液体培养基中天然变链素的纯化

目的 从变形链球菌临床株的液体培养基中分离纯化变链素,为进一步从分子水平研究变链素奠定基础.方法 通过抑菌活性检测,从变链临床株中选择出抑菌活性较强的菌株.用氯仿抽提法从该菌株的培养液中粗提变链素,经固相萃取和反相高效液相色谱(RP-HPLC)对粗提物进行纯化.结果 获得变链素活性较强的菌株"1G".从其200 ml液体培养基中粗提出变链素约15 μg,经固相萃取柱洗脱,再经过RP-HPLC 2次纯化,得到有抑菌活性的成分,此为纯化的变链素.结论 变链素分子量小,分离提纯步骤复杂,本实验得到纯化的变链素,为下一步研究变链素的氨基酸序列和基因序列奠定了基础.

Purification of natural mutacin in liquid medium

Objective To separate and purify mutacin produced from liquid medium by Streptococci mutans (S. mutans) strains,and lay a foundation for further molecular biological research of mutacin. Method The antibacteria activity of 80 strains of S. mutans were tested by the stab culture technique against Streptococcus oralis ATCC 10557. The mutacin produced by the strain "1G" was initially purified by SPE(Solid-phase extraction) after crude extraction by chloroform. And then the active substances were purified by RP-HPLC (Reversed-phase high performance liquid chromatography) twice. Then the purified target peptide(mutacin) was collected and freeze-dried for further study. Result Roughly 15 μg of crude mutacin was extracted from 200 ml of liquid medium of the strain "1G". Then the purified mutacin was obtained through SPE and twice RP-HPLC. Conclusion The separation and purification of mutacin has been a complex procedure due to its small molecular mass. This study on the purification of mutacin may contribute to further research of mutacin.