Microbial Biotechnology最新文献

Infectious diseases continue to pose a significant global health challenge, necessitating innovative approaches for predicting outbreaks, detecting variants, conducting contact tracing, discovering new drugs and managing misinformation. Artificial intelligence (AI) has significantly supported work in these areas, particularly during the COVID-19 pandemic. However, the benefits of AI must be equitably distributed, and its use must be responsible and inclusive. As various nations implement AI regulations, the global nature of AI necessitates international collaboration to establish ethical guidelines and governance frameworks. In response to these needs, the Global South AI for Pandemic & Epidemic Preparedness & Response Network (AI4PEP) is leading a multinational effort across 16 countries to strengthen public health systems through responsible, Southern-led AI solutions. This opinion piece highlights AI4PEP's initiatives in Latin America and the Caribbean (LAC), examining the region's AI governance models and the challenges they present. By lowering barriers to AI adoption and fostering equitable access to AI-driven public health innovations, our network empowers researchers, healthcare professionals and policymakers in LAC to harness AI for infectious disease preparedness and response, ultimately improving health outcomes in low- and middle-income countries.

The Pseudomonas syringae complex WHOP genomic island underpins virulence in woody hosts by mediating the catabolism of aromatic compounds. However, the biochemical functions of the ipoABC and dhoAB operons and the regulatory gene whpR remain unknown. Comparative genomics revealed WHOP-like clusters beyond P. syringae, found in diverse plant-associated, environmental and clinical bacteria, including indole degraders. We propose that ipoABC and dhoAB mediate indole degradation via anthranilate, linking indole detoxification to central metabolism through the β-ketoadipate pathway. In the olive pathogen P. savastanoi pv. savastanoi, ipoABC promotes indole degradation, indigo production, cell aggregation and biofilm formation. WhpR, an AraC-family regulator structurally related to CuxR and ToxT, defines a regulon comprising repression of most WHOP operons along with genes outside this region, including trpAB, reflecting integrated regulation of indole catabolism and tryptophan biosynthesis. In line with the observed transcriptional repression of WHOP genes, deletion of whpR led to hypervirulence and significantly altered bacterial fitness in woody olive plants. These findings define the WHOP region as a regulatory hub linking indole detoxification, multicellular behaviour and virulence, emerging as a target for novel control strategies against woody plant diseases.

Rapid and reliable analytical techniques play important roles in various research fields and are particularly crucial for diagnosing infectious diseases in clinical settings. African swine fever (ASF) is a devastating viral pig disease for which no effective vaccine is available. The ongoing ASF pandemic has highlighted the importance of rapid and accurate diagnosis, which enables the timely implementation of control and eradication measures. In this study, a ready-to-use bioluminescence immunosensor based on a split-nanoluciferase (NanoLuc) reporter system was proposed for the one-step sensitive detection of ASF virus (ASFV) antibodies. Specifically, the NanoLuc subunits SmBiT/LgBiT were each genetically fused to the ASFV p30 protein and protein G and used as probes. The simultaneous binding of the probes to ASFV IgGs induced the reconstitution of functional NanoLuc, which can generate a strong bioluminescent signal output by catalysing the substrate furimazine. This immunosensor allows the rapid and homogeneous detection of ASFV antibodies in solution, requiring only one incubation step of 10 min. This immunosensor also has high sensitivity, high specificity, and a wide dynamic range and is particularly promising for point-of-care testing. Comparative analysis of clinical samples validated the reliability and robustness of this approach and demonstrated high consistency with enzyme-linked immunosorbent assay (ELISA) results (concordance rate: 98.71%). These results suggest that the proposed immunosensor provides an attractive alternative to conventional immunoassays and could be easily repurposed by generating specific probes for antibody detection in other diseases.

Ethanol stress poses a considerable challenge for Saccharomyces cerevisiae during fermentation. Strains carrying an extra copy of chromosome III exhibit enhanced ethanol tolerance. Here, we investigated the underlying mechanisms of this tolerance, focusing on gene dosage effects and differential gene expression under ethanol stress. We compared the gene expression profiles of a strain with three copies of chromosome III and its derivative with two copies, exposed to 6% and 10% ethanol. Our analysis identified TUP1, located on chromosome III, as a key regulator of the ethanol stress response. Deleting one copy of TUP1 in the tolerant strain diminished its ethanol tolerance, suggesting that chromosome III aneuploidy in ethanol-tolerant strains enhances adaptive responses by increasing TUP1 copy number. Our findings offer insights into the genetic basis of ethanol tolerance, with potential applications for optimising industrial fermentation processes and understanding the role of aneuploidy in the domestication of industrial yeasts.

Ethanol stress poses a considerable challenge for Saccharomyces cerevisiae during fermentation. Strains carrying an extra copy of chromosome III exhibit enhanced ethanol tolerance. Here, we investigated the underlying mechanisms of this tolerance, focusing on gene dosage effects and differential gene expression under ethanol stress. We compared the gene expression profiles of a strain with three copies of chromosome III and its derivative with two copies, exposed to 6% and 10% ethanol. Our analysis identified TUP1, located on chromosome III, as a key regulator of the ethanol stress response. Deleting one copy of TUP1 in the tolerant strain diminished its ethanol tolerance, suggesting that chromosome III aneuploidy in ethanol-tolerant strains enhances adaptive responses by increasing TUP1 copy number. Our findings offer insights into the genetic basis of ethanol tolerance, with potential applications for optimising industrial fermentation processes and understanding the role of aneuploidy in the domestication of industrial yeasts.

