FEMS microbiology reviews最新文献

Plant-microbiome symbiotic interactions play a crucial role in regulating plant health and productivity. To establish symbiotic relationships, the plant secretes a variety of substances to facilitate microbial community recruitment and assembly. In recent years, important progress has been made in studying how plant exudates attract beneficial microorganisms and regulate plant health. However, the mechanisms of plant exudates-mediated microbial community recruitment and assembly and their effects on plant health are no comprehensive review. Here, we summarize the interaction mechanisms among plant exudates, microbial community recruitment and assembly, and plant health. First, we systematically evaluate the type and distribution of plant exudates, as well as their role in microbiome recruitment and assembly. Second, we summarize the mechanisms of plant exudates in terms of microbiome recruitment, diversity regulation and chemotaxis. Finally, we list some typical examples for elucidating the importance of plant exudates in promoting plant health and development. This review contributes to utilizing plant exudate or beneficial microbiome resources to manage plant health and productivity.

Studies on the epidemiology and clinical relevance of Mycobacterium tuberculosis complex (MTBC) have immensely benefited from molecular typing methods, associated software applications, and bioinformatics tools. Over the last two decades, the Pasteur Institute of Guadeloupe has developed a range of bioinformatic resources, including databases and software, to advance understanding of TB epidemiology. Traditional methods, such as IS6110-RFLP, MIRU-VNTR typing, and spoligotyping, have been instrumental but are increasingly supplanted by more precise and high-throughput techniques. These typing methods offer relatively good discrimination and reproducibility, making them popular choices for epidemiological studies. However, the advent of whole-genome sequencing (WGS) has revolutionized Mycobacterium tuberculosis complex (MTBC) typing, providing unparalleled resolution and data analysis depth. WGS enables the identification of single nucleotide polymorphisms and other genetic variations, facilitating robust phylogenetic reconstructions, and detailed outbreak investigations. This review summarizes current molecular typing methods, as well as databases and software tools used for MTBC data analysis. A comprehensive comparison of available tools and databases is provided to guide future research on the epidemiology of TB and pathogen-associated variables (drug resistance or virulence) and public health initiatives.

Synthetic C1 assimilation holds the promise of facilitating carbon capture while mitigating greenhouse gas emissions, yet practical implementation in microbial hosts remains relatively limited. Despite substantial progress in pathway design and prototyping, most efforts stay at the proof-of-concept stage, with frequent failures observed even under in vitro conditions. This review identifies seven major barriers constraining the deployment of synthetic C1 metabolism in microorganisms and proposes targeted strategies for overcoming these issues. A primary limitation is the low catalytic activity of carbon-fixing enzymes, particularly carboxylases, which restricts the overall pathway performance. In parallel, challenges in expressing multiple heterologous genes-especially those encoding metal-dependent or oxygen-sensitive enzymes-further hinder pathway functionality. At the systems level, synthetic C1 pathways often exhibit poor flux distribution, limited integration with the host metabolism, accumulation of toxic intermediates, and disruptions in redox and energy balance. These factors collectively reduce biomass formation and compromise product yields in biotechnological setups. Overcoming these interconnected challenges is essential for moving synthetic C1 assimilation beyond conceptual stages and enabling its application in scalable, efficient bioprocesses towards a circular bioeconomy.

Enteropathogens cause many gastrointestinal infections every year. However, it is often overlooked that many individuals remain asymptomatic despite exposure to these pathogens. The mechanisms underlying this effective protection against infection may hold important clues for disease prevention or therapy. Here, we focus on Salmonella enterica serovar Typhimurium (S. Tm), a well-studied enteropathogen closely related to commensal Escherichia coli. We discuss the host's multi-layered defence mechanisms that protect against S. Tm infection of the intestine, with an emphasis on the microbiota, epithelial barrier, and immune system. Perturbations in these defences, such as microbiota dysbiosis, variability in epithelial barrier integrity, or immune defects, can impair protection and increase susceptibility to disease. Additionally, we review the virulence mechanisms and metabolic adaptations that S. Tm has evolved to overcome these protective layers. This complex interplay between host defence layers and pathogen traits, shaped by both intrinsic and extrinsic factors, ultimately determines whether exposure results in asymptomatic carriage or symptomatic disease. Understanding these dynamics is critical for developing targeted interventions to prevent S. Tm infections and mitigate their impact on public health.

