木薯淀粉废水培养复合微生物絮凝剂产生菌的营养条件优化

研究开发新型复合微生物絮凝剂及木薯淀粉废水资源化利用新途径。从厌氧废水中筛选出两株对木薯淀粉废水具有高絮凝活性的乳酸菌LB3、LB5,经16S r DNA基因序列分析鉴定分别为干酪乳杆菌(Lactobacillus casei)和植物乳杆菌(Lactobacillus plantarum)。通过单因素实验表明,木薯淀粉废水培养复合菌体产絮凝剂的最佳营养条件为:在不添加磷酸二氢钾原浓度木薯淀粉废水中,采用葡萄糖为废水培养基的补充碳源,酵母膏和蛋白胨作为复配氮源按1∶2配比添加,其补充碳氮总量为4.5%,碳氮比值为1.5。在该条件下,发酵液对淀粉废水和高岭土悬液的絮凝率最高可达89.2%和91.4%。 

Culture of complex bioflocculant-producing strains and optimization of its nutritional conditions by using cassava starch wastewater

A new style of combined microbial flocculant and a new way for cassava starch wastewater reutilization were proposed. Two lactic acid bacterial strains LB3 and LB5 which could produce bioflocculant with high flocculating to cassava starch wastewater were screened from anaerobic wastewater. 16 S r DNA gene sequence analysis showed that the two strains could be identified as Lactobacillus casei and Lactobacillus plantarum respectively. The nutritional conditions which combined strains fermented cassava starch wastewater to produce bioflocculant were optimized through single factor test. The optimization nutritional compositions were :raw concentration cassava starch wastewater without adding KH_2PO_4,with glucose as the optimal carbon source in wastewater culture medium,combined nitrogen source of yeast extract and peptone by 1∶2,4.5% of total carbon and nitrogen amount with C/N ratio of 1.5. With the condition above,the flocculation rate of fermentation broth to starch wastewater and Kaolin clay suspension was found to be 89.2% and 91.4% respectively.