Search Results (540)

Aspergillus flavus, a ubiquitous phytopathogen, produces mycotoxins, especially aflatoxin B₁ (AFB₁), and infects crops worldwide. Glycerol-3-phosphate dehydrogenase (G3PDH) is a key enzyme in the glycerol synthesis and metabolic pathway catalyzing the reversible conversion reaction between glycerol-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP). However, the biological function of G3PDH in A. flavus remains uncharacterized. In this study, the glycerol-3-phosphate dehydrogenase GfdA and GfdB recombinant proteins of A. flavus were expressed, and the enzymatic activity of the GfdA protein was successfully determined. Subsequently, single-gene knockout strains (ΔgfdA, ΔgfdB), double-gene knockout strains (ΔgfdAΔgfdB) and their corresponding complemented strains (gfdA^C, gfdB^C) were constructed by a homologous recombination method to explore the biological functions of these two genes in A. flavus. The phenotypic analyses revealed that although both gfdA and gfdB encoded glycerol-3-phosphate dehydrogenases, gfdA plays major roles in colony growth, conidiation, sclerotium formation, crop infection and osmotic stress tolerance in A. flavus. Notably, the performance of the ΔgfdAΔgfdB strains is almost similar to that of the ΔgfdA strain. Biochemical assays demonstrated that the intracellular glycerol content increased significantly in all mutants compared to the wild type (WT) under both normal and osmotic stress conditions. Furthermore, we found that exogenous glycerol supplementation rescued the growth defect of the ΔgfdA and ΔgfdAΔgfdB strains. Taken together, GfdA is important for glycerol synthesis, while GfdB is functionally redundant with respect to GfdA. This study preliminarily explores the main biological functions of GfdA and GfdB, providing a theoretical basis for the study of glycerol anabolic pathways of A. flavus and also offering novel insights into the development of strategies to control aflatoxin contamination. Full article

Aspergillus westerdijkiae, a filamentous fungus commonly isolated from pickled vegetables and high-salt condiments, can cause spoilage and produce nephrotoxic ochratoxin A (OTA) under saline conditions. However, its adaptive mechanisms to salt stress remain unclear. To address this, the pickle-derived strain NDX1 was subjected to 0, 1.0, 1.5, and 2.0 mol/L NaCl treatments. Colony growth was assessed after 7 days of incubation on PDA plates supplemented with the respective NaCl concentrations. For physiological indices, mycelia were pre-cultured in salt-free PDB for 5 days, followed by the addition of NaCl to final concentrations (0, 1.0, 1.5, and 2.0 mol/L) and further incubation for 2 days, after which relative electrical conductivity (REC) and malondialdehyde (MDA) content were measured. Colony diameters were recorded to evaluate vegetative growth; REC was determined by conductometry to assess cell membrane permeability; and MDA content was measured via the thiobarbituric acid (TBA) colorimetric method to indicate lipid peroxidation levels. Transcriptome sequencing combined with qRT-PCR validation was employed to identify differentially expressed genes (DEGs) involved in osmotic adaptation. Results showed that low salinity (1.0 mol/L NaCl) promoted growth, while higher concentrations (≥1.5 mol/L NaCl) inhibited it, accompanied by increased REC and decreased MDA, forming a distinctive high-permeability, low-lipid-peroxidation phenotype. A total of 3155 DEGs were detected, mainly associated with the HOG-MAPK cascade, glycerol biosynthesis, and ion transport pathways. Eight key HOG-MAPK genes and 21 glycerol metabolic genes were upregulated in a concentration-dependent manner, with the terminal kinase Hog1 coordinating transcription of downstream effectors governing glycerol synthesis and ion homeostasis. These findings demonstrate that A. westerdijkiae integrates de novo glycerol production and intracellular lipid remodeling via the HOG-MAPK pathway to achieve osmotic adaptation under hypersaline stress. This work identifies potential molecular targets for controlling toxigenic spoilage caused by this species in high-salt fermented foods. Full article