The gut-testis axis enables gut microbes to influence host reproduction; nonetheless, the specific role of microbial genetic variation in this process remains elusive. In this study, using Caenorhabditis elegans (C. elegans) as a model organism, we identified 46 Escherichia coli (E. coli) strains that markedly enhanced C. elegans fertility. Of them, 26 strains were mutant variants capable of mitigating cyclophosphamide (CTX)-induced reproductive disorders in C. elegans. To investigate their application, we constructed probiotics to validate their effectiveness in mouse reproduction. The engineering probiotic Ecn Δpal significantly improved spermatogenesis in mice with CTX-induced reproductive disorders. Finally, comprehensive metabolome and transcriptome analysis suggested that the purine metabolism pathway may contribute to ameliorating cyclophosphamide-induced male reproductive toxicity. Overall, our study provides novel insights into the impact of gut microbial genetic variation on host reproduction and elucidates novel therapeutic avenues for mitigating CTX-induced male reproductive toxicity.

The phyllosphere, the aerial surfaces of plants, represents a primary entry point for airborne fungal pathogens, posing a critical challenge to plant health and productivity. The phyllosphere hosts diverse microbial communities that play a pivotal role in suppressing foliar pathogens through complex ecological interactions. In this mini review, we synthesise recent advances in understanding how phyllosphere microbial diversity contributes to fungal pathogen suppression through multiple ecological mechanisms, including resource competition, secretion of antifungal metabolites, contact-dependent killing and activation of host immune responses. We highlight emerging evidence on the role of viruses in controlling fungal pathogens and propose a conceptual framework based on virus-mediated strategies for fungal disease control. We emphasise that better mechanistic understanding of plant–fungus–microbiota interactions is critical to developing sustainable and microbiota-based approaches for plant resilience enhancement and global food security within a One Health framework.

The phyllosphere, the aerial surfaces of plants, represents a primary entry point for airborne fungal pathogens, posing a critical challenge to plant health and productivity. The phyllosphere hosts diverse microbial communities that play a pivotal role in suppressing foliar pathogens through complex ecological interactions. In this mini review, we synthesise recent advances in understanding how phyllosphere microbial diversity contributes to fungal pathogen suppression through multiple ecological mechanisms, including resource competition, secretion of antifungal metabolites, contact-dependent killing and activation of host immune responses. We highlight emerging evidence on the role of viruses in controlling fungal pathogens and propose a conceptual framework based on virus-mediated strategies for fungal disease control. We emphasise that better mechanistic understanding of plant–fungus–microbiota interactions is critical to developing sustainable and microbiota-based approaches for plant resilience enhancement and global food security within a One Health framework.

The gut-testis axis enables gut microbes to influence host reproduction; nonetheless, the specific role of microbial genetic variation in this process remains elusive. In this study, using Caenorhabditis elegans (C. elegans) as a model organism, we identified 46 Escherichia coli (E. coli) strains that markedly enhanced C. elegans fertility. Of them, 26 strains were mutant variants capable of mitigating cyclophosphamide (CTX)-induced reproductive disorders in C. elegans. To investigate their application, we constructed probiotics to validate their effectiveness in mouse reproduction. The engineering probiotic Ecn Δpal significantly improved spermatogenesis in mice with CTX-induced reproductive disorders. Finally, comprehensive metabolome and transcriptome analysis suggested that the purine metabolism pathway may contribute to ameliorating cyclophosphamide-induced male reproductive toxicity. Overall, our study provides novel insights into the impact of gut microbial genetic variation on host reproduction and elucidates novel therapeutic avenues for mitigating CTX-induced male reproductive toxicity.

Flavonoids are valuable for pharmaceutical, cosmetic and food applications. However, poor solubility and bioavailability limit their widespread use. Biotechnological glycosylation of flavonoids helps address these limitations, but such bioprocesses remain constrained by the cost and availability of uridine diphosphate glucose (UDPG) and the inherent toxicity of flavonoids. In this study we demonstrate that Escherichia coli W is an optimal microbial host for glycosylation bioprocesses using sucrose as a carbon and UDPG source. Escherichia coli W outperforms the model E. coli K12 strain in terms of flavonoid tolerance and glycosylation capabilities. Optimization of sucrose metabolism through adaptive laboratory evolution (ALE) and targeted metabolic engineering to reroute glucose metabolism to UDPG further enhances E. coli W's glycosylation abilities. We validated our glycosylation platform for bench-scale production of chrysin-7-O-glucoside (C7O), a valuable flavonoid glucoside, overcoming key challenges related to the low solubility and bioavailability of its precursor, chrysin. To address bioavailability limitations, we implemented a fed-batch bioprocess in a 3 L bioreactor which returned 1844 mg/L (3.3 mM) C7O, a specific production rate of 0.17 mmol C7O/g DCW·h and a 25.24 mg/g Yp/s after 76 h. An 82.1% yield (1515 mg/L C7O) post extraction and purification demonstrates the efficiency and scalability of the process for industrial bioproduction.