Microbial Biotechnology最新文献

Acute pancreatitis (AP) pathogenesis involves gut microbiota dysbiosis. Although Lactobacillus salivarius Li01 (Li01) is a well-characterised probiotic strain, its specific role in AP via the ‘gut-pancreas axis’ remains unclear. Li01 pretreatment via oral gavage was assessed in an L-arginine-induced AP mouse model. The gut microbiota composition and abundance were analysed via 16S rRNA sequencing, complemented by untargeted faecal metabolomics and pancreatic transcriptomics analyses. Li01 pretreatment significantly alleviated histopathological damage to the pancreas and reduced serum amylase activity in AP model mice. Pancreatic transcriptomic analysis revealed that Li01 modulated the expression of 89 differentially expressed genes (DEGs), thereby impacting key immune-related signalling pathways, including the TNF-α signalling pathway. Furthermore, Li01 mitigated gut microbiota dysbiosis in AP mice, notably by increasing the relative abundance of bacteria such as Paramuribaculum. Faecal metabolomics analysis indicated that Li01 intervention significantly increased the levels of metabolites involved in steroid hormone biosynthesis, including 17α-estradiol. Li01 may alleviate AP by modulating the gut microbiota composition, increasing the relative abundance of bacteria such as Paramuribaculum, and regulating faecal metabolite profiles, particularly those involved in the steroid hormone biosynthesis pathway. These modulations, in turn, appear to influence pancreatic inflammation-related signalling pathways, including the TNF signalling pathway.

This article explores how microbiology can be meaningfully integrated into science education for preschoolers, children under 6 years old. Current research shows that the early years represent a critical period for scientific learning. Microbiology offers a unique opportunity to engage children in curiosity, and reflection by connecting the invisible microbial world with their everyday experiences. Its introduction at a young age supports the development of scientific thinking skills and helps correct prevalent misconceptions about microorganisms that often continue into adulthood. To overcome these misunderstandings, we designed and implemented a programme for early childhood to learn fundamental microbiological concepts within the framework of a science communication initiative called Ciencia Maravilla. This programme, created by teachers and researchers from the National University of Rosario, combines play, storytelling, and experimentation to encourage curiosity, critical thinking, and early scientific literacy. We propose to teach the microscopic nature of microorganisms, their vast diversity, their ubiquitous presence across all environments, and their essential functions as living organisms. Furthermore, we invite the educational community to critically examine anthropocentric perspectives that primarily associate microorganisms with human health, disease, and benefits. Instead, we advocate for a broader ecological approach, anchored in pedagogical practices that promote deep learning, reflection, and authentic inquiry experiences, which is crucial for fostering a balanced and nuanced understanding of the microbial world through science education.

Tens of thousands of biosynthetic gene clusters (BGCs) have been identified in microbial genomes, but the vast majority of associated natural products (NPs) and their underlying biosyntheses remain unknown. Metabologenomics approaches integrate genomic and metabolomic datasets to statistically associate BGCs to their cognate NPs, yet often suggest many false links. Here, we show that incorporating information on the producer strains' phylogeny greatly improves accuracy. We sequenced 72 Sorangium spp. genomes (myxobacteria), predicting 2030 BGCs in 265 gene cluster families (GCFs). Mass spectrometry (MS¹) revealed 99 metabolite families (MFs) from the same strains. Using a phylogeny-aware statistical analysis, we identified 43 high-confidence associations between GCFs and MFs, correctly including 89% of previously characterised links and reducing spurious associations by 33-fold, compared to simple correlational analysis. Our approach identified previously unknown BGCs for rowithocin and an undescribed poly-glycosylated NP. It also identified a distinct BGC associated with the production of chlorotonil C variants and refined the BGC for maracen. This study demonstrates the effectiveness of phylogeny-aware metabologenomics as a scalable strategy for NP discovery and biosynthetic pathway elucidation, and provides a roadmap to improved analyses of paired-omics data towards NP discovery.

