Suitability of different growth substrate for mass multiplication of bacterial antagonists.

摘要

Nine substrates viz., clay, farmyard manure + sand, biogas slurry, ecomax fermenta, molasses, neem oil cake, saw dust and wheat bran were evaluated for mass multiplication of bacterial antagonists, Pseudomonas fluorescens and Bacillus cereus isolated from the rhizosphere of tomato crop. Proliferation of the antagonists was enumerated on KB medium and correlated with factors like temperature and pH. Out of nine substrates clay F.Y.M.+sand and ecomax supported maximum growth (100x10s cfu/g) of the antagonist after 72 hr. of incubation at 25+or-10 degrees C followed by molasses (77.5x106 cfu/ml) and biogas slurry (22.50x106 cfu/ml). Similarly the substrate clay (100x106 cfu/g), FYM+sand (95x106 cfu/g) and ecomax (88x106 cfu/g) supported maximum multiplication of the antagonists. Temperature studies revealed that P. fluorescens and B. cereus did not show growth at 20 degrees C after 24 hr. of incubation. However, after 48 hr. the colony count was progressively increased with the rise in temperature and maximum growth occurred at 30 degrees C and decreased at 35 degrees C. Thus maximum proliferation of the bacterial anatagonists occurred at 30 degrees C and 7.5 pH.