Sucrose utilization by Zymomonas mobilis: formation of a levan

Abstract

1. Molar growth-yield coefficients of Zymomonas mobilis for glucose, fructose, glucose plus fructose, and sucrose are reported. Yield coefficients for sucrose are appreciably lower than those for the equivalent concentrations of glucose plus fructose. 2. Only 2.6% of [U-(14)C]glucose supplied in the growth medium is incorporated into cell substance by Z. mobilis utilizing glucose as the energy source. 3. During growth on sucrose a levan is formed. It has been characterized and shown to resemble other bacterial levans. 4. Levan formation from sucrose could be demonstrated with both washed cell suspensions and cell extracts of Z. mobilis. 5. Sucrose phosphorylase could not be demonstrated in extracts of the organism.

Nutritional requirements of Zymomonas mobilis CCT 4494 for levan production

“…The highest cellular mass was 3.3 g.L -1 in medium 3, which contained initial glucose concentration of 50.0 g.L -1 . Dawes et al (1966) obtained the same results and observed that medium containing sucrose gave the lowest growth and the highest levan production. Cote and Ahlgren (1993) studied the growth of Erwinia herbicola and the production of levansucrase in different fermentation media.…”

Glucose and fructose metabolism in Zymomonas anaerobia

“…The balance equation for glucose fermentation during growth of Z. anaerobia is: The fermentation of fructose by Z. mobili presumably resembles that for glucose since, unlike Z. anaerobia, the growth yields recorded (Dawes, Ribbons & Rees, 1966) for this organism are similar for both sugars. Z. anaerobia differs from Z. mobilis, however, in its inability to grow on sucrose (Millis, 1956).…”

The effect of temperature on the kinetics of ethanol production by strains of Zymomonas mobilis

“…Previous studies on the effect of temperature on Z.mobilis havebeen concerned with its use in control of Z.mobilis infections of cider (Millis, 1951(Millis, , 1956 and with the role of temperature in uncoupling substrate catabolism from growth (Belaich and Senez, 1965;Bauchop and Elsden, 1960;Dawes et al, 1966;Forrest 1967;Forrest and Walker, 1971). Investigations by Forrest (1967) with Z.mobilis ATCC 10988 (using relatively low substrate concentrations compared with those employed in the present study) indicated that catabolism and growth were closely coupled up to 33uC, but at higher temperatures (up to a temperature of 39°C) decreasing biomass yields were obtained.…”