Intergeneric Hybridization between Streptomyces albulus and Bacillus subtilis Facilitates Production of ε-Poly-L-lysine from Corn Starch Residues

Intergeneric hybridization between S.albulus and B. subtilis to produce ε-poly-L-lysine (ε-PL) from corn starch residues (CSR) was investigated in this study. One hybrid, designated S. albulus LS-84, which incorporated the protease gene from B. subtilis, could effectively utilize the protein in CSR as a nitrogen source. In fed-batch fermentation, LS-84 produced 32.6 g/L ε-PL in the presence of 20 g/L CSR. This was an increase of 256.1% compared to that of the parent strain S. albulus LS-01. The rapid hydrolysis of CSR by protease caused rapid growth for LS-84, which allowed higher respiratory activity. As a result, activities of several key enzymes in LS-84 were higher than those in LS-01; additionally, the content of several intracellular amino acids, such as Asp, Glu, and Arg, was also much higher in LS-84. Therefore, intergeneric hybridization between S. albulus and B. subtilis to produce ε-PL from CSR is an economical method for effective utilization of waste resources.