Search Results (46)

Biosurfactants produced by halophilic bacteria are gaining attention as eco-friendly and biocompatible alternatives to synthetic surfactants due to their high surface activity, stability under extreme conditions, and intrinsic antimicrobial properties. These amphiphilic biomolecules hold great promise for bioremediation, biomedical, and pharmaceutical applications. In this study, moderately halophilic bacteria capable of biosurfactant production were isolated from saline mud collected at the Burgas solar salterns (Bulgaria). The halophilic microbiota was enriched in Bushnell–Haas (BH) medium containing 10% NaCl amended with different carbon sources. Primary screening in BH liquid medium evaluated the isolates’ ability to degrade n-hexadecane while at the same time producing biosurfactants. Thirty halophilic bacterial strains were isolated on BH agar plates supplemented with 2% n-hexadecane, 2% olive oil, or 2% glycerol. Four isolates—BS7OL, BS8OL, BS9GL, and BS10HD—with strong emulsifying activity (E₂₄ = 56%) and reduced surface tension in the range of 27.3–45 mN/m were derived after 7 days of batch fermentation. Strain BS10HD was chosen as the most potent biosurfactant producer. Its phylogenetic affiliation was determined by 16S rRNA gene sequence analysis; according to the nucleotide sequence, it was assigned to Halomonas ventosae. The extract material was analysed by thin-layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR). Upon spraying the TLC plate with ninhydrin reagent, the appearance of a pink spot indicated the presence of amine functional groups. FTIR analysis showed characteristic peaks for both lipid and peptide functional groups. Based on the observed physicochemical properties and analytical data, it can be suggested that the biosurfactant produced by Halomonas ventosae BS10HD is a lipopeptide compound. Full article

Nelumbo nucifera (Lotus) is an economically important aquatic crop frequently challenged by abiotic stresses. The plant cell wall, a primary interface with the environment, undergoes dynamic remodeling to balance structural integrity with adaptation. UDP-glucuronic acid decarboxylase (UXS), a key enzyme synthesizing the nucleotide sugar precursor UDP-xylose, exists in distinct membrane-bound (e.g., Golgi) and cytosolic forms, channeling substrates into compartmentalized polysaccharide biosynthesis pathways and positioning the UXS family as a crucial regulator linking cell wall metabolism to plant adaptation. Here, we systematically characterized the NnUXS gene family in lotus through genome-wide identification, evolutionary synteny analysis, and functional validation. Integrated bioinformatic analysis revealed their physicochemical properties, motif patterns, and regulatory cis-elements, suggesting potential roles in growth and salt stress responses. Among the family, NnUXS3 was prioritized due to its preferentially upregulated in small plant architecture (SPA) varieties, its early induction under salt stress (0.5 days, 200 mM NaCl), and its highest predicted binding affinity for UDP-GlcA (−8.9 kcal/mol). Subsequent functional validation confirmed its dual role: heterologous overexpression in tobacco reduced plant height (47.22%) and leaf area (67.61%), while transient overexpression in lotus enhanced salt tolerance and shortened the petioles. This enhanced tolerance was achieved by upregulating key genes involved in polysaccharide biosynthesis (NnCSLC4, NnXTH22, NnCESA1) and antioxidant defense (NnSOD, NnPOD). Our findings establish NnUXS3 as a key mediator in balancing plant architecture and abiotic stress resilience. This work not only identifies a valuable genetic target for lotus breeding but also provides insights into the growth-stress trade-off, highlighting the importance of UXS subcellular localization in tailoring cell wall remodeling for environmental adaptation. Full article