In the innovative field of engineered living materials (ELMs) microbiology and material sciences meet. These materials incorporate living organisms, such as bacteria, fungi, plants, or algae, to enable unique functions like self-assembly, actuation, and dynamic interaction. By utilizing (micro)biological systems in material design, ELMs promise to transform industries including healthcare, construction, and agriculture. In the early phase of ELM technology development, researchers implemented a single living strain in an already established user material. However, the complexity and potential of these materials is limited by the abilities of this single strain. Even though synthetic biology brings the opportunity to add a range of nonnative bioactivities to these cells and thus the material, the increasing metabolic burden upon implementation of multiple nonnative pathways limits the capacity of a single strain. Furthermore, higher organisms and nonstandard hosts are often desired in material settings for their native physical or metabolic advantages. However these are not always straightforward to further engineer. Thus, the use of multiple, specialized strains broadens the functionalities and thus the applicability of ELMs. Multistrain ELMs are a brand-new technology, with many promising applications.

The exquisite ability of bacteria to adapt to their environment is essential for their capacity to colonize hostile niches. In the cystic fibrosis (CF) lung, hypoxia is among several environmental stresses that opportunistic pathogens must overcome to persist and chronically colonize. Although the role of hypoxia in the host has been widely reviewed, the impact of hypoxia on bacterial pathogens has not yet been studied extensively. This review considers the bacterial oxygen-sensing mechanisms in three species that effectively colonize the lungs of people with CF, namely Pseudomonas aeruginosa, Burkholderia cepacia complex, and Mycobacterium abscessus and draws parallels between their three proposed oxygen-sensing two-component systems: BfiSR, FixLJ, and DosRS, respectively. Moreover, each species expresses regulons that respond to hypoxia: Anr, Lxa, and DosR, and encode multiple proteins that share similar homologies and function. Many adaptations that these pathogens undergo during chronic infection, including antibiotic resistance, protease expression, or changes in motility, have parallels in the responses of the respective species to hypoxia. It is likely that exposure to hypoxia in their environmental habitats predispose these pathogens to colonization of hypoxic niches, arming them with mechanisms than enable their evasion of the immune system and establish chronic infections. Overcoming hypoxia presents a new target for therapeutic options against chronic lung infections.

Microbial manufacturing offers a sustainable and environmentally friendly approach for chemical production. However, the inherent toxicity of certain high-value chemicals to microbial cell factories presents a significant challenge, severely constraining production efficiency. To enhance microbial tolerance, extensive synthetic biology strategies have been developed. The cell envelope serves as the primary natural barrier in microorganisms, and both its intrinsic composition, including membrane lipids, membrane proteins, and cell wall components, and the regulation of these components play crucial roles in modulating cellular responses to environmental stress. Engineering strategies targeting intracellular components, such as transcription factors and repair pathways, have demonstrated effectiveness in enhancing microbial tolerance to toxic end-products and intermediates. Additionally, recent advances have focused on extracellular engineering, including biofilm formation and the modulation of intercellular interactions, which have garnered significant scientific interest. This review aims to provide a systematic overview of these strategies and offers insights to facilitate the industrial translation and commercialization of microbial production of toxic end-products and intermediates.

Following over a century's worth of research, our understanding of Pneumocystis has significantly expanded in various facets, spanning from its fundamental biology to its impacts on animal and human health. Its significance in public health has been underscored by its inclusion in the 2022 WHO fungal priority pathogens list. We present this review to summarize pivotal advancements in Pneumocystis epidemiology, host specificity, genetic diversity and evolution. Following a concise discussion of Pneumocystis species classification and divergence at the species and strain levels, we devoted the main focus to the following aspects: the epidemiological characteristics of Pneumocystis across nearly 260 mammal species, the increasing recognition of coinfection involving multiple Pneumocystis species in the same host species, the diminishing host specificity of Pneumocystis among closely related host species, and the intriguingly discordant evolution of certain Pneumocystis species with their host species. A comprehensive understanding of host specificity, genetic diversity, and evolution of Pneumocystis can provide important insights into pathogenic mechanisms and transmission modes. This, in turn, holds the potential to facilitate the development of innovative strategies for the prevention and control of Pneumocystis infection.

Bacteria require sophisticated sensing mechanisms to adjust their metabolism in response to stressful conditions and survive in hostile environments. Among them, toxin-antitoxin (TA) systems play a crucial role in bacterial adaptation to environmental challenges. TA systems are considered as stress-responsive elements, consisting of both toxin and antitoxin genes, typically organized in operons or encoded on complementary DNA strands. A decrease in the antitoxin-toxin ratio, often triggered by specific stress conditions, leads to toxin excess, disrupting essential cellular processes and inhibiting bacterial growth. These systems are categorized into eight types based on the nature of the antitoxin (RNA or protein) and the mode of action of toxin inhibition. While the well-established biological roles of TA systems include phage inhibition and the maintenance of genetic elements, the environmental cues regulating their expression remain insufficiently documented. In this review, we highlight the diversity and complexity of the environmental cues influencing TA systems expression. A comprehensive understanding of how these genetic modules are regulated could provide deeper insights into their functions and support the development of innovative antimicrobial strategies.