Screening and Identification of An Antagonistic O157：H7 Actinomycetes and Study of Its Fermentation Medium

Abstract:

The purpose of this paper is to screen actinomycetes to inhabit the growth of O157：H7，and identify them by Morphological and physiological identification ，then optimize the fermentation medium of producing antibacterial substance. The antibacterial ability of the actinomycetes were detected by the method of tube plate detection. We obtained two actinomycete strains AM-8 and AM-10 which restrained O157：H7，and the genus were identified as Streptomyces. In the single factor test，the highest yield of antibacterial substances occured in the medium with corn flour as carbon source，and pep-tone as nitrogen source. After optimization of fermentation medium by response surface method，The optimum fermentation medium of AM-8 was：corn flour 20.10 g/L，peptone 2.00 g/L，K2HPO4 0.50 g/L，MgSO4·7H2O 0.50 g/L，NaCl 5.92 g/L，F2SO4 0.01 g/L，CaCO3 1.89 g/L.