The effect of osmo-induced stress on product formation by Zymomonas mobilis on sucrose

The intensification of biosynthesis of fructooligosaccharides in the presen ce of high salt concentrations was observed during sucrose (10%) fermentati on by Zymomonas mobilis 113S. A 0.6 M NaCl concentration led to an increase of oligosaccharide productivity by 3.5-fold. Sorbitol formation was increa sed in the presence of 0.16 M NaCl and was inhibited at highest salt concen trations. In a medium with high (65%, w/w) sucrose content the salts gave i nhibitory effects on fructooligosaccharide production by lyophilised Z. mob ilis cells. Influence of salts on gluconic acid and sorbitol formation unde r these conditions was studied. The ratio of oligosaccharides and gluconic acid productivity (Q(olig.)/Q(glucon.)) was increased approximately 2 times at 1% KCl. Sorbitol formation was not significantly influenced in the pres ence of KCl (up to 2%). (C) 2000 Elsevier Science B.V. All rights reserved.