Introduction: The study purpose was to identify possible key metabolites that determine the adaptation of the Endomyces magnusii yeast to long-term cultivation (four weeks) using glycerol as an “oxidative” and glucose as a “fermentative” substrate. Methods: The metabolic profile was assayed using gas chromatography combined with mass spectrometry, followed by bioinformatic analysis (PARADISe, Golm metabolome database (GMD), MassBank, UniChrom). Results: PCA and PLS-DA analyses showed that the type of carbon source contributed significantly to the overall variability of the data, and the greatest variance was observed for the groups grown on different substrates for the first cultivation week. Growth on glycerol increased the chronological lifespan of E. magnusii due to the early launch of adaptive oxidative stress, the active use of lipids as an energy source, the accumulation of membrane sterols, osmo-protective polyols, organic acids (malic, methyl glycerinic, palmitic, linoleic), and some sugars (lyxose, galactose), which increased the overall resistance and maintained high cell survival. On the contrary, cultivation using glucose provoked a sharp substrate depletion, inducing passive storage of sugars (trehalose), diauxic shock, and less effective antioxidant protection, which provided lower cell survival upon prolonged growth. Conclusions: (1) Metabolic signs associated with prolonged culturing were identified in all the compounds classes tested (polyols, fatty acids, lactones); (2) some metabolites (in particular, dulcitol), being hypothetical biomarkers of aging, are at the same time protective agents involved in the adaptation of yeast cells to the deep stationary growth stages. Our data can serve as a basis for comparative studies of aging-related metabolism in other eukaryotic models. Full article

The industrial use of non-Saccharomyces yeasts offers a robust bioprocess strategy for modulating volatile biochemical profiles and reducing climate-driven ethanol production in fermented beverages. This study explores the metabolic diversity of indigenous non-Saccharomyces, with a particular focus on Starmerella bacillaris MI151, selected for sequential inoculation with Saccharomyces cerevisiae MI118. Pilot-scale bioreactor fermentations (25 L) of two Romanian matrix-specific aromatic grape cultivars, Busuioacă de Bohotin and Tămâioasă Românească, exhibited clear strain-dependent carbon flux changes. The sequential culture actively triggered the glycerol-pyruvic pathway, which consistently reduced the final ethanol concentration to up to 0.94% (v/v) and maintained a balanced profile of volatile compounds. GC-MS-based metabolomic profiling revealed substantial changes in the esterification kinetics and glycosidic precursor cleavage. The sequential fermentation resulted in a synergistic increase in n-hexyl acetate (up to 2310.01 µg/L) and bypassing of the standard enzymatic repression, freeing highly volatile monoterpenes (β-citronellol and β-geraniol) in the analyzed matrices. This targeted microbial system successfully modulated the organic acid–phenolic balance, neutralizing harsh structural finishes, as confirmed by quantitative sensory mapping. Finally, these specific local yeast strains exhibit strong bioprocess scalability, offering a predictable, non-engineered strategy to lower the ethanol yield while driving targeted flavor enhancement in climate-vulnerable viticultural regions. Full article

Olive (Olea europaea L.) is one of the oldest woody oil crops. Previous studies, by integrating transcriptomics and metabolomics, have identified glycerol-3-phosphate acyltransferase 4 (GPAT4) as a key regulatory gene involved in oil biosynthesis in olive fruits. Although GPAT4 was identified as a key regulator, the overall function of the GPAT gene family in olive remains largely unknown. As a critical rate-limiting enzyme catalyzing triacylglycerol production, GPAT plays an important role in oil synthesis in oil crops. However, the function of the GPAT gene in olive remains unclear. A systematic analysis of the olive GPAT gene family showed that 12 OeGPAT proteins can be divided into four subclasses, all containing the conserved GPAT domain. These genes are distributed across chromosomes and scaffolds, with highly conserved motifs and variable gene structures. Functional studies revealed that overexpression of OeGPAT1.1, OeGPAT1.2, OeGPAT2, OeGPAT3, OeGPAT4, OeGPAT7, and OeGPAT8 significantly increased total oil content in transgenic Arabidopsis leaves and seeds. Further experiments in olive fruit at maturity stages II, III, and IV demonstrated that overexpression of the same set of OeGPAT genes elevated total oil content, while their silencing resulted in a decrease. In summary, this study reveals that OeGPATs can serve as ideal targets in metabolic engineering to regulate oil content in oil crops, providing a theoretical foundation for further research on oil biosynthesis in olive fruit. Full article

