Biocatalytic production of 10‐hydroxystearic acid, 10‐ketostearic acid, and their primary fatty amides

Abstract

AbstractThe objective of this study was to develop scaleup bioprocesses for producing 10‐hydroxystearic acid (10‐HSA) and 10‐ketostearic acid (10‐KSA) as well as their primary amides for potential new uses. A reactor process was examined to obtain the mono‐oxygenated FA using Sphingobacterium thalpophilum (NRRL B‐14797) and Bacillus sphaericus (NRRL NRS‐732), which solely produce 10‐HSA and 10‐KSA, respectively, from technical‐grade oleic acid. By using an 8‐h‐old B‐14797 culture grown in a manganese‐containing WF6 medium, pH 7.3, at 28°C under 350 rpm agitation and 0–50% dissolved oxygen concentrations provided by a controlled sparger aeration, the production of 10‐HSA reached 7 g/L with a 40% yield in 4 d. In using a 12‐h‐old NRS‐732 culture grown in a pyruvate‐containing PF6 medium, pH 6.5, at 30°C under 750 rpm agitation without any sparger aeration during the conversion reaction, 10‐KSA production reached 7.9 g/L with a yield of more than 54% in 72 h. The scaleup reactor process provided crystalline 10‐HSA and 10‐KSA for producting new primary amides via a lipase‐catalyzed amidation reaction with yields of 94 and 92%, respectively. The primary amides of 10‐HSA and 10‐KSA displayed m.p of 115 and 120°C, respectively.