Galactose is a ubiquitous monosaccharide in nature, serving not only as a primary carbon source for bioenergy metabolism but also as a precursor for various biological synthesis reactions. In eukaryotic cells, galactose or its derivatives can act as signaling molecules to participate in intercellular communication. Recent studies have revealed that galactose can modulate bacterial virulence by regulating intracellular signal transduction. Accordingly, galactose is considered an underappreciated environmental regulator in bacterial infection. However, the specific regulatory mechanisms remain incompletely elucidated. This review integrates the latest research findings to summarize the bacterial galactose metabolic pathway, the biological implications of galactose metabolism in bacterial virulence and interactions with hosts, and the key proteins (enzymes) in the galactose metabolism pathway as potential targets for developing novel vaccines. It offers new insights and reference for comprehending bacterial infection mechanisms and exploring innovative antibacterial strategies.

Acinetobacter spp. are the common opportunistic pathogens worldwide and pose a threat to the health of humans and animals. As the resistance rate to carbapenems aggravates, tigecycline has become one of the last lines for the treatment of multidrug-resistant Acinetobacter spp. infection. The rapid dissemination of tigecycline resistance genes tet(X3), tet(X4), tet(X5), tet(X6), and other variants in recent years has seriously affected the clinical application of new tetracycline antibiotics such as tigecycline, eravacycline, and omadacycline, whereas there is a lack of review on the tet(X) genes in Acinetobacter spp. This article comprehensively expounds the mechanisms of action, epidemiological characteristics, transmission risks, and inhibitors of tet(X) genes in Acinetobacter spp. and evaluates the diversity of their variants, bacterial hosts, geographical distribution, and sampling sources, aiming to provide a theoretical basis for the prevention and control of tet(X)-positive Acinetobacter spp.

Adenosine diphosphate-ribosylation (ADPr) is a reversible post-translational modification that is catalyzed by adenosine diphosphate-ribosyltransferases (ARTs) and adenosine diphosphate- ribosylhydrolases (ARHs), and it widely occurs in eukaryotes and prokaryotes. ARHs are a class of key enzymes that can reverse ADPr modification of specific amino acid residues or specific sites/sequences of DNA and RNA. They can regulate the physiological metabolism, signal transduction, gene expression, and other key life processes in bacteria or hosts, playing an important role in the inter/intraspecific competition, stress responses, and pathogenicity of bacteria. This article reviews the classification, structural characteristics, and catalytic mechanisms of bacterial ARHs, aiming to enrich our understanding about the catalytic mechanisms and biological functions of ARHs in bacterial life.

Ferroptosis is a novel form of programmed cell death that is iron-dependent and primarily characterized by lipid peroxidation. Studies have indicated that ferroptosis is closely related to the occurrence and development of various diseases. A variety of pathogens have been confirmed to induce ferroptosis of host cells, which facilitates pathogen proliferation and counteracting host immunity. Therefore, ferroptosis extensively participates in the pathophysiological processes caused by pathogen infection. In addition, ferroptosis is involved in the pathological process of many metabolic and poisoning diseases. This paper reviews the research progress in the occurrence and mechanism of ferroptosis in livestock and poultry diseases, aiming to provide reference for further exploring the effect and mechanism of ferroptosis in livestock and poultry diseases.

The first human Pegivirus (HPgV-1) and the second human Pegivirus (HPgV-2) are the only two human Pegiviruses that have been identified until now. They share some common features including similar viral genome structure and low pathogenicity, while they also represent unique biological characteristics. HPgV-1 is called "good virus" because of its ability to slow down disease progression and reduce disease severity when co-infecting with HIV and Ebola virus. In addition, HPgV-1 was recently found to be related with lymphoma and neurological diseases. Therefore, HPgV-1 might be a possible breakthrough point in the treatment of refractory diseases caused by HIV and other viruses. HPgV-2 was firstly discovered from the plasma of a hepatitis C virus (HCV)-infected patient in 2015 and was found to always co-infect with HCV but hardly infect healthy people. However, the underlying mechanism of HPgV-2 and HCV co-infection remains to be elucidated. Distinct from most of RNA viruses, HPgV-2 exhibits low genomic diversity with high sequence identity and low intra-host variation, which give the implication of HPgV-2 as an excellent model for studying the mechanisms of viral genome variations. In conclusion, the human Pegiviruses are worthy of sustaining attention and study.

