Expression Of Vitreoscilla Hemoglobin Gene In Streptomyces Venezuelae And Its Effect On Cell Growth And Metabolish

Zuelacmycin is a new agricultural antibiotic which was produced by a strain that isolated from the soil of qinling mountainous areas in shanxi province, China. Through physiological and biochemical ananlysis, the Streptomyces belongs Streptomyces venezuelae var. Qinlingensis. n. Var. Earlier stage studies showed that the zuelacmycin exhibited strong fungicidal activity against pathogenic fungi, but the biological activity material of the fermentation product was very low, and also its further research and development was limited. To improve the antimicrobial activity and antibiotics production of Streptomyces venezuelae var. Qinlingensis. we studied from following two aspects: Firstly, intergeneric genetic transfer system was demonstrated and optimized, and this is the first report to express vhb gene in Streptomyces venezuelae var. Qinlingensis. Secondly, based on this , studied on effect of Vitreoscilla Hemoglobin Gene expression on growth and metabolish of Streptomyces venezuelae var. qinlingensis. n. Var. The main results are as follows:(1)Intergeneric genetic transfer system was based upon plasmid pSET152 and pHZ1358 from Donor E.coli ET12567(pUZ8002) to Streptomyces venezuelae var. Qinlingensis Our data showed that Intergeneric genetic transfer system was demonstrated and optimized. Integrating plasmid pJD100 containing Perm Eand construction gene of vhb, constructed by SOE-PCR, was transformed to ET12567(pUZ8002), and then transfered to Streptomyces venezuelae var. Qinlingensis by conjugation. The integrating expression of vhb gene in Streptomyces venezuelae var. Qinlingensis was verified by PCR and CO binding diference spectrum.(2)Vitreoscilla hemoglobin Gene was expressed in Streptomyces venezuelae var. qinlingensis. n. Var through promoter of erythromycin resistance gene, characteristics of engineered strain and original strain growth and metabolism and metabolism and Zuelaemycin valence were studied in 5L fermenter. The result showed that: in high dissolved oxygen concentrations, the growthrate and ammonia nitrogen expenditure of engineered strain was slightly lower than the original strain, but starch utilization rate was higher than the original strain, Zuelaemycin valence of engineered strain was decreased by 8% than that of original strain; in low dissolved oxygen concentrations, espression of hemoglobin enhanced growth, metabolish and utilization rate of starch, and Zuelaemycin valence of engineered strain was more 45% than that of original strain.