Biotechnology and applied biochemistry最新文献

Azo-oxime ligands, namely, Ar-HL^Ph, 1 (Ar = phenyl, pyridyl, and naphthyl) and Ar⁄-HL^py 2 (Ar⁄ = phenyl, p-tolyl) were used to synthesize three trinuclear mixed valence iron complexes of type [Fe^III(Fe^II(Ar-L^Ph)₃)₂]ClO₄ 3⁺ClO₄ ^- and four bis-chelates [M^II(Ar⁄-L^py)₂] (M = Fe, 4 and M = Mn, 5). The SCXRD structures of [Mn^II(Ar⁄-L^py)₂] and [Fe^II(Ar⁄-L^py)₂] (Ar⁄ = p-tolyl) are consistent with the theoretically optimized structures. The N─N (azo) distances are longer in comparison to their nickel(II) congeners and the order of average N─N (azo) lengths of [Ni^II(Ar⁄-L^py)₂] < [Fe^II(Ar⁄-L^py)₂] < [Mn^II(Ar⁄-L^py)₂], reported earlier. This is ascribed to greater π-acceptance by azo function with Ni(II) → Fe(II) → Mn(II). The nature of the FMOs of [Mn^II(Ar⁄-L^py)₂] and [Fe^II(Ar⁄-L^py)₂] (Ar⁄ = p-tolyl) has been inspected, and their absorption spectra were supported by TDDFT analysis. The complexes were subjected to anti-bacterial screening against two Gram-positive, namely, Streptococcus mutans and Staphylococcus aureus and two Gram-negative strains, namely, Escherichia. coli, and Salmonella sp. and their mode of action have also been detected. IC₅₀ values of the complexes for all four bacterial strains designates that Gram-negative bacterial strains were more susceptible than the Gram-positive strains and among the two Gram-negative strains, Salmonella sp. was more affected than Escherichia coli. All seven complexes have significant broad-spectrum antibacterial potential for MDR bacterial strains, and the mode of antibacterial action appears to progress via a versatile molecular mechanism, including all the biomolecular fronts, namely, proteins, lipids, and nucleic acids damage.

Minimal change disease (MCD) is a glomerular disorder, which is the most common cause of nephrotic syndrome in children. Additionally, the prevalence of MCD in adults has been increasing in recent years. During protein synthesis, noncoding RNAs can be regulated through a variety of modifications, which helps preserve biological diversity and complexity. This study aims to investigate the role of m5C-modified miRNAs in MCD, with the goal of identifying promising biomarkers and therapeutic targets for patients with this condition. Our findings revealed a substantial number of differentially modified m5C miRNAs in patients with MCD, predominantly exhibiting downregulation of modification. Notable miRNAs showing differential modification included miR-1282, miR-340-3p, miR-526b-3p, miR-3925-3p, and miR-511-5p. Further bioinformatics analysis demonstrated that the pathogenic mechanism of miR-511-5p in MCD may involve lipid metabolism by decreasing the expression of ectonucleotide pyrophosphatase/phosphodiesterase 4 (ENPP4) and ecto-nucleoside triphosphate diphosphohydrolase (ENTPD1). Both m5C writer and target genes had high-confidence interactions with miR-511-5p. This study confirmed the pathogenic role of m5C-modified miRNAs in MCD. The m5C modification of miRNAs in MCD is primarily downregulated, which is likely due to the downregulated of DNMT1. Finally, we focused on the downregulated m5C-modified miR-511-5p, which contributes to MCD by regulating metabolic pathways and decreasing the expression of ENPP4 and ENTPD1.

Salt stress is a major challenge to the production of legumes as it affects their germination, growth, yield, and general physiology. Further, it also impairs their nitrogen fixation by causing osmotic stress and sodium-induced nutrient imbalances. Treatment with melatonin, a potent antioxidant and growth regulator, leads to the metabolic reprogramming of the plants to improve the stress tolerance capabilities of plants, and therefore, could be useful for improving resilience to salt stress. Horsegram, a nutraceutical legume, shows genotype-dependent variability toward salt stress tolerance; however, how the contrasting genotypes (salt-tolerant and susceptible) respond to melatonin treatment is relatively unclear. Based on our previous findings, two salt-tolerant (DH-22 and DH-29) and two salt-sensitive (DH-11 and DH-12) genotypes of horsegram were selected to investigate the effects of melatonin on salt-stressed seedlings. All four horsegram accessions were subjected to exogenous melatonin treatment at concentrations of 50, 100, and 150 µM under 100 mM NaCl. Results suggested that the melatonin treatment significantly improved growth and biochemical profiles in all horsegram genotypes under salt stress. The tolerant genotypes showed superior root and shoot growth, higher relative water content, chlorophyll, carotenoids, proline, phenolic, and flavonoid compounds, and increased antioxidant enzyme activity. They also exhibited lower levels of oxidative stress markers like malondialdehyde, hydrogen peroxide, and ion leakage compared with sensitive genotypes. The histochemical staining methods involving 3,3'-diaminobenzidine, nitro blue tetrazolium, and trypan blue stains further indicated the melatonin-induced reduction in cell death and reactive oxygen species accumulation in salt-affected horsegram seedlings. Overall, the tolerant genotypes were recorded to respond better to melatonin-mediated stress amelioration than the sensitive genotypes. Further, the present study also underlines the melatonin's potential to improve stress tolerance in legume crops like horsegram to improve salt stress resilience. Future research should concentrate on identifying the molecular processes that explain horsegram's melatonin-mediated salt tolerance. Furthermore, field-based assessments are required to confirm its usefulness for crop development programs.

