacterium identified as a novel Paenibacillus sp. strain via small ribosomal RNA (16S) gene sequencing was isolated from the GI tract of a gray wolf (Canis lupus). The bacterium was typed as Gram-variable, both catalase/oxidase-positive and positive via starch hydrolysis and lipase assays. The bacterium inhibited the growth of Staphylococcus aureus, Escherichia coli and Micrococcus luteus. The draft whole genome sequence (WGS) assembly was 7,034,206 bp in length, encoding 6543 genes, and is similar in size and coding capacity to other closely related Paenibacillus spp. The isolate’s genome encodes several germination and sporulation gene products along with antimicrobials such as a bacteriocin system and chitinase. Enzyme genes such as alpha amylase, cellulase, lipases and pectin lyase are also present in the genome. An incomplete lysogenic bacteriophage genome was also present in the isolate’s genome. Phenotypic characteristics combined with a WGS genotype analysis indicate that this bacterium, designated Paenibacillus sp. ClWae2A, could be a potential candidate probiotic for domestic dogs. Full article

This study aimed to economically develop the yeast whole-cell biocatalyst from the lipase-secreting Magnusiomyces spicifer SPB2 to serve green biodiesel production. The scaled-up productions of lipases were optimized using a 5-L stirred-tank bioreactor. The maximum extracellular lipase and cell-bound lipase (CBL) yields of 1189.65 U/L and 5603.74 U/L were achieved at 24 h and 60 h, respectively, in the modified IMY medium (pH 5.0) containing 2% of soybean oil as a carbon source and 0.2% Gum Arabic as an emulsifying agent. The optimized cultivation was initiated with an inoculum size of 1 × 10⁷ cells/mL and conducted under an aeration rate of 0.75 vvm with an agitation speed of 400 rpm. The obtained whole-cell biocatalyst of M. spicifer SPB2 was applied to catalyze the transesterification reaction using palm oil and methanol as substrates. The greatest yield of 97.93% fatty acid methyl ester (FAME) was reached at 72 h using a palm oil/methanol ratio of 1:7, indicating high methanol stability of the biocatalyst. Moreover, substrate homogenization accelerated the reaction to achieve FAME production of 97.01% at 48 h and remained stable afterwards. Without homogenization, the highest FAME of 98.20% was obtained at 60 h. The whole-cell biocatalyst prepared from lipase-secreting M. spicifer SPB2 at an up-scaled level greatly enhanced efficiency and feasibility for commercial biodiesel production through a green conversion process. Full article

The mealworm (Tenebrio molitor Linnaeus 1758) is gaining importance as one of the most popular edible insects. Studies focusing on its bioactivities are increasing, although alternative forms of consumption other than the whole insect or flour, such as bioactive non-protein extracts, remain underexplored. Furthermore, the incidence of metabolic syndrome-related pathologies keeps increasing, hence the importance of seeking novel natural sources for reducing the impact of certain risk factors. The aim was to study the potential of a non-protein mealworm extract on metabolic syndrome-related pathologies, obtained with ethanol:water (1:1, v/v) by ultrasound-assisted extraction. We characterized the extract by gas-chromatography mass-spectrometry and assessed its hypolipidemic potential, its ability to scavenger free radicals, to attenuate the inflammatory response in microglial cells, to affect mitochondrial respiration and to enhance insulin sensitivity in mouse hepatocytes. The extract contained fatty acids, monoglycerides, amino acids, certain acids and sugars. The mealworm extract caused a 30% pancreatic lipase inhibition, 80% DPPH· scavenging activity and 55.9% reduction in the bioaccessibility of cholesterol (p = 0.009). The extract was effective in decreasing iNOS levels, increasing basal, maximal and ATP coupled respiration as well as enhancing insulin-mediated AKT phosphorylation at low insulin concentrations (p < 0.05). The potential of a non-protein bioactive mealworm extract against metabolic syndrome-related pathologies is shown, although further studies are needed to elucidate the mechanisms and relationship with compounds. Full article

In the human body, docosahexaenoic acid (DHA) contained in fish oil is converted to trace amounts of specialized pro-resolving mediators (SPMs) as the principal bioactive metabolites for their pharmacological effects. Protectin Dx (PDX), an SPM, is an important medicinal compound with biological activities such as modulation of endogenous antioxidant systems, inflammation pro-resolving action, and inhibition of influenza virus replication. Although it can be biotechnologically synthesized from DHA, it has not yet been produced quantitatively. Here, we found that 15S-lipoxygenase from Burkholderia thailandensis (BT 15SLOX) converted 10S-hydroxydocosahexaenoic acid (10S-HDHA) to PDX using enzymatic reactions, which was confirmed by LC-MS/MS and NMR analyses. Thus, whole-cell reactions of Escherichia coli cells expressing BT 15SLOX were performed in flasks to produce PDX from lipase-treated DHA-enriched fish oil along with E. coli cells expressing Mus musculus (mouse) 8S-lipoxygenase (MO 8SLOX) that converted DHA to 10S-HDHA. First, 1 mM DHA (DHA-enriched fish oil hydrolysate, DFOH) was obtained from 455 mg/L DHA-enriched fish oil by lipase for 1 h. Second, E. coli cells expressing MO 8SLOX converted 1 mM DHA in DFOH to 0.43 mM 10S-HDHA for 6 h. Finally, E. coli cells expressing BT 15SLOX converted 0.43 mM 10S-HDHA in MO 8SLOX-treated DFOH to 0.30 mM (108 mg/L) PDX for 5 h. Consequently, DHA-enriched fish oil at 455 mg/L was converted to 108 mg/L PDX after a total of 12 h (conversion yield: 24% (w/w); productivity: 4.5 mg/L/h). This study is the first report on the quantitative production of PDX via biotechnological approaches. Full article