Effect of solvents to maximize the extraction of Crude antibiotics of Bacillus spp. and their influence on Meloidogyne incognita and Fusarium oxysporum f.sp. lycopersici

摘要

Different polar and nonpolar solvents viz., ethyl acetate, methanol, chloroform, petroleum ether and hexane were tried for the extraction of crude antibiotics of indigenous endophytic isolates of Bacillus weihenstephanensis (TS B4), B. cereus (CL B2D), B.subtilis (TS B5), B. cereus (TS B4D) and B. licheniformis (TS B3) and to study their inhibitory effect over Meloidogyne incognita and Fusarium oxysporum f.sp. lycopersici. The results indicated that all the five solvents were effective to maximize the yield of crude antibiotics of above five isolates of Bacillus spp. Further, there was increase in their nematicidal/fungicidal activities with increase in the concentration from 25 to 100% but it was gradually decreased as the period of exposure increased from 24 to 120 hrs invariably with all the five isolates. Among the solvents, ethyl acetate was observed as the most effective-solvent in this regard. In respect to Bacillus spp. :he ethyl acetate extract of crude antibiotics of B. weihenstephanensiswas found as the; most effective one to inhibit egg hatching and to cause mortality of M. incognita J2 and to exert antifungal effect over Fusarium oxysporum i.sp.lycopersici.