Frontiers in Microbiology最新文献

Terrestrial mud volcanoes represent surface features of channels for subsurface methane transport and, therefore, constitute an important source of methane emission from natural environments. How microbial processes regulate methane emissions in terrestrial mud volcanoes has yet to be fully addressed. This study demonstrated the geochemical characteristics and microbial communities of four mud volcano and seep sites in two geological settings of Sicily, Italy. At sites within the accretionary wedge that exhibited higher methane and sulfate concentrations, the communities were dominated by members capable of catalyzing methane and sulfate metabolisms and organic degradation. In particular, both anaerobic and aerobic methanotrophs were abundant and their abundance distribution coincided with the geochemical transition. In contrast, the sites near Mount Etna were characterized by high fluid salinity, CO₂, and low methane and sulfate concentrations, with communities consisting of halophilic organic degraders and sulfur metabolizers, along with a minor presence of aerobic methanotrophs. Substantial variations in community composition and geochemistry across spatial and vertical redox gradients suggest that physicochemical contexts imposed by the geology, fluid path, and source characteristics play a vital role in shaping community composition and cycling of methane, sulfur and organic carbon in Sicily mud volcanoes.

Estrogens are a growing problem in wastewater discharges because they are continuously entering the environment and are biologically active at extremely low concentrations. Their effects on wildlife were first identified several decades before, but the environmental limits and the remedial measures are still not completely elucidated. Most conventional treatment processes were not designed with sufficiently long retention times to effectively remove estrogens. Nature-based wastewater treatment technologies such as treatment wetlands (TW) and high-rate algal ponds (HRAP) are economically feasible alternatives for decentralized wastewater treatment and have promise for removing steroid hormones including estrogens. For small communities with populations below 50,000, the overall cost of TWs and HRAPs is considerably lower than that of advanced decentralized treatment technologies such as activated sludge systems (AS) and sequencing batch reactors (SBR). This results from the simplicity of design, use of less materials in construction, lower energy use, operation and maintenance costs, and operation by non-skilled personnel. The nature-based technologies show high removal (>80%) for both natural and synthetic estrogens. Estrogen removal in TWs can be enhanced using alternative media such as palm mulch, biochar, and construction wastes such as bricks, instead of traditional substrates such as sand and gravel. While TWs are effective in estrogen removal, they have the disadvantage of requiring a relatively large footprint, but this can be reduced by using intensified multilayer wetland filters (IMWF). Using filamentous algae in HRAP (high-rate filamentous algal pond; HRFAP) is an emerging technology for wastewater treatment. The algae supply oxygen via photosynthesis and assimilate nutrients into readily harvestable filamentous algal biomass. Diurnal fluctuations in oxygen supply and pH in these systems provide conditions conducive to the breakdown of estrogens and a wide range of other emerging contaminants. The performance of these nature-based systems varies with seasonal changes in environmental conditions (particularly temperature and solar irradiation), however a greater understanding of operating conditions such as loading rate, hydraulic retention time (HRT), pond/bed depth, dissolved oxygen (DO) concentration and pH, which influence the removal mechanisms (biodegradation, sorption and photodegradation) enable TWs and HRAPs to be successfully used for removing estrogens.

Introduction: Earthen sites are essential cultural relic resources, and site museums are a fundamental component of China's cultural heritage protection. The mausoleum of the Qin Shi Huang Emperor is one of the largest, most peculiar, and richest imperial tombs in the world. The exhibition hall of the burial pit No. 1 of the Terra Cotta Warriors is the earliest exhibition hall built and opened to the public. However, after years of excavation and open exhibitions, the earthen site of the Emperor Qinshihuang's Mausoleum Site Museum has deteriorated to varying degrees due to changes in the modern environment. There is an urgent need to control microbial diseases and protect the earthen site.

Methods: We analyzed the physical and chemical properties and bioindicators of the collected soil samples. We also established a metagenomic library and conducted a correlation analysis between microbial community composition and environmental factors. Cultivable fungi obtained from air and soil samples were identified, and allicin volatile gas fungistasis test was conducted.

Result: Research has found that four different areas of the exhibition hall have different types of microbial diseases owing to their different environments. The main pathogenic fungi in earthen site may lead to potential microbial diseases that affect important cultural relics such as the Terra Cotta Warriors. Penicillium, Aspergillus and Talaromyces showed relatively specific growth in relation to environmental factors and showed a better raw growth advantage.Allicin gas had a inhibitory effect on 12 types of fungi, therefore allicin gas had a potent inhibitory effect on the growth of the most culturable fungal hyphae.

