Polyphasic taxonomy of daldinia (hypoxylaceae) in Thailand and their potentials as biofilm inhibitors

Abstract

In an investigation of related stromatic Xylariales in Thailand, several fungal specimens with affinities to the genus Daldinia are commonly found. Out of these, eight species have been reported in Thailand. Based on morphological characters, the concatenated ITS, LSU, RPB2 and TUB2 sequence data and secondary metabolite profiles using high performance liquid chromatography coupled to diode array detection and mass spectrometry (HPLC-MS), three fungal taxa (i.e., D. flavogranulata, D. phadaengensis and D. chiangdaoensis) are newly discovered. In this study, D. brachysperma, which had hitherto been reported in America, was found for the first time in Asia. Our phylogenetic and morphological evidences confirmed that D. brachysperma is closely related to D. eschscholtzii and D. bambusicola, which are common in Thailand and also closely related to our new taxon (Daldinia flavogranulata). In addition, D. phadaengensis and D. chiangdaoensis are similar to D. korfii and D. kretzschmarioides, respectively. Based on the effect of secondary metabolites on bacterial biofilm formation, our results demonstrated that Daldinia eschscoltzii had highly inhibited to the biofilm of the Staphylococus aureus ATCC 25923