Bacterial cellulose (BC) is a high-purity biopolymer with significant potential for sustainable material applications. However, its production remains limited by the metabolic behavior and compositional complexity of available carbon substrates. Simple sugars such as fructose, glucose, and sucrose support BC synthesis but differ in their metabolic pathways and associated byproduct formation, which can influence medium pH and cellulose biosynthesis. Across refined substrates, fructose generally outperforms glucose, producing the most favorable balance between productivity and structure. Reported fructose-based yields range from 1.55 to 6.29 g/L depending on the composition. In media containing hexoses, such as fructose, and three-carbon compounds, such as glycerol and pyruvate, biosynthesis proceeds via the pentose phosphate pathway. Additionally, pyruvate can be further metabolized via gluconeogenesis coupled with the tricarboxylic acid cycle, producing more BC precursors. In contrast, glucose-based yields are limited primarily by oxidation to gluconic acid, and sucrose often shows slower or lower initial production due to delayed metabolism, depending on the medium’s composition. Interestingly, structural trends showed that yield and structural quality are not always coupled. Fructose-based BC can reach around 90% to 92% crystallinity index (CrI) and is associated with lower porosity and larger nanoribbon networks, while sucrose-based BC can reach up to a 95.2% CrI despite slower initial production. Dual sugar systems further reveal differences in metabolism. Glucose-containing carbon sources are often suppressive because glucose dominates metabolism and acidification, whereas fructose-containing systems more often show synergistic behavior and support higher yields. Structural outcomes in these systems depend more on biosynthesis rates and strain-specific behavior than on carbon sources only. Additionally, low-cost substrates derived from agro-industrial residues and lignocellulosic biomass offer economically viable feedstock but introduce variability due to inhibitory compounds such as organic acids and phenolics. This review examines how sugar type and substrate complexity affect BC production and its structural properties in acetic acid bacteria, particularly the genera Acetobacter, Gluconacetobacter, and Komagataeibacter, with emphasis on the relationship between BC yield and CrI. Our analysis of the reported fermentation and characterization data in this review reveals a recurring paradox between yield and structural quality, in which substrates that promote higher BC yields do not always produce materials with superior structural properties such as crystallinity or degree of polymerization. Comparative examination of the literature revealed that inhibitory compounds such as phenolic compounds may act as structural modulators rather than simple yield suppressors. Phenolic compounds are predicted to bind to BC through non-covalent interactions facilitated by the large surface area and porous structure of BC. These interactions may influence the self-assembly of BC nanofibers. These findings indicate that fructose often offers the best balance of yield and structure. While sucrose tends to favor structural order, glucose is susceptible to yield loss from acidification, and waste-derived substrates can provide economic, high-yield, and structural properties only when their inhibitory compounds are well controlled. Full article

Leptobotia elongata, an endangered freshwater fish endemic to the upper Yangtze River, increasingly depends on artificial reproduction for conservation. However, a captive juvenile population fed a conventional diet commonly exhibits ovarian development arrested at stages I–II, representing a critical bottleneck for captive reproduction. To address this, juvenile L. elongata were reared for 6 months on either a basal diet (control group, CG) or a lipid-enriched diet in which soybean oil was replaced by fish oil and soybean lecithin, with vitamin E added (treatment group, TG). Histological examination revealed that TG ovaries advanced from stage I–II to stage III, with markedly larger oocytes and centralized nucleoli. LC-MS/MS-based untargeted metabolomics profiling identified 1773 metabolites, of which 566 differed significantly between groups (374 up- and 192 down-regulated in TG). KEGG enrichment revealed 15 significantly perturbed pathways, with nucleotide metabolism showing the highest enrichment (Rich factor = 0.22), accompanied by changes in fatty acid biosynthesis, biosynthesis of unsaturated fatty acids, glycerophospholipid metabolism, aminoacyl-tRNA biosynthesis, pantothenate and CoA biosynthesis, and TCA-related modules. Coordinated up-regulation of long-chain polyunsaturated fatty acids (DHA, EPA, ARA, α-linolenic acid), DHA-phosphatidylethanolamine, phosphatidylcholine and CDP-choline, together with depletion of their precursors (sn-glycerol-3-phosphate, LPI(20:4), pyrophosphate), was consistent with enhanced phospholipid remodeling and Lands-cycle activity. A multi-tier regulatory network was constructed, anchored on three pathway hubs (nucleotide metabolism, pyrimidine metabolism and fatty acid elongation) and five functional modules. This network indicated that dietary lipid supplementation was associated with coordinated changes across four interconnected metabolic axes: lipid supply and membrane remodeling, nucleotide synthesis and turnover, amino acid–protein translation, and energy–coenzyme metabolism. Collectively, these findings propose a metabolic framework and identify candidate biomarkers (e.g., DHA-PE, PC) for optimizing feed formulations of L. elongata. Full article