This study investigated the effects of direct vat set commercial yoghurt starter (B) and yeast starter (Y) on the quality of fermented large yellow croaker surimi balls, with natural fermentation (CTR) as a control. Surimi products were inoculated and fermented at 25 °C for 4 h, then analyzed for physicochemical, sensory, and oxidative properties. Yoghurt starter significantly inhibited protein oxidation, as indicated by the highest sulfhydryl content (9.10 nmol/mg protein, p < 0.05), improved textural properties (hardness was 28% higher than CTR, p < 0.05), and promoted a balanced flavor profile, accompanied by the highest equivalent umami concentration (1.66%, p < 0.05). However, B also caused the greatest MDA accumulation (1.49 mg/kg, p < 0.05), reflecting enhanced lipid oxidation. By comparison, Y enhanced umami primarily through significant enrichment of aspartic acid (53.88 mg/100 g, p < 0.05) and accelerated nucleotide degradation, resulting in the highest AMP and hypoxanthine levels (p < 0.05). These advantages were offset by severe protein carbonylation (54.32 nmol/mg protein, p < 0.05) and evident color deterioration. Sensory analysis revealed no significant difference between B and CTR (p > 0.05), whereas Y received significantly lower acceptance scores (p < 0.05) due to impaired color and taste. These findings suggest that B is a promising starter for improving texture and flavor in fermented surimi balls, while Y, despite enhancing umami and controlling lipid oxidation, negatively affects color, texture, and protein stability. Full article

This study systematically compared the genetic characteristics and functional activities of hirudins and their encoding genes between Hirudo nipponia (Hnip1–3) and Hirudo tianjinensis (Htia1–3) through bioinformatics analysis, recombinant protein eukaryotic expression, and activity assays. The results revealed 42 nucleotide variation sites and 27 amino acid variation sites across both species. All six genes were expressed and significant pairwise differences between genes were detected within each species. All hirudins were identified as secretory proteins, with Hnip2, Hnip3, and Htia1 showing higher docking scores with thrombin. Four recombinant proteins (Hnip1, Hnip2, Htia1, and Htia2) exhibited antithrombin activity, with Hnip1 displaying the strongest activity. No significant differences were observed in the sequence variation, gene expression, physicochemical properties, predicted three-dimensional structures, or antithrombin activity of hirudins between the two leech species. This may stem from substantial heterogeneity in the genetic makeup and functional characteristics of distinct hirudins within each species, ultimately reducing the statistical power of these interspecific comparisons. Integrating gene expression profiles with recombinant protein activity assessments revealed that H. nipponia hirudins exhibit superior antithrombotic potency compared to those of H. tianjinensis. This study establishes a theoretical foundation for medicinal leech resource development and provides critical data for innovative antithrombotic drug discovery. Full article

The aim of this study was to investigate the effect of ice-temperature (IT) storage on the umami-enhancing nucleotide content in white mullet (Ophiocephalus argus var. Kimnra) meat. White mullet dorsal muscle was used as the raw material, and 4 °C chilled storage was used as a reference. After determining the ice temperature (−0.6 °C) of the dorsal muscle, the effect of IT storage on its umami-enhancing nucleotides was investigated. The umami nucleotide levels, physicochemical properties (pH, muscle color, water-holding capacity, and cooking loss rate), glycolytic metabolites (lactic acid, pyruvic acid, and glycogen), and enzyme activities (lactate dehydrogenase, pyruvate kinase, and 5′-nucleotidase) in the dorsal muscle were examined. The results indicate that IT storage significantly (p < 0.05) lowered pH while improving the water-holding capacity compared to 4 °C chilled storage. Both storage conditions showed an initial increase followed by a decrease in the inosine 5′-monophosphate (IMP) content, while the content of guanosine 5′-monophosphate (GMP) progressively declined. IT storage maintained significantly (p < 0.05) higher IMP and GMP levels than chilled storage in the late storage stage. The accumulation of the bitter taste substances hypoxanthine (Hx), lactic acid, and pyruvic acid was reduced under IT storage. These findings demonstrate that IT storage effectively inhibits the degradation of umami-enhancing nucleotides and is beneficial for preserving the meaty taste of white mullet meat. Full article

