稀酸水解玉米芯制备丁二酸

利用正交设计得到稀H2SO4水解玉米芯制备混合糖液的优化工艺:玉米芯料液比1∶5(质量体积比),物料粒径250~380μm、H2SO4用量3%(体积分数)、水解温度126℃、反应时间2.5 h。此工艺条件下的总糖收率达90%,总糖质量浓度为60 g/L,发酵抑制物糠醛含量为0.87 g/L,5-羟甲基糠醛含量为0.68 g/L。在此基础上利用活性炭吸附和Ca(OH)2中和对玉米芯混合糖液进行脱毒及脱盐处理,SO42-脱除率达96%,色素脱除率为96%,糠醛、5-羟甲基糠醛及多酚类物质脱除率均高于50%。处理后的玉米芯多组分糖液作为产琥珀酸放线杆菌(Actinobacillus succino-genes)NJ113的发酵C源,当培养基中初始总糖质量浓度为50 g/L时,丁二酸收率为61.68%,丁二酸质量浓度为30.8 g/L;初始总糖质量浓度为70 g/L时,丁二酸收率仍可达50%以上,丁二酸质量浓度为35.2 g/L。发酵实验表明,将经过脱毒脱盐处理的玉米芯多组分糖液替代葡萄糖作为C源发酵制备丁二酸具有可行性。

Preparation of saccharification liquid for succinic acid by fermentation from corncob sulfuric acid hydrolysis

The techniques of saccharification liquid preparation from corncobs were studied by dilute sulfuric acid hydrolysis.The parameter optimization for the hydrolysis was determined by orthogonal experiments： the ratio of material to liquor 1∶5（W/V）,diameter 40~60 meshes,sulfuric acid dosage 3%（V/V）,hydrolysis temperature 126 ℃,and reaction time 2.5 h.The yield of the total sugar was 90%,the concentration of the total sugar was 60 g/L,the furfurol concentration was 0.87 g/L,and the concentration of 5-hydroxymethyl furfural was 0.68 g/L.The saccharification liquid from corncobs was detoxified by the active carbon and desalted by the calcium hydroxide,the desalination ratio of the sulfate was 96%,decoloration ratio was 96%,more than 50% of furfurol,5-hydroxymethyl furfural and polyphenol compounds were removed.The saccharification liquid after refinement was consumed by Actinobacillus succinogenes NJ113.When total sugar concentration was 50 g/L in medium,the final succinic acid concentration of 30.8 g/L was obtained,resulting in a succinic acid yield of 61.68%.When total sugar concentration was 70 g/L in medium,the succinic acid concentration was 35.2 g/L,and the yield was more than 50%.The saccharification liquid from corncobs after detoxification and desalination was the substitution of glucose as the carbon source was used for the succinic acid production by the anaerobic fermentation.