Ethanol generated during yeast fermentation has potential oxidative damaging effects, which can induce yeast aging and death. It has been reported that water extract of Ligusticum chuanxiong Hort (Lch) exhibits antiaging effects on Saccharomyces cerevisiae. However, the role and underlying mechanisms of Lch in S. cerevisiae under ethanol stress remain elusive. Herein, we showed that Lch significantly improves the survival of S. cerevisiae under ethanol stress. Transcriptome analysis revealed that carbohydrate metabolism, amino acid metabolism, and ribosome biogenesis pathways were enriched in ethanol-treated S. cerevisiae. Compared with ethanol treatment, ribosome biogenesis and RNA polymerase pathways were enriched in Lch and ethanol co-treated S. cerevisiae. Additionally, glutathione (GSH) metabolism pathway was exclusively enriched in S. cerevisiae co-treated with Lch and ethanol. Supplementation with GSH significantly enhanced the survival of ethanol-treated S. cerevisiae. Taken together, these results suggest that Lch protects S. cerevisiae against ethanol stress by modulating ribosome biogenesis and GSH metabolism pathways.

Plant phenylpropanoid metabolism is a crucial process involving phenylalanine ammonia lyase (PAL) enzyme, which is essential for plant growth and development. PAL generates secondary metabolites and also has a significant impact on plant defense against disease and stress. Salt stress is a common abiotic stress that severely impacts wheat growth and restricts its productivity worldwide. However, genome-wide and functional characterization of the PAL gene family in wheat is limited. In this study, 54 PAL genes were identified in wheat, distributed across 15 chromosomes, with one located on an unknown chromosome. The analysis of gene structures, conserved motifs, duplication events, and cis-acting elements was performed to understand their functional diversity. Phylogenetic analysis classified wheat PAL proteins into nine subfamilies, highlighting evolutionary diversification specific to monocots. Additionally, evolutionary analysis of PAL genes in Triticum aestivum, Triticum turgidum, and Aegilops tauschii grouped them into six subgroups. Promoter analysis indicated that TaPAL genes contain multiple cis-regulatory elements associated with stress, growth, hormonal regulation, and light response. TaPAL genes displayed dynamic expression profiles across different tissues and developmental stages, and were significantly regulated under various stress conditions. Quantitative real-time PCR (qRT-PCR) analysis revealed the expression patterns of TaPAL genes under salt stress, indicating their potential role in abiotic stress response. These findings provide valuable insights into the evolutionary and functional significance of PAL genes in wheat, offering a foundation for future research on their role in stress tolerance and crop improvement.

Lactic acid bacteria (LAB) are pivotal in food, pharmaceutical, and environmental applications due to their metabolic versatility and probiotic potential. This review explores the advancements in genetic engineering and synthetic biology strategies to enhance LAB functionality. We examine the genomic architecture of key LAB species, such as Lactobacillus and Lactococcus, highlighting their natural genetic traits and metabolic constraints. Emerging genetic tools, including electroporation, conjugation, and CRISPR-Cas systems, have revolutionized LAB modification, enabling precise gene editing and expression control. Synthetic biology approaches, such as genetic circuits, riboswitches, and biosensor development, offer novel pathways for optimizing LAB for functional foods, mucosal therapeutics, and industrial biotechnology. We discuss applications in probiotic delivery, bioremediation, and agricultural enhancement, emphasizing LAB's role in producing bioactive metabolites and combating pathogens. Challenges, including plasmid instability, metabolic burden, and regulatory hurdles, are addressed alongside socio-ethical considerations for genetically modified LAB. The integration of genome-scale engineering and CRISPR-based technologies holds promise for overcoming these barriers, paving the way for next-generation LAB with enhanced stress tolerance and tailored functionalities. This review synthesizes current knowledge and future prospects, underscoring the transformative potential of engineered LAB in addressing global health, environmental, and industrial needs while navigating biosafety and public perception challenges.

