Improved production of heterologous protein from Streptomyces lividans

Abstract

Protein-secreting procaryotic host organisms are currently being sought as alternatives to Escherichia coli for recombinant processing. In this study we examined how manipulation of the cultivation conditions can enhance heterologous protein production by Streptomyces lividans. The recombinant S. lividans used in this study expressed and excreted a Flavobacterium enzyme capable of hydrolyzing organophosphates. Initial shake-flask studies demonstrated that supplementing Luria-Bertani medium with moderate amounts of glucose (30 g/l), led to improved enzyme production. In fermentor studies with controlled pH, a further twofold increase in production was observed when glucose was fed continuously as compared to batch cultivation. This improved production in the glucose-fed culture may be related to a reduced accumulation of acids. Continuous feeding of both glucose and tryptone led to a further sixfold increase in production. In addition to enhancing production 25-fold, the efficiency of enzyme production and the specific activity of the excreted enzyme were also improved by glucose and tryptone feeding. These results demonstrate that in addition to genetic manipulations, optimization of cultivation conditions can lead to significant improvements in the production of heterologous proteins from Streptomyces.

Fed-batch production ofThermomonospora fusca endoglucanase by recombinantStreptomyces lividans

“…6). The effects of peptone on protein production in Streptomyces species were reported in other studies (Delacruz et al, 1992;Payne et al, 1990). Payne et al showed that degradation of heterologous protein could be prevented by the addition of peptone, resulting in an increase in enzyme productivity.…”

Characterization and large-scale production of recombinant Streptoverticillium platensis transglutaminase

“…Limitations in DO after the cell growth became maximal or inadequate aeration may result in the low activity of the recombinant MtgA in the 250 l stirredtank fermenter. Feed-batch fermentation with continuous feeding of both glucose and tryptone may lead to a further increase in production of the enzyme [44], and we are continuing to investigate this possibility.…”

Filamentous Fungi Fermentation

“…With respect to filamentous fungi, expression systems using Streptomyces species as the host are particularly attractive, since they have been found capable of secreting high concentrations of enzymes [29]. Several researchers have investigated protein production from Streptomyces [30].…”