Rapid Ethanol Production from Sucrose Using Zymomonas mobilis

Abstract

A new mutant strain of Zymomonas mobilis UQM 2716 was developed which lost its ability to produce sorbitol from fructose. The mutant, Zymomonas mobilis ACM 3963 was co-immobilised with invertase on alginate. This combination allowed theoretical yields of ethanol from 100 and 150 g 1^-1 sucrose using either semi-defined media or sugarcane syrup within 3–5 h, respectively. The increased immobilised biomass concentration reduced batch fermentation times by 5070%. The strain also improved significantly fed-batch fermentation with final yields of 14.3% v/v or 113 g l⁻¹ and 13.8% v/v or 109 g l⁻¹ ethanol for semi-defined media and sugarcane syrup, respectively.