High cell density cultivation of Pseudomonas putida strain HKT554 and its application for optically active sulfoxide production.

Said Hamad Ramadhan, Toru Matsui, Kazuma Nakano, Hirofumi Minami

Index: Appl. Microbiol. Biotechnol. 97(5) , 1903-7, (2013)

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Abstract

Culture conditions with Pseudomonas putida strain HKT554, expressing naphthalene dioxygenase, known as the biocatalyst showing wide substrate specificity, were optimized for high cell density cultivation (HCDC). Culture in a medium TK-B modified from that for HCDC of Escherichia coli with glucose fed-batch and dissolved oxygen stat resulted in a high cell density growth of 114 g dry cell/l at 40 h of cultivation. This system was further applied for S-(+)-methyl phenyl sulfoxide (MPSO) production from methyl phenyl sulfide. Addition of nonpolar organic solvent, such as n-hexadecane, greatly enhanced the MPSO production due to the prevention of substrate evaporation, resulting in a MPSO production up to 39 mM in 30 h with a conversion rate of 95.7 mol%.