Hyaluronic acid (HA) is a linear heteropolysaccharide that naturally occurs in vertebrates. Thanks to its unique physico-chemical properties, it is involved in many key processes in living organisms. These biological activities provide the basis for its broad applications in cosmetics, medicine, and the food industry. The molecular weight of HA might vary significantly, as it can be less than 10 kDa or reach more than 6000 kDa. There is a strong correlation between variations in its molecular weight and bioactivities, as well as with various pathological processes. Consequently, monodispersity is a crucial requirement for HA production, together with purity and safety. Common industrial approaches, such as extraction from animal sources and microbial fermentation, have limits in fulfilling these requests. Research and protein engineering with hyaluronic acid synthases can provide a strong tool for the production of monodisperse HA. One-pot multi-enzyme reactions that include in situ nucleotide phosphate regeneration systems might represent the future of HA production. In this review, we explore the current knowledge about HA, its production, hyaluronic synthases, the most recent stage of in vitro enzymatic synthesis research, and one-pot approaches. Full article

Xanthii Fructus (XF) not only has medicinal function in traditional Chinese medicine (TCM) but also contains rich oil and protein. The aim of this research was to develop the edible value of its protein based on the investigation on the extraction, basic characteristics and functions, safety, gut microbiota, and metabolomics, especially the effect of the concocting process. The proteins from raw and concocted XF were prepared using two methods: alkaline solubilization followed by acid precipitation and ammonium sulfate salting-out, respectively. The secondary structure and physicochemical properties of the proteins were characterized through spectroscopic analysis and property determination. The effects of alkaline and the concocting process on the proteins were systematically compared. The results indicated that the salting-out method could retain the protein activity better. Both alkali treatment and the concocting process altered the folding state of proteins. The toxicological results in mice indicated that a high dose (0.35 g/kg) of raw Xanthii Fructus protein (XFP) might cause damage to the liver and small intestine, and the concocting process could significantly alleviate the damage. The 16S rRNA sequencing technology was used to untangle their impact on gut microbiota in mice and the result showed that raw protein had a certain regulatory effect on Bifidobacterium, Rhodococcus, Lactococcus, and Clostridium, while the concocted protein had a smaller impact, mainly affecting Bacteroides and Bifidobacterium. The untargeted metabolomics using liquid chromatography-mass spectrometry (LC-MS) showed that the proteins of raw XF affected the metabolic level through cysteine and methionine metabolism, purine metabolism, amino sugar and nucleotide sugar metabolism pathways, and the concocted protein mainly involved histidine metabolism and purine metabolism pathways. Overall, XFP had potential development prospects, but the anti-nutritional factors might have some toxicity. The concocting process could significantly improve its safety, and the concocted proteins were worth developing as a food source. In the future, the processing conditions should be further optimized and more systematic investigation should be performed to ensure the safety of XF as a food source. Full article

The succession of microbial communities during the fermentation process in sesame-flavored Baijiu cellars profoundly influences the flavor profile of the liquor. However, the key factors driving microbial succession in these cellars remain unclear. This study focuses on the fermentation process of sesame-flavored Baijiu Zaopei in traditional Tongcheng cellars. Samples were collected from the surface, middle, and bottom of the cellar, categorized by fermentation time. Various techniques were employed to analyze the physicochemical properties (including moisture, ethanol, total acid, starch, and reducing sugars), flavor compounds (volatile substances and amino acids), and microbial communities (bacteria and fungi) of the Zaopei during fermentation. A total of 68 flavor compounds were detected, with 16 key flavor compounds and 16 amino acids identified. Microbiologically, the Lactobacillus genus dominated in the later stages of fermentation, while the Issatchenkia species were the predominant fungi. Correlation analysis indicated that environmental factors play a significant role in driving microbial community succession. Acetobacter, Staphylococcus, Pichia, Bacillus, and Kroppenstedtia species may contribute to the synthesis of key flavor compounds. The relative contents of acetic acid, 2-phenylethyl ester, and Benzenepropanoic acid ethyl ester were influenced by multiple microbial groups, suggesting a synergistic fermentation effect. PICRUSt2 predictions revealed significant differences in 41 KEGG pathways at level 2 and 293 pathways at level 3 across different fermentation intervals. These pathways are primarily associated with amino acid, ester, and nucleotide metabolism, as well as bacterial transcription, translation, and signal transduction. This research provides a theoretical foundation for understanding the fermentation mechanisms of sesame-flavored Baijiu. Full article

