A strategy for screening microbial strains with lipolytic specificity toward monoacylglycerols

Abstract

For easy obtaining the microorganisms with lipolytic specificity toward monoacylglycerols, we developed a simple and effective method to isolate the objective strains. This method employed a nile-blue agar-plate culture containing mono- and tri- acylglycerols for microorganism screening and selected the desired microorganisms by analysis of free fatty acid contents in lipid extracts obtained from culture broth. Using this strategy, we successfully isolated one mold strain with superior lipolytic ability for the hydrolysis of monoacylglycerols. The mold was identified and designated as Paecilomyces nostocoides NTU-FC-LP01. The lyophilized mycelia of the isolated mold used as a biocatalyst showed high specificity toward monoacylglycerols rather than di- and tri- acylglycerols. Furthermore, the lyophilized mycelia catalyzed the monoolein synthesis through the direct esterification of oleic acid and glycerol. It indicated that the lyophilized mycelia of the present P. nostocoides NTU-FC-LP01 could be used as a natural immobilized biocatalyst for the glycerol/oleic acid esterification to produce monoolein.