有效利用木糖的肠道细菌的筛选及转化

Screening and Transformation of Enteric Bacteria Utilizing Xylose Efficiently

以木糖为惟一碳源筛选得到了 32株能利用木糖快速生长的肠道细菌 ,初步鉴定结果表明 ,有效利用木糖的菌株多为肺炎克雷伯氏杆菌 ,其次是大肠杆菌 .选择合适的质粒对其中的 94 7菌株、15 6 9菌株及E .coliJM 10 9进行转化 ,检验转化子中的质粒在无选择压力条件下的传代稳定性 ,结果野生型菌株的转化率均明显低于E .coliJM 10 9,质粒 pET 2 8a在所试验的几株菌中稳定性相对较差 ,pKK2 2 3 3能在 94 7菌株中稳定存在 .

Thirty two strains of enteric bacteria were isolated using xylose as sole carbon source. Identification was carried out and the results indicated that most of these strains were Klebsiella pneumoniae and then Escherichia coli . Appropriate plasmids were selected to transform 947, 1569 and E.coli JM109 strains. Plasmid stability of the transformants without selective pressure was also tested. The results indicated that transformation ratio of the wild type strains was much lower than that of E.coli JM109. Plasmid pET 28a was relatively easier to be lost in the test strains while pKK223 3 was very stable in strain 947.