Fel d1 is the most important allergen secreted by cats, which can trigger asthma in sensitive individuals. Our objective was to knock-out the Fel d1 gene in the fetal fibroblasts of cats through CRISPR–Cas9 technology with two sgRNAs and to determine the impact of such mutations on the antigenicity of the Fel d1 protein. DNA samples from 38 domestic cats were collected and amplified by PCR to obtain the complete sequence of the Fel d1 gene. Throughout evolution, Fel d1 polypeptide chain 1(CH1) has proven to be much more conserved than Fel d1 polypeptide chain 2(CH2); therefore, we targeted CH2 and designed two single-guide RNAs (CH2-sgRNA-1 and CH2-sgRNA-2) for this region. Using these constructed sgRNAs, we performed gene knock-out in fetal fibroblasts, resulting in two mutations within the target gene. Following this, DNA was extracted and the target site product was cloned using TA cloning via PCR, and a single colony from this process was sequenced to analyze the physicochemical properties, antigenic sites, and three-dimensional structure of the mutated protein. The results revealed that there were 12 and 51 polymorphic loci (single-nucleotide polymorphisms, or SNPs) found in the CH1 and CH2 sequences, respectively, with most loci located in the GC-rich intron 2, while others were found in exon 2, intron 3, and exon 3. These SNPs guided sgRNA design by identifying conserved regions in the CH2 gene. The gene editing efficiency for the CH2 region, with this dual CRISPR system, was 40%, with 35% attributed to Type 1 mutation and 5% to Type 2 mutation. In conclusion, CH1 is significantly more conserved than CH2, and the antigenicity of the Fel d1 CH2 gene in domestic cats can be effectively reduced through CRISPR–Cas9 gene editing. Full article

Background: Tumor cells engage in continuous self-replication by utilizing a large number of resources and capabilities, typically within an aberrant metabolic regulatory network to meet their own demands. This metabolic dysregulation leads to the formation of the tumor microenvironment (TME) in most solid tumors. Nanomedicines, due to their unique physicochemical properties, can achieve passive targeting in certain solid tumors through the enhanced permeability and retention (EPR) effect, or active targeting through deliberate design optimization, resulting in accumulation within the TME. The use of nanomedicines to target critical metabolic pathways in tumors holds significant promise. However, the design of nanomedicines requires the careful selection of relevant drugs and materials, taking into account multiple factors. The traditional trial-and-error process is relatively inefficient. Artificial intelligence (AI) can integrate big data to evaluate the accumulation and delivery efficiency of nanomedicines, thereby assisting in the design of nanodrugs. Methods: We have conducted a detailed review of key papers from databases, such as ScienceDirect, Scopus, Wiley, Web of Science, and PubMed, focusing on tumor metabolic reprogramming, the mechanisms of action of nanomedicines, the development of nanomedicines targeting tumor metabolism, and the application of AI in empowering nanomedicines. We have integrated the relevant content to present the current status of research on nanomedicines targeting tumor metabolism and potential future directions in this field. Results: Nanomedicines possess excellent TME targeting properties, which can be utilized to disrupt key metabolic pathways in tumor cells, including glycolysis, lipid metabolism, amino acid metabolism, and nucleotide metabolism. This disruption leads to the selective killing of tumor cells and disturbance of the TME. Extensive research has demonstrated that AI-driven methodologies have revolutionized nanomedicine development, while concurrently enabling the precise identification of critical molecular regulators involved in oncogenic metabolic reprogramming pathways, thereby catalyzing transformative innovations in targeted cancer therapeutics. Conclusions: The development of nanomedicines targeting tumor metabolic pathways holds great promise. Additionally, AI will accelerate the discovery of metabolism-related targets, empower the design and optimization of nanomedicines, and help minimize their toxicity, thereby providing a new paradigm for future nanomedicine development. Full article

