PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERISTICS OF FAST- AND SLOW-GROWING RHIZOBIUM SP PIGEONPEA (CAJANUS CAJAN)

Thirty-two of 38 cultures isolated from the nodules of pigeonpea plants were rapid growers. The generation time of rapid growers varied from 0.71 to 1.31 h and slow growers from 7.7 to 9.9 h. Rapid growers oxidized pentoses, hexoses, polyhydric alcohols (except dulcitol), tricarboxylic acid cycle intermediates (except citrate) and disaccharides more rapidly than slow growers; disaccharides were not oxidized by any of the slow growers. The Embden-Meyerhof-Parnas and Entner-Doudoroff pathways and the tricarboxylic acid cycle were present in both rapid and slow growers, whereas the pentose-phosphate pathway was present only in rapid growers.