拟通过根霉菌发酵小麦麸皮纤维质实现其高效生物转化制备富马酸的目标。在单因素试验研究基础上,对发酵工艺进行响应曲面法优化,并开展代谢机理初步探索。通过单因素试验确定了酵母浸粉、硫酸镁及硫酸锰质量浓度为主要影响因素,响应曲面研究结果显示:当发酵水解液总糖浓度80.Og/L、硫酸铵2.00g/L、酵母浸粉0.29g/L、硫酸镁0.26g/L、硫酸锰0.07g/L、硫酸亚铁0.05g/L时,富马酸产量最高,其值为27.423g/L。对戴尔根霉RhizopusdelemorCLCC41341的木糖代谢途径的初步分析结果表明木酮糖激酶为该菌株木糖代谢的关键限速酶。论文研究结果可为纤维质糖液工业发酵制备平台有机酸提供一定支持。
The aim of this study was to produce fumaric acid through wheat bran cellulose fermentation by Rhizopus species in order to achieve highly efficient biological transformation. On the basis of single factor experiments method, we optimized the fermentation technology by response surface, and preliminarily studied the metabolic mechanism of the strain. Results from single factor experiments showed that the yeast extract powder, magnesium sulfate and manganous sulfate were determined to have significant effects. The response surface results were as follows: the tota sugars in the hydrolyzates, the (NH4)2S04, the yeast extract powder, MgSO4.7H20, MnSO4.H20 and FeSO4.7H20 were 80.Og/L, 2.00g/L, 0.29g/L, 0.26g/L, O.07g/L and O.05g/L respectively. Under such conditions, the production of fumaric acid was 27.485g/L The preliminary analysis result from the xylose metabolic pathway of Rhizopus delemar CICC41341 ndicated that the xylulokinase was the key enzyme for the xylose metabolism of this strain. We could draw the following conclusion that our research provided some supports for the industrial organic acid production through cellulosic sugar solution fermentation.