Plant natural products comprise a diverse array of secondary metabolites, including terpenoids, flavonoids, and alkaloids. Owing to their anticancer, anti inflammatory, and antioxidant activities, these compounds exhibit great potential in the food, pharmaceutical, and cosmetic industries. However, the extraction of plant natural products is hindered by resource scarcity, low extraction efficiency, and difficulties in product separation. Meanwhile, their complex molecular structures also impede total chemical synthesis. Consequently, the sustainable biosynthesis of target products using microbial cell factories has emerged as an economically viable alternative. In recent years, non conventional yeasts have gradually become promising and excellent hosts for microbial product synthesis due to their strong environmental tolerance and broad substrate utilization spectrum. This paper reviews the physiological characteristics of several common non-conventional yeasts, mainly including Yarrowia lipolytica, Pichia pastoris, Ogataea polymorpha and Rhodosporidium toruloides. It summarizes the engineering strategies and latest research advances in their biosynthesis of natural products, such as terpenoids, flavonoids and alkaloids. Finally, the challenges faced by non-conventional yeasts in the synthesis of natural products are discussed, and future research directions are prospected.

To enhance the ethanol production efficiency of Saccharomyces cerevisiae in inulin fermentation, this study investigated the combined strategy of optimizing the secretion pathway and constructing diploid strains to improve the secretion efficiency of sucrose invertase（Suc2）and ethanol yield. Starting with the BY4741 and BY4742 strains, a PGK1p promoter replacement strategy was applied to construct recombinant strains BYCO and BY2CO, which overexpress the vesicle transport-related genes SEC1 and SSO2. Diploid strain BY3CO was obtained through diploid mating. Following the transformation of the engineered strains with an MFα signal peptide-tagged Suc2 expression vector, the transcription levels of SEC1 and SSO2, extracellular protein secretion, and Suc2 secretion efficiency were assessed. The results showed significant upregulation of SEC1 and SSO2 transcription in the recombinant strains. The extracellular protein secretion of the diploid strain BY3COmS increased by 216.67% compared to the original strain BYmS, and Suc2 secretion efficiency improved by 86.46%. Continuous fermentation analysis revealed that after 84 h, BY3COmS achieved a biomass of 35.00 g/L and ethanol production of 100.38 g/L, representing increases of 33.49% and 12.61%, respectively, compared to BYmS. Additionally, the inulin conversion rate improved by 10.32%, reaching 94.77%. This study demonstrates that the synergistic enhancement of vesicle transport pathways and the construction of diploid strains significantly improve Suc2 secretion efficiency and ethanol production performance in S. cerevisiae. These findings provide a novel technical approach for the development of efficient inulin-converting S. cerevisiae strains for bioethanol production.

Untargeted metabolomics analysis using a UHPLC-Exploris240 system was used to analyze intracellular metabolites and regulatory mechanisms between the high erythritol-producing mutant and wild-type strain of Yarrowia lipolytica during fermentation. A total of 482 significantly differential metabolites were identified. KEGG pathway enrichment analysis revealed that the pathways related to erythritol biosynthesis of this strain were significantly enriched, involving the pathways related to carbon flux utilization, which also preliminarily revealed that carbon flux redistribution may be a key regulatory mechanism affecting the increase of erythritol production of this mutant strain. In addition, the study also showed that the enhancement of the cofactor had a synergistic effect on erythritol synthesis in this mutant strain. Further analysis revealed that the intracellular content of glycerol, which can serve as a non-oxidative carbon source, significantly increased in the mutant strain. Subsequent fermentation experiments further demonstrated that under mixed carbon source (glycerol/glucose) conditions, the mutant strain achieved a higher erythritol yield of 73.67 g/L. This indicates that appropriate exogenous glycerol has a certain promoting effect on erythritol synthesis in the mutant strain. Thus, this study provides insights into the metabolic regulation of erythritol synthesis in Y. lipolytica at the metabolite level through metabolomic analysis, and also offers a basis for the rational strain modification via metabolic engineering strategies to enhance erythritol production.