Discussion: This study provides basic data for the study of microbial diversity in the exhibition hall of Pit No. 1 at the Terracotta Warriors Museum in Emperor Qinshihuang's Mausoleum Site Museum. It provides a reference for future protection work, which is of great significance.

The efficacy of the tuberculosis treatment is restricted by innate drug resistance of Mycobacterial tuberculosis and its ability to acquire resistance to all anti-tuberculosis drugs in clinical use. A profound understanding of bacterial ploys that decrease the effectiveness of drugs would identify new mechanisms for drug resistance, which would subsequently lead to the development of more potent TB therapies. In the current study, we identified a virulence-associated small RNA (sRNA) MTS1338-driven drug efflux mechanism in M. tuberculosis. The treatment of a frontline antitubercular drug rifampicin upregulated MTS1338 by >4-fold. Higher intrabacterial abundance of MTS1338 increased the growth rate of cells in rifampicin-treated conditions. This fact was attributed by the upregulation of an efflux protein CydC by MTS1338. Gel-shift assay identified a stable interaction of MTS1338 with the coding region of cydC mRNA thereby potentially stabilizing it at the posttranscriptional level. The drug efflux measurement assays revealed that cells with higher MTS1338 abundance accumulate less drug in the cells. This study identified a new regulatory mechanism of drug efflux controlled by an infection-induced sRNA in M. tuberculosis.

Insomnia is a common sleep disorder observed in clinical settings, with a globally rising prevalence rate. It not only impairs sleep quality and daytime functioning but also contributes to a range of physiological and psychological conditions, often co-occurring with somatic and mental disorders. Currently, the pathophysiology of this condition is not fully understood. Treatment primarily involves symptomatic management with benzodiazepine receptor agonists, melatonin and its receptor agonists, sedative antidepressants, atypical antipsychotics, and orexin receptor antagonists. However, due to the adverse side effects of these drugs, including dependency, addiction, and tolerance, there is an urgent need for safer, more effective, and environmentally friendly treatment methods. In recent years, research on the microbiota-gut-brain axis has received significant attention and is expected to be key in uncovering the pathogenesis of insomnia. Acupuncture stimulates acupoints, activating the body's intrinsic regulatory abilities and exerting multi-pathway, multi-target regulatory effects. A substantial body of evidence-based research indicates that acupuncture is effective in treating insomnia. However, the unclear mechanisms of its action have limited its further clinical application in insomnia treatment. Therefore, this study aims to elucidate the pathogenesis of insomnia from the perspective of the microbiota-gut-brain axis by examining metabolic, neuro-endocrine, autonomic nervous, and immune pathways. Additionally, this study discusses the comprehensive application of acupuncture in treating insomnia, aiming to provide new strategies for its treatment.

To develop a unique flavor of rice wine, coffee flowers (by-products of the coffee industry) were added because of their biologically active compounds that are conducive to health, and the fermentation parameters were optimized. In addition, the dynamic changes of microbial communities and volatile flavor compounds (VFCs) during the different fermentation stages were investigated. After the optimization of the fermentation parameters, a novel product, i.e., the coffee flower rice wine (CFRW), was obtained with a bright yellow transparent, fragrant, and harmonious aroma and mellow and refreshing taste by sensory evaluation, when 4.62% of the coffee flowers and 1.93% koji were added and fermented at 24.10°C for 3.88 days. The results showed that Lactococcus was the dominant bacteria, accounting for 87.0-95.7%, while Rhizopus and Cladosporium were the main fungi, accounting for 68.2% and 11.3% on average, respectively, in the fermentation process of the CFRW. Meanwhile, twenty-three VFCs were detected in the CFRW, which included three alcohols, six terpenes, ten esters, three aromatics, and one furan. The correlation analysis revealed that there were 16 significant positive correlations and 23 significant negative correlations between the bacterium and VFCs (|ρ| > 0.6, p < 0.05), while there were 12 significant positive correlations and one significant negative correlation between the fungi and VFCs (|ρ| > 0.6, p < 0.05). Furthermore, five VFCs, including linalool, geraniol, ethyl acetate, 1-hexanol, and 3-methyl-1-butanol, contributed vital flavors to the CFRW, and they were all significantly negatively correlated with the changes of Massilia and Acinetobacter (|ρ| > 0.6, p < 0.05). Moreover a significant positive correlation was found between the relative abundance of Lactococcus and the contents of 3-methyl-1-butanol and ethyl acetate (|ρ| > 0.6, p < 0.05). Therefore, this study provides a valuable theoretical basis for further improving the quality and production technology of CFRW.

