Some parts of the Indian Himalayan region are covered by established and abandoned tea bushes.
Rhizospheric soils of these plants were studied for bacterial dominance and antagonism. Amongst bacteria, Bacillus
(up to 45%) and Pseudomonas
(up to 85%) were found to dominate the rhizosphere of established and abandoned tea
bushes, respectively. Amongst the species, B. subtilis
and B. mycoides
appeared to be closely associated with roots of
established tea bushes, and the rhizosphere of abandoned tea bushes was dominated by Pseudomonas putida. Four
bacterial strains each of B. subtilis
and P. putida
were selected on the basis of maximum antibacterial activity.
Incubation of indicator strains with different concentrations of bacteriocin exhibited bactericidal activity. Various
species of Bacillus
behaved antagonistically amongst themselves due to the production of
bacteriocins under in vitro conditions.