Different genera of bacteria and fungi were isolated from the rhizosphere of soybean and clover plants. They were identified and tested for their activity to produce pectinase and cellulase enzymes.
The activity of these enzymes were determined by bioassay tests. The role of these crude enzymes were tested for their effect on the rhizobial invasion into root hairs of legume plants in relation to the incidence of curling root hairs and nodulation on legume roots, also were tested for their effect on the rhizobial biomass. The results revealed that the significantly highest activity of polygalacturonase and pectin-methyl estrase enzymes were produced by isolates of Erwinia sp. From bacteria, while Aspergillus sp. Isolates were the most significant active from fungi in this respect. On the other hand, the isolates of Bacillus and Rhizopus sp. Were significantly lowest in these enzymes activity. The significantly highest cellulase activity was obtained by strains of Pseudomonas and Aspergillus sp., while the isolates of Bacillus and Rhizopus sp. were the lowest in this respect. The addition of these crude enzymes, secreted by soil microflora, to the germinated legume seeds inoculated with specific rhizobia, significantly increased the number of curled root hairs and subsequently the nodule formation. Lower levels of these enzymes stimulated infection by rhizobia more than higher levels, but these crude enzymes had no effect on the rhizobial biomass
N. S. Ghazal ,M. A. Azzazy ,
Assessment of the role of crude pectinolytic and cellulolytic enzymes on the curling of root hairs and nodulation in some legume plants,
Egypt. J. Microbiol. 1994;
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