Abstract
The nature and amounts of by-products formed during conversion of sugar beets to ethanol by Z.mobilis in Conventional Submerged Fermentation (CSF) and Solid-State Fermentation (SSF) were investigated. It was found that the bacterium produced fewer by-products in SSF than CSF, and that by-products profile was different. The influence of fermentation temperature on synthesis of by-products in SSF was also studied. High fermentation temperature favoured sorbitol synthesis and low fermentation temperature the synthesis of levan. The best results were obtained at 35-degrees-C. An ethanol yield of up to 95% of the theoretical value with final ethanol concentration of 142 g/L were obtained.