Preliminary analysis of the lipase gene (gehM) expression of Staphylococcus xylosus in vitro and during fermentation of naturally fermented sausages (in situ.

Coagulase-negative catalase-positive cocci (CNCPC) play a very important role during the fermentation of sausages. In particular, they are involved in the aroma formation of the final product, because they release lipases that are able to free short-chain fatty acids that are contributing to the sensory characteristics of the fermented sausage. Few studies have been undertaken to elucidate the regulation of lipase gene expression in Staphylococcus xylosus by substrate molecules or products of lipolysis. The aim of this study was to analyze the gehM gene expression of S. xylosus DSMZ 6179 in vitro with growth media containing different concentrations of lipids and in situ during the maturation of fermented sausages. The results obtained suggest that a concentration that increases in triglycerides in the growth medium suppresses the expression of the lipase gene.