Journal of Chemical Technology and Biotechnology, Vol.94, No.12, 3915-3923, 2019
Production of 2,3-butanediol by fermentation of enzymatic hydrolysed bagasse from agave mezcal-waste using the native Klebsiella oxytoca UM2-17 strain
Background 2,3-butanediol is a chemical component with wide industrial applications, such as biofuels and chemical precursors. Reducing 2,3-butanediol production costs is a high priority and recent focus has been on its biological synthesis from raw renewable materials rather than through conventional chemical procedures. In this study, a 2,3-butanediol native bacterial producer was selected for the fermentation of Agave cupreata bagasse waste by enzymatic hydrolysation to obtain 2,3-butanediol. Results The native Klebsiella oxytoca UM2-17 strain was selected to efficiently produce 2,3-butanediol on synthetic mineral media. Using glucose (100 g L-1) and glucose: xylose (50 g L-1:50 g L-1) as sugar sources obtained titres of 29.36 g L-1 and 25.9 g L-1 of 2,3-butanediol, corresponding to yields of 0.29 g g(-1) and 0.26 g g(-1), respectively. Agave bagasse solid waste after acid pre-treatment was utilized to obtain enzymatic hydrolysates, obtaining liquors with glucose/xylose/arabinose at 25.8 g L-1 with efficiency of similar to 52.5% sugar conversion from residual solid pre-hydrolysed bagasse. The production of 2,3-butanediol through batch fermentation of the enzymatic-hydrolysate by the UM2-17 strain showed total depletion of glucose and xylose, achieving a maximal production of 10.3 g L-1 of 2,3-butanediol plus 0.28 g L-1 ethanol, corresponding to 2,3-butanediol yield of 0.40 g g(-1). Conclusion The results indicate that A. cupreata bagasse waste from mezcal beverage elaboration is a sustainable bioresource for production of 2,3-butanediol by fermentation of enzymatic bagasse-hydrolysate using the K. oxytoca UM2-17 strain. (c) 2019 Society of Chemical Industry