Sustainable production of optically pure platform chemical bio-based (R,R)−2,3-butanediol from sugarcane molasses in a low-cost salt medium

Abstract

Bio-based 2,3-butanediol (2,3-BDO) viability production on a large scale depends on the culture medium costs, fermentation broth, and bioprocess biosafety. This study investigated sugarcane molasses, corn steep liquor, and ammonium chloride to replace commercial glucose and yeast extract for 2,3-BDO production by a safe and wild-type Paenibacillus peoriae NRRL BD-62. A savings of 75.2% were achieved using sugarcane molasses and NH4Cl-based medium, whose final cost was 4.74 US$/kg2,3-BDO. Levo-2,3-BDO was produced with high optical purity and no acetoin accumulation in batch fermentation. The selectivity was maintained above 90% in fed-batch fermentation at constant feeding. In contrast, the yield showed a 20% reduction, indicating that this feeding strategy was less efficient than batch cultures. To the best of our knowledge, this is the first time that levo-2,3-BDO with high optical purity has been produced by a newly isolated P. peoriae strain from sugarcane molasses in a low-cost salt medium, making the large-scale process sustainably promising.