The methylated flavonoid sakuranetin, primarily found in barks and leaves, exhibits potent antifungal, antiviral, and anti-inflammatory effects. Microbial metabolic engineering strategies for its synthesis have gained interest because the extraction of this compound from plants is inefficient. Moreover, whereas the sakuranetin yields from microorganisms remain low, the yeast Yarrowia lipolytica has received recent attention as a promising host cell for compound biosynthesis. In this study, the de novo synthesis of sakuranetin from glucose was achieved in Y. lipolytica through metabolic engineering. First, a synthetic titer of 154.80 mg/L was obtained by introducing methyltransferase into the naringenin-synthesizing strain. By screening promoters to enhance the expression of methyltransferase, augmenting the supply of the methyl donor SAM, increasing shikimic acid pathway flux, and adjusting the copy number of gene involved in sakuranetin synthesis, the breakthrough sakuranetin titer reached 345.42 mg/L, which was 1.2 times higher than that when using the primary strain. Finally, the strategy to optimize the glucose concentration resulted in a sakuranetin titer that increased to 686.81 mg/L. This paper reports the highest yield of de novo synthesis of sakuranetin by Y. lipolytica, as a potential synthetic chassis for the biosynthesis of naringenin and other flavonoid compounds.

For engineering any human tissue, a scaffold for adhesion and proliferation of human cells is very necessary. Many different natural and synthetic biopolymers have been used, each with its own advantages and drawbacks. Many synthetic biopolymers have drawbacks such as hydrophobicity, less cell adhesion, and inflammation. To overcome these disadvantages, natural biopolymers are used to enhance biocompatibility and cell adhesion and reduce immunogenicity. In the present work, we have mixed three natural biopolymers-chitosan, gelatin, and pectin-in different ratios and crosslinked them with glutaraldehyde. These mixtures underwent repeated freeze-thaw cycles, followed by drying in a hot air oven to form solid scaffolds. A chitosan-glutaraldehyde scaffold was prepared in the same way as a control. All the scaffolds were characterized for their structure using x-ray diffraction and scanning electron microscopy. Their functional groups were determined using Fourier transform infrared spectroscopy. Water absorption and degradation properties of all scaffolds were studied. It was found that the water absorption capacity of scaffolds was improved by adding gelatin and pectin to chitosan. Also, the partial crystalline nature of these scaffolds increased, in comparison to the control, when pectin and gelatin were mixed with chitosan. Thus, these chitosan-gelatin-pectin scaffolds can have the potential to be used for tissue engineering applications.

Environmental biotechnology still faces several difficulties with bioremediation of potentially toxic element pollution. To our knowledge, the application performance of some fungi in bioremediation can be greatly improved by the combination with nanotechnology. This work develops a recent approach for extracting metals out of water via their absorption on Rhizopus stolonifer chitin nanofibers (ChNFs) that were isolated via a purification procedure, mechanically treated, and then grown under ideal culture conditions. It is a promising, hassle-free, and environmentally benign method for wastewater bioremediation. The ChNFs were applied as adsorbents for Cu²⁺, Pb²⁺, Ni²⁺, Co²⁺, and Ba²⁺ separately. Among the five metal ions, chitin nanoparticles displayed the largest removal percentage (%) for Cu²⁺ (90.4%), followed by Pb²⁺ (78.9%), and the lowest removal percentage (%) was for Ba²⁺ (20.3%). Herein, we deem that this study will strengthen the basic knowledge and provide valuable insight into the various applications of R. stolonifer ChNFs in the bioremediation field.

The valorization of agro-industrial fruit by-products presents a sustainable strategy to enhance animal nutrition while reducing environmental waste. This study investigates the physicochemical attributes, dietary fiber profile, and prebiotic potential of the enzyme treated Manilkara zapota (sapota) seed powder (eSSP) for functional use in poultry feed. The eSSP flour demonstrated high crude fiber content (23.94 ± 1.86 g/100 g), with total dietary fiber comprising 83.45% insoluble and 16.54% soluble fractions. Enzymatic hydrolysis optimized at 6 h revealed peak concentrations of fermentable oligosaccharides, including galacto-oligosaccharides (12.06 ± 0.45%), manno-oligosaccharides (8.04 ± 0.30%), fructo-oligosaccharides (9.83 ± 0.25%), and xylo-oligosaccharides (10.83 ± 0.50%). Supplementation with e₆SSP resulted in a significant increase in both qualitative and quantitative volatile fatty acid (VFA) production, indicating its prebiotic potential. Notably, the high xylo-oligosaccharide (XOS) content (∼10%) contributed to elevated butyric acid levels in fermentation assays, reinforcing the stimbiotic properties of eSSP. Symbiotic assays with Lactobacillus casei confirmed the eSSP's capacity to support probiotic growth, while in vitro fermentation demonstrated enhanced production of short-chain fatty acids (SCFAs), particularly butyrate. Antioxidant profiling further validated the seed's bioactive potential, with total phenolic content of 767.65 ± 1.24 mg GAE/100 g and flavonoid content of 2223.6 ± 0.87 mg QE/100 g. These findings establish eSSP as a potent, cost-effective, and natural prebiotic candidate for improving gut health and sustainability in animal feed systems.