Microbial resolution of dl-homoserine for the production of d-homoserine using a novel isolate, Arthrobacter nicotinovorans strain 2-3

Microbial optical resolution was investigated for the practical production of d-homoserine from dl-homoserine. A bacterial strain, 2-3, that enantioselectively degrades the l-enantiomer from dl-homoserine was isolated and identified as Arthrobacter nicotinovorans. Strain 2-3 grew on medium containing 5% (w/v) dl-homoserine hydrobromide (275 mM) as the sole carbon and nitrogen source and enantioselectively exhausted the l-enantiomer in 48 h. The d-enantiomer was recovered from the culture broth with an enantiomeric excess of >99.9%. In addition, washed cells of the strain 2-3 were able to perform complete optical resolution at an initial dl-homoserine hydrobromide concentration of up to 510 mM, with a velocity of 0.28 mmol (g cell dry weight)−1 h−1.