Effects of NaCl on gene expression of agmatine deiminase pathway genes of putrescine inLactobacillus delbrueckiiandEscherichia coli

Abstract

To investigated the mechanism of NaCl concentration on the production of putrescine in lactobacilli mf661779 and Escherichia coli mf661780. We explored the effect of NaCl concentration on the putrescine production mechanism in Lactobacillus delbrueckii MF661779 and Escherichia coli MF661780, both of which produce putrescine via the agmatine deiminase (AGDI) pathway. Reverse-transcription quantitative PCR (RT-qPCR) was used to analyse expression of AGDI pathway genes, and ultra-performance liquid chromatography (UPLC) was used to monitor putrescine production over 48 hr. The results showed that NaCl had a lager inhibitory effect on the growth of E. coli MF661780, while NaCl affected the pH of L. delbrueckii MF661779 cultures to a greater extent. NaCl had minimal influence on expression of the transmembrane transcription activator aguR, but it markedly inhibited the transcription of the aguBDAC operon (p < .01). Differences in augB gene expression in L. delbrueckii at different NaCl concentrations were greater than in E. coli. Practical applications In this research paper, we explored the effect of NaCl concentration on the putrescine production mechanism in Lactobacillus delbrueckii MF661779 and Escherichia coli MF661780, both of which produce putrescine via the agmatine deiminase (AGDI) pathway. NaCl had a lager inhibitory effect on the growth of E. coli MF661780, while NaCl affected the pH of L. delbrueckii MF661779 cultures to a greater extent. NaCl had minimal influence on expression of the transmembrane transcription activator aguR, but it markedly inhibited the transcription of the aguBDAC operon. This study was to determine the effects of NaCl on the putrescine production mechanism in L. delbrueckii and E. coli. According to the experiment, the research work is beneficial for evaluated the safety of fermented foods.