As a newly discovered virus, Decapoda iridovirus 1 (DIV1) can cause a mortality rate of up to 100% in crustaceans, leading to huge economic losses. At present, there is no effective prevention and control measures for this disease. In the present study, the specific primers targeting highly conserved regions of MCP gene were designed, and then a quantitative real-time PCR method was established. The results indicate that DIV1 quantitative real-time PCR established has good specificity and does not cross react with other pathogens including white spot syndrome virus (WSSV), infectious subcutaneous and hematopoietic necrosis virus (IHHNV) and Vibrio parahaemolyticus induced acute hepatopancreatic necrosis disease (VpAHPND). The real-time PCR was capable of detecting DIV1 DNA at a minimum concentration of 10 copies/μL within 34 cycles. The method has good repeatability, with intra group and inter group coefficients of variation both less than 2%. Thirty-two clinical samples were assessed using both the real-time PCR and conventional PCR. The results shown real-time PCR we established are more sensitive than conventional PCR. In conclusion, this method has strong specificity, stable repeatability, and high sensitivity, providing technical support for clinical diagnosis, epidemiology investigation and monitoring of DIV1.

Pseudorabies virus (PRV) exhibits a complex interplay of host-pathogen interactions, primarily by modulating host cell death pathways to optimize its replication and spread in Neuro-2a cells. Using high-throughput RNA sequencing, we identified 2,382 upregulated differentially expressed genes (DEGs) and 3,998 downregulated DEGs, indicating a intricate interaction between viral pathogenesis and host cellular responses. This research offers valuable insights into the molecular processes involved in PRV infection, highlighting the substantial inhibition of crucial cell death pathways in Neuro-2a cells, including necroptosis, pyroptosis, autophagy, ferroptosis, and cuproptosis. Cells infected with PRV exhibit decreased expression of genes critical in these pathways, potentially as a mechanism to avoid host immune reactions and ensure cell survival to support ongoing viral replication. This extensive inhibition of apoptosis and metabolic alterations highlights the sophisticated tactics utilized by PRV, enhancing our comprehension of herpesvirus biology and the feasibility of creating specific antiviral treatments. This research contributes to our understanding of how viruses manipulate host cell death and presents potential opportunities for therapeutic interventions to disrupt the virus's lifecycle.

Airborne fungi and bacteria have been extensively studied by researchers due to their significant effects on human health. We provided an overview of the distribution and sources of airborne pathogenic microbes, and a detailed description of the detrimental effects that these microorganisms cause to human health in both outdoor and indoor environments. By analyzing the large body of literature published in this field, we offered valuable insights into how airborne microbes influence our well-being. The findings highlight the harmful consequences associated with the exposure to airborne fungi and bacteria in a variety of natural and human-mediated environments. Certain demographic groups, including children and the elderly, immunocompromised individuals, and various categories of workers are particularly exposed and vulnerable to the detrimental effect on health of air microbial pollution. A number of studies performed up to date consistently identified Alternaria, Cladosporium, Penicillium, Aspergillus, and Fusarium as the predominant fungal genera in various indoor and outdoor environments. Among bacteria, Bacillus, Streptococcus, Micrococcus, Enterococcus, and Pseudomonas emerged as the dominant genera in air samples collected from numerous environments. All these findings contributed to expanding our knowledge on airborne microbe distribution, emphasizing the crucial need for further research and increased public awareness. Collectively, these efforts may play a vital role in safeguarding human health in the face of risks posed by airborne microbial contaminants.

Bacterial infections pose a significant clinical burden on global health. The growing incidence of drug-resistant pathogens highlights the critical necessity to identify and isolate bioactive compounds from marine resources. Marine-derived fungi could provide novel lead compounds against pathogenic bacteria. Due to the particularity of the marine environment, Aspergillus species derived from marine sources have proven to be potent producers of bioactive secondary metabolites and have played a considerable role in advancing drug development. This study reviews the structural diversity and activities against pathogenic bacteria of secondary metabolites isolated from marine-derived Aspergillus species over the past 14 years (January 2010-June 2024), and 337 natural products (including 145 new compounds) were described. The structures were divided into five major categories-terpenoids, nitrogen-containing compounds, polyketides, steroids, and other classes. These antimicrobial metabolites will offer lead compounds to the development and innovation of antimicrobial agents.