一株高产糖化酶生产菌的筛选与鉴定

Screening and Identification of a High-yield Glucoamylase Bacteria

从吉林某豆制品加工厂污水排放口处的土样中,采用稀释平板法从中分离筛选得到一株高产糖化酶菌株ZWL-1(18SrDNA基因的GenBank登录号:KC433410)。在进行形态观察的基础上,结合18S rDNA序列分析并建立系统发育树进一步对该菌进行了种类鉴定。18S rDNA序列分析表明,菌株ZWL-1与黑曲霉(Aspergillus niger)的18S rDNA的同源性均在99.0%以上;从构建的系统进化树中可以看出,ZWL-1与Aspergillussp.LQ21共同构成一个分支,并与黑曲霉(Aspergillus nigerstrain CS1-1)聚成一大支,最终确定该菌株为黑曲霉。

An high-yield glucoamylase bacterial strain of ZWL-1 （ GenBank accession number of the 18S rDNA gene ： KC433410 ） used dilution plate method was isolated from a soy processing plant in Jilin sewage outfall at soil samples . The species identification was made on it, on the basis of morphological observation and through 18S rDNA sequence analysis further to the bacterial strain. The 18S rDNA sequence shows that the homology of this bacterial strain and thel8S rDNA of Aspergillus niger was above 99.0%. As shown in the phylogenetic tree, strain ZWL-1 and Aspergillus sp. LQ21 constituted a branch and they constituted a high-order branch together with Aspergillus niger strain.CSl-1. Thus, the primary identification proved that this bacterial strain is Aspergillus niger.