2,3-Butanediol production using soy-based nitrogen source and fermentation process evaluation by a novel isolate of...

Area of Science:

• Biotechnology and Industrial Microbiology
• Sustainable Chemical Production
• Metabolic Engineering

Background:

• 2,3-Butanediol (2,3-BDO) is a valuable chemical with diverse industrial applications.
• Current microbial production often relies on pathogenic strains (Klebsiella, Enterobacter, Serratia), limiting industrial scalability.
• There is a need for safe, non-pathogenic microbial producers and cost-effective fermentation strategies.

Purpose of the Study:

• To investigate the potential of a non-pathogenic soil isolate, Bacillus licheniformis (BL1), for 2,3-BDO production.
• To evaluate the efficacy of soy-based hydrolysates as sustainable nitrogen sources, replacing yeast extract and peptone.
• To optimize fermentation parameters and feeding strategies for enhanced 2,3-BDO yield and productivity.

Main Methods:

• Screening of Bacillus licheniformis BL1 for 2,3-BDO production.
• Replacement of traditional nitrogen sources (yeast extract, peptone) with soy flake and soybean meal hydrolysates.
• Optimization of fermentation conditions (pH, oxygen) and glucose feeding strategies (batch vs. fed-batch).
• Analysis of 2,3-BDO titer, yield, and productivity under various conditions.

Main Results:

• Soy hydrolysates (defatted soy flakes, soybean meal) supported 2,3-BDO production comparable to conventional nitrogen sources.
• Optimized batch fermentation with soy hydrolysate yielded 11.06 g/L of 2,3-BDO with 0.43 g/g yield and 0.48 g/L h productivity.
• Fed-batch fermentation with intermittent glucose feeding overcame substrate inhibition, achieving a titer of 49.8 g/L and productivity of 0.62 g/L h.
• The use of soy hydrolysates reduced medium costs by 67%.

Conclusions:

• Bacillus licheniformis BL1 is a promising non-pathogenic producer of 2,3-BDO.
• Soy-based hydrolysates offer a cost-effective and sustainable alternative nitrogen source for 2,3-BDO fermentation.
• Optimized fed-batch strategies are crucial for achieving high titers and productivities, making industrial-scale 2,3-BDO production more economically viable.