Co-culture of microorganisms with plant cells is a promising approach for inducing gene expression for the synthesis of bioactive compounds in cultured plant cells. However, the use of microorganisms is often difficult because they tend to inhibit the growth of cultured plant cells. In this study, we explored the potential of plant immunity–activating endophytic bacteria for inducing metabolic changes in cultured plant cells. Delftia sp. BR1R-2, originally isolated from a Brassicaceae plant, reportedly activates plant immunity without inhibiting plant growth. Here, we found that strain BR1R-2 had no adverse effects on the growth of tobacco BY-2 cells, even though Escherichia coli, which was examined as a control, markedly inhibited cell growth. In addition, the metabolic profile of BY-2 cells was significantly altered by co-culture with BR1R-2 cells. Strain BR1R-2 induced the expression of defence-related genes and the production of antibacterial compounds in BY-2 cells. Using two wells separated by a 0.6-μm-pore-size filter, we demonstrated that physical contact with strain BR1R-2 was required for the induction of metabolic changes in BY-2 cells. Another plant immunity–activating endophytic bacterium, Pseudomonas sp. RS1P-1, also induced metabolic changes in not only tobacco BY-2 cells but also Arabidopsis T87 cells, without inhibiting their growth. These results indicate that plant immunity–activating endophytic bacteria exhibit great potential for use in altering the metabolic profile of cultured plant cells for the production of valuable phytochemicals.

Aeromonas dhakensis is an emerging multidrug-resistant (MDR) bacterial pathogen that presents significant threats to public health and aquaculture. This study reports the isolation and comprehensive characterisation of jumbo bacteriophage P19. It is a lytic phage with a long, contractile tail and is placed in the genus Ceceduovirus of the family Straboviridae. P19 possesses a large genome typical of jumbo phages, which likely contributes to its enhanced replication efficiency and adaptability. P19 exhibited strong lytic activity with a high efficiency of plating (EOP) against multiple A. dhakensis strains, a burst size of approximately 50 plaque-forming units (PFU) per cell, and a latent period of 30 min. It remained highly stable across pH 6–10 and temperatures up to 60°C. Genomic analysis revealed a 228 kb genome with 414 open reading frames (ORFs) and absence of genes related to lysogeny, antibiotic resistance or virulence, indicating its potential for safe therapeutic and biocontrol applications. ORF_358 encodes a stable and soluble T4-type lysozyme endolysin (molecular weight 18.8 kDa) belonging to the glycoside hydrolase family 24. Molecular docking analysis demonstrated strong binding affinity (−6.4 kcal/mol) between P19_358 and the peptidoglycan NAG-NAM dimer. Recombinant P19_358 endolysin exhibited 99.98% relative lytic activity against Gram-positive bacterium Bacillus subtilis at a concentration of 75 μg/mL without EDTA pre-treatment; whereas, it showed broad-spectrum antibacterial activity against several Gram-negative pathogens, including A. dhakensis, Shigella flexneri, Salmonella Typhimurium, Pseudomonas aeruginosa and Escherichia coli, with relative activity ranging from 71% to 97% following pre-treatment with 100 mM EDTA. These findings collectively indicate that phage P19 and its endolysin P19_358 possess potent lytic activity and favourable stability profiles, supporting their development as promising antimicrobial agents against MDR Gram-negative pathogens.

Fish aquaculture faces significant economic losses from disease outbreaks. Vaccination is the most effective prevention strategy, and bacterial extracellular vesicles (EVs) show promise as vaccine platforms due to their strong immuno-stimulating properties. However, the application of EVs derived from pathogenic bacteria is limited by toxicity risks and production challenges. Alternatively, genetic engineering of non-pathogenic microorganisms is being explored to produce tailored EVs to deliver antigens and serve as carriers of therapeutic proteins. Recently, we have engineered the model cyanobacterium Synechocystis sp. PCC 6803 for the expression of the reporter green fluorescent protein (sfGFP) and its targeting to EVs. Here, taking advantage of the Synechocystis sfGFP-loaded EVs, the stability of vesicles and their cargo was evaluated in the long term when stored under different temperature conditions and after freeze-drying. The possibility of using Synechocystis EVs as a tool for eliciting specific/adaptive immune responses was assessed in European seabass, a high commercial value fish, by following the amount of total and sfGFP-specific immunoglobulins produced after immunisation through injection. Synechocystis EVs were shown to be resilient nanostructures that can induce specific immune responses in fish with additional adjuvant features. This represents a biotechnological breakthrough towards a novel antigen-carrier platform for sustainable fish-pathogen control.

