Abstract: Escherichia coli is frequently influenced by various stresses in the process of exogenous protein expression and established various stress signaling systems that sensing and responding to specific stimuli. Recently it has been identified that many small non-coding RNAs (sRNA) have an important role in regulating mRNA translation by influencing the stability and translation efficiency of mRNA. In this research, in order to block sigma E-mediated cell lysis signal pathway, we studied the effect of overexpressing anti-micAs on the tolerance of E. coli to ethanol, pullulanase production and the trans-coded RNA interference efficiency, by using artificial trans-coded sRNAs of micA anti-micAs (bprO and omU) to silence micA. Moreover, the influencing factors of function of artificial trans-coded sRNAs were also discussed. Research found that in bprO and omU overexpression strains, the colony forming units (CFU) were raised by half and one order of magnitude, respectively; the ompA mRNA levels were improved by 7.2-fold and 6.9-fold, respectively and the content of OmpA protein was also significantly increased; pullulanase production was enhanced by 1.4-fold and 1.8-fold, respectively. Moreover, the effect of omU overexpression on Escherichia coli was slightly larger than that of bprO.

Key words: stress, artificial sRNA, viability, cell lysis, pullulanase