title: Poly(β-L-malic acid) production by diverse phylogenetic clades of Aureobasidium pullulans.
abstract: Poly(β-L-malic acid) (PMA) is a natural biopolyester that has pharmaceutical applications and other potential uses. In this study, we examined PMA production by 56 strains of the fungus Aureobasidium pullulans representing genetically diverse phylogenetic clades. Thirty-six strains were isolated from various locations in Iceland and Thailand. All strains from Iceland belonged to a newly recognized clade 13, while strains from Thailand were distributed among 8 other clades, including a novel clade 14. Thirty of these isolates, along with 26 previously described strains, were examined for PMA production in medium containing 5% glucose. Most strains produced at least 4 g PMA/L, and several strains in clades 9, 11, and 13 made 9-11 g PMA/L. Strains also produced both pullulan and heavy oil, but PMA isolated by differential precipitation in ethanol exhibited up to 72% purity with no more than 12% contamination by pullulan. The molecular weight of PMA from A. pullulans ranged from 5.1 to 7.9 kDa. Results indicate that certain genetic groups of A. pullulans are promising for the production of PMA.
authors: Biochemistry Unit, Department of Medical Sciences, Faculty of Science, Rangsit University, Muangake, Lakhok, Patumthani, 12000, Thailand.
authors: Pennapa
authors: P
authors: Manitchotpisit
authors: Christopher D
authors: CD
authors: Skory
authors: Stephen W
authors: SW
authors: Peterson
authors: Neil P J
authors: NP
authors: Price
authors: Karl E
authors: KE
authors: Vermillion
authors: Timothy D
authors: TD
authors: Leathers
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D005936:Glucans / Q000096:biosynthesis; D007055:Iceland; D008293:Malates / Q000737:chemistry / Q000378:metabolism*; D008970:Molecular Weight; D009821:Oils / Q000378:metabolism; D010802:Phylogeny; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D013785:Thailand
chemical_list: D005936:Glucans; D008293:Malates; D009821:Oils; D011108:Polymers; C121060:poly(malic acid); C009109:pullulan