Abstractβ-poly(l-malic acid) (PMLA) is a water-soluble biopolymer used in medicine, food, and other industries. However, the low level of PMLA biosynthesis in microorganisms limits its further application in the biotechnological industry. In this study, corn steep liquor (CSL), which processes high nutritional value and low-cost characteristics, was selected as a growth factor to increase the PMLA production in strain, Aureobasidium melanogenum, and its metabolomics change under the CSL addition was investigated. The results indicated that, with 3 g/L CSL, PMLA production, cell growth, and yield (Yp/x) were increased by 32.76%, 41.82%, and 47.43%, respectively. The intracellular metabolites of A. melanogenum, such as amino acids, organic acids, and key intermediates in the TCA cycle, increased after the addition of CSL, and the enrichment analysis showed that tyrosine may play a major role in the PMLA biosynthesis. The results presented in this study demonstrated that the addition of CSL would be an efficient approach to improve PMLA production.

ß-poly(L-malic acid) (PMLA) is a water-soluble biopolymer used in medicine and other industries. However, the concentration of PMLA produced by microorganisms was too low for large-scale production. In this experiment, corn steep liquor (CSL) was selected due to its high nutritional value and low-cost growth factor to increase the production capacity of PMLA in the strain Aureobasidium melanogenum, and the strain’s CSL-influenced metabolic change was investigated. The PMLA production, cell growth, and yield (Yp/x) of A. melanogenum increased by 32.76%, 41.82%, and 47.43%, respectively, with the addition of 3 g/L CSL. Metabolomics analysis showed that the intracellular metabolites of A. melanogenum, such as amino acids, organic acids, and key intermediates in the TCA cycle, increased after the addition of CSL. Meanwhile, the data found that tyrosine may play a key role in the PMLA biosynthesis. These results demonstrated that the addition of CSL is an efficient approach for improving the production of PMLA.

ß-poly(L-malic acid) (PMLA) is a water-soluble biopolymer used in medicine, food, and other industries. However, the low level of PMLA biosynthesis in microorganisms limits its further application in the biotechnological industry. In this study, corn steep liquor(CSL), which processes high nutritional value and low-cost characteristics, was selected as a growth factor to increase the PMLA production in strain, Aureobasidium melanogenum, and its metabolomics change under the CSL addition was investigated. The results indicated that, with 3g/L CSL, PMLA production, cell growth, and yield (Yp/x) were increased by 32.76%, 41.82%, and 47.43%, respectively. The intracellular metabolites of A. melanogenum, such as amino acids, organic acids, and key intermediates in the TCA cycle, increased after the addition of CSL, and the enrichment analysis showed that tyrosine may play a major role in the PMLA biosynthesis. The results presented in this study demonstrated that the addition of CSL would be an efficient approach to improve PMLA production.