Production of functional malic acid polymer by Aureobasidium and its application

研究了短梗霉A-91菌株非生长细胞生产聚L-苹果酸（PMA）的情况。使用菌株A-91的非生长细胞优化反应条件。在细胞制备培养基中加入CuSO_4可有效地制备PMA活性细胞。在最佳培养条件下（160 g/l葡萄糖，40 g/l CaCO_3），30 ℃培养5天，非生长细胞的PMA产量可达80.0g/l。进行检查的目的是阐明这些产品生产的监管机制。发酵液中氮源的种类对多元醇脂质的产生有重要影响，初始培养pH值对PMA的产生有重要影响。此外，含硫氨基酸，如蛋氨酸或半胱氨酸，和锌离子促进PMA的生产。对菌株A-91进行诱变，得到两株与出发菌株相同的突变株。这些菌株似乎是有用的阐明这些产品的生产的调节机制。

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.