[Study on effect of Vitreoscilla hemoglobin gene expression on growth and metabolism of Streptomyces aureofaciens]

Abstract

Vitreoscilla hemoglobin gene was expressed in S. aureofaciens through promoter of tetracycline resistance gene. Characteristics of S. aureofaciens growth and metabolism were studied in 1 m3 fermenter. In high dissolved oxygen concentrations, expression of hemoglobin gene had little effect on growth and metabolism of S. aureofaciens, and there were no obvious differences between engineering strain and control. The chlortetracycline of engineering strain was 22905 u/mL and of control was 22896 u/mL respectively. Under conditions of low dissolved oxygen, expression of hemoglobin enhanced growth, maintenance of energetic mycelium configuration and chlortetracycline yield of S. aureofaciens: the mycelium concentrations of engineering strain were more about 5%-10% and yield was more 11.4% than control.