[Objective] To clarify the domestication characteristics and resistant mechanism of wild watermelon plants and provide a theoretical basis and technical support for building a new evaluation system for watermelon breeding and developing beneficial microorganisms, we compared the endophytic microbial community structure in roots between wild and cultivated watermelon varieties. [Methods] High-throughput sequencing was employed to reveal the community structures of endophytic microorganisms (bacteria and fungi) in the roots of wild and cultivated watermelon varieties. [Results] The phyla and genera of endophytic bacteria and fungi in the roots were significantly different between wild and cultivated watermelon varieties. The roots of wild watermelon varieties had significantly higher relative abundance of Nocardioides and Microbacterium than those of cultivated watermelon varieties. Actinoplanes, Mycobacterium, Lechevalieria, Amycolatopsis, Bradyrhizobium, and Rhodococcus were the special dominant endophytic bacterial genera in the roots of wild watermelon varieties. The relative abundance of unclassified_o__Chaetothyriale in the roots of wild watermelon varieties was significantly higher than that in cultivated watermelon varieties. unclassified__o_Chaetothyriales, Preussia, and unclassified_f__Microascaceae were the dominant endophytic fungi specific to wild watermelon varieties. [Conclusion] The beneficial bacteria, such as Nocardioides, Microbacterium, and Rhodococcus, which were capable of fixing nitrogen, solubilizing phosphorus, secreting siderophores, and producing bioactive substances and antibiotics, and the growth hormone-producing fungi, such as Preussia, were lost in the roots of cultivated watermelon varieties after the domestication of wild watermelon. Therefore, it can be concluded that parts of endophytic microorganisms in the roots disappear during the domestication process of watermelon varieties, which is a major reason for the weak resistance of cultivated watermelon varieties to stresses. In addition, the bacterial genera such as Nocardioides, Microbacterium, and Rhodococcus and the fungal genus Preussia can be taken as the candidate microbial resources for enhancing watermelon resistance.

[Objective] To study the role of napF3 in Thermoanaerobacter tengcongensis at different temperatures. [Methods] We constructed ΔnapF3 from T. tengcongensis by homologous recombination and observed the growth of ΔnapF3 at 50 ℃, 60 ℃, 75 ℃, and 80 ℃. Transcriptome sequencing was employed to identify the differentially expressed genes (DEGs) between ΔnapF3 and the wild type (WT) at 75 ℃. real-time PCR was conducted to measure the transcriptional levels of 13 genes and 3 sRNAs in WT and ΔnapF3 at 50 ℃, 60 ℃, 75 ℃, and 80 ℃. [Results] ΔnapF3 was successfully constructed, and it showcased suspended growth at 50 ℃ and 80 ℃ and slow growth at 60 ℃ and 75 ℃. A total of 899 DEGs between WT and ΔnapF3 at 75 ℃ were identified, including 363 genes with up-regulated expression and 536 genes with down-regulated expression. These DEGs were mainly involved in the biosynthesis of valine, leucine and isoleucine, ABC transporters, two-component system, fatty acid synthesis, thiamine metabolism and other pathways. The transcriptional levels of 13 genes and 3 sRNAs related to the thermophilic mechanism changed under specific temperatures. [Conclusion] napF3 plays a role in the thermophilic adaptation of T. tengcongensis.

Bacterial biofilms are aggregates surrounded by extracellular polymeric substances produced by bacteria, exhibiting significant resistance to antimicrobials and host immune defense mechanisms. As a result, they become a crucial factor in the recalcitrance of bacterial infections. Phages, as a class of viruses capable of specifically infecting and lysing bacteria, have demonstrated immense potential in the prevention and treatment of biofilm-associated infections. This review summarizes the efficacy, in vitro and in vivo research methods, and mechanisms of phages, phage endolysins, and phage-antibiotic combinations in combating biofilm-associated infections. Furthermore, it discusses the prospects and potential obstacles of phages in this field, aiming to give insights into the development of more effective therapeutic agents.

Innate immunity constitutes the first line of immune defense. As a part of the body's innate immunity, the antimicrobial peptide LL-37 plays a crucial role in maintaining homeostasis, with two primary functions: direct antimicrobial activity and immunomodulation. Currently, research on LL-37 mainly focuses on its function, while its induced expression in vivo has rarely been studied. However, understanding the induced expression of LL-37 is essential for delving into the body's immune defense mechanisms. Therefore, this paper briefly reviewed the research progress on the synthesis and functions of LL-37, the factors inducing its secretion, and the regulatory pathways involved in its induced expression. The aim is to offer new insights into the regulatory pathways and immune defense functions of LL-37 in the human body.

