Open AccessOptimization of Reaction Parameters and Cultivation Conditions for Biocatalytic Hydrogen Transfer Employing Overexpressed ADH‐‘A’ from Rhodococcus ruber DSM 44541 in E. coli
Author(s) -
Edegger K.,
Gruber C. C.,
Faber K.,
Hafner A.,
Kroutil W.
Publication year - 2006
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.200620902
Subject(s) - cofactor , chemistry , escherichia coli , catalysis , rhodococcus , alcohol dehydrogenase , substrate (aquarium) , acetone , enzyme , biochemistry , hydrogen , organic chemistry , biology , ecology , gene
The alcohol dehydrogenase ADH‐‘A’ from Rhodococcus ruber DSM 44541 represents a highly efficient catalyst for biocatalytic hydrogen transfer reactions. Starting from an exceedingly low level of active ADH‐‘A’ in Escherichia coli , the apparent specific activity of ADH‐‘A’ overexpressed in E. coli cells could be drastically enhanced by a factor of 550 by optimizing the host and induction/growth conditions. The influence of reaction parameters like pH, cosubstrate (2‐propanol, acetone) concentration, substrate concentration temperature and additional cofactor on the apparent activity was investigated. In contrast to the purified enzyme, the pH optimum for oxidation and reduction were identical. Due to the employment of whole cells of E. coli /ADH‐‘A’ as catalyst lower operational stability was found.