AGGLUTINATION RESPONSE OF PSEUDOMONAS-FLUORESCENS AND TRICHODERMA-HARZIANUM TO MACROPHOMINA-PHASEOLINA UNDER DIFFERENT GROWTH-CONDITIONS

Agglutination of cells of Pseudomonas fluorescens and conidia of Trich oderma harzianum with Macrophomina phaseolina agglutinin and the influ ence of media constituents, pH and temperature on agglutination was st udied. Maximum agglutination of cells/conidia was recorded when synthe tic media were supplemented with glucose or fructose as the carbon sou rce, and histidine, leucine, proline and phenylalanine or ammonium nit rate as the nitrogen source. The cells/conidia of P. fluorescens and T . harzianum did not agglutinate up to 4 mg ml(-1) glucose concentratio n. Maximum agglutination (62%) was recorded with the crude agglutinin obtained from the media supplemented with 9 mg ml(-1) glucose. A posit ive correlation (P = 0.05, r = 0.89-0.92) was obtained between aggluti nation of cells/conidia with agglutinin obtained from the media contai ning different concentration of glucose. Mineral salts such as FeSO4 a nd ZnSO4 showed significant (P = 0.05) increase in agglutination at a concentration of 2 mu g ml(-1). Release of agglutinin component of M, phaseolina was greatly influenced by temperature, pH of media and age of the culture. The agglutination of cells/conidia was maximum in the crude agglutinin of M. phaseolina obtained from the cultures grown at pH 6 to 6.5 at 30 degrees C. Maximum agglutinin activity was recorded from 6-days old (log phase) cultures filtrates of M. phaseolina.