Microbially enhanced coalbed methane production has become a research hotspot of coalbed methane production in recent years. Methanogens, the essential microorganisms in coalbed methane production, are usually strictly anaerobic and sensitive to oxygen. [Objective] To understand the changes in the methane production and composition of the anaerobic microbiome after exposure to oxygen, we conducted the enrichment culture of coalbed formation water collected from different regions along the east edge of Ordos Basin in China for air exposure experiments. Our findings are expected to provide scientific support for the future in-situ utilization of large-scale anaerobic fermentation products in coalbed methane production. [Methods] We used the enrichment cultures of coalbed formation water collected from Hancheng (HC), Baode (BD), and Linfen (LF) for air exposure for a series of time schedules within 24 h. The air-exposed enrichment cultures were re-inoculated and cultured. The methane production and community succession were analyzed to evaluate the microbiome tolerance to the aerobic condition. [Results] The microorganisms in all the three regions were still active after 24 hours of air exposure and showed the methane production comparable to that before air exposure. The dominant groups involved in the hydrolysis, acidification, and acetoxylation mainly included Firmicutes, Synergistetes, Proteobacteria, and Bacteroidetes. Methanogenic archaea were mainly Methanosarcina, Methanofollis, and Methanobacterium, belonging to Euryarchaeota. [Conclusion] After 24 hours of air exposure, the methane-producing capacity of the microbiome from the coalbed formation water was not affected and was comparable to that before air exposure. The microbiome did not showcase obvious succession, while the relative abundance of different groups changed accordingly. Our study can give scientific support for the in-situ industrial application of anaerobic enrichment culture from deep coalbed seams during coal degrading in methane production.

[Objective] To screen and identify cadmium (Cd)-tolerant bacteria with plant growth-promoting effect from contaminated soil of a mining area in Guangxi, characterize the strain screened out in terms of the Cd tolerance, Cd²⁺ removal efficiency, plant growth-promoting effect, and influence on rice growth under Cd stress, and demonstrate the potential of the strain in plant growth and soil remediation. [Methods] Cd-tolerant bacteria were isolated by the dilution coating method and Cd²⁺ concentration gradient acclimation and further identified based on the morphological, physiological, biochemical characteristics and the 16S rRNA gene phylogenetic tree. The Cd tolerance, Cd²⁺ removal efficiency, and plant growth-promoting effect of the target strain were measured by microdilution, inductively coupled plasma mass spectrometry, and colorimetry. Finally, the effect of the strain on the growth of rice plants under Cd stress was investigated by a pot experiment. [Results] Twelve strains of bacteria with good tolerance to Cd²⁺ were isolated from heavy metal-contaminated soil, and one strain with the best tolerance to Cd was identified as Achromobacter sp. A81, which could grow in the presence of 800 mg/L Cd²⁺. Strain A81 cultured with 10 mg/L Cd²⁺ for 7 days showed the maximum Cd²⁺ removal rate of 44.66%. Both the supernatant and cells of strain A81 demonstrated the ability to adsorb Cd²⁺. Under Cd stress, the strain secreted a large amount of extracellular polymeric substances (EPS) primarily composed of insoluble and soluble proteins. Furthermore, this strain was capable of fixing nitrogen, solubilizing phosphorus, and secreting siderophores, indole-3-acetic acid (IAA), and 1-aminocyclopropane-l-carboxylate (ACC) deaminase, demonstrating remarkable plant growth-promoting effect. Pot experiment results revealed that compared with the group subjected to Cd stress, the rice plants inoculated with strain A81 showed increases of 9.08%, 39.59%, 41.94%, and 73.58% in plant height, root length, stem diameter, and fresh weight, respectively. [Conclusion] This study investigated the Cd tolerance, Cd removal efficiency, and plant growth-promoting effect of Achromobacter sp. A81 and assessed the application potential of this strain in Cd-contaminated soil remediation, providing a scientific basis and high-quality strain resources for the microbial remediation of heavy metal pollution and green agricultural development.

[Objective] To explore the formation process of multi-species biofilms in paddy soils developed from different parent materials mediated by soil minerals, thus providing a scientific basis for revealing the interaction mechanisms between soil components and multi-species biofilms. [Methods] The multi-species biofilms were extracted from reddish clayey soil and acidic purple soil, and kaolinite and goethite were used as the mineral media. Modern biological microscopy, high-throughput sequencing, and infrared spectroscopy were employed to study the mineral-mediated formation process, structural changes, and bacterial community structure of the biofilm. [Results] Based on the high-throughput sequencing technology of 16S rRNA gene, the flora in the multi-species biofilms in the paddy soils developed from the two parent materials was dominated by Chloroflexi, Acidobacteria, Proteobacteria, Nitrospirae, and Desulfobacterota. Compared with the control without mineral addition, goethite and kaolinite significantly inhibited the formation of the multi-species biofilm dominated by Chloroflexi in the acidic purple soil, decreasing the biofilm biomass by 18.38% and 17.30%, respectively. In the reddish clayey soil dominated by Acidobacteria, goethite and kaolinite promoted the multi-species biofilm formation to varying degrees. Kaolinite demonstrated more significant promotion effect, increasing the biofilm thickness, the secretion of polysaccharides in the biofilm by 7.69%, and the biofilm biomass by 18.99%. [Conclusion] Kaolinite stimulated bacterial production of extracellular substances, promoted the multi-species biofilm formation in reddish clayey soil, and inhibited the multi-species biofilm formation in acidic purple soil. Goethite inhibited the multi-species biofilm formation in acidic purple soil. Compared with kaolinite, goethite is likely to cause cell inactivation. This study further revealed the interaction mechanism between soil components and multi-species biofilms, and the results provided a scientific theoretical basis for promoting the sustainable development of soil health.

