(231e) Research on Optimization and Characterization for 2,3-Butanediol Biosynthesis from Paenibacillus Polymyxa zj-9 By Solid State Fermentation

 Can Cao^a,b, Li Zhang^a, Jian Gao^a,*, Hong Xu^b

a School of Marine and Bioengineering, Yancheng Institute of Technology, Yancheng 224051, PR China

b State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816,PR China

Abstract: As a high-value chemical, 2, 3-butanediol (2, 3-BD) is a promising bulk chemical due to its extensive industry applications. Paenibacillus polymyxa has the potential for industrialized production of pure R,R-2,3-BD. More importantly, P. polymyxa does not have pathogenicity and can ferment different carbohydrate polymers. Jerusalem artichoke (Helianthus tuberosus L.) is an inexpensive non-staple crop with high sugar content, which can grow particularly well on marginal land, thus avoiding competition with food production for arable land. The dry Jerusalem artichoke powder comprises about 75-85% (w/w) sugars, with inulin as a principal constituent. Solid state fermentation (SSF) is defined as a fermentation process where the microorganisms grow in solid substrates with almost no free water. However, there is enough moisture in the substrate to support the growth and metabolism of the microorganisms. The impact of solid substrates was studied by using five different compositions of solid residue (wheat bran (WB), apple pomace (AP), jerusalem artichoke pomace (JAP), JW(JAP and WB) and JA(JAP and AP)). JAP was chosen to serve as the solid substrate because of the high yield of 2, 3-BD.The environmental parameters can affect the SSF, such as temperature, pH, moisture, ventilation and particle size. The yield of 2, 3-BD gradually increased to a maximum value of 28.46 g/kg (a mass proportion indicated the ratio of 2,3-BD yield to oven-dried SSF substrates) at 30 â??. When the initial pH was 7, the yield of 2, 3-BD reached peak. The optimum initial moisture of the solid substrates is 65%. Yeast extract is the best nitrogen source for P. polymyxa ZJ-9 when compared to peptone, (NH₄)₂SO₄ and KNO₃. Under the optimum conditions, the titer of 2, 3-BD could reach 31.57 g/kg solid substrate. Because of the low energy requirement, high product yield and less wastewater production, SSF has gained significant attention for the biotech industries recently and has emerged as an attractive alternative to submerged fermentation.

Key wordsï¼?Paenibacillus polymyxa; R,R-2,3-butanediol; Solid state fermentation