Background/Objective: Antimicrobial resistance poses a critical public health crisis, highlighting the urgent requirement to investigate bacterial evolutionary adaptations and pioneer alternative therapeutics. Consequently, bacteriophages and metal-based compounds are emerging as viable options to combat drug-resistant infections. Building on our finding that T4 phage resistance in E. coli B also confers adaptation to high iron(III), we used RNA-sequencing (RNA-seq) to explore bacterial gene expression in resistant and control populations. We analyzed samples from our five experimental groups—Ancestor (ANC), control (CON), phage-selected (Phage), iron(III)-selected (FE), and phage/iron(III)-selected (PF), to understand how these regimes drive transcriptional changes. Method: Total RNA was extracted using the TRIzol protocol, and sequencing libraries were prepared with the Illumina RNA Total Library Prep Kit. Sequencing was performed on the Illumina NextSeq 1000/2000 platform. Reads were aligned to the E. coli B ATCC 11303 reference genome, and pairwise comparisons between the five experimental groups were conducted to determine differential gene expression profiles. Results: Principal component analysis (PCA) showed that iron-adapted populations (FE and PF) separated distinctly from the Ancestor and control populations along PC1 (capturing 40% of the variance), while the phage-selected replicates were split, with one (Phage5) clustering with CON3 and two (Phage2, Phage4) falling closer to, but clearly separated from, the Ancestor. Differential expression analysis (P_adj < 0.05 and |log₂FC| ≥ 1) revealed extensive transcriptional rewiring, with 482 and 381 differentially expressed genes (DEGs) in the FE and PF populations, respectively, compared to the Ancestor, and 177 DEGs in the phage-selected population compared to the Ancestor. The direct pairwise comparison between the iron-selected and phage/iron-selected populations yielded zero DEGs, demonstrating that both iron-adapted populations converged on a near-identical gene expression profile regardless of their distinct genetic and evolutionary backgrounds. Conclusions: This study suggests that pmrB and arn pathway genes may serve as primary markers for resistance to iron stress. These results are significant because they demonstrate a coordinated, multi-gene defense mechanism in E. coli B against high iron(III) stress, in which the arn operon and eptA remodel lipid A and the outer membrane, while glycerol-3-phosphate metabolism and phage-shock/chaperone pathways are repressed. Full article

The stipe of Hypsizygus marmoreus is a low-value byproduct generated during mushroom processing. Reutilization of this agricultural waste as a functional feed additive may provide both economic and environmental benefits for sustainable aquaculture. This study evaluated the effects of dietary H. marmoreus stipe (HMS) supplementation on the growth performance and survival of juvenile Micropterus salmoides and explored the underlying metabolic and transcriptional responses. Juvenile largemouth bass (initial body weight: 1.13 ± 0.05 g) were fed diets containing 0% (HMS0), 5% (HMS5), or 10% (HMS10) HMS for 46 days. HMS supplementation did not significantly affect growth performance but significantly increased survival rate in both HMS5 and HMS10 groups. Widely targeted metabolomic profiling suggested that dietary HMS may drive prominent shifts in the hepatic and gastric metabolic profiles, with potential changes observed in pathways associated with pyrimidine metabolism, glycerophospholipid metabolism, and ABC transporters. Hepatic transcriptomic analysis further identified differentially expressed genes enriched in these pathways. Integrated multi-omics analysis indicated potential coordinated associations between key metabolites, including orotic acid, ureidosuccinic acid, LPG (16:1), and Val-Cys, and genes involved in nucleotide metabolism, lipid metabolism, and transporter functions, such as DPYD (dihydropyrimidine dehydrogenase), NDK (nucleoside diphosphate kinase), ENTP5 (ectonucleoside triphosphate diphosphohydrolase 5), NT5D2 (5′-nucleotidase domain containing 2), GPT3L (glycerol-3-phosphate acyltransferase-like), ABCA1 (ATP-binding cassette subfamily A member 1), and ABCD4 (ATP-binding cassette subfamily D member 4). In addition, antioxidant enzyme activities were significantly enhanced in the HMS5 group, whereas no further improvement was observed at the 10% supplementation level. Collectively, these findings suggest that dietary HMS supplementation may enhance the survival of largemouth bass via coordinated metabolic regulation and antioxidant responses. This study highlights the potential application of mushroom-processing byproducts as sustainable functional feed ingredients in aquaculture. Full article

