Cofactor and CO_2 donor regulation involved in reductive routes for polymalic acid production by Aureobasidium pullulans CCTCC M2012223

摘要

Polymalic acid (PMA) is a water-soluble polyester with many attractive properties for biomedical application. Its monomer L-malic acid is widely used in the food industry and also a potential C4 platform chemical. Cofactor and CO_2 donor involved in the reductive routes were investigated for PMA production by Aureobasidium pullulans. Biotin as the key cofactor of pyruvate carbox-ylase was favor for the PMA biosynthesis. Na_2CO_3 as CO_2 donor can obviously improved PMA titer when compared with no CO_2 supplier NaOH, and also exhibit more advantages than the other donor CaCO_3 because of its water-soluble characteristic. A combinational process with addition of biotin 70 mg/L and Na_2CO_3 as the CO_2 donor was scaled-up in 50 L fermentor, achieving the high product 34.3 g/L of PMA and productivity of 0.41 g/L h. This process provides an efficient and economical way for PMA and malic acid production, and is promising for industrial application.