Microbial resolution of Nɛ-acetyl-dl-lysine with Rhodococcus sp. AIU Z-35-1

An enantioselective resolution of Nɛ-acetyl-dl-lysine was investigated using cells from Rhodococcus sp. AIU Z-35-1 cultivated with l-lysine medium. Nɛ-Acetyl-l-lysine was deaminated by the resting cells, and 6-acetylamino-2-oxohexanoic acid was formed, but Nɛ-acetyl-d-lysine was not. This reaction was optimum at pH 6.5 and 30 °C, and the highest reaction speed was obtained by cells harvested after 1 day of cultivation. When 150 mM Nɛ-acetyl-dl-lysine was incubated at pH 6.5 and 30 °C for 5 days with cells harvested after 1 day of cultivation, more than 98% of the Nɛ-acetyl-l-lysine was converted to 6-acetylamino-2-oxohexanoic acid, and Nɛ-acetyl-d-lysine completely remained. Thus, Nɛ-acetyl-d-lysine was enantioselectively produced from Nɛ-acetyl-dl-lysine by the cell reaction with Rhodococcus sp. AIU Z-35-1. This cell reaction was also useful for the efficient production of 6-acetylamino-2-oxohexanoic acid from Nɛ-acetyl-l-lysine.