Microbial Biotechnology最新文献

This manuscript summarises the 5-year journey of the International Microbiology Literacy Initiative (IMiLI) and its South Asian Regional Centre (IMiLI-SAC). The main focus of the centre has been to propagate microbiology literacy and at the same time translate microbiome science into society. IMiLI-SAC played an important role in engaging audiences from diverse backgrounds across India and beyond by conducting lectures, organising workshops and outreach programs. In addition, it has also translated many educational resources in regional and cultural languages for wider presentation. IMiLI-SAC played a pivotal role in connecting microbial science with real-world issues like sustainable development, human health, dietary choices, lifestyle, preventive healthcare and planetary health. This initiative practically translates the role of microbes in different contexts using examples like microbiome studies in India, extremophiles and their biotechnological applications, and bioremediation of contaminated sites. It emphasises the important role of microbes as essential players to sustain life on earth, and changing the perception of society that views microbes as harmful or pathogens. It also supports the concept of ‘food as medicine’ and ‘antibiotic stewardship’. However, there are certain challenges like financial constraints, resources limitations and not as much awareness. Yet, IMiLI-SAC proposes that coordinated and multilingual community engagement will address this gap between science and society. The long-lasting vision of IMiLI-SAC is to incorporate microbiology literacy into school curricula, policies and public health to have a sustainable and healthy world.

Pleurotus ostreatus is a globally cultivated edible and medicinal fungus, but its growth and yield are significantly affected by heat stress during cultivation. The basic leucine zipper (bZIP) transcription factors play a critical role in various biological processes, including development, growth, and abiotic stress responses. However, the role of the bZIP transcription factor in regulating the stress tolerance, growth and development of P. ostreatus remains poorly understood. In this study, PobZIP8 was cloned, revealing a 1632 bp open reading frame encoding 525 amino acids with a conserved bZIP domain. Subcellular localization confirmed PobZIP8 as a nuclear protein with transcriptional activation activity. We investigated the regulatory mechanisms of PobZIP8 in response to heat stress and the physiological characteristics and yield performance under different developmental stages. Overexpression of PobZIP8 enhanced mycelial tolerance to heat stress and improved recovery ability after stress. Physiological indicators showed that PobZIP8 can regulate antioxidant protective enzymes including peroxidase (POD) and superoxide dismutase (SOD) to eliminate excess reactive oxygen species, promote proline accumulation, and reduce the degree of membrane lipid peroxidation. However, PobZIP8 negatively regulated the growth and development of the fruiting body, delaying primordium and fruiting body formation and reducing fruiting body size and weight. Transcriptomic analysis exhibited that PobZIP8 regulated multiple metabolic and signalling pathways across different developmental stages, including ribosome biosynthesis, energy metabolism, antioxidant processes, and secondary metabolite synthesis. These findings suggest that PobZIP8 plays a dual role in balancing stress tolerance and growth, providing insights for improving both heat resistance and yield in P. ostreatus through genetic modification.

Scientific academies are not prize clubs. They are public institutions with independence, expertise, and convening power. In a period of climate instability, widening inequality, and declining trust in science, these attributes carry a duty to lead. This is not leadership as authority or control, but as stewardship: setting standards, shaping policy with evidence, mobilising networks to deliver practical solutions, and assessing impact in the public interest. Academies exist because of public investment in their members; their obligation is to apply collective expertise to the most pressing and serious societal challenges of the time.

