Fungi are the most harmful microorganisms responsible for the deterioration of nonmetallic materials such as glass, polymers, and composites. To date, biological aspects of glass deterioration have been poorly investigated. The present study aimed to evaluate the diversity of the fungal community colonizing eyepieces of binoculars collected from museums of the northern provinces of Vietnam and the biodeterioration effects on accurate glass reproductions. A total of 40 isolates belonging to 14 genera were identified based on internal transcribed spacer (ITS) sequencing, morphological features, and maximum likelihood analysis. The most abundant fungal genera included Aspergillus (43.8%) and Penicillium (31.3%). Among those detected, Byssochlamys, Curvularia, Phomopsis, Coprinellus, Perenniporia, Talaromyces, Pithomyces, Neopestalotiopsis, Trichoderma, Pleospora, and Humicola were found for the first time. Of the 40 strains tested, 8 strains showed great organic acid production, and the extent of mycelium covered from 33.6 to 46.24%. Specifically, the highest extracellular polymeric substance production was observed in Byssochlamys spectabilis BXMA1-2 (14.96 g/L), Aspergillus niger BXMA5-2 (12.17 g/L), and Aspergillus ochraceopetaliformis BMLC1-2 (9.89 g/L). Glass biodeterioration experiments revealed that the light transmission through the fungal-treated glasses was decreased by 30–42.2% as compared to the nontreated glass. In addition, the main alterations resulted from hyphal fingerprints and spots, leading to apparent damage and biocorrosion.

Biotechnological applications of cytochromes P450 show difficulties, such as low activity, thermal and/or solvent instability, narrow substrate specificity and redox partner dependence. In an attempt to overcome these limitations, an exploitation of novel thermophilic P450 enzymes from nature via uncultured approaches is desirable due to their great advantages that can resolve nearly all mentioned impediments. From the metagenomics library of the Binh Chau hot spring, an open reading frame (ORF) encoding a thermostable cytochrome P450—designated as P450-T3—which shared 66.6% amino acid sequence identity with CYP109C2 of Sorangium cellulosum So ce56 was selected for further identification and characterization. The ORF was synthesized artificially and heterologously expressed in Escherichia coli C43(DE3) using the pET17b system. The purified enzyme had a molecular weight of approximately 43 kDa. The melting temperature of the purified enzyme was 76.2 °C and its apparent half-life at 60 °C was 38.7 min. Redox partner screening revealed that P450-T3 was reduced well by the mammalian AdR-Adx_4-108 and the yeast Arh1-Etp1 redox partners. Lauric acid, palmitic acid, embelin, retinoic acid (all-trans) and retinoic acid (13-cis) demonstrated binding to P450-T3. Interestingly, P450-T3 also bound and converted testosterone. Overall, P450-T3 might become a good candidate for biocatalytic applications on a larger scale.

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.

Panax vietnamensis Ha et Grushv. is a high-value endemic ginseng species and a rich source of biologically active ginsenosides. However, low productivity and high susceptibility to phytopathogens limit supply relative to demand. Here, we evaluated the efficacy of bacterial strain VCCM 22715 against phytopathogenic fungi and assessed its effects on the growth of P. vietnamensis. Among 61 strains, VCCM 22715 showed the strongest activity against Rhizoctonia solani, inhibiting mycelial growth by 80.1 ± 5.7%. An ethyl acetate extract also inhibited R. solani (52.8 ± 5.3%), Magnaporthe oryzae (73.5 ± 0.3%), and Fusarium solani (52.8 ± 5.3%). Based on phenotypic characterization and molecular analyses, the strain was identified as Streptomyces albus VCCM 22715. Notably, the strain produced 24.3 ± 2.5 µg/mL indole-3-acetic acid (IAA) and significantly increased plant height, root length, fresh weight, and dry weight of P. vietnamensis (p < 0.05). Whole-genome analysis revealed an 8.0 Mb linear chromosome with 73% GC content, 6,796 protein-coding sequences, and 16 secondary metabolite biosynthetic gene clusters. Key genes implicated in IAA biosynthesis were also detected. Collectively, these results indicate that S. albus VCCM 22715 is a promising biocontrol and plant growth-promoting agent for field-cultivated ginseng.