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Enzymatic Production of l ‐Menthol by a High Substrate Concentration Tolerable Esterase from Newly Isolated Bacillus subtilis ECU0554
Author(s) -
Zheng GaoWei,
Yu HuiLei,
Zhang JianDong,
Xu JianHe
Publication year - 2009
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200800412
Subject(s) - menthol , chemistry , bacillus subtilis , biocatalysis , esterase , hydrolysis , substrate (aquarium) , enzyme , lipase , enzymatic hydrolysis , enantioselective synthesis , organic chemistry , catalysis , food science , bacteria , ionic liquid , genetics , oceanography , biology , geology
AbstractEnzymatic preparation of l ‐menthol has been attracting much attention in the flavor and fragrance industry. A new ideal strain, Bacillus subtilis ECU0554, which exhibited high hydrolytic activity and excellent enantioselectivity towards l ‐menthyl ester, has been successfully isolated from soil samples through enrichment culture and identified as Bacillus subtilis by 16S rDNA gene sequencing. The esterase extracted from B. subtilis ECU0554 (BSE) showed the best catalytic properties ( E >200) for dl ‐menthyl acetate among the five menthyl esters examined. Enantioselective hydrolysis of 100 mM dl ‐menthyl acetate at 30°C and pH 7.0, using crude BSE as biocatalyst and 10% ethanol (v/v) as cosolvent, resulted in 49.0% conversion (3 h) and 98.0% ee for the l ‐menthol produced, which were much better than those using commercial enzymes tested. Moreover, BSE exhibited strong tolerance against high substrate concentration (up to 500 mM), and the concentration of l ‐menthol produced could reach as high as 182 mM, and more importantly, the optical purity of l ‐menthol produced was kept above 97% ee , which were not found in previous reports. These results imply that BSE is a potentially promising biocatalyst for the large‐scale enzymatic preparation of l ‐menthol. Using this excellent biocatalyst, the enzymatic production of l ‐menthol will become a mild, efficient, inexpensive and easy‐to‐use “green chemistry” methodology.