Efficient Bioethanol Production from Waste Bread Employing Zymomonas mobilis

The global push for renewable energy has spurred research into bioethanol, a renewable fuel source that also reduces air pollution. A significant source of potential feedstock is the substantial amount of bread waste generated annually: over ۱۰۰ million tons of wheat bread are produced globally, with ۷-۱۰% becoming waste. This study explored using this waste to produce bioethanol with Zymomonas mobilis. The process was conducted in two key steps. First, enzymatic hydrolysis using α-amylase and amyloglucosidase yielded a maximum reducing sugar concentration of ۱۴۱ g/l. Second, fermentation was optimized using response surface methodology (RSM) by manipulating four factors: initial sugar concentration (۸۵ g/l), bacterial dry weight (۰.۰۳۲۵ g), peptone weight (۰.۳۶ g), and fermentation time (۲۷ h). These conditions resulted in a maximum ethanol production of ۳۱.۴ g/l. This represents an ۸۰.۸۳% sugar consumption and an ethanol yield of ۰.۴۵۷. This efficient bioethanol production from waste bread using Zymomonas mobilis demonstrates the potential for sustainable fuel generation and waste reduction.

Keywords:

Bioethanol , Waste bread , Zymomonas mobilis , Fermentation , Optimization