Optimization of production medium for expression and secretion of a heterologous cutinase by a recombinant Escherichia coli strain

摘要

This work was carried out to find the optimal conditions to maximize the expression and secretion of a heterologous cutinase by a new recombinant Escherichia coli strain. With successful secretion to extracellular medium of active cutinase it is possible to avoid the need of extensive purification methods that often cause significant decrease of enzyme production yield. The secretion of cutinase to production medium avoids the traditional methods of extraction of intracellular enzymes such as osmotic shock, sonication or homogenization that causes the contamination with intracellular proteins, DNA, RNA, and cellular waste fragments. With this goal in mind, the composition of production medium and aeration conditions for expression and simultaneously secretion of cutinase by this new E. coli strain were optimized. The influence of yeast extract, tryptone, the enzyme transcription inductor (IPTG), MgSO₄, and ampicillin concentrations and the volume of the headspace given for aeration were studied.