Isolation of Rhodococcus sp. strain ECU0066, a new sulfide monooxygenase-producing strain for asymmetric sulfoxidation

A new and efficient sulfide monooxygenase-producing strain, ECU0066, was isolated and identified as a Rhodococcus sp. that could transform phenylmethyl sulfide (PMS) to (S)-sulfoxide with 99% enantiomeric excess via two steps of enantioselective oxidations. Its enzyme activity could be effectively induced by adding PMS or phenylmethyl sulfoxide (PMSO) directly to a rich medium at the early log phase (6 h) of fermentation, resulting in over 10-times-higher production of the enzyme. This bacterial strain also displayed fairly good activity and enantioselectivity toward seven other sulfides, indicating a good potential for practical application in asymmetric synthesis of chiral sulfoxides.