菌株CZZX16的多相分类鉴定及其紫外线诱变选育

Polyphasic Taxonomy and Identification for Strain CZZX16 and Its Mutagenesis Breeding by UV

以多年生凤丹牡丹营养器官为材料,通过以糯米粉和普鲁兰糖为唯一碳源的初筛分离培养和鉴别培养,获得一株具有产普鲁兰酶活性菌株,将其编号为CZZX16。采用DNS法对菌株CZZX16的初始产普鲁兰糖活性进行了初步评估,37℃发酵培养30 h时酶活性最高达到2.3 U/mL,因而确定CZZX16具有产普鲁兰酶活性。综合目标菌株的显微观察特征、生化测定特征和16S r RNA序列的克隆分析结果,对菌株CZZX16进行了多相分类鉴定,将其确定为克雷伯氏菌属一种Klebsiella sp.,暂命名为Klebsiella sp.CZZX16。为挖掘菌株CZZX16的产普鲁兰酶活性潜力,对其进行了紫外线诱变选育,筛选得到产酶活性较高的突变株CZZX16-2,37℃发酵培养30 h时其产酶活性最高达到7.8 U/mL,是出发菌株CZZX16的2.21倍。因此,CZZX16可作为产油牡丹专用菌肥开发的良好备选菌株。

Take the vegetative organs of perennial Fengdan peony as materials, a strain with pullulanase activity was obtained with glutinous rice flour and pullulan as the sole carbon source for the screening and isolation of differential culture, and its number was CZZX16. The initial production of pullulan activity of CZZX16 strain was preliminarily evaluated by using the method of DNS, and the enzyme activity reached 2.3 U/mL when the fermentation condition of 37℃ and 30 h, thus the CZZX16 had pullulanase producing activity. The strain CZZX16 was identified by integrating microscopic morphological characteristics, biochemical index determination and the analysis results of 16 S rRNA conserved sequence, CZZX16 was defined as Klebsiella genus Klebsiella sp., and named as Klebsiella sp. CZZX16. In order to explore the potential of pullulanase producing activity of strain CZZX16, the study has carried on the UV mutagenesis breeding, the mutant strain CZZX16-2 with high enzyme activity was obtained, and the highest enzyme activity reached 7.8 U/mL when the fermentation condition of 37℃and 30 h, which was 2.21 times that of CZZX16. Therefore, CZZX16 might be used as a good alternative bacteria strain of special fertilizer development for oil peony.