ARS | Publication request: Aureobasidium thailandensis, a new species isolated from leaves and wooden surfaces in Thailand

Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 13, 2012
Publication Date: N/A

Interpretive Summary: Molds in the Aureobasidium group can produce the valuable product pullulan, but the quality and quantity of pullulan depends on which Aureobasidium is used to produce it. Using genetic tools we were able to determine that two Aureobasidium molds isolated in Thailand represent a novel species, which we describe as Aureobasidium thailandensis. A. thailandense does not produce pullulans, but does produce a novel extracellular polysaccharide whose characteristics are unknown. Our description of this novel mold increases the known genetic and phenotypic diversity of Aureobasidium and will help streamline future searches for new sources of pullulans and other extracellular polysaccharides. The results will be of value to biotechnologists, fermentation microbiologists, and academic microbiologists.

Technical Abstract: Aureobasidium thailandense is described from material collected on leaves and wooden surfaces in Thailand. Phylogenetically it is distinct from other species of Aureobasidium. Phenotypically it is distinguished by its cardinal temperatures, salt tolerance, and production of reddish brown hyphal pigmentation in PDA cultures. Unlike A. pullulans, A. thailandense produces a non-pullulan extracellular polysaccharide whose characteristics are unknown. The two known isolates of A. thailandense possess a ca 500 bp type I intron in the 18S ribosomal RNA that is present in ITS amplification using primers ITS4 and ITS5. Aureobasidium pullulans isolates uniformly lack this intron.