[Objective] To isolate and identify actinomycetes from two mangrove soil samples in Quanzhou Bay as well as secondary metabolites from the target strain Streptomyces sp. W444 with antifungal activity. [Methods] The rhizosphere soil samples of two different mangrove plants were collected from Luoyang River in Quanzhou Bay. Actinomycetes were isolated from the soil samples by the dilution plating method. The isolates were classified by the phylogenetic tree constructed based on 16S rRNA gene sequences. The antifungal activities of the isolates were examined by the agar diffusion method. The target strain Streptomyces sp. W444 was subjected to fermentation scale-up for the isolation of secondary metabolites. Furthermore, the biosynthetic gene clusters were analyzed to deduce the biosynthetic pathway of staurosporine. [Results] A total of 56 strains of actinomycetes were isolated from mangrove soil samples and categorized into 8 genera belonging to 6 families of 6 orders. Among them, Streptomyces and Micromonospora were dominant, with the relative abundance of 41.0% and 33.9%, respectively. Strain Streptomyces sp. W444 exhibited excellent antifungal activity, and three indoles (staurosporine, K252c, and streptochlorin) were isolated and identified from this strain. The biosynthetic gene cluster of staurosporine was localized in the genome of Streptomyces sp. W444 by bioinformatics analysis. The biosynthetic pathway of staurosporine was then proposed. [Conclusion] Actinomycetes in the rhizosphere soil of mangrove plants in Quanzhou Bay had high diversity and contained potential natural product resources. Staurosporine, K252c, and streptochlorin were isolated from strain W444. These findings lay a solid foundation for studying the diversity and secondary metabolites of cultivable actinomycetes in mangrove forests in Quanzhou Bay.

Crop diseases caused by phytopathogens result in great harm to global agriculture. Biocontrol has garnered increasing attention in plant disease prevention and control because of its effectiveness and environmental friendliness. [Objective] To identify, analyze the genome, and evaluate the disease-resistant and plant growth-promoting effects of the strains with antagonistic activities that were screened from the culture collection. [Methods] Antagonistic strains were screened by plate confrontation method. and identified by morphological observation, phylogenetic analysis based on the 16S rRNA gene and genome, comparative analysis of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values, and physiological and biochemical tests. The whole genome sequence of the target strain was analyzed for the mining of functional genes. The plant growth-promoting effect of the target strain was characterized in terms of the phosphorus-solubilizing, siderophore-producing, and proteinase- and cellulose-producing properties. The inhibition of volatile gas produced by the target strain on phytopathogenic fungi was examined in petri dishes with a septum. The effects of the target strain on tomato growth and diseases were studied by pot experiments. [Results] Strain MB1019 with obvious inhibitory effects on Ralstonia solanacearum and three phytopathogenic fungal strains was screened out and identified as Bacillus velezensis. The physiological and biochemical tests showed that strain MB1019 tolerated the temperature of 15-50 ℃, 10.0% NaCl, and pH 5.0-9.0. The genome of strain MB1019 was 3.8 Mb in length, with the G+C content of 46.4%. The prediction on antiSMASH suggested that the MB1019 genome had 17 synthetic gene clusters for secondary metabolites. The prediction on dbCAN2 suggested that MB1019 carried 108 genes belonging to 52 types of the CAZy family, among which glycoside hydrolases (GHs) were the richest and most abundant. The volatile gas produced by MB1019 significantly inhibited the growth of phytopathogenic fungi. The results of pot experiments showed that MB1019 promoted the growth and inhibited the diseases of tomato seedlings. [Conclusion] B. velezensis MB1019 capable of antagonizing R. solanacearum and phytopathogenic fungi has tolerance to high temperatures and saline-alkali and demonstrates plant growth-promoting effects. Its genome contains a large number of functional genes, and the volatile gas produced by this strain can inhibit the growth of pathogenic fungi. The fermentation broth of MB1019 has the effects of promoting the growth and preventing the diseases of tomato seedlings. In summary, B. velezensis MB1019 can be used as an elite strain in the research and development of microbial fertilizers and pesticides, demonstrating promising development and application prospects.

Succinic acid is an important four-carbon dicarboxylic acid widely used in the food, pharmaceutical, and chemical industries. Compared with petrochemical-based chemical synthesis methods, microbial fermentation offers an economical and environmentally friendly alternative for succinic acid production, presenting significant potential for industrial applications. Due to the robust environmental tolerance, yeast cell factories for succinic acid production have gradually become a research focus. This review centers on succinic acid production in yeast, providing an overview of metabolic engineering and regulatory strategies for constructing yeast cell factories. The research hotspots in this field include the development of succinic acid biosynthetic pathways, optimization of cofactor supply, and modification of transmembrane transport systems. Additionally, recent advances in cost-effective succinic acid biosynthesis and approaches to enhance yeast strain robustness are discussed. Finally, the review provides the prospects of yeast in succinic acid biosynthesis.