Microalgal lipids are promising sustainable feedstocks for high-value functional ingredients. However, the influence of cultivation-driven lipid composition on enzymatic conversion remains poorly understood. This study integrated cultivation strategy and enzymatic upgrading to tailor Neochloris oleoabundans lipids for mono- and diacylglycerol (MAG and DAG) production. Heterotrophic cultivation achieved a maximum dry biomass concentration of 2.78 ± 0.14 g L⁻¹, whereas autotrophic cultivation reached 0.39 ± 0.01 g L⁻¹, confirming the superior biomass productivity of heterotrophic metabolism. Lipid fractions obtained under both trophic conditions were characterized and subjected to glycerolysis catalyzed by Novozym 435 under a 5:1 glycerol-to-oil ratio for 16 h. Heterotrophic oils, characterized by triacylglycerol-rich and low-free fatty acid (FFA) profiles, achieved higher MAG + DAG conversion (45%), while autotrophic oils reached 43% conversion despite elevated FFAs and polar lipids. The presence of FFAs, pigments, and phospholipids in non-refined microalgal oils influenced catalytic behavior, reducing conversion efficiency and favoring competing esterification and hydrolysis pathways. These findings demonstrate that substrate purity, acylglycerol distribution, and cultivation-specific lipid architecture strongly affect lipase performance, highlighting oil refining and cultivation optimization as key strategies for improving sustainable MAG and DAG production. Full article

MAFLD progression is closely linked to a systemic failure of antioxidant defense systems. Se and Zn play crucial roles in maintaining redox balance in the liver. This study evaluated the effects of micronutrient-biofortified chickpea flours as functional ingredients for the prevention and management of MAFLD disturbances. Chickpea seeds were germinated with Na₂SeO₃, ZnSO₄, ZnSeO₃, or ZnSO₄ + Na₂SeO₃, processed into flours, and then subjected to gastrointestinal digestion to obtain biofortified-chickpea digests (BCD). SDS-PAGE and FTIR indicated treatment-dependent changes in the protein/peptide profile and in the structural organization of the digested matrix. Isoflavone content was higher in ZnSO₄-BCDs. The oleic acid-induced HepG2 cell model was used to emulate MAFLD conditions. Under preventive conditions, except for ZnSeO₃-BCD, all treatments reduce triglyceride accumulation from 17.1 to 38.6%. Non-biofortified (GC) chickpea flour and ZnSeO₃-BCD had greater effects on lipolysis and glycerol release. Overall, Se-BCD affected redox regulation 1.2–1.3-fold, suggesting potential improvement in lipid utilization. GC and ZnSO₄ + Na₂SeO₃ BCDs decreased triglyceride accumulation (21.1 and 20.5%, respectively) when evaluated post lipid exposure. In both experimental conditions, BCDs significantly reduced IL-6 levels by 25.1 to 34.7%, demonstrating their immunomodulatory potential. Biofortified chickpea flours exhibit complementary and coordinated biological activities against the main metabolic disturbances associated with MAFLD. Zn/Se-biofortification of chickpea is a valuable strategy for addressing micronutrient deficiencies and for producing functional ingredients to prevent or ameliorate MAFLD-associated disturbances and improve liver health. Full article

Onion peel extract (OPE) is rich in polyphenolic compounds with antimicrobial potential. Salmonella Enteritidis (SE) infection in young broiler chicks causes morbidity, reduced growth, and contributes to human gastroenteritis through contaminated poultry products. The spleen is a key secondary lymphoid organ coordinating systemic responses to pathogens in chicken. This study evaluated how dietary OPE influences spleen metabolic profiles during SE infection. Day-old Ross 708 male chicks (n = 128) were assigned to four treatments: CON, CON-SE, OPE (6 g/kg), and OPE-SE. Chicks in CON and OPE received sterile broth, whereas CON-SE and OPE-SE received 2.25 × 10⁸ CFU/mL SE at 2 d of age. At 5 and 12 dpi, spleens from six chicks per treatment were collected for untargeted HPLC-MS metabolomics. A total of 857 metabolites were identified and analyzed using MetaboAnalyst 6.0 (p < 0.05; fold change ≥ 2.0; VIP score > 1.0). In CON-SE chicks, energy generating metabolites (6-phosphogluconic acid, methylmalonic acid, propionic acid) increased, while 13,14-dihydro-15-keto-prostaglandin D2 and kynurenic acid decreased. Dietary OPE elevated several dipeptides (L-Val-Gly, L-Leu-Gly, Gly-Gly-Leu, L-Val-L-Met) and reduced ATP linked metabolites (3,6-di-O-methyl-beta-D-glucose and 3-O-beta-D-galactosyl-sn-glycerol). Enrichment analysis showed that SE infection altered valine, leucine, and isoleucine degradation and aromatic amino acid biosynthesis, whereas OPE enriched galactose and biotin metabolism in uninfected chicks, but enriched tryptophan, taurine and hypotaurine metabolism in SE-infected chicks. Overall, dietary OPE optimized response of metabolic pathways associated with immune activation, unlike corresponding pathways in CON-SE birds. Full article

