ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary The conversion of starch to ethanol in a mixed culture of an amylolytic yeast, Saccharomycopsis fibuliger and an anaerobic bacterium, Zymomonas mobilis, was studied. Interactions between the component cultures were commensalism and competition for glucose. Control of oxygen supply to the culture was used as an external regulator of growth and competition. No accumulation of reducing sugars was observed in the mixed culture when compared to a monoculture of Saccharomycopsis fibuliger grown on starch. The glucose formed was instantly used by Zymomonas mobilis for ethanol production and the glucose inhibition of hydrolysis of non-glucose reducting sugars was released. The final concentration of ethanol, 9.7 g·l−1, produced from 30 g·l−1 of starch, shows out that all the glucose available from starch hydrolysis was converted to ethanol. Glucose production from starch was the rate-limiting reaction in the system, causing a lower ethanol production rate in the mixed culture than in the monoculture of Zymomonas mobilis, grown on glucose.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00508019