The Aldehyde Dehydrogenase (ALDH) superfamily comprises a group of NAD⁺ or NADP⁺-dependent enzymes that play essential roles in responding to abiotic stresses in plants. In Brassica napus L., however, the increasing frequency of extremely low temperatures during winter in recent years has significantly affected both yield and quality. This study conducted a genome-wide screening of ALDH superfamily genes, analyzing their gene structures, evolutionary relationships, protein physicochemical properties, and expression patterns under low-temperature stress to explore the function of the ALDH superfamily gene in cold tolerance in Brassica napus L. A total of six BnALDH genes with significant differences in expression levels were verified utilizing quantitative real-time polymerase chain reaction (qRT-PCR), revealing that BnALDH11A2, BnALDH7B2, BnALDH3F5, BnALDH12A3, BnALDH2B6, and BnALDH7B3 all exhibited higher expression in cold-tolerant material 24W233 compared with cold-sensitive material 24W259. Additionally, a single nucleotide polymorphism (SNP) in the BnALDH11A2 promoter region shows differences between the cold-tolerant (24W233) and the cold-sensitive (24W259) Brassica napus varieties, and it may be associated with the cold tolerance of these two varieties. This comprehensive analysis offers valuable insights into the role of ALDH family genes in low-temperature stress adaptation in Brassica napus and offers genetic resources for the development of novel cold-tolerant cultivars. Full article

Arid desert regions are among the harshest ecological environments on Earth. Halophytes, with their unique physiological characteristics and adaptability, have become the dominant vegetation in these areas. Currently, research on halophytes in this region is relatively limited, particularly concerning studies related to their root endophytic fungi, which have been rarely reported on. Therefore, investigating the diversity and composition of endophytic fungi in halophytes is crucial for maintaining ecological balance in such an arid environment. This study focuses on eight representative angiosperm halophytes from the West Ordos Desert in China (including Nitraria tangutorum, Salsola passerina, Suaeda glauca, Reaumuria trigyna, Reaumuria kaschgarica, Limonium aureum, Apocynum venetum, and Tripolium vulgare), utilizing Illumina MiSeq high-throughput sequencing technology combined with soil physicochemical factor data to analyze the diversity, composition, and ecological functions of their root-associated fungal communities. Ascomycota dominated the fungal composition in most halophytes, particularly among the recretohalophytes, where it accounted for an average of 88.45%, while Basidiomycota was predominant in Suaeda glauca. A Circos analysis of the top 10 most abundant genera revealed Fusarium, Dipodascus, Curvularia, Penicillium, and other dominant genera. Co-occurrence network analysis showed significant differences in fungal networks across halophyte types, with the most complex network observed in excreting halophytes, characterized by the highest number of nodes and connections, indicating tighter fungal symbiotic relationships. In contrast, fungal networks in pseudohalophytes were relatively simple, reflecting lower community cohesiveness. Redundancy analysis (RDA) and Mantel tests demonstrated that soil factors such as organic matter, available sulfur, and urease significantly influenced fungal diversity, richness, and evenness, suggesting that soil physicochemical properties play a critical role in regulating fungal–plant symbiosis. Functional predictions indicated that endophytic fungi play important roles in metabolic pathways such as nucleotide biosynthesis, carbohydrate degradation, and lipid metabolism, which may enhance plant survival in saline–alkaline and arid environments. Furthermore, the high abundance of plant pathogens and saprotrophs in some fungal communities suggests their potential roles in plant defense and organic matter decomposition. The results of this study provide a reference for advancing the development and utilization of halophyte endophytic fungal resources, with applications in desert ecosystem restoration and halophyte cultivation. Full article

