Higher alcohols, major metabolic byproducts produced by Saccharomyces cerevisiae during winemaking, are intricately regulated by a multilevel system. While the enzymatic machinery and their encoding genes involved in the metabolic pathways of higher alcohols in S. cerevisiae have been largely elucidated, the transcriptional regulation underlying this process remains poorly understood. This paper, building upon a summary of the metabolic pathways and regulatory strategies of higher alcohols metabolism in yeast, focuses on the transcription factors Aro80p, GATA and Leu3p implicated in the regulation of higher alcohols metabolism in yeast and their mechanisms of action. The review aims to give theoretical insights into a comprehensive understanding of the transcriptional regulation of higher alcohols metabolism in yeast and facilitate the breeding of yeast strains with moderate production of higher alcohols.

Marine mammals mainly include Cetacea living in the water, Sirenia primarily inhabiting water, and Pinnipedia which are amphibious. All these animals are rare and included in the list of national second-class or higher protected animals. Microorganisms play crucial roles in nutrient absorption, assisting the digestive process, and enhancing immune function of mammals, being an indispensable component of the host. The unique living conditions and diets of marine mammals result in significant differences in their microbiomes compared with terrestrial mammals. As a result, our knowledge about the microbiomes derived from terrestrial mammals is not applicable to marine mammals. Therefore, understanding the structures and functions of marine mammal microbiomes is essential for comprehending the interactions between marine mammals and their living environment and enhancing conservation efforts. This paper summarizes the recent advances in research on the microbiomes of marine mammals, discusses relevant technical methods, and highlights worthy scientific issues in future research.

Although the large scale of industrial nitrogen fixation and chemical nitrogen fertilizer application have increased crop yields and alleviated food crisis, the excess discharge of nitrogen nutrients have affected the environment and human health. The treatment of nitrogen contamination is largely dependent on the nitrogen cycle driven by microorganisms. In the last three decades, researchers have discovered the inorganic nitrogen metabolism pathways such as anaerobic ammonia oxidation (Anammox), complete ammonia oxidation (Comammox), and direct ammonia oxidation (Dirammox). Shewanella, a genus of known bacteria with abundant respiration pathways, are ubiquitous in natural habitats and have potential applications in both microbial fuel cells and environmental bioremediation. In this review, we described the modulation mechanisms of denitrification and dissimilatory nitrate reduction to ammonium pathways in Shewanella from the nitrate reductase systems, regulation of the cyclic AMP (cAMP) receptor proteins (Crp), and modulation and switching of nitrate reduction pathways, aiming to give insights into the microbial-driven nitrogen cycling mechanism in the hydrosphere and the development of novel biotechniques and bioreactors for the removal and mitigation of nitrogen pollution.

The nitrogen fixation in legume root nodules is of great significance for sustainable agricultural development and natural eco-environment protection. The growth period of root nodules can be divided into young, active, and senescence stages. Root nodule senescence is a complex physiological process involving the interactions of multiple genes and environmental factors. The functions and lifespan of root nodules can be altered by regulating nitrogenase activity and leghemoglobin gene expression levels. Biotic and abiotic stresses can accelerate the senescence of root nodules and reduce the biomass and productivity of leguminous plants. This article expounds the mechanism of morphological, physiological, biochemical, and molecular changes of root nodules during senescence and summarizes the biotic and abiotic factors that affect root nodule senescence. Furthermore, the measures for delaying the senescence of root nodules are discussed. These measures will prolong the symbiotic nitrogen fixation, improve the nitrogen utilization efficiency, and increase the overall nitrogen supply for seed filling of leguminous plants, thereby enhancing food security and reducing the adverse effects of chemical fertilizers on the environment.

Cable bacteria are a new group of filamentous electroactive microorganisms with the ability of long-distance electron transfer (LDET), playing an important role in the geochemical cycling of elements. Their unique structural and functional characteristics make them like "biological cables". Since the first discovery in marine sediments in 2012, cable bacteria have attracted widespread attention. They have shown unique ecological potential in maintaining the health of aquatic ecosystems, environmental restoration, and climate regulation. Focusing on the "biological cable" structures and functions of cable bacteria, this paper reviews their filamentous structural characteristics, electrogenic sulfur oxidation characteristics, diversity and distribution characteristics, and LDET mechanism in sediments, and summarizes their influences on the cycling of key elements such as S, C, N, and P and the migration and transformation of metal ions. In addition, this paper summarizes the interactions of cable bacteria with other organisms and their roles in the natural restoration of ecosystems and analyzes the existing problems and future development directions, with a view to providing a reference for further giving play to the role of "biological cables" in the natural restoration of ecosystems.

[Objective] To explore the regulatory role of the metalloregulator ZntR in metal homeostasis and clarify the effects of ZntR on the oxidative stress resistance and virulence of Vibrio parahemolyticus. [Methods] Growth curve analysis and intracellular metal content quantification were performed to investigate the regulatory effect of ZntR on the metal homeostasis in V. parahaemolyticus. The effects of ZntR on the oxidative stress resistance and virulence of V. parahaemolyticus were explored by the growth curve analysis and the competitive infection assay in the zebrafish model, respectively. The genes regulated by ZntR were identified by RNA sequencing. [Results] The zntR-deleted strain (ΔzntR) exhibited growth defects under zinc, nickel excess and iron restriction conditions, and the growth defects were related to zinc homeostasis disturbance. The overexpression of zntA in ΔzntR promoted the growth under zinc, nickel excess and iron restriction conditions. In the case of zinc excess, ΔzntR demonstrated weakened resistance to H₂O₂-induced oxidative stress. The virulence of ΔzntR was attenuated in a competitive infection assay in the zebrafish model. RNA sequencing revealed that ZntR regulated the expression of several virulence genes. [Conclusion] ZntR modulates zinc homeostasis and improves oxidative stress resistance and virulence of V. parahaemolyticus.

