Expression of the key enzyme gene of the proteolytic system in Lacbobacillus bulgaricus

摘要

The objective of this study was to investigate the expression of the key protease genes of the proteolysis system in Lacbobacillus bulgaricus at the transcriptional level. The technique real-time fluorescence quantitative PCR was used to analyze the kinesis of the seven key peptidases (oppd, prtb, pepc, pepf, pepq, pepx, and pept) genes of seven L bulgaricus strains. Results showed that the key enzyme genes expression of proteolytic system was significantly different among different L. bulgaricus strains (P<0.05), but which do not show certain regularity. The strains of LB08012, LB08014, and LB08016 cultured at 30°C, 37°C, 42°C, and 45 °C for 12 h, the key enzyme gene expression levels was significantly different among strains (P<0.05). The seven kinds of protease gene expression were significantly decreased (P <0.05) with elevated temperature. Therefore, there are significant differences in the transcriptional levels of seven key genes of proteolytic system among different strains, which also are influenced by incubation temperature.