Biosynthesis of acetate esters by dominate strains, isolated from Chinese traditional fermented fish (Suan yu)

Biosynthesis of acetate esters by Lactobacillus plantarum 120, Staphylococcus xylosus 135 and Saccharomyces cerevisiae 31, isolated from Chinese traditional fermented fish (Suan yu) were studied. A buffer system containing acyl donors (acetic acid/glyceryl triacetate/acetyl-CoA) and aliphatic alcohols (C2-C6) was established, inoculated with intracellular and extracellular extracts of the three strains. The results showed that the biosynthesis pathway of L. plantarum 120 was esterification and alcoholysis, while the biosynthesis pathway of S. xylosus 135 and S. cerevisiae 31 was hydrolysis and esterification, rather than alcoholysis. The ester-synthesizing activity of L. plantarum 120 via alcoholysis was higher than that via esterification at high pH value, while an opposite result for each strain was observed at low pH value. Moreover, the ester-synthesis activity of L. plantarum 120 was higher than that of S. xylosus 135 and S. cerevisiae 31. In addition, microbial ester-synthesis activity increased with the increase of aliphatic alcohol carbon number.