To diagnose an unidentified disease affecting tobacco fields at Daozhen County in Zunyi, and to investigate the phyllosphere microecological characteristics associated with the disease, a comprehensive study was conducted. Phyllosphere fungi were isolated and purified using tissue isolation methods, and identified by molecular biology techniques. The pathogenicity of these phyllosphere fungi was assessed based on Koch′s postulates. Amplicon sequencing was employed to analyze the microbial community structure and diversity, while Biolog ECO microplate assays were used to evaluate the metabolic activity of the phyllosphere microorganisms. A total of 24 fungal isolates belonging to 10 genera were obtained from symptomatic tobacco leaf tissues through tissue isolation. Pathogenicity tests demonstrated that fungi of the genus Diaporthe were pathogenic. Phylogenetic analysis based on ITS, HIS and TEF1-α gene sequences combined with morphological identification revealed that the pathogen responsible for the tobacco leaf spot disease was identified as Diaporthe eres. Amplicon sequencing results indicated that the dominant fungal genera in both healthy and diseased tobacco phyllosphere samples were Bullera (22.89% in healthy and 10.33% in diseased samples), Abrothallus (44.01% and 41.21%). There was no significant difference in fungal diversity index between healthy and diseased tobacco leaves; however, the richness index was lower in diseased samples. Functional prediction suggested that the relative abundance of plant pathogenic fungi was higher in diseased tobacco leaf tissues compared to healthy ones. Carbon substrate utilization assays revealed that the metabolic activity of phyllosphere microorganisms from healthy tobacco leaves was stronger than that of those from diseased leaves. Microorganisms from healthy leaves exhibited high metabolic capability toward 28 carbon sources. In contrast, phyllosphere microorganisms from diseased leaves showed relatively higher metabolic activity toward 12 carbon sources. In conclusion, the previously unknown tobacco leaf spot disease was identified and determined to be caused by Diaporthe eres. Additionally, other pathogenic genera such as Alternaria, Abrothallus, Aspergillus, and Colletotrichum were also present in the disease-associated phyllosphere. These findings provide insight into the fungal microecological characteristics of the phyllosphere associated with the what so called unknown tobacco leaf spot disease.

The use of plant growth-promoting rhizobacteria (PGPR) to enhance plant growth and development is a novel, green, and sustainable agricultural strategy. In this study, microbial strains were isolated from rhizosphere soil samples of Elaeagnus angustifolia from the western edge of the Tarim Basin, and evaluated their phosphate-solubilizing, nitrogen-fixing, ammonia-producing, and other growth-promoting abilities. Through the re-inoculation experiment, the growth and physiological indexes of plants were determined to verify their growth-promoting effects. The results showed that 66 bacterial strains were isolated from the rhizosphere soil of Elaeagnus angustifolia, among which 10 strains exhibited three or more plant growth-promoting traits. The Pantoea strain SZ1 possessed six growth-promoting characteristics and showed the activity of four types of hydrolases. After re-inoculation of strain SZ1 into the seeds and seedlings of Elaeagnus angustifolia, the germination potential, germination rate, root length, seedling height, number of leaves, stem diameter, and fresh weight increased by 76.47%, 64.00%, 53.61%, 50.98%, 32.47%, 51.49%, and 51.27%, respectively, compared with the sterile water control (CK1), and by 70.45%, 65.32%, 49.21%, 48.98%, 30.52%, 42.99%, and 51.94%, respectively, compared with the blank NB medium control (CK2). In addition, chlorophyll and leaf nitrogen contents increased by 26.35% and 40.54% over CK1, and by 23.84% and 35.58% over CK2. The activities of antioxidant enzymes (SOD, CAT and POD) in the leaves were also enhanced by 21.46%, 29.18%, and 33.74% compared with CK1, and by 19.90%, 17.82%, and 31.81% compared with CK2. In this study, 10 strains of rhizosphere bacteria with multiple growth-promoting functions were screened, among which the Pantoea strain SZ1 had a significant growth-promoting effect, providing important strain resources for the development of microbial agents/fertilizers required for promoting plant growth.

