Production of functional malic acid polymer by Aureobasidium and its application

点击翻译按钮获取中文摘要

Poly (L-malic acid), PMA,production by the non-growing cells of Aureobasidium sp.strain A-91 was investigated. Reaction conditions were optimized using non-growing cells of strain A-91. The addition of CuSO_4 to the cell preparation medium was found to be effective to prepare active cells for PMA production. The non-growing cells of the strain yielded 80.0g/l PMA during 5 days' incubation at 30ﾟC under optimal conditions (160g/l glucose and 40g/l CaCO_3).On the other hand, strain A-91 also produces pullulan and polyol lipid, which are useful for chemical industries, by changing some culture conditions. Examinations were done as a purpose of elucidating regulatory mechanism of production of these products. The kind of N-source in culture broth seemed to be important for the polyol lipid production and the initial culture pH was important for PMA production. In addition, sulfur containing amino acid, such as methionine or cysteine, and zinc ion enhanced PMA production. Copper and iron ions were found to enhance pullulan production.Mutation was performed using strain A-91 and two Met-mutants showed the same productivities as those of parent strain. These strains seemed to be useful for elucidating regulatory mechanism of production of these products.