[Objective] To analyze the application trends and distribution of artificial intelligence in synthetic biology from the patent perspective, providing practical insights and theoretical support for technological innovation, research and development (R&D) direction, and industrial layout of this field. [Methods] The paper presents a comprehensive overview of the research contents and methodologies of synthetic biology, and delves into the evolving landscape of artificial intelligence in synthetic biology by extensive patent network mining and literature analysis. [Results] Through thorough examination of pertinent patent data, this study unveils the application patterns and disclosure trends of artificial intelligence in synthetic biology alongside the major countries involved and key applicants. Furthermore, it analyzes the advancements in biosynthetic gene clusters, protein structure analysis, and transcription factor binding sites from the patent perspective. Additionally, this paper expounds the challenges confronting the integration of artificial intelligence into synthetic biology while offering recommendations to address them. [Conclusion] The findings presented herein offer valuable insights into understanding the technical developmental context surrounding artificial intelligence in synthetic biology while serving as a reference for relevant enterprises and research institutions when making R&D decisions. Moreover, this paper underscores the pivotal role played by artificial intelligence in advancing development of synthetic biology while emphasizing its significance. Simultaneously, it provides suggestions to further bolster research efforts on integrating artificial intelligence into synthetic biology with an aim to generate innovative ideas and technical support for constructing national science and technology information systems in global science and technology competition scenarios—particularly concerning advances in synthetic biology.

[Objective] To isolate the strain for solubilizing both inorganic and organic phosphorus (P) from the rhizosphere of Moso bamboo (Phyllostachys edulis) and mine the related genes, laying a foundation for activating the soil P pool and improving P bioavailability by P-solubilizing microorganisms (PSM). [Methods] High-throughput screening was employed to isolate PSM strains from the rhizosphere of Moso bamboo, an important economic plant in subtropical regions. The P-solubilizing activities of the strain under various carbon sources and soil P levels were investigated by microplate culture and soil inoculation experiments, respectively. The genes involved in P solubilizing of the strain were mined by whole-genome sequencing. [Results] The strain zafu-3 (Achromobacter xylosoxidans) capable of solubilizing P via multiple pathways was isolated from the rhizosphere of Moso bamboo. The strain solubilized Ca₃(PO₄)₂, FePO₄, AlPO₄, lecithin, and calcium phytate by using four carbon sources such as glucose and citric acid, with the highest P-solubilizing activity of 32.75 mg/(L·d). Compared with the control group, the zafu-3 inoculation group showed increases of 4.21%-33.88% and 13.54%-112.06% in activities of acid phosphatase and alkaline phosphatase, respectively. In the high P-level soil, inoculation of the strain decreased the soil pH by 0.04 and increased the available P content by 16.32%. The whole genome of strain zafu-3 contained 35 genes encoding phosphohydrolases and 53 genes involved in organic acid metabolisms. Furthermore, strain zafu-3 carried the genes associated with the production of indole-3-acetic acid and siderophores, and the degradation of lignin. [Conclusion] Strain zafu-3 directly solubilized inorganic and organic P by secreting diverse organic acids and phosphatases, and indirectly activated soil P pools by promoting plant growth. These findings provide an important microbial resource and theoretical foundation for the development of multifunctional biofertilizers.

Cryptococcus, a genus of invasive fungi with global distribution, have caused serious public health problems. Notably, Cryptococcus neoformans (Cryptococcus neoformans, C. neoformans) represents the main pathogenic species of Cryptococcus. The infection of C. neoformans can cause pulmonary cryptococcosis and cryptococcal meningitis with high mortality rates. The commonly used antifungal drugs are polyenes, flucytosine, echinocandins, and azoles, which have limited efficacy and may induce resistance when being used alone in clinical practice. Therefore, researchers have studied combined therapy. They have discovered that the combinations of some traditional Chinese medicines and natural plant extracts and derivatives with the commonly used antifungal drugs demonstrate synergistic effects in the treatment of cryptococcosis. This paper reviews the research progress in the combined application of antifungal drugs and traditional Chinese medicines.