In order to improve the yield of total flavonoids from fruiting body of Sanghuangporus vaninii, and to evaluate biological activity of the total flavonoids, the ultrasonic-assisted method was used to extract total flavonoids from raw material of S. vaninii fruiting body with the yield of total flavonoids as indicator, the extraction process was optimized using response surface methodology, and the hypoglycemic activity and antioxidant activity were determined. The results showed that the optimal extraction process of S. vaninii total flavonoids was with 60％ethanol as solvent, liquid-solid ratio of 42∶1 mL/g , extraction time of 2.7 h, and extraction temperature of 75 ℃, and the yield of S. vaninii total flavonoids was （49.31±0.45） mg/g, and the total antioxidant capacity of S. vaninii total flavonoids through the experiments in vitro are good. The IC₅₀ of S. vaninii total flavonoids for scavenging DPPH free radicals and hydroxyl free radicals were （1.31±0.06） μg/mL and （73.62±1.50） μg/mL, respectively. The results of hypoglycemic activity analysis in vitro showed that IC₅₀ of S. vaninii total flavonoids for inhibiting α-glucosidase and α-amylase were （0.042±0.002）μg/mL and （0.324±0.083）μg/mL with both of competitive-noncompetitive mixed inhibition, respectively. The extraction process of S. vaninii total flavonoids is simple and feasible to conduct, and S. vaninii total flavonoids have good antioxidant and hypoglycemic activity.

The gene expression in Hericium coralloides on the process of producing γ-aminobutyric acid (GABA) was investigated under Schisandra chinensis （Turcz.）Baill. induction environment at different growth stages. H. coralloides RT25 was used in this research. The H. coralloides RT25 growth state of the fermentation mycelium and the primordium, the various indicators of the fruiting body were compared and analyzed between the experimental group with Schisandra and the control group without Schisandra. Transcriptome sequencing technology was used to analyze the differentially expressed genes and related enrichment pathways of H. coralloides at different growth and development stages. The results showed that the fermentation broth mycelial pellets of the Schisandra group had higher uniformity and density than those of the control group. The fruiting body of the Schisandra group showed significant improvement in mycelium growth rate, primordium formation and biological efficiency. Transcriptome study showed that the DN344 gene expression of H. coralloides RT25 with Schisandra group was up-regulated during the mycelium fermentation stage, and the activity of glutamic acid dehydrogenase was enhanced, resulting in the increase of L-glutamic acid, thereby promoting the increase of GABA content. The DN3464 gene expression of H. coralloides RT25 with Schisandra induction was up-regulated in the primordium formation period, and the activity of glutamic acid decarboxylase was improved, leading to improve the biological synthesis efficiency of GABA. The DN344 gene expression was up-regulated in the fruiting body maturity, the glutamic acid dehydrogenase activity was enhanced, and the L-glutamic acid content increased while the expression level of DN3464 gene and the activity of glutamic acid decarboxylase remained stable, and the activity of γ-aminobutyric acid transaminase was enhanced, which finally led to the increase of GABA content. Schisandra regulates the signal transduction pathway in cells, affects the expression of the related genes for GABA synthesis, and then regulates the activity of enzymes related to the GABA metabolic pathway, promotes the conversion of glutamic acid to GABA, finally improves the yield of GABA.

Ganoderma leucocontextum is an edible and medicinal fungus with significant scientific and economic values. In recent years, important progress has been made in the research on the biological characteristics, artificial cultivation, and bioactive components of G. leucocontextum. This paper provides a systematic review of the morphological characteristics and molecular identification methods for the species of G. leucocontextum. In terms of the biological properties and cultivation techniques, the influence of various environmental conditions such as temperature, pH, and carbon/nitrogen sources on the development of mycelia and fruiting bodies were discussed along with comparing the advantages and disadvantages of different cultivation modes, and exploring the culture substrate optimization, high-yield strain breeding, and microbial mediation of continuous cropping obstacles as well. At the genetic and multi-omics levels, it was outlined as to the characteristics of its whole genome and mitochondrial genome, the analysis of mating-type loci, and the application of metabolomics in species identification and functional component differentiation of G. leucocontextum. The extraction and purification processes, chemical structures, biological activities, and mechanisms of the major bioactive compounds such as triterpenoids and polysaccharides were elaborated, including functions in hypoglycemic, hypolipidemic, antitumor, and neuroprotective effects. Finally, the current challenges in research and industrial development as well as the future prospects were addressed. This review provides a scientific basis for further development and industrial application.