Cyanobacteria have garnered great attention as important players in the marine hydrosphere and the source of bioactive compounds. Type Ⅳ pili (TFP) play a crucial role in cyanobacteria by participating in various physiological functions such as substrate surface movement, phototaxis, and natural transformation. With the continuous advancements in the visualization of pili, we have gained a deeper understanding of the TFP-mediated cell behaviors of cyanobacteria. We review the recent progress and applications of visualization of pili in the research on the twitching, phototaxis, and natural transformation of cyanobacteria. This review is expected to improve our understanding of the TFP-mediated cell behaviors and the ecological function and significance of cyanobacteria in the hydrosphere. Additionally, it provides new insights for developing TFP-based regulation on cell behaviors of cyanobacteria.

Vitamin B₁₂ (VB₁₂) is an essential nutrient and growth cofactor for the majority of organisms. It exerts influence not only on the structure of microbial communities and marine primary productivity but also on the global biogeochemical cycles, thus justifying its designation as a "hard currency" in marine ecosystems. Ammonia-oxidizing archaea (AOA), initially isolated from the ocean in 2005, are distinguished by their chemolithoautotrophic characteristics. Genomic, metabolomic, and culture studies have demonstrated that AOA are among the few microbial groups capable of synthesizing VB₁₂ in the ocean. This capability is crucial for maintaining microbial community stability and biogeochemical functions. This review summarizes the measurement methods and distribution characteristics of VB₁₂ in the ocean and the pathways through which AOA produce VB₁₂. It discusses the importance of AOA in marine VB₁₂ supply and outlines the future research directions for VB₁₂ production by AOA.

Chitin is a polysaccharide that is polymerized by N-acetylglucosamine through β-1, 4 glycosidic linkages and ubiquitous in the global terrestrial and aquatic ecosystems. Chitin is one of the most abundant organic macromolecular polymers on earth. Chitinases are a class of enzymes that catalyze the degradation of chitin. Chitinases are not only the focus of basic research but also have shown broad application potential in a variety of fields such as agriculture, medicine, and environmental science. This paper systematically reviewed the research progress in fungal chitinases in terms of the classification, distribution characteristics in different fungal taxa, biological functions in yeasts and filamentous fungi, enzymatic characteristics, and applications in agricultural pest and disease control, disease treatment, and production of chitooligosaccharides. Furthermore, we discussed the future research directions of fungal chitinases. This paper provides new perspectives for the study of fungal chitinases.

[Objective] To study the transcriptome regulation mechanism of Fusarium graminearum under different pH stress conditions, analyze the changes in gene expression levels, explore the metabolic pathways involved in the responses of F. graminearum cells to acidic or alkaline conditions, and reveal how F. graminearum regulates intracellular metabolism and synthesis to adapt to the changes in extracellular pH. [Methods] F. graminearum was cultured in the PDB media with initial pH 4.5, 6.5, and 8.0 for 48 h, and the total RNA of the strains was extracted to construct the cDNA library. Transcriptome sequencing and bioinformatics analysis were used to identify the differentially expressed genes (DEGs), and the metabolic pathways involved were analyzed. The expression levels of target genes were determined by RT-qPCR. [Results] Under acidic conditions, a total of 4 283 DEGs were identified, including 2 032 genes with up-regulated expression and 2 251 genes with down-regulated expression. Under alkaline conditions, a total of 498 DEGs were identified, including 269 genes with up-regulated expression and 229 genes with down-regulated expression. Gene ontology (GO) enrichment analysis revealed 211 GO terms for the up-regulated genes and 72 GO terms for the down-regulated genes under acidic conditions. Under alkaline conditions, GO analysis yielded 33 GO terms for the up-regulated genes and 40 GO terms for the down-regulated genes. The results of Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed 22 up-regulated pathways and 32 down-regulated pathways under acidic conditions as well as 8 up-regulated pathways and 13 down-regulated pathways under alkaline conditions. The expression of the genes associated with membrane transporters and hydrolysis of carbohydrates was up-regulated, and that of the genes related to protein metabolism was down-regulated, which assisted F. graminearum cells to adapt to changes in the external environment. At the same time, F. graminearum maintained the internal environment balance by reducing secondary metabolism and amino acid metabolism under acidic and alkaline conditions, respectively, to resist extracellular pH stress. [Conclusion] In the acidic environment, F. graminearum adapts to the changes in the extracellular environment by promoting the production of ribonucleoprotein complexes and secondary metabolism. In an alkaline environment, F. graminearum senses and responds to external stresses via amino acid metabolism. The analysis of the metabolic pathways of F. graminearum cells provides gene expression data for studying the responses of F. graminearum to different pH environments. The findings of this study are helpful to understand the pathogenic mechanism of F. graminearum.