The SCD is a rate-limiting enzyme that catalyzes the synthesis of monounsaturated fatty acids (MUFAs) in dairy cows; however, its role in the mammary gland of buffalo is not well understood. In this study, we isolated and characterized the complete coding sequence (CDS) of the buffalo SCD gene from mammary gland tissue and investigated its effects on milk fat synthesis using bioinformatics analyses, tissue differential expression detection, and cellular functional experiments. The cloned SCD gene has a CDS length of 1080 bp, encoding a protein of 359 amino acids. This protein is hydrophilic, lacks a signal peptide, and contains four transmembrane domains, including 10 conserved motifs and a Delta9-FADS domain, characteristic of the fatty acid desaturase family involved in unsaturated fatty acid biosynthesis within the endoplasmic reticulum. Molecular characterization revealed that the physicochemical properties, conserved domains, structures, and functions of buffalo SCD are highly similar to those in other Bovidae species. Among the tissues analyzed, SCD expression was highest in the mammary gland during lactation and in the cerebellum during dry-off period. Notably, SCD expression in the mammary gland was significantly higher during lactation compared to the dry-off period. Subcellular localization experiments confirmed that SCD functions in the endoplasmic reticulum of buffalo mammary epithelial cells (BuMECs). Functional overexpression and interference experiments in BuMECs demonstrated that SCD promotes milk fat synthesis by affecting the expression of lipid synthesis-related genes such as ACACA, FASN, and DGAT1, as well as milk fat regulatory genes like SREBFs and PPARG, thereby influencing intracellular triglyceride (TAG) content. Additionally, 18 single-nucleotide polymorphisms (SNPs) were identified in the buffalo SCD gene, with a specific SNP at c.-605, showing potential as molecular markers for improving milk production traits. These findings highlight that the SCD gene is a key gene in buffalo milk fat synthesis, involved in the de novo synthesis of milk fatty acids. Full article

Norisoprenoids are important chemical compounds to grape and wine aroma, and their content in the grape berries can be greatly affected by varietal, terroir, and environmental factors. In this study, we investigate how major factors, such as genotype and climate conditions, influence the physicochemical properties of grape juice, volatile C13-norisoprenoid compounds, and gene expression profiles of three Vitis vinifera grape varieties: Muscat blanc à Petit grain, Muscat à petits grains rouges, and Gewürztraminer during the production period in 2010 and 2011. The total soluble solids (TSS) of both Muscat varieties were significantly higher in 2011 compared to 2010, reflecting interannual climatic variations, while Gewürztraminer showed no significant differences. At full maturity, total acid of all three cultivars was consistent between the years, indicating genetic determination. Thirteen norisoprenoids were identified, with Muscat varieties showing consistently higher levels than Gewürztraminer, irrespective of the production year. Varietal differences were significant for 13 out of 14 volatile compounds, and vintage effects were notable for 11 compounds, including key aroma contributors β-damascenone and β-ionone. OPLS-DA analysis highlighted distinct volatile profiles for each variety and vintage, influenced by climatic factors such as precipitation and sunlight hours. Gene expression analysis revealed strong correlations between VvCCD1, VvCCD4a, and VvCCD4b genes and C13-norisoprenoid accumulation, with these genes also implicated in the ABA biosynthesis pathway. Single nucleotide polymorphisms (SNPs) in VvCCD1, VvCCD4a, and VvCCD4b were linked to variations in norisoprenoid content among the cultivars. Altogether, these findings revealed the interaction of genetic and environmental factors in shaping the physicochemical properties for the grape, volatile profiles, and gene expression patterns of grape berries, with significant implications for viticulture and the winemaking process. Full article

Lectins are proteins of a non-immune nature with activity against microorganisms, insects, and tumor cells. The aim of this work was to predict the physicochemical characteristics, structure, and functional properties of a Bauhinia holophylla lectin (BhL), sequenced from genomic material obtained from calli cultures, through bioinformatics tools. The results showed a high similarity between the Bhl gene and nucleotide sequences that encode lectins expressed by Bauhinia species and a high identity between the protein sequence of BhL and lectins from B. forficata (90%), B. variegata (79.04%), B. purpurea (78.01%), and B. ungulata (85.27%). BhL has 289 amino acids, of which 30, 85, and 174 residues are related to α-helix, β-sheet, and disordered regions, respectively. Their estimated molecular weight is 31.9 kDa and the theoretical isoelectric point is 5.79. Bauhinia holophylla lectin possibly undergoes phosphorylation and glycosylation at specific sites. Conserved protein domains, catalytic sites, and conserved amino acids were observed in BhL, bringing it closer to lectin families from other legume species. The prediction signaled the presence of a sequence of 28 amino acids at the N-terminal end of BhL, with a high hydropathicity index and conceptualized as a signal peptide. The molecular function predicted for BhL was associated with carbohydrate recognition activity. BhL could be an extracellular protein, and its three-dimensional structure showed 78.82% identity with the B. purpurea lectin. Full article