Human papillomavirus (HPV) infection is a major global health challenge closely related to diseases such as cervical cancer. At present, there is no effective treatment for HPV, and thus it is essential to develop new antiviral biological agents to reduce the harm of HPV infection. Recent studies have revealed a complex relationship between HPV infection and the human microbiome, suggesting that HPV infection can disrupt the balance of the microbiome and cause immune dysfunction in the body. In recent years, studies have found that oral or topical use of specific probiotic strains can reduce HPV titers in patients and prevent viral infection-related cancers, demonstrating probiotics as a new class of anti-HPV preparations with a development value. From the molecular biological characteristics of HPV, this article systematically summarizes the pathogenic mechanism of HPV infection and explains the antiviral mechanisms of probiotics from four perspectives: inhibiting virus replication, regulating immune responses, enhancing the mucosal barrier function, and reshaping the human microbiome. This review aims to provide theoretical references for the efficient breeding and mechanism analysis of anti-HPV probiotics.

[Objective] To investigate the plant microbiome changes in response to wheat head blight and the correlation between the abundance of differential microorganisms and the pathogen Fusarium graminearum, and elucidate the intricate interplay between plant microbiome and disease occurrence. [Methods] We collected samples from both healthy and diseased plants in the field, combined with high-throughput sequencing to analyze the characteristics of plant microbiome changes, and the abundance of pathogen was determined by RT-qPCR to reveal the response of plant microbial community changes to wheat head blight. [Results] The alpha diversity of bacteria in wheat spikes and fungi in the rhizosphere significant increased under the disease stress, with enrichment of potentially beneficial bacteria in spikes of diseased wheat plants. Healthy plants displayed higher stability of microbial community and network than diseased plants. Plant microbial diversity can predict alterations in pathogen abundance. Notably, the microbial diversity and community stability explained the most (76.95%) variations in pathogen abundance. High fungal diversity and community stability were associated with reduced pathogen colonization. [Conclusion] Significant discrepancies of the plant microbiome were identified between healthy and diseased plants. The stable microbial community and network interactions in the spikes of healthy plants facilitate the resistance against F. graminearum infection. Additionally, the “call for help” phenomenon was observed as wheat plants recruited beneficial microflora in spikes, expanding the applicability of the “call for help” strategy. By examining the connection between plant microbiome and disease occurrence, this study presents crucial data and a theoretical framework for the targeted manipulation of plant microbiome to enhance disease prevention and control.

[Objective] To investigate the regulatory effect of transforming growth factor-beta 1 (TGF-β1)/Smad3 on orosomucoid (ORM) expression during infection with influenza A/WSN/33 virus (hereinafter referred to as WSN). [Methods] A549 cells were either infected with WSN or treated with TGF-β1, followed by treatment with Smad3 inhibitors. The mRNA levels of ORMs were assessed by RT-PCR. Subsequently, cell lines with signal transducer and activator of transcription 3 (STAT3) overexpression and knockdown were established, and RT-PCR and Western blotting were employed to evaluate the impact of STAT3 on ORM expression induced by the influenza virus. Furthermore, A549 cells underwent treatment with TGF-β1, after which the phosphorylation status of STAT3 was analyzed via Western blotting. Finally, the phosphorylation level of STAT3 was detected after inhibiting the activity of Smad3 or knocking down the expression of Smad3 in A549 cells infected with WSN or treated with TGF-β1. [Results] TGF-β1 regulated the expression of ORM1 and ORM2 through the activation of Smad3, a key mediator in the TGF-β signaling pathway. Concurrently, STAT3 was implicated in modulating ORM1 and ORM2 expression during WSN infection. Additionally, TGF-β1 was shown to induce STAT3 phosphorylation. Notably, inhibiting Smad3 activation or knocking down Smad3 expression suppressed STAT3 phosphorylation. [Conclusion] The regulation of ORM1 and ORM2 expression by WSN relied on STAT3 phosphorylation mediated by TGF-β1/Smad3.

chitooligosaccharide (COS) are degradation products of chitin or chitosan, demonstrating good biocompatibility, degradability, non-toxicity, and multiple bioactivities. COS have been widely used in food, cosmetics, composite materials, wastewater treatment, and biomedical industries. Currently, researchers mainly use physical, chemical, and biological enzyme methods to prepare COS. Physical and chemical methods have large limitations, and it is difficult to synthesize the target products with specific requirements in an efficient and green way. Bio-enzymatic preparation of COS shows a mild, controllable, and environmental friendly reaction process, overcoming the drawbacks of physical and chemical methods. The purity of COS can be improved by separation and purification techniques such as membrane separation, gel filtration chromatography, CM-SephadexC-25 ion-exchange column chromatography, and immobilized metal affinity chromatography. This review summarized the research progress in COS preparation using bio-enzymatic technology, aiming to lay theoretical foundation for high-quality industrial COS preparation. It also gave an overview of the structure, properties, and application of COS, contributing for the research on COS preparation and isolation.