STUDIES ON FERMENTATION CONDITIONS OF STRAIN 20#-5 OF PSEUDOMONAS SP.

A recently isolated strain of Pseudomonas sp., 20#-5, was found to produce active substances that are resistant to many bacteria and pathogenic fungi. In the present study, the proper compositions of its culture medium (C and N sources) and technological conditions (temperature, pH and others) for its fermentation were investigated. Single factor experiments and orthogonal experiment showed that the optimum composition for the fermentation medium was wheat bran 3% + soybean meal powder 2% + Na2HPO4·12H2O 0.05% + MgSO4·7H2O 0.1% and that the optimum temperature was 30℃ and the optimum pH 9.0. Under the optimal conditions, the microbe-inhibiting circle was 1.5 cm in diameter. The favorable temperature for the growth of the strain and its initial pH were 28～32℃ and 7.0～9.0, respectively.