Parkinson's disease is a common neurodegenerative disorder that seriously threatens the health of middle-aged and elderly individuals. However, the pathogenesis of Parkinson's disease is not fully understood. Recent studies have shown that gut microbiota plays an important role in the occurrence and development of Parkinson's disease. Gut microbiota and its metabolites influence the intestinal mucosal barrier, neuroinflammation, endocrine system, and other aspects through the microbiota-gut-brain axis, thereby participating in the occurrence and development of Parkinson's disease. Gut microbiota can be regulated by various methods such as probiotic supplementation, fecal microbiota transplantation, dietary adjustments, and traditional Chinese medicine interventions, being an important target for the prevention and treatment of Parkinson's disease. This article reviews the possible mechanisms of gut microbiota being involved in the occurrence of Parkinson's disease and further discusses the current status of prevention and treatment of gut microbiota dysbiosis.

[Objective] Within the framework of global climate governance and considering the pivotal role of the Yellow River basin in China's ecological progress, this study focused on the Inner Mongolia segment of the Yellow River in July 2023. [Methods] We collected the surface sediment, water, and gas samples, with the aim of investigating the dissolved nitrous oxide (N₂O) concentration in the water, the N₂O emission flux (FN₂O) at the water-air interface, and the microbial community composition and diversity in surface sediments. [Results] The results revealed that the dissolved nitrous oxide (N₂O) concentration in the water of this segment varied between 0.547 8 mg/m³ and 0.598 2 mg/m³, with an average of 0.574 1 mg/m³. The FN₂O at the water-air interface ranged from −3.645 3 mg/(m²·d) to 4.392 5 mg/(m²·d), averaging 1.086 1 mg/(m²·d), which suggested this area was a net source of atmospheric N₂O. FN₂O showed a significantly positive correlation with pH and a significantly negative correlation with potential. The surface sediments harbored 7 784 operational taxonomic units (OTUs), with Proteobacteria (average abundance of 35.13%) being dominant. Ammonia-oxidizing archaea (AOA), a category of nitrifying bacteria, presented low abundance, with 116 OTUs among which unclassified_d__Unclassified (average abundance of 31.69%) was the dominant genus. For denitrifying bacteria, 3 660 OTUs were identified, with unclassified_k__norank_d__Bacteria (average abundance of 63.12%) being the dominant genus. In view of the scarcity of N₂O data for the Inner Mongolia section of the Yellow River, the findings of this study enrich the N₂O data repository of the Yellow River. [Conclusion] This study not only augments our understanding of the microbial community structure and functionality in sediments but also supports the conservation and purification of the Yellow River.

Porcine epidemic diarrhea virus (PEDV) is an enterovirus that can cause severe diarrhea and dehydration. The widespread epidemic of PEDV has caused huge economic losses to the pig breeding industry, which, however, lacks effective means for prevention and treatment. Nsp8 is an important non-structural protein involved in the replication of PEDV, while the host proteins interacting with Nsp8 remains unclear. [Objective] To screen the host proteins interacting with PEDV Nsp8 and explore the effects of the host proteins on the replication of PEDV, so as to provide a theoretical basis for discovering new key functional receptors or therapeutic targets of PEDV. [Methods] The eukaryotic expression plasmid of PEDV Nsp8 was successfully constructed with the eukaryotic expression vector pcDNA3.1(+). The host proteins interacting with PEDV Nsp8 were screened by co-immunoprecipitation, mass spectrometry, and laser confocal microscopy. The effects of the host proteins on PEDV replication were explored by overexpression and knockdown in LLC-PK cells. [Results] Thirty-six potential host proteins interacting with Nsp8 were screened by mass spectrometry, and the interaction between heat shock protein member 8 (HSPA8) and Nsp8 was verified. The overexpression of HSPA8 in LLC-PK cells inhibited the overexpression of Nsp8 in a dose-dependent manner. Meanwhile, it significantly inhibited the replication of PEDV in a dose-dependent manner at the protein and transcriptional levels. Interfering with endogenous HSPA8 expression significantly promoted the replication of PEDV. The 50% tissue culture infectious dose (TCID₅₀) and indirect immunofluorescence further proved that HSPA8 inhibited PEDV replication. [Conclusion] This study screened out the host protein HSPA8 interacting with PEDV Nsp8 and proved that HSPA8 could significantly inhibit PEDV replication, which provided a new idea for the design of HSPA8-targeted drugs for the prevention or treatment of PEDV.