Microbial electrosynthesis (MES) enables a variety of microorganisms, particularly acetogens, to utilize electrical energy in the form of electrons to produce valuable compounds from CO₂. In the closely related process of gas fermentation, hydrogen gas (H₂) is provided as the energy source, whereas in MES, H₂ is produced in situ via water electrolysis. Despite the potential of MES for energy and carbon storage, it still faces major limitations, like low efficiency and low-value products. Here, we identify key limitations of the model MES biocatalyst Clostridium ljungdahlii through comparative transcriptomics, proteomics, and electron microscopy in both processes. We show that cell integrity is severely impaired in MES, consistent with membrane depolarization hampering ATP synthesis. The struggle for ATP is compensated for by activating arginine catabolism to produce ATP, a reaction that is likely fueled by cyanophycin degradation. Diversion of the Wood-Ljungdahl pathway toward the glycine synthase-reductase pathway (GSRP) resulted in a broader spectrum of reduced products, including the two amino compounds ethanolamine and glycine, which appeared exclusively under the electrochemical environment. Additionally, we observed strong induction of bacterial microcompartments, raising questions about their role during MES. This work demonstrates that MES drives C. ljungdahlii into a distinct physiological state that challenges cellular fitness and expands our understanding of MES.

Gut microbial single nucleotide polymorphisms (SNPs) offer stable, specific genetic markers for disease diagnosis. Escherichia coli (E. coli), a dominant gut bacterium, is associated with colorectal cancer (CRC), but limited enteric reference genomes hinder SNP annotation in intestinal strains. Metagenomic sequencing profiled gut microbiota in 200 CRC patients and 200 healthy controls. The E. coli strain WDP was fully sequenced via PacBio single-molecule technology for genome assembly and functional annotation. Wilcoxon tests identified differentially abundant microbes, while Lasso regression models integrated microbial features (bacteria, viruses, virus-host pairs) and E. coli SNPs to predict CRC risk. E. coli abundance did not differ between groups, but genomic analysis revealed 7460 CRC-associated SNPs. The SNP-based model achieved superior accuracy (92.86% training, 93.33% testing, 84.00% validation) and AUC (0.986, 0.983, 0.913), outperforming models based on microbial abundances (e.g., Staphylococcus capitis, Zindervirus) or virus-host interactions. PacBio-generated E. coli genomic maps enable precise SNP annotation, establishing E. coli SNPs as highly accurate biomarkers for CRC risk prediction. This approach leverages microbial genetic stability to advance non-invasive early detection, offering a novel target for precision microbiome-based diagnostics.

Streptomycetes exhibit a complex multicellular life cycle, including programmed cell death and hyphal differentiation, and can generate extracellular vesicles and wall-deficient cells such as S-cells and L-forms. These wall-deficient morphotypes are increasingly recognised as functional bacterial states with emerging biotechnological relevance, yet the environmental signals that trigger their formation remain poorly defined. Here, we show that the flavonoids daidzein and genistein act as defined chemical inducers of wall-deficient cell formation in Streptomyces coelicolor under hyperosmotic stress (0.64 M sucrose). Although the wild-type strain fails to produce wall-deficient cells in standard laboratory media under hyperosmotic conditions, robust formation of non-dividing stress-induced cells (S-cells), along with a small proportion of dividing L-forms, is observed in soya flour–mannitol medium (SFM) supplemented with high sucrose concentrations. We show that wall-deficient cell formation can be induced by the addition of daidzein and genistein, the most abundant soybean flavonoids, to flavonoid-free media containing high sucrose concentrations, at levels comparable to those found in SFM. These results identify flavonoids as defined chemical inducers of wall-deficient morphogenesis in Streptomyces. More broadly, our findings suggest a link between plant secondary metabolites and bacterial morphological plasticity, with potential implications for plant–microbe interactions and microbial biotechnology.

The intratumoural mycobiome is a critical constituent of the tumour microenvironment; however, its specific impact on epithelial ovarian cancer (EOC) progression and the underlying molecular mechanisms remain largely elusive. In this study, internal transcribed spacer 1 (ITS1) sequencing revealed a significant enrichment of Malassezia in EOC tissues compared with epithelial borderline ovarian tumours, with its abundance positively correlated with disease progression. Subsequent intratumoural microbiota transplantation and mono-colonisation in a murine EOC model demonstrated that Malassezia restricta substantially accelerated tumour growth and increased M2 macrophage infiltration. Furthermore, in vitro assays established that M. restricta-derived extracellular vesicles (MrEVs) play a pivotal role in inducing M2 macrophage polarisation. Mechanistically, both in vitro and in vivo data showed that MrEVs activate the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signalling pathway, thereby driving M2 polarisation and tumour malignancy. Collectively, these findings identify M. restricta as a pro-tumourigenic fungus in EOC and uncover a previously unrecognised fungal–immune axis that promotes tumour progression. This study provides new insight into the oncogenic role of tumour-resident fungi and highlights the M. restricta EV–JAK2/STAT3 axis as a potential therapeutic target for immune modulation.