Early-life nutrition is critical for the development and health of dairy calves, necessitating alternatives to in-feed antibiotics. This study investigated whether dietary glycerol monolaurate (GML) enhances growth performance, reduces diarrhea incidence, improves systemic antioxidant and immune status, and modulates hepatic immunometabolic function in calves. Twenty-four Holstein bull calves (7 ± 0.5 d of age) were randomly assigned by body weight and age to a control group or a GML-supplemented group, both fed milk replacer with starter feed provided throughout the 45-day trial. Calves in the GML group received GML at a dosage of 100 mg/kg of body weight, mixed into the milk replacer prior to feeding. Calves in the GML group had significantly greater final body weight, average daily gain, and starter intake during the latter period (d 23–45) compared with the control group. GML supplementation also significantly reduced the incidence of diarrhea and fever, alongside lower fecal scores and fewer antibiotic treatments. Plasma analysis revealed enhanced antioxidant capacity, as indicated by increased total antioxidant capacity and glutathione peroxidase, along with an improved immune profile characterized by elevated immunoglobulin G and reduced interleukin-2. Transcriptomic analysis of the liver showed that GML upregulated genes and pathways related to innate antiviral immunity, such as radical S-adenosyl methionine domain containing 2, interferon-stimulated gene 15, and MX dynamin like GTPase 1. Lipidomics further indicated that GML induced a targeted remodeling of hepatic lipids, including increased diacylglycerols and triacylglycerols and decreased specific phospholipids and sphingolipids, suggesting a metabolic shift supportive of immune activation and inflammatory control. In conclusion, dietary GML enhances growth and health in suckling calves, which is mediated through a coordinated immunometabolic reprogramming in the liver. GML represents a promising functional fat additive for sustainable calf rearing. Full article

This study evaluated how a lemon essential oil–rutin–chitosan coating (CS-LEO/NE-R), prepared from a 5:95 (v/v) lemon essential oil/rutin-containing nanoemulsion and a chitosan solution containing 1.5% chitosan, 1% acetic acid, and 5% glycerol, combined with controlled freezing-point storage preserves seasoned white snakehead fillets. Compared with controlled freezing-point storage alone, the combined treatment significantly inhibited oxidation, volatile nitrogen accumulation, texture softening, and microbial growth. On Day 10, the coating group recorded a total viable count of 4.98 log CFU/g, which was below the national limit (5 log CFU/g), whereas the control group went beyond this limit by Day 7. This extended the microbiological and physicochemical acceptability period by approximately 3 days under the present experimental conditions. Untargeted metabolomics revealed 2267 metabolites, and the differentially abundant ones mainly comprised amino acids, heterocyclic compounds, aldehydes, ketones, and esters. KEGG enrichment suggested that changes in linoleic acid metabolism, terpenoid related annotations, the actin cytoskeleton, and the phospholipase D signaling pathway were associated with delayed quality deterioration. This work provides a theoretical basis for the composite biopreservation of aquatic products. Full article

Beta-alanine, a naturally occurring non-proteinogenic beta-amino acid, is widely used in delaying fatigue, enhancing exercise performance, and alleviating hyperuricemia. It also serves as a three-carbon platform for the synthesis of various high-value compounds, thus showing extremely broad market prospects. However, the practical application of beta-alanine is severely limited by the harsh reaction conditions and abundant by-products in chemical synthesis, as well as the low endogenous content and complex biosynthetic pathway. Recently, advances have been made in the one-pot, one- or two-step production of beta-alanine using genetically engineered recombinant enzymes, and in the microbial synthesis of beta-alanine via whole-cell biocatalysis. These advances are based on a series of attempts, including the enzymatic conversion to beta-alanine using 1,3-diaminopropane (DAP), L-aspartate (L-Asp), fumarate, or 3-aminopropionitrile as substrates, and the whole-cell biosynthesis of beta-alanine by regulating metabolic flux from carbon sources (e.g., glucose, oil, and glycerol) to L-Asp—the precursor for beta-alanine synthesis catalyzed by L-aspartate-α-decarboxylase (ADC). This study provides a rational theoretical basis and valuable practical references for the future industrial application of beta-alanine. Full article