Soil salinity poses a major challenge to the legume-rhizobia symbiosis development, thereby affecting sustainable agriculture. Selecting NaCl-tolerant strains and enhancing the native strains' fitness under salt stress are essential steps for the restoration of marginal areas. In this work, 49 Sinorhizobium meliloti strains, the rhizobial species forming symbiotic nitrogen-fixing associations with alfalfa-including 21 de novo-sequenced field isolates-were subjected to a thorough in vitro screening for salt tolerance at progressively higher NaCl concentrations. Field isolates showed genome-based geographical clustering but contrasting salt tolerance abilities. Indeed, genome-wide association (GWA) analysis on the strains' whole-genome sequencing data indicated several loci associated with the variability in salt tolerance. Candidate genes were involved in various processes including cell wall organisation, LPS biosynthesis, quorum sensing, and carbohydrate transport and metabolism. The relationship with carbohydrate metabolism was further confirmed by Phenotype Microarray analysis which indicated salt-tolerant strains having enhanced capacity in carbon source usage. These findings reveal synergistic pathways underlying salt tolerance and suggest candidate traits (e.g., quorum sensing, carbohydrate synthesis and modification) for developing bioinoculants to enhance legume performance in saline soils.

Zhao, X., S. Li, J. Ding, J. Wei, P. Tian, H. Wei, and T. Chen. 2021. “Combination of an Engineered Lactococcus lactis Expressing CXCL12 With Light-Emitting Diode Yellow Light as a Treatment for Scalded Skin in Mice.” Microbial Biotechnology 14, no. 5: 2090–2100.

In Figure 2A, two unintentional image issues were identified: one is an unintentional reuse of images from the same HE section; the other is an inadvertent swapping of image positions representing two different time points within the same experimental group. These have been corrected in the version of Figure 2 shown below. It is important to note that these corrections do not affect the core conclusions of this study in any way.

We apologize for this error.

This study demonstrates that synergistic integration of thermal cycling (28°C–58°C) and fungal inoculants (Fomes lignosus, Penicillium glabrum) enhances humification in cattle manure composting by restructuring microbial communities toward metabolic adaptation. Through a temperature-phased aerobic system, both inoculants significantly improved carbon conversion efficiency, with F. lignosus (B) and P. glabrum (G) increasing total organic matter by 4.71% and 3.42% (vs. control), humic acid content by 4.58-fold and 2.35-fold, and FDA hydrolase activity by 3.28-fold and 1.22-fold, respectively, confirming improved humification and nutrient cycling. Temperature–inoculant synergy drove functional differentiation. Respiratory profiling revealed that P. glabrum enhanced oxygen consumption by 1.3-fold during the early thermophilic phase (0–168 h at 58°C). Subsequently, temperature-induced respiration hierarchies (control > B > G) converged over time with microbial domestication. High-throughput sequencing and network analyses revealed that temperature–inoculant synergy reshaped the microbiome into simplified consortia, which comprise seven dominant bacterial phyla (e.g., Firmicutes, Actinobacteriota) and three dominant fungal phyla (e.g., Ascomycota), with marked functional differentiation characteristics. P. glabrum selectively enriched humification-related taxa, providing regulatory strategies for enhanced carbon stabilization; whereas F. lignosus favoured lignocellulose-degrading communities, optimising substrate valorisation efficiency. This strategy establishes a targeted microbial framework for optimising the resource utilisation efficiency of lignocellulosic waste within fermentation systems, thereby contributing to circular bioeconomy goals in sustainable organic waste management.

Staphylococcus aureus biofilms are major contributors to chronic and recurrent infections due to their intrinsic tolerance to antibiotics and host immune clearance, highlighting the urgent need for safe and effective antibiofilm strategies. This study evaluated the inhibitory effects and underlying mechanisms of betulinic acid (BA), the principal active constituent of the traditional Chinese medicine Liquidambaris fructus, against S. aureus biofilms. In vitro assays demonstrated that the minimum biofilm inhibitory concentration (MBIC) of BA was 32 μg/mL, which was markedly lower than its minimum inhibitory concentration (MIC, 512 μg/mL), indicating preferential activity against biofilm formation. Serial passage experiments revealed no detectable induction of drug resistance. Mechanistic studies revealed that BA suppressed early biofilm adhesion and aggregation, downregulated the expression of adhesion-related genes (clfA, clfB, fnbpA and fnbpB), and reduced the production of extracellular polysaccharide (EPS) and extracellular DNA (eDNA). BA further disrupted mature biofilm architecture, promoted macrophage infiltration, enhanced bacterial clearance and attenuated the expression of immune evasion factors (scin, chip, lukE and nuc). In vivo, BA significantly alleviated implant-associated infections, mitigated local inflammatory responses and facilitated tissue repair. Collectively, these findings reveal that BA inhibits S. aureus biofilms through multiple coordinated mechanisms, with a low propensity for resistance development and favourable biosafety, supporting its potential as a promising lead compound for the development of novel antibiofilm therapeutics.