可产酸快生小菌的分离鉴定

目的：鉴定在实验过程中分离到的一株生长快速,并且可以将L-山梨糖转化为2-酮基-L-古龙酸的菌株。方法：将快生小菌传代,并进行产酸、抗菌谱、山梨糖脱氢酶活性等分析,通过PCR方法扩增并分析16S rDNA。结果：在传代过程中还分离得到了不产酸菌株;从快生小菌中扩增得到了普通酮古龙酸菌16S rDNA;从产酸菌中能够扩增得到包含酮古龙酸菌和乙酸钙不动杆菌的16S rDNA序列;在不产酸菌中只检测到乙酸钙不动杆菌的16S rDNA序列。结论：产酸的快生小菌可能是普通酮古龙酸菌和乙酸钙不动杆菌形成的融合细胞,这种融合细胞基因组表现为很不稳定,普通酮古龙酸菌基因组容易丢失,且丢失后也失去了产酸能力。

Isolation and Identification of Fast Growing Ketogulonigenium-Like Stains

Objective：To isolate and identify fast growing Ketogulonigenium-like strains which are able to convert sorbose to KGA. Methods： From the culture of the fast growing Ketogulonigenium-like strains, some stains which can not produce KGA were isolated. To investigate the characteritics of the two types of strains by comparing their KGA production, sensitivity to antibiotics and sorbose dehydrogenase activity. To amplify and analyze the 16S rDNA of the strains by PCR method. Results： The sequences of the 16S rDNA were obtained and sequenced. Two kinds of 16S rDNA sequences were obtained from the KGA producing, one identical to that from Ketogulonigenium strain, another identical to that of Acinetobacter strain. Conclusion： The fast growing Ketogulonigenium-like strain is possibly a fusion cell of Ketogulonigenium and Acinetobacter. The fusion cell is unstable and the Ketogulonigenium genome can get lost easily to form Acinetobacter cells.