[Objective] This study isolated the dominant indole-3-acetic acid (IAA)-producing bacteria from the rhizosphere soil of Prunus sachalinensis, determined their plant growth-promoting properties, and clarified the growth-promoting effect by inoculation to the seedlings of the common rootstock Gisela 6, aiming to provide theoretical reference and practical approaches for exploring the biological potential of cherry, establish a benign root-microbial interaction relationship, and solve weak root development. [Methods] We used the beef extract peptone medium to isolate bacteria from the rhizosphere soil and selected various specific media to screen the bacteria and determine the IAA-producing, nitrogen-fixing, phosphorus-solubilizing, potassium-solubilizing, and chemotactic abilities of the bacteria. Then, we constructed a phylogenetic tree based on 16S rRNA gene sequences to identify the bacteria. Finally, potted cherry plants were used to explore the plant growth-promoting effects of the strains. [Results] Five IAA-producing strains were screened from the rhizosphere soil of P. sachalinensis, among which strain D46 had the highest IAA yield (53.10 mg/L). D5 was identified as Priestia sp. D27 and D46 were identified as Enterobacter sp. D43 and D79 were identified as Bacillus sp. All the five strains had the ability to fix nitrogen. D27, D46, and D79 had the ability to solubilize phosphorus, and D5 and D43 had the ability to solubilize potassium. Strains D27, D46, and D79 showed strong integrative chemotaxis to sugars, organic acids, and amino acids. Pot experiments showed that the inoculation of strains D27, D43, D46, and D79 significantly increased the root activity. After the inoculation of strain D27, the total root respiration rate increased by 51.40% compared with that in the control group (CK), and the root respiration rates of glycolysis (EMP), tricarboxylic acid cycle (TCA), and pentose phosphate pathway (PPP) also significantly increased. Strain D27 significantly improved the root architecture of cherry seedlings. After inoculation of strain D5, the net photosynthetic rate of leaves significantly increased by 58.82% compared with that in CK, and the inoculation of strain D27 demonstrated the best performance in improving the water use efficiency of leaves. Strains D27, D46, and D79 significantly increased the plant biomass. [Conclusion] There were IAA-producing bacteria in the rhizosphere of cherry, and the five IAA-producing strains isolated had other plant growth-promoting properties. Strains D27, D46, and D79 demonstrated comprehensive plant growth-promoting effects on cherry seedlings. In the future, we can explore the spectra of plants with growth promoted by the strains and the environmental tolerance of the strains, providing a theoretical basis for mining and enriching the strain resources of plant growth-promoting rhizobacteria.

[Objective] We investigated the occurrence of ginger bacterial wilt, identified the pathogens, and screened the antagonistic bacteria, aiming to provide a scientific basis for the control of the disease. [Methods] We systematically investigated the occurrence of bacterial wilt in the main ginger production areas in Chenzhou City, Hunan Province. The ginger tubers with typical symptoms of bacterial wilt and the rhizosphere soil were collected. Major pathogens were isolated and identified based on morphological characteristics and molecular evidence. The pathogenicity of the isolates was determined by inoculation of the isolates to ginger seedlings. Moreover, the sequevars of Ralstonia solanacearum isolates were identified based on the endogenous glucanase gene egl. Finally, the Bacillus strains for biocontrol of the pathogens were screened, and their biocontrol effects were measured. [Results] The average incidence of ginger bacterial wilt in the field was 8.52%. Two bacterial strains FJAT-15492 and FJAT-15494 were isolated from diseased ginger tubers, and three bacterial strains FJAT-15495, FJAT-15496, and FJAT-15497 were isolated from the rhizosphere soil of diseased ginger. The strain FJAT-15492 was identified as Enterobacter mori and the other four isolates were R. solanacearum. Both the isolates of E. mori and R. solanacearum could infect ginger seedlings and cause bacterial wilt. R. solanacearum strains existed in both diseased ginger tubers and rhizosphere soil, while E. mori only existed in diseased ginger tubers, with the count (1.33×10³ CFU/g) lower than that (5.67×10³ CFU/g) of R. solanacearum.Furthermore, the R. Solanacearum isolates were identified as phylotype Ⅰ and sequevar 14. Brevibacillus brevis FJAT-JK-2 demonstrated inhibitory effect on R. solanacearum, and Bacillus velezensis FJAT-54560 on E. mori, with inhibition zone diameters of 19.41 mm and 16.11 mm and indoor control effects of 69.45% and 61.11%, respectively. Moreover, the fermentation mixture of the two biocontrol strains had the field control effect of 52.57%. [Conclusion] This work identified the pathogens of ginger bacterial wilt and provided two new biocontrol strains against the disease.