米根霉直接发酵小麦淀粉废水生产L(+)-乳酸研究  

Direct fermentation of wheat starch wastewater to produce L(+)-lactic acid by Rhizopus oryzae

作　　者：韩玉婕 呼世斌[1] 贾婵[1] 张春慧[1] 王效国[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《西北农林科技大学学报（自然科学版）》2015年第4期149-156,共8页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家"863"计划项目(2012AA101404)

摘　　要：【目的】研究利用米根霉(Rhizopus oryzae)As3.866直接发酵小麦淀粉废水生产L(+)-乳酸的最佳条件,为小麦淀粉废水资源化利用提供参考。【方法】以米根霉As3.866为供试菌种,以小麦淀粉废水为发酵培养基直接发酵生产L(+)-乳酸,通过摇瓶发酵培养,依次研究米根霉种龄、接种量、装液量、转速、温度、pH、中和剂种类、CaCO3添加量及添加时间对L(+)-乳酸质量浓度以及米根霉菌丝体生物量和生长状况的影响,确定最佳发酵条件,并在此基础上考察发酵后废水中COD的去除效果。【结果】得到利用米根霉直接发酵小麦淀粉废水的最佳发酵条件:米根霉种龄为18h,接种量为10%,装液量为20%,温度为26℃,pH为5.5,转速为170r/min,发酵8h后添加10g/L的CaCO3,发酵周期为52h。【结论】获得了利用米根霉直接发酵小麦淀粉废水生产L(+)-乳酸的最佳发酵条件,在该条件下,L(+)-乳酸质量浓度可达15.28g/L,废水中COD的去除率达85%。【Objective】This research studied the optimal fermentation conditions for direct fermentation of wheat starch wastewater to produce L(+)-lactic acid by Rhizopus oryzae.This would provide reference for utilization of wheat starch wastewater resource.【Method】Rhizopus oryzae As3.866 was selected to produce L(+)-lactic acid using starch wastewater as fermentation medium.By liquid flask fermentation,effects of seed age,seed culturing amount,working volume,agitation speed,temperature,pH value,neutralizing agent,as well as amount and time of CaCO3 addition on concentration and biomass of L(+)-lactic acid were studied.Then the optimum fermentation conditions were determined and COD removal efficiency in wastewater was evaluated.【Result】The optimum fermentation conditions of flask fermentation were:seed age of R.oryzae 18 h,seed culturing amount 10%,working volume 20%,pH 5.5,agitation speed 170r/min,addition of 10g/L CaCO3 after 8h,and fermentation period 52 hours.【Conclusion】Under the obtained optimum fermentation conditions,the concentration of L(+)-lactic acid produced by R.arrhizus As3.866 was 15.28g/L and removal efficiency of COD reached 85%.

关 键 词：L(+)-乳酸 米根霉 小麦淀粉废水 发酵条件 

分 类 号：X792[环境科学与工程—环境工程]