Research on Pectase Secreted by Aspergillus Niger Degumming Kenaf Bast Fiber

In this paper, the aerobic metabolism mechanism of Aspergillus Niger （AS 3.3 50 ）, which is the most suitable bacteria for degumming kenaf fiber, is expounded, and macromolecular structure of pectin is also analyzed. The fracture position of the macromolecular chain of kenaf pectin and its outgrowth structure, affected by Endo-PG and Exo-PG are secreted by AS 3. 350 and explored in molecule scale. The optimal value of degumming parameters are fixed： temperature 34 - 36℃, time 48 - 50 h, pH 6.5 - 7.5. Compared with kenaf fibers obtained by natural method, the ones deguntmed by bio-enzymatic method possess of smoother surface, .better. Separation, less impairment and higher strength with. residual pectin percentage of 14.5 %.     

红麻生物酶脱胶BP神经网络预测模型的构建

针对红麻韧皮纤维生物酶脱胶过程具有的时变、非线性和不确定等特性,提出采用BP神经网络对脱胶过程进行预测建模的方法。根据脱胶实验中采用的多种不同的工艺参数和对应的脱胶效果,通过网络训练误差的横向和纵向的对比分析,选择采用traincgf函数主导的具有5-12-3结构的BP神经网络,成功地构建起脱胶过程的预测模型。     

琼脂扩散法测定罗布麻韧皮中酮类物质的抑菌活性

罗布麻在生物法脱胶方面存在一定困难.主要原因是因为有抑菌物质的存在.对青海罗布麻韧皮中的酮类物质进行了分离提取,用梯度稀释法测定了酮类物质对金黄葡萄球菌的最小抑菌浓度,用琼脂扩散法对金黄葡萄球菌、大肠杆菌、啤酒酵母菌、黑曲霉的抑菌活性进行了研究.结果表明,罗布麻酮类化合物对金黄色葡萄球菌的最小抑菌浓度为1.563 μg·mL-1,浓度为1 g·L-1的罗布麻酮类化合物对金黄色葡萄球菌、大肠杆菌、啤酒酵母菌、黑曲霉的抑菌活性分别为32.835,15.734,21.521,21.322IU·mg-1.从抑菌活性看,罗布麻酮类化合物对革兰氏阳性菌金黄色葡萄球菌有较强的抑制作用,对革兰氏阴性菌黑曲霉的抑制作用较弱.证实罗布麻酮类化合物对细菌和真菌有抑制作用.