Discovery of novel xylosides in co-culture of basidiomycetes Trametes versicolor and Ganoderma applanatum by integrated metabolomics and bioinformatics

Abstract

Transcriptomic analysis of cultured fungi suggests that many genes for secondary metabolite synthesis are presumably silent under standard laboratory condition. In order to investigate the expression of silent genes in symbiotic systems, 136 fungi-fungi symbiotic systems were built up by co-culturing seventeen basidiomycetes, among which the co-culture of Trametes versicolor and Ganoderma applanatum demonstrated the strongest coloration of confrontation zones. Metabolomics study of this co-culture discovered that sixty-two features were either newly synthesized or highly produced in the co-culture compared with individual cultures. Molecular network analysis highlighted a subnetwork including two novel xylosides (compounds 2 and 3). Compound 2 was further identified as N-(4-methoxyphenyl)formamide 2-O-β-D-xyloside and was revealed to have the potential to enhance the cell viability of human immortalized bronchial epithelial cell line of Beas-2B. Moreover, bioinformatics and transcriptional analysis of T. versicolor revealed a potential candidate gene (GI: 636605689) encoding xylosyltransferases for xylosylation. Additionally, 3-phenyllactic acid and orsellinic acid were detected for the first time in G. applanatum, which may be ascribed to response against T.versicolor stress. In general, the described co-culture platform provides a powerful tool to discover novel metabolites and help gain insights into the mechanism of silent gene activation in fungal defense.

Metabolomics Investigation of an Association of Induced Features and Corresponding Fungus during the Co-culture of Trametes versicolor and Ganoderma applanatum

“…The mono-culture procedure was adapted from our previous publication (Yao et al, 2016 ), and mono-culture medium was the same as above. Briefly, a 5 mm agar plug of each fungus scraped from agar slant culture-medium was cultured on a Petri dish (9 cm diameter), and were incubated at 28°C for 10 days.…”

“…The co-culture of Trichoderma Reesei with Coprinus comatus was an important approach for an on-site generation of lignocellulolytic enzyme leading to the increase of lignocellulose degradation rate as described by Ma and Ruan ( 2015 ). In our previous work, fifteen wood-decaying basidiomycetes and two straw-decaying basidiomycetes were used to establish 136 pairwise co-cultures on agar plates (Yao et al, 2016 ). The co-culture system of Trametes versicolor and Ganoderma applanatum showed an interaction zone, in which the accumulation of a series of known carboxylic acids as well as novel xylosides were observed.…”

Diversity and function of fungi associated with the fungivorous millipede, Brachycybe lecontii

“…However, in contrast, white filamentous fungi were only identified from 48.3% of B. lecontii colonies (Chapter 2). Members of the Polyporales are also known to produce many secondary metabolites (Yao et al 2016), and it is possible that B. lecontii sequesters those compounds and uses them for their own purposes. If any of these hypotheses are correct, the absence of pathogenicity in B. lecontii would offer evidence to support this assertion.…”

Unusual and Highly Bioactive Sesterterpenes Synthesized by Pleurotus ostreatus during Coculture with Trametes robiniophila Murr

“…Six pieces of mycelia with a diameter of 6 mm were picked from the PDA plates and inoculated into flasks which were then incubated at 28°C with constant shaking at 150 rpm for 5 days. After 5 days, inoculation of the cocultures was performed using a previously established method (7). Briefly, 100 ml of fermentation broth of strain A (e.g., T. robiniophila Murr) was transferred into a 100-ml culture of strain B (e.g., P. ostreatus), followed by addition of 50 ml fresh liquid culture medium as described above.…”