Isolation, diversity, and antimicrobial activity of fungal endophytes from Rohdea chinensis (Baker) N.Tanaka (synonym Tupistra chinensis Baker) of Qinling Mountains, China

Abstract

Endophytic fungi have been emerged as fruitful resources for producing structurally fascinating and biologically active secondary metabolites. However, endophytic fungi from medicinal plants of Qinling Mountains–the most important natural climatic boundary between the subtropical and warm temperate zones of China with an astonishingly high level of biodiversity–have rarely been explored as potential sources of novel fungal species and active secondary metabolites. In this study, a total of 371 fungal colonies were successfully isolated from 510 tissue segments of the medicinal Tupistra chinensis Baker collected from Qinling Mountains, China. Roots of T. chinensis Baker are used as a folk medicine to ameliorate pharyngitis and treat rheumatic diseases. A total of 100 representative morphotype strains were identified according to ITS rDNA sequence analyses and were grouped into three phyla (Ascomycota, Basidiomycota, Mucoromycota), seven classes (Dothideomycetes, Sordariomycetes, Eurotiomycetes, Microbotryomycetes, Agaricomycetes, Leotiomycetes, Mortierellomycetes), and at least 35 genera. The genera of Collectotrichum (IF, 29.92%), Fusarium (IF, 8.36%), Aspergillus (IF, 8.09%), and Dactylonectria (IF, 5.39%) were most frequently isolated from the tissues of T. chinensis Baker. The Species Richness Index (S, 65) and the Shannon-Wiener Index (H′, 3.7914) indicated that T. chinensis Baker harbored abundant fungal resources. Moreover, five isolates were potential new taxa because of low similarity of ITS sequences ranged from 95.09%∼96.61%. Fifteen out of 100 endophytic fungal ethyl acetate extracts exhibited inhibitory activities against at least one pathogenic bacterium or fungus. Two important lead compounds produced by two stains (F8047 and F8075) with high antimicrobial activities were identified using high performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC–QTOF MS) analyses. In addition, it was noteworthy that the strain F8001, which may be a potential new species, showed antimicrobial activity and should be investigated further. Overall, these results indicated that the endophytic fungi from T. chinensis Baker could be exploited as a novel source of bioactive compounds.

Diversity and Ginsenoside Biotransformation Potential of Cultivable Endophytic Fungi Associated With Panax bipinnatifidus var. bipinnatifidus in Qinling Mountains, China

“…In our previous study, it was found that there was some similarity between the endophytic fungi composition of C. japonicus Sieb (dominant genera: Colletotrichum, Aspergillus, and Diaporthe ) and that of T. chinensis Baker (dominant genera: Collectotrichum, Fusarium, Aspergillus ) from Yingpan town (Qinling Mountains region), Shaanxi province of China. However, the results obtained in this study (dominant genera: Plectosphaerella, Paraphoma, and Fusarium ) showed significant difference from those of the aforementioned studies ( An et al, 2020a ; An et al, 2020b ). Also, rare genera such as Lecanicillium , Sarocladium , Thelonectria , Valutella , Exserohilum , Flavodon , and Rigidoporus obtained in this study were quite different from those in our previous studies, including Biscogniauxia , Leptostroma , Stachybotrys , Didymella , Peniophora , Peniophora , Rhodotorula , Setophaeosphaeria , Clitopilus , Muyocopron , Thanatephorus , and Ceriporia .…”

Antimicrobial properties of marine fungi from sponges and brown algae of Mauritius

“…has been recovered from sediments and hard substrates/rock substrates in the marine environment (Wu et al 2016 ; Fouillaud et al 2017 ). A study by An et al ( 2020 ) has shown that Biscogniauxia sp. endophyte has antimicrobial activity against two pathogenic bacteria.…”

Marine endophytic fungal metabolites: A whole new world of pharmaceutical therapy exploration

“…Mangrove forests represent an exclusive and dominant ecosystem consists of intertidal marine plants, commonly trees, predominantly bordering margins of tropical coastlines around the world. They provide about 70 halophytic salt tolerant plant species grow in salt coastal habitats [ 44 ]. Marine endophytic fungi from mangrove grow in habitats with distinctive conditions that attributed to the activation of fungal metabolic pathways and the diversity of the unidentified molecules produced by the endophytes [ 4 , 45 ].…”

“…They are a diverse group of about 70 species of plants that grow in salt coastal habitats. They are belonging to many botanical families, among which Rhizophoraceae , Combretaceae , Lythraceae , and Avicenniaceae are the most prevalent examples [ 44 , 45 ]. Moreover, mangroves supply a distinctive and dominant ecosystem consisting of intertidal marine plants, generally trees, predominantly on tropical coastal margins around the world.…”