Clostridium acetobutylicum细胞的无机载体吸附固定化及其应用研究

为避免渗透汽化膜原位分离过程中丁醇生产菌对膜的污染,对无机载体吸附固定Clostridium acetobutylicum XY16进行了研究,考察了多种无机载体对菌体的固定效率及其发酵产丁醇性能的影响.研究发现:在静电引力的作用下,携带正电荷的沸石对荷负电的菌体具有良好的吸附作用.在此基础上,对沸石载体进行负载阳离子改性,沸石负载铁离子改变了载体表面Zeta电位,可增强对菌体的固定效率,并提高发酵性能.当培养基中葡萄糖浓度为60 g?L?1时,添加Fe3+-沸石18%(W/V)进行批式发酵,总溶剂的转化率为0.31 g?g?1,对菌体的固定效率达到87%,比未改性沸石提高了22%,丁醇产量为13.5 g?L?1,总溶剂可达20 g?L?1,比沸石改性前分别提高了8%和11.1%.对该材料固载的细胞进行4次重复批式发酵,总溶剂的基质得率与游离细胞批式发酵结果类似.以上研究结果表明Fe3+-沸石对Clostridium acetobutylicum XY16具有较好的细胞固定效率,并对其生产性能具有一定的促进作用,适宜作为丁醇生产菌的吸附载体.

The Immobilization of Clostridium acetobutylicum by Adsorbing on the Inorganic Carrier Material and its Application

In order to prevent the membrane fouling by cells during the in-situ recovery process of the pervaporation membrane,the immobilization of Clostridium acetobutylicum XY16 on different inorganic carriers and its effects on butanol fermentation were investigated.The results show that the zeolite can well adsorb the cell with negative charge,and the zeolite can be further modified by treating it with cationic modification.The zeta potential of zeolite surface was changed after the zeolite was modified by loading it with iron(Ⅲ),then its efficiency of cells immobilization was increased,and the butanol production was enhanced.In the batch fermentation,when the glucose concentration in fermentation medium is 60 g L1 and the added Fe 3+-zeolite amount is 18%(W/V),the conversion ratio of the total solvent is 0.31gg 1 and the immobilized efficiency is 87% which increases by 22%;the butanol concentration of 13.5 g L1 and total solvent’s of 20 g L1 can be obtained,which increase respectively by 8% and 11.1% compared with those when unmodified zeolite is used.The batch fermentation experiment of immobilized cells by Fe 3+-zeolite was repeated for four times,and each time the yield of total solvent is higher than that of batch fermentation with free cells.It shows that the Fe 3+-zeolite is suitable to be used as immobilized carrier for butanol production by Clostridium acetobutylicum XY16.