Effects of amino acids on poly malic acid fermentation by Aureobasidium pullulans

The effects of added amino acids on poly malic acid(PMLA) fermentation by A. pullulans CGMCC3337 were studied,the types and adding amount of the amino acids were optimized by single factor experiment and orthogonal experiments. Single factor experiment showed that aspartic acid(Asp),leucine(Leu),valine(Val)and threonine(Thr) were favorable for the synthesis of PMLA and cell growth. Orthogonal experiment showed that the optimal combination of amino acids added(g/L):Asp 0.4,Leu 0.4,Val 0.4,Thr 0.4. Under the optimizing condition,the production and molecular weight of PMLA achieved 57.89 g/L and 8879 u,respectively. Compared with the previous,the production and molecular weight of PMLA were increased by 40.92% and 45.20%,respectively.