Amentotaxus yunnanensis H.L.Li is a threatened conifer distributed only in China, Laos, and Vietnam, whose fungal endophytes have not been exploited yet. The aims of this study were to screen and characterize antioxidant metabolites from endophytic fungi obtained from A. yunnanensis. Using the surface sterilization method, sixteen endophytic fungi were isolated from A. yunnanensis and classified into seven genera including Fusarium, Penicillium, Aspergillus, Diaporthe, Neopestalotiopsis, Purpureocillium, and Simplicillium through the analysis of Internal Transcribed Spacer (ITS) gene sequences. Among the ethyl acetate crude extracts, Fusarium foetens AQF6 contained the highest amount of polyphenol (117.76 ± 0.94 mg gallic acid equivalent/g) and flavonoid (169.01 ± 2.09 mg quercetin equivalent/g). Importantly, 400 µg/mL AQF6 extract exhibited 95.75 ± 1.1% and 85.66 ± 1.91% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities, respectively. Chemical investigation led to the isolation and identification of a new bisabolane-type sesquiterpene fusafoetriol (FUS) and 14 known compounds, among which six pure compounds showed free-radical scavenging activity against DPPH and hydroxyl radicals. Under H₂O₂ stress, the yeast model Saccharomyces cerevisiae treated with 4 mM FUS showed 43.31% increase in viability. FUS has the potential to be applied in nutraceutical, pharmaceutical and food technological applications. Thus, this is the first report demonstrating the presence of endophytic fungi inhabiting A. yunnanensis and their potential as a prolific source of antioxidant metabolites.

Fungal endophytes colonizing plant tissues are considered a reservoir of secondary metabolites that exhibit diverse bioactivities applicable in biomedicine. This study aims to reveal for the first time endophytic fungi associated with Keteleeria evelyniana as a potential source of bioactive compounds. A total of 24 fungal endophytes were successfully isolated from K. evelyniana and classified into 10 genera: Aspergillus, Penicillium, Fusarium, Xylaria, Talaromyces, Nodulisporium, Apiospora, Neopestalotiopsis, Diaporthe, and Hypoxylon. Screening for antimicrobial activity revealed that 8 out of 24 ethyl acetate extracts inhibited antimicrobial activity against at least one tested pathogen. Among them, Xylaria sp. KET18 showed the most potent antimicrobial activity with inhibition diameters ranging from 16.5 to 21.5 mm. In addition, the KET18 extract showed the most significant cytotoxic effects against A549 (IC₅₀ = 18.8 ± 3.1 µg/mL) and MCF7 cell lines (IC₅₀ = 24.1 ± 2.5 µg/mL). The KET18 extract showed moderate antioxidant activity against hydroxyl and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. The chemical characterization and structural elucidation indicated the presence of four bioactive compounds that have not been found in fungi, including methyl pyroglutamate, prunetin, macrolactin A, and macrolactin F. These findings demonstrated that K. evelyniana is a host of endophytic fungi with antimicrobial, anticancer, and antioxidant potential.

Probiotic microbial inoculants have been used to improve fermentation quality of green forage feed in pig farming This study aimed to formulate and evaluate effects of microbial inoculants on quality and digestibility of elephant grass-based silage. Green forage formula was made based on economical and agro ingredients resulting in 36% of cost reduction in comparison to the basal diet. The additive containing 1% microbial mixture of Lactobacillus plantarum LCN13, Bacillus velezensis VTX9 and Saccharomyces cerevisiae MCN9 as starter cultures significantly reduced crude fiber (12.39 ± 1.01% Dry Matter (DM)) and neutral detergent fiber concentrations (28.49 ± 0.93% DM) after 120 h (p < 0.05). In contrast, remarkable increases (p < 0.05) were determined in metabolizable energy (2972 ± 18.18% DM) and crude protein (16.32±1.15% DM). These results indicated that metabolic activities by microbial inoculants contributed considerably to the nutritive value of the elephant grass-based diet. The experiment along ensiling time revealed that significant changes in nutritive compositions were observed at 120 h and 168 h (p < 0.05). In support of these results, in vitro digestibility indexes including dry matter, organic matter, and crude protein showed an increasing trend corresponding to ensiling times. Since there were no significant differences between 120 h and 168 h, fermentation time of 120 h was sufficient to obtain desired outcomes. These findings emphasized that elephant grass-based forage fermented with microbial inoculant could be a promising cost-effective and high-quality feed for pig production. Further investigations are required to evaluate safety, growth performance, and pig intestinal microbiota.