提高唾液酸分泌量对克雷伯氏菌NIII2高产高活性糖蛋白絮凝剂的影响作用

摘要

探究克雷伯氏菌NIII2发酵产微生物絮凝剂(MBF)过程中提高唾液酸(SA)分泌量对其高产高活性糖蛋白絮凝剂的影响作用.采用摇瓶发酵,产物冻干后称重,利用高岭土悬浊液测定其絮凝活性,并利用酶标仪测定唾液酸量,从而得出相应结果.研究发现在一定范围内,SA分泌量越高,絮凝剂产量及其活性也会越高.当MBF中SA含量约为12 ng/g MBF时,MBF产量约为12 g/L.在SA分泌量提高的同时,MBF中蛋白质含量和Zeta电位值也得到提高.探索出一种能最大程度提高SA分泌量和MBF产量的三碳源发酵体系︰m蔗糖︰m丙酮酸钠︰m柠檬酸钠=20 g︰4 g︰2 g,此时MBF的产量为13.85 g/L,蛋白含量为0.41 g/g MBF,絮凝活性为98%.研究结果为高产高活MBF的发酵以及工业化生产提供了可能.%he Effects of increasing saliva secretion on high yielding and high active glycoprotein during the process of microbio-flocculant (MBF) ferment production by Klebsiella sp. NIII2were studied. The corresponding results were obtained adopting shaking flask fermentation, weighing after freeze drying the product, using kaolin turbid liquid to measure its flocculent activity,and using enzyme-labeled instrument to measure its acid content. It was found through the study that within a certain range,the higher the amount of saliva secretion is,the higher production and flocculant yielding and activity are. When the content of saliva in MBF was about at 12 ng/g MBF,the production of MBF yield-ing was about 12 g/L. The secretion increasing of saliva the protein content in MBF and Zeta potential also increased. It had explored three carbon sources fermentation system that could furthest increase the secretion of saliva and MBF production:m(saccharose):m(sodium pyruvate):m(sodium citrate) =20 g︰4 g︰2 g. Under this circumstance, the production of MBF was 13.85 g/L,protein came to 0.41 g/g MBF and flocculation activity was 98%. The results of this study provided a possibility for high yielding and high active MBF fermentation as well as industrialization pro-duction.