Archives of Microbiology最新文献

Polylactic acid (PLA) is one of the most widely used biodegradable bioplastics; however, its slow degradation under natural conditions limits its environmental sustainability. This review summarizes recent advances in microbial and biotechnological strategies that enhance PLA biodegradation across diverse ecosystems. Emerging approaches include screening insect gut microbiota, isolating fungal species with strong adsorption or enzymatic capacities, and exploring soil, compost, and aquatic microbiomes using metagenomics and environmental DNA (eDNA) tools. Microbial consortia, thermophilic degraders, and co-culture systems are highlighted as effective solutions to overcome the intrinsic crystallinity and hydrolysis-dependent breakdown of PLA. Beyond natural systems, this review emphasizes the increasing role of synthetic biology, directed evolution, and artificial intelligence (AI) in engineering high-performance PLA-degrading enzymes. AI-driven structural prediction and machine-learning platforms offer new possibilities for designing robust depolymerases with improved specificity, thermostability, and catalytic efficiency. Collectively, these multidisciplinary strategies provide a roadmap for accelerating PLA degradation in industrial composting, wastewater treatment, and bioremediation. Future integration of ecological screening with computational enzyme engineering is expected to advance scalable and sustainable PLA waste management.

The fungus Aspergillus flavus is one of the most important mycotoxigenic species that produces potent carcinogenic secondary metabolites called aflatoxins, and its harmful ability has a considerable negative impact on human and livestock health. This study assessed an antifungal activity against A. flavus and evaluated in vitro probiotic properties of lactic acid bacteria newly isolated from the digestive tract of two popular edible crickets, Gryllus bimaculatus (GL) and Acheta domesticus (AL). Moreover, metabolic profiles including anti-A. flavus compounds produced by promising lactic acid bacteria were investigated. In total of 22 isolates, four lactic acid bacterial candidates comprising AL01, GL01, GL05, and GL11 exhibited inhibitory effect on mycelial growth and anti-fungal spore germination of Aspergillus flavus TISTR 3366. Based on molecular analysis of 16S rRNA gene sequences and biochemical tests using API 50 CHL, these isolates were identified as Lacticaseibacillus paracasei (AL01), Lacticaseibacillus rhamnosus (GL01, and GL11), and Pediococcus pentosaceus (GL05). Among them, two potential strains comprising Lb. paracasei AL01 and P. pentosaceus GL05 showed the potent probiotic characteristics based on bacterial viability in gastrointestinal tract conditions, good cell surface properties, and bacterial safety. Metabolic profiles of the cell-free supernatant (CFS) obtained from AL01- and GL05-cultures were investigated using gas chromatography mass spectrometry (GC-MS), and revealed a complex mixture of bioactive compounds, including short-chain hydrocarbons, organic acids, and other antifungal metabolites. Overall results suggested that the lactic acid bacteria obtained from edible crickets can be a promising probiotic and biocontrol agent against A. flavus. The finding in this study benefits for biologically reducing mycotoxicity of harmful fungi in food and agriculture.

Fungal infections, particularly those caused by dermatophytes, affect over 25% of the world's population and pose a significant public health risk to both humans and animals. Conventional antifungal treatments face substantial challenges like drug resistance, adverse effects, and require long-term systemic medications. Essential oils (EOs) have attracted attention for their antimicrobial properties; however, their therapeutic applications have been hampered by their low solubility and rapid degradation. Nanotechnology addresses these limitations by encapsulating EOs to enhance their durability, bioavailability, and antifungal properties. This review covers the potential EO-based nanoformulations for treating fungal infections, with a focus on dermatophytes. It also highlights how nanoencapsulation may help reduce drug resistance, toxicity, and adverse effects. However, there are some limitations. The effectiveness of treating fungal infection can vary depending on the EO's composition, fungal species, and how the nanoformulation is formulated. Future research should emphasize standardizing formulation protocol and evaluating in vivo efficacy and safety through well-designed clinical trials. While EOs represent a promising approach, they are not a substitute for evidence-based antifungal treatment and must not be used without medical guidance.

The human gut microbiome harbors diverse beneficial bacteria with potential roles in supporting host health. Parabacteroides distasonis has recently attracted interest as a next-generation probiotic (NGP) candidate; however, functional evidence for human-derived strains remains limited. Here, three human gut-derived P. distasonis strains (B2-S-102, B2-Q-110, and Y3-G-102) were isolated from healthy individuals and characterized using comparative genomics and in vitro functional assays. Species-level identity was supported by 16S rRNA gene analysis and whole-genome relatedness metrics (ANI > 97% and dDDH > 70%), consistent with established species delineation thresholds. Under controlled laboratory conditions, the strains showed tolerance to acidic pH (pH 2.0), bile salts (0.3%), and simulated gastric and intestinal fluids. Functionally, the strains exhibited measurable antioxidant activity (35.03 ± 7.76% to 51.22 ± 5.60% DPPH inhibition) and α-amylase inhibitory activity (51.03 ± 32.12% to 69.23 ± 4.26%) in vitro. Cell-free supernatants inhibited albumin denaturation (47.65 ± 3.56% to 65.26 ± 4.15%), while live bacteria reduced nitric oxide production and pro-inflammatory cytokines (IL-6, TNF-α, IFN-γ, and IL-1β) in LPS-stimulated RAW 264.7 macrophages (p < 0.05). The strains also displayed in vitro growth-inhibitory activity against Escherichia coli, Acinetobacter baumannii, and Salmonella enteritidis. Genome mining identified multiple biosynthetic gene clusters, indicating genetic potential for secondary metabolite production; however, expression and metabolite identity were not experimentally validated. No haemolytic activity was observed, supporting a favorable preliminary safety profile. Overall, these findings provide preliminary in vitro evidence supporting the potential of human-derived P. distasonis strains as NGP candidates for further evaluation.