D-Pantolactone serves as a pivotal chiral intermediate in the synthesis of D-pantothenic acid (vitamin B₅) and its derivative compounds. Given the escalating global demand for D-pantolactone, the development of efficient and environmentally benign production routes has emerged as a critical research focus. Enzymatic synthesis of D-pantolactone stands out as a highly promising approach, distinguished by its green and eco-friendly attributes, and has become the predominant method in industrial production. This comprehensive review delves into the recent advancements in the enzymatic synthesis of D-pantolactone. It meticulously examines the enzymatic properties, expression, and directed evolution of D-pantolactone hydrolase under different experimental conditions. Additionally, it explores the latest progress in the asymmetric reduction of keto-pantolactone. By comparing the merits of various synthesis methods, this review offers valuable insights and guidance for the future design of production strategies for D-pantolactone and its derivatives.

Plant growth-promoting bacteria (PGPB) have received intensive interests due to its important roles in improving plant growth, disease resistance and stress tolerance, crop yield and quality. The distinct benefits of PGPB-based technologies include diverse spectrum of action, future effectiveness, and environmental safety, which are compared to traditional fertilization because in most cases chemical fertilizers cause extensive environmental harm. The colonization of host plants by the PGPB must be effective in order to provide stable growth-promoting effects. Hence, the enhancements in colonization and PGPB functional expression have become a major research topic. In this review, an overview of the principle functions of PGPB, their mode of colonization (pathways and detectability mechanisms), and factors that affect colonization including bacterial characteristics, root exudate composition, microbial interactions, and abiotic environmental factors are discussed. Among the strategies to improve the efficiency of PGPB colonization, this review covers genetic engineering of the bacterial strains, nature exogenous use of plant root exudates, microbial immobilisation methods, and artificial microbial consortia. It creates a theoretical base and work roadmap to comprehend the overall principles of PGPB colonization and maximize their performance and provides real-life resolutions to ensure sustainable agriculture.

With the rapid development of artificial intelligence (AI) technology, the food industry is accelerating its transformation toward intelligence in areas such as quality control and supply chain optimization; however, traditional "Food Microbiology" teaching remains primarily centered on theoretical lectures and basic experiments such as microbial cultivation, counting, and Gram staining. This significant disconnect between teaching content and cutting-edge industry demands constrains the cultivation of interdisciplinary talents. "Food Microbiology" grounded in microbiology, integrates advanced domains from multiple disciplines, including food science, bioinformatics, food chemistry, and fermentation engineering. This article systematically explores reform for AI-empowered undergraduate "Food Microbiology" course instruction. It advocates advancing educational reforms by restructuring course content, innovating teaching models, and enhancing practical training. By incorporating AI foundational theory and frontier case studies, an integrated online-offline teaching resource repository is constructed. Hybrid virtual-physical experimental projects are designed to strengthen students′ ability to utilize AI tools in solving practical problems like fermentation optimization and microbial identification. Industry-academia-research platforms are leveraged to establish an innovation capability cultivation mechanism. Based on a case study at Zhejiang A&F University, this article details the reform plan for AI integration into the food microbiology curriculum, demonstrating concrete applications of AI technology in enhancing instructional content such as food fermentation, metabolic prediction, and food safety early-warning systems. The integration of AI with "Food Microbiology" education will propel a transition from "experience-driven" to "data-driven" pedagogy, thereby providing sustainable talent support for the intelligent advancement of the food industry.