微胶囊固定化混合菌群发酵产氢——构建一种虚拟“细胞工厂”的尝试

Immobilization of mixed bacteria by microcapsulation for hydrogen production―a trial of pseudo “Cell Factory”

摘要:

采用硫酸纤维素钠 (NaCS)/聚二甲基二烯丙基氯化铵 (PDMDAAC) 微胶囊体系，固定混合产氢菌群，构建成一个能高效产氢的虚拟“细胞工厂”。经过菌群活化预处理，激活了产氢活力，进一步通过NaCS/PDMDAAC微胶囊固定化，形成适宜的内部微环境，有效增强了菌群对温度的适应能力，提高了底物浓度，氢气产量比游离细胞增长30％以上，菌体浓度提高2倍到3.2 g/L。连续15批培养，囊内菌体浓度显著提高，发酵时间缩短，氢气产率保持在1.73~1.81 mol H2/mol glucose，平均产氢速率提高了198.6％。同时还发现发酵产物中有较高比例的丁酸和乙酸，由此可以使该虚拟“细胞工厂”成为一个多产物联产体系。

Abstract:

Sodium cellulose sulfate (NaCS)/Ploy-dimethyl-dially-ammonium-chloride (PDMDAAC) microcapsules were used as a novel pseudo “Cell Factory” to immobilize mixed bacteria for hydrogen production under anaerobic conditions. Compared to free cells, the hydrogen production was increased more than 30% with NaCS/PDMDAAC microcapsules as the pseudo “Cell Factory”. The biomass was increased from 1.5 g/L in free cell culture to 3.2 g/L in the pseudo “Cell Factory”. This pseudo “Cell Factory” system showed the excellent stability during 15 repeated-batches. The hydrogen yield maintained 1.73?1.81 mol H2/mol glucose. The fermentation cycle was shortened from 48 h to 24 h, resulting in an increase of 198.6% in the hydrogen production rate. There were high percentage of butyric acid and acetic acid in the culture broth, which meant that the pseudo “Cell Factory” established in the present work could be used for the multi-product system.