|Kuo, Tsung Min|
Submitted to: Current Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2004
Publication Date: 6/1/2004
Citation: Labeda, D.P., Jackson, M.A., Kuo, T., Nakamura, L.K. 2004. Enantioselective hydrolysis of butyl 2-ethylhexanoate by a strain of nocardia corynebacteroides nrrl 21057. Current Microbiology. 49:133-135. Interpretive Summary: The compound DEHP [di-(2-ethylhexyl)phthalate] is used industrially as a plasticizer which as an environmental pollutant can ultimately find its way into humans. This chemical is degraded in humans and animals to another compound, 2-ethylhexanoic acid, which has the potential to cause birth defects if present during pregnancy. This compound can exist as a mixture of two forms, the S and R isomers, which are mirror images, but only the R isomer is toxic. Production of only the S isomer is difficult, but the procedure described provides a starting point for a microbial means of producing the single isomer. The application of this technology can help to provide a safer environment by significantly reducing the potential impact of plasticizers on unborn children.
Technical Abstract: The results of a screen for microbial esterases that have enantioselective activity for the hydrolysis of butyl 2-ethylhexanoate are described. The preliminary screen determined that a nocardioform bacterial strain, NRRL 21057, exhibited significant activity in preferentially hydrolyzing the S enantiomer of butyl 2-ethylhexanoate. Molecular systematics methods identified NRRL 21057 as a strain of Nocardia corynebacteroides. A survey of phylogenetically related species in the genera Gordonia, Rhodococcus, and Nocardia strains demonstrated that N. corynebacteroides NRRL 21057 is the most active strain known for the specific hydrolysis of the R-isomer of butyl 2-ethylhexanoate and that it provides the S-isomer of 2-ethylhexanoate in 86% enantiomeric excess within 22 hours.