Effects of amino acids on the fermentation of inulin or glucose to produce R,R-2,3-butanediol using Paenibacillus polymyxa ZJ-9

This study investigated the effects of different amino acids on the fermentation of pure inulin and glucose using Paenibacillus polymyxa ZJ-9 in order to improve the production of R,R-2,3-butanediol (R,R-2,3-BD) respectively. The inulin extract from Jerusalem artichoke tubers contained 19 common amino acids, which were detected by HPLC. Arg featured the highest content (1290 mg l(-1)). A single add-back experiment of 20 common amino acids indicated that Asn, Ser, His and Arg are key amino acids in R,R-2,3-BD synthesis during inulin fermentation using P. polymyxa ZJ-9. The corresponding yields of R,R-2,3-BD reached 2432, 2232, 2203 and 2104 g l(-1) after the four key amino acids (15 g l(-1) each) and glucose were evaluated in this fermentation. The yields were considerably higher than that of the control group (1211 g l(-1)). With the addition of the mixture of four amino acids (15 g l(-1) each), the highest yields of R,R-2,3-BD (2507 and 1747 g l(-1)) were obtained with the increase of 1070 and 891% during the fermentation of glucose and pure inulin respectively. Significance and Impact of the StudyPaenibacillus polymyxa is a micro-organism with a reported potential for industrialized production of R,R-2,3-butanediol. The nitrogen sources have a significant effect on R,R-2,3-butanediol formation using P. polymyxa. This study demonstrated a highly efficient new method to improve the yield of R,R-2,3-butanediol without adding other nitrogen sources except amino acids during the fermentation. This will therefore decrease the production cost of R,R-2,3-butanediol and provide a new strategy for promoting synthesis of amino acid-dependent products.