East China University of Science and Technology, Shanghai, China.
Lett Appl Microbiol. 2011 Feb;52(2):129-37. doi: 10.1111/j.1472-765X.2010.02973.x. Epub 2010 Dec 22.
To overproduce erythromycin C, B or D and evaluate the effect of disruption of tailoring genes eryK and eryG in an industrial erythromycin producer.
The tailoring genes eryG and eryK were inactivated individually or simultaneously by targeted gene disruption in an industrial strain Saccharopolyspora erythraea HL3168 E3, resulting in the overproduction of erythromycin C (2·48 g l(-1) ), B (1·70 g l(-1) ) or D (2·15 g l(-1) ) in the mutant strain QL-G, QL-K or QL-KG, respectively. Analysis of the erythromycin congeners throughout the fermentation indicated that, at the end of fermentation, comparatively large amount of erythromycin D (0·67 g l(-1) ) was accumulated in QL-G, whereas only small amount of erythromycin D (0·10 g l(-1) ) was produced in QL-K.
Inactivation of tailoring genes eryG and eryK in the high producer did not affect the biosynthesis of erythromycin. However, erythromycin D could be more efficiently methylated by EryG than be hydroxylated by EryK.
Development of the mutant strains provides a method for the economical large-scale production of potent lead compounds. The information about the accumulation and conversion of erythromycins in the industrial strains may contribute to further improving erythromycin production.
大量生产红霉素 C、B 或 D，并评估在工业红霉素生产菌中破坏修饰基因 eryK 和 eryG 的效果。
通过靶向基因敲除，分别或同时失活工业菌株糖多孢红霉菌 HL3168 E3 中的修饰基因 eryG 和 eryK，导致突变株 QL-G、QL-K 和 QL-KG 中红霉素 C（2.48 g/L）、B（1.70 g/L）或 D（2.15 g/L）的产量增加。对发酵过程中红霉素同系物的分析表明，在发酵结束时，QL-G 中积累了相对大量的红霉素 D（0.67 g/L），而 QL-K 中仅产生了少量的红霉素 D（0.10 g/L）。
在高产菌中失活修饰基因 eryG 和 eryK 并不影响红霉素的生物合成。然而，EryG 对红霉素 D 的甲基化效率比对 EryK 的羟基化效率更高。
突变株的开发为经济高效地大规模生产有效先导化合物提供了一种方法。关于工业菌株中红霉素积累和转化的信息可能有助于进一步提高红霉素的产量。
