固定化产絮菌生产生物絮凝剂的研究

Production of bioflocculant using immobilized bioflocculant-producing bacteria

摘要:

为降低发酵成本及实现生物絮凝剂的连续发酵生产,采用吸附法固定化生物絮凝剂产生菌,发酵生产生物絮凝剂．从载体稳定性、生物絮凝剂产量、发酵液絮凝率等方面对比颗粒活性碳、聚氨酯泡沫和菌丝球3种固定化载体性能,并优化了活性碳和菌丝球两种载体的固液比．结果表明:颗粒活性碳、聚氨酯泡沫和菌丝球均可有效固定化产絮菌F+,采用颗粒活性碳和菌丝球两种载体固定化发酵的生物絮凝剂产率高于聚氨酯泡沫载体. 载体吸附试验表明:菌丝球载体对于产絮菌F+的24 h吸附率高于颗粒活性碳载体;使用菌丝球固定化发酵时,固液比1.0 g/L,发酵时间24 h,粗提生物絮凝剂2.234 g/L,比传统分批发酵生物絮凝剂的产量提高14％.摇瓶试验表明,3种载体均可连续使用15次以上. 从发酵液絮凝率和成本两方面考虑,确定活性碳和菌丝球两种载体的最适固液比均为1 g/L．

Abstract:

To reduce fermentation costs and achieve continuous fermentation of bio-flocculant, the immobilized fermentation to produce bioflocculant was used. The performances of the carriers including activated carbon, pllyurethane foam and mycelial pellets were contrasted by comparing the carrier stability, bio-flocculant production and bio-flocculant activity. The solid-liquid ratio of activated carbon and mycelial pellets were optimized. The results show that the activated carbon, polyurethane foam and mycelial pellets could adsorb bioflocculant-producing bacteria F+ and retain high flocculanting activity for long time. The yields of activated carbon and mycelial pellets were higher than that of polyurethane foam. The adsorption rate of mycelial pellets in 24 h was higher than that of granular activated carbon. Under the optimized conditions (solid-liquid ratio 1.0 g/L; the fermentation time 24 h), the crude bio-flocculant yield of immobilized fermentation by mycelial pellets (2.234 g/L) increased 14％. The shake flask experiments show that the three carriers could produce bioflocculant more than 15 batches. The solid-liquid ration was optimized as 1.0 g/L by considering the flocculation rate and cost.