Bioconversion of lignocellulosic waste to bioethanol by Trichoderma and yeast fermentation

Area of Science:

• Biotechnology and Bioengineering
• Renewable Energy Sources
• Microbial Fermentation

Background:

• Lignocellulosic waste, such as sawdust, presents a sustainable feedstock for bioenergy production.
• Marine yeasts offer unique metabolic capabilities for converting biomass into valuable products like bioethanol.
• Efficient pretreatment and enzymatic hydrolysis are crucial for maximizing sugar yield from recalcitrant lignocellulosic materials.

Purpose of the Study:

• To optimize the conversion of lignocellulosic waste sawdust into monosugars.
• To enhance bioethanol production using marine yeast fermentation.
• To investigate the statistical optimization of experimental conditions for efficient biomass conversion.

Main Methods:

• Acid hydrolysis followed by cellulase enzyme treatment for lignocellulosic biomass saccharification.
• Statistical optimization of pH, temperature, enzyme concentration, and substrate loading for glucose yield.
• Fermentation of hydrolyzed sawdust using marine yeast strains (H. estonica and S. cerevisiae) under optimized conditions.

Main Results:

• Achieved an efficient conversion of sawdust to glucose of 78.56% under optimized conditions (pH 6.19, 29°C, 8.16 IU/ml cellulase, 7.95 g/l sawdust).
• Obtained a maximum bioethanol yield of 85.6% (55.2 g/l) through fermentation using H. estonica and S. cerevisiae.
• Optimized fermentation conditions included 36.5°C, 102 h incubation, 45.14 ml/l enzyme-treated sawdust, and 330 rpm agitation.

Conclusions:

• The study successfully demonstrated the potential of lignocellulosic waste sawdust as a viable feedstock for bioethanol production.
• Marine yeast fermentation, coupled with optimized hydrolysis, offers an effective strategy for sustainable bioenergy generation.
• Statistical optimization significantly improved both glucose yield from sawdust and subsequent bioethanol production efficiency.