Engineering Streptomyces tenebrarius to synthesize single component of carbamoyl tobramycin.

AIMS

To engineer Streptomyces tenebrarius for producing carbamoyl tobramycin as a main component.

METHODS AND RESULTS

The aprH-M gene fragment (apramycin biosynthetic gene from GenBank) in S. tenebrarius Tt49 was knocked out by genetic engineering to form S. tenebrarius T106 (ΔaprH-M). Compared to the wild-type strain, mutant strain T106 (ΔaprH-M) no longer produced apramycin, while mainly synthesize carbamoyl tobramycin. TLC and HPLC-MS analyses indicated that the mutant strain significantly increased the production of carbamoyl tobramycin.

CONCLUSIONS

The metabolic flow for the apramycin and its analogues biosynthesis was blocked by disrupting the aprH-M gene clusters. The aprH-M gene clusters might be essential for the biosynthesis of apramycin. The mutant strain T106 mainly synthesized carbamoyl tobramycin.

SIGNIFICANCE AND IMPACT OF STUDY

The mutant T106 mainly produces carbamoyl tobramycin without synthesizing apramycin, which will reduce cost of postextraction from fermentation products. Therefore, it has good prospects for industrial application.