Sugarcane smut caused by Sporisorium scitamineum is one of the major diseases affecting the development of China's sugar industry, and biocontrol is currently the most efficient and safe means, which necessitates the screening of antagonists with strong environmental adaptability and inhibitory effects. [Objective] To isolate and identify the strains with good antagonistic effects against S. scitamineum from soil and provide high-quality biocontrol strain resources for the efficient prevention and control of sugarcane smut. [Methods] The antagonists were isolated by the plate confrontation assay, and their taxonomic status was determined by morphological observation, physiological and biochemical tests, and 16S rRNA gene sequencing. The pot and field experiments were conducted to study the inhibition effects of the antagonists on sugarcane smut. [Results] Three strains of bacteria with significant antagonistic effects were obtained. Strains GB-3 and GH16-3 were identified as Bacillus velezensis and GH16-8 as B. amyloliquefaciens, with the inhibition zone diameters of (30.00±1.07), (44.00±1.21), and (18.00±0.89) mm and the inhibition rates of 16.12%, 31.92%, and 5.91%, respectively. The inhibition effects of the three strains against sugarcane smut were 74.33%, 76.57%, and 69.07% in pots and 20.08%, 55.59%, and 50.08% in fields, respectively. All the three strains had phosphorus-solubilizing ability, tolerance to extreme salt-alkaline environments, and inhibitory effects on a variety of phytopathogenic bacteria and fungi, with the indole-3-acetic acid (IAA) yields of 2.12, 1.30, and 1.22 mg/L, respectively. The application of the three strains increased the sugarcane plant height by 28.25%, 17.09%, and 23.31%, respectively. [Conclusion] Strain GH16-3 has strong environmental adaptability, growth-promoting effect, and prevention effect against sugarcane smut, demonstrating a promising application prospect.

[Objective] Soft rot is one of the major diseases affecting the yield and quality of konjac. This study screened a strain with antagonistic effect on Pectinobacterium aroidearum from the rhizosphere soil of konjac, aiming to provide germplasm resources for the biocontrol of soft rot in konjac. [Methods] An antagonistic strain was screened by the plate confrontation method, and its antagonistic effects on pathogenic fungi were measured. The control effect of GZA12 on soft rot in konjac was examined by the inoculation in konjac corm tissue, pot experiment, and root irrigation. The growth-promoting effect of this strain was tested indoors and preliminarily verified by tomato pot experiments. [Results] A strain GZA12 with antagonistic effect was screened out and identified as Bacillus velezensis. This strain showed the inhibition zone diameter of 21.33 mm against P. aroidearum and the inhibition rates of 58.16%, 47.30%, and 54.53% against Botryosphaeria dothidea, Fusarium oxysporum, and F. solani, respectively. Inoculation of GZA12 in konjac corm tissue decreased the disease index by 26.67%, 33.33%, and 40.00%, respectively, compared with the inoculation of B. dothidea alone. In the pot experiment, the treatment with GZA12 suspension decreased the disease index by 22.85% compared with the control group and reached the control effect of 53.31%. The results from the root irrigation experiment showed that compared with water irrigation, irrigation with GZA12 fermentation broth reduced the disease index by 4.89% and reached the control effect of 21.57%. Strain GZA12 had the ability to fix nitrogen, solubilize phosphorus, and produce siderophores and indole-3-acetic acid (IAA). Inoculation with GZA12 suspension promoted the growth of tomato seedlings in a concentration-dependent manner. [Conclusion] Strain GZA12 can inhibit the pathogen causing soft rot and promote the growth of konjac, demonstrating the potential for further development and utilization.

[Objective] To study the effects of adding different concentrations of garlic juice on the fermentation of pickled Chinese cabbage. [Methods] The physicochemical indicators and OD₆₀₀ during the fermentation process were measured, and the effects of garlic juice concentration on the richness, community structure, and abundance of bacteria during the fermentation were studied with natural fermentation as the control. The 16S rRNA gene high-throughput sequencing was carried out in the late fermentation stage for the pickled Chinese cabbage samples with the addition of garlic juice at different concentrations. Fuzzy mathematics-based evaluation was conducted for the sensory quality of garlic-flavored samples to select the lactic acid bacterial strains with excellent fermentation performance. [Results] Different concentrations of garlic juice had minor effects on the pH and OD₆₀₀ but significantly reduced the peak value of nitrite. Adding 0.2%–0.4% garlic juice was beneficial for the growth of Lactiplantibacillus, and the species richness of the product fermented with the addition of garlic juice was higher than that of the naturally fermented product. The fermentation liquid with the addition of 0.3% garlic juice had the highest species richness, with much higher number of genera than other concentration groups. The product from fermentation with 0.3% garlic juice showcased the best quality, presenting better sensory quality and appearance. The product with high species richness and a large number of genera had good sensory quality. A strain of lactic acid bacteria with excellent fermentation performance was screened out and identified as Lactiplantibacillus pentosus, which produced the most acids during fermentation, had the highest nitrite degradation rate, and exhibited tolerance to garlic. [Conclusion] This study provides a strain for the development of lactic acid bacteria fermentation agents and lays a theoretical foundation for the industrialization of garlic-flavored pickled Chinese cabbage.