Saccharification of agricultural residues by Streptomyces sp. and ethanol production from agro-waste mixture hydrolysate

Abstract

The present work demonstrated the potential of different agro-waste mixtures to produce ethanol. The forest soil bacterium (Streptomyces sp.) was exploited for the saccharification of the agro-waste mixture formulated by extreme vertices mixture design and the hydrolysate produced by saccharification was used for fermentation. The best formulation contained 43.33% orange peel, 33.33 % pumpkin pulp + seeds, and 23.33% pomegranate peel which exhibited significantly high reducing sugar (22.36 ± 0.54 mg/g dry weight) among all other mixtures. The hydrolysate of this mixture when supplemented with 2% w/v fructose produced a maximum of 7.86 ± 0.08% v/v ethanol by the yeast isolated from the brewer’s spent grains. Thus, easily available waste could be a promising source for yeast isolation and feedstock for ethanol production. Further, this study aids to reduce the risk of health, and environmental pollution, and developing the economy.

Keywords

• Streptomyces sp.
• Mixture formulation
• Agro-waste
• Saccharification