Influenza causes approximately one billion infections and hundreds of thousands of deaths each year. Occasionally, highly pathogenic new virus strains emerge. Research on emerging influenza viruses or multiple viral strains is often limited by the need for high biosafety level (BSL) laboratories. To overcome this limitation, we attempt to establish a BSL-1-compatible influenza research platform using baculovirus surface display technology. We constructed influenza virus pseudotypes HA-Bac and NA-Bac by displaying hemagglutinin (HA) and neuraminidase (NA) proteins from influenza viruses on the surface of baculoviruses. Different HA-Bac and NA-Bac induced a unique inflammatory cytokine profile after transduction into respiratory epithelial and macrophage cell lines. Using insect cells infected with these HA-Bac and NA-Bac as antigens, we established cell-based and lysate-based ELISA to detect HA and NA antibodies. The lysate-based ELISA showed excellent performance in detecting IgG antibodies in patients' serum samples. Finally, hemagglutination induced by HA-Bac-infected insect cells and neuraminidase activity generated by NA-Bac-infected cells were both inhibited by the corresponding antiviral drugs in functional inhibition assays. In summary, this study established a safe influenza research system capable of performing cytokine profiling, serological detection and antiviral drug screening under BSL-1 conditions. This system holds promise for application to other emerging respiratory viruses and support of public health preparedness.

Three different cultures of cyanobacteria: Synechocystis sp., Leptolyngbya sp., and a co-culture of both Synechocystis sp. and Synechococcus sp. were tested for their polyhydroxybutyrate (PHB) production potential under diverse conditions. High-throughput screening in a multi-well plate, using Nile blue fluorescence to estimate PHB accumulation, enabled simultaneous testing of multiple parameters without complex setups and faster PHB estimation compared to conventional gas chromatography. Fluorescence results indicated that the best conditions for PHB accumulation were nitrogen depletion under darkness at 30°C with acetate supplementation after 4 days of glycogen accumulation. Finally, these optimal conditions were validated in single-batch proof-of-concept photobioreactors (1 L working volume). The scale-up proved successful, yielding 7% PHB dry cell weight (dcw) for Synechocystis sp. and a promising 13% PHB dcw for Leptolyngbya sp. In addition, scale-up experiments in 1-L photobioreactors demonstrated that a dedicated glycogen pre-accumulation step is unnecessary, as PHB can be efficiently synthesized directly from acetate.

Although veterinary vaccines against West Nile virus (WNV) have been developed, no approved human vaccine is currently available, highlighting the need for scalable and safer WNV vaccine candidates. In this study, a recombinant WNV subunit nanoparticle vaccine was developed by displaying the envelope protein domain III (ED3) on a cholera toxin B subunit (CTB) pentameric scaffold. The resulting recombinant protein comprising CTB-ED3 was expressed predominantly as soluble nanoparticles in Escherichia coli. Immunized mice produced strong humoral responses with balanced IgG1/IgG2a ratios, and some constructs achieved neutralizing titres comparable to those elicited by formalin-inactivated WNV. Importantly, no cross-reactivity with other flaviviruses was observed, alleviating potential concerns about ADE. These findings demonstrate that CTB-ED3 is assembled into multimeric nanoparticles in bacteria, offering a cost-effective, scalable, and biosafe platform for developing subunit nanoparticle vaccines against WNV and potentially other flaviviruses.