Rhizoctonia wilt suppression of brinjal (Solanum melongena L) and plant growth activity by Bacillus BS2.

An antibiotic-producing and hydrogen-cyanide-producing rhizobacteria strain Bacillus BS2 showed a wide range of antifungal activity against many Fusarium sp. and brinjal wilt disease pathogen Rhizoctonia solani. Seed bacterization with the strain BS2 promoted seed germination and plant growth in leguminous plants Phaseolus vulgaris and non-leguminous plants Solanum melongena L, Brassica oleracea var. capitata, B. oleraceae var. gongylodes and Lycopersicon esculentum Mill in terms of relative growth rate, shoot