树脂对小麦秸秆水解液中丁醇发酵抑制物的脱除效果

Removal effect of resins on butanol fermentation inhibitors in wheat straw hydrolysate

酸水解产生的副产物会严重抑制小麦秸秆水解液丁醇发酵。该文针对树脂对小麦秸秆水解液中丁醇发酵抑制物的脱除效果进行研究。通过强酸性苯乙烯系阳离子交换树脂732及大孔树脂XAD-4对小麦秸秆水解液进行抑制物脱除处理,以未处理组作为对照。离子交换树脂732处理后丁醇得率及含量均高于大孔树脂XAD-4处理。离子交换树脂732处理后在糖质量浓度为33.23 g/L的条件下发酵,丁醇和总溶剂质量浓度可达到7.58、13.09 g/L,得率分别可达到0.23、0.40 g/g,相对于对照组产量分别提高了5.3、5.9倍。在发酵前期,对照组丙酮丁醇梭菌的ATP和烟酰胺腺嘌呤二核苷酸(nicotinamide adenine dinucleotide, NADH)积累缓慢,在发酵进行到24 h的时候达到峰值。随着发酵的进行,对照组中丙酮丁醇梭菌的乙醇脱氢酶和丁醇脱氢酶活性最高仅能达到初始状态的29%和44%,而在离子交换树脂732处理组中可以达到初始状态的171%和142%。

By-products from acid hydrolysis of wheat straw can seriously inhibit butanol fermentation. The removal effect of resins on butanol fermentation inhibitors was studied here. Strong acid styrene cation exchange resin 732 and microporous resin XAD-4 were used for the removal of inhibitors in wheat straw hydrolysate, while the untreated group was set as control. Higher yield and concentration of butanol were obtained from the fermentation with resin 732 treatment than those from macroporous resin XAD-4 treatment. Additionally, after resin 732 treatment, fermentation was conducted at a sugar content of 33.23 g/L, and the concentration of butanol and total solvent reached 7.58 and 13.09 g/L, with the yield of 0.23 and 0.40 g/g, which were 5.3 and 5.9 times higher than those from the control group, respectively. In the control group, the accumulation rates of ATP and NADH were slow at the early fermentation stage and reached top values at 24 h. More importantly, during the fermentation, the highest activities of ethanol dehydrogenase and butanol dehydrogenase only reached 29% and 44% of the initial value, while in resin 732 treated group, these could reach as high as 171% and 142%, respectively.