以乳糖为唯一碳源,X-gal为显色剂,从变质的牛奶中筛选获得一株低聚半乳糖的产生菌,综合其形态学特征、生理生化特征及18S rDNA序列同源分析结果,将其鉴定成为斜卧青霉(Penicillium decumberns).通过正交试验,对菌株生产低聚半乳糖的培养条件进行优化.研究了pH值、温度、乳糖浓度、发酵时间等因素对该菌株全细胞以乳糖为唯一碳源生成低聚半乳糖的影响,最优化反应的转糖基产物经TLC、HPLC分析,确定该菌株具有生产低聚半乳糖的能力.

Use lactose as the only carbon source,the X-gal as colo r agent,a strain of mucedine producing galacto-oligosaccharides,which was screened from spoiled milk,was identified as Penicillium decumberns by its morphological characteristics,physiological and biochemical characteristics and the result of 18s rDNA sequence.The culture condition of the stain producing galacto-oligosaccharides was optimized by orthogonal test.The effect of pH value,temperature,the concentration of lactose and fermentation time on the galacto-oligosaccharides production of the whole cell strain was studied,using lactose as the only carbon source.It was determined that this strain has the ability of producing galacto-oligosaccharides by analyzing the galactosylation production of the optimization reaction with TLC and HPLC.