NOVEL TECHNOLOGIES FOR PRODUCING RENEWABLE CHEMICALS AND POLYMERS FROM CARBOHYDRATES DERIVED FROM AGRICULTURAL FEEDSTOCKS
Location: Renewable Product Technology Research Unit
Title: Biotechnology of Aureobasidium pullulans: A phylogenetic perspective
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 31, 2012
Publication Date: August 31, 2012
Citation: Manitchotpisit, P., Leathers, T.D., Peterson, S.W., Skory, C.D., Price, N.P., Rich, J.O. 2012. Biotechnology of Aureobasidium pullulans: A phylogenetic perspective [abstract]. International Congress on Yeasts. p. 194.
Aureobasidium pullulans is a fungus historically included among the "black yeasts." Although many strains are predominantly yeast-like, the species is actually polymorphic, exhibiting complex forms ranging from blastic conidia and swollen cells to pseudophyphae, hyphae, and chlamydospores. A. pullulans is now considered to be a filamentous ascomycete in class Dothideomycetes, subclass Dothideomycetidae. The fungus is ubiquitous and a cosmopolitan saprophyte routinely found on the surface of leaves, wood, painted walls, etc. Biotechnologically, A. pullulans is perhaps best known as the source of the commercial polysaccharide, pullulan. Pullulan has unique film- and fiber-forming properties that have found uses in the food and pharmaceutical industries. Besides pullulan, A. pullulans produces a number of other valuable bioproducts, including enzymes such as xylanase, esterase, mannanase, laccase, lipase, pectinase, and protease. The fungus also produces the biopolyester, poly(beta-L-malic acid) (PMA), which has potential as a platform molecule for second-generation bioplastics. A. pullulans is also the sole source of a novel heavy oil with potential as an anti-cancer agent and biosurfactant. We recently developed a multilocus molecular phylogeny for A. pullulans and have now expanded this study to include nearly 100 strains isolated from around the world. Thus far, more than a dozen phylogenetic clades of A. pullulans have been identified. Many clades exhibit characteristic phenotypic traits, such as colonial and cellular morphologies. Strains in certain clades produce distinctive pigments of pink, red, yellow, purple, olive, or deep black. More importantly, the production of specific valuable bioproducts such as pullulan, xylanase, PMA, heavy oil, laccase, and lipase is associated with specific phylogenetic clades. These results will be useful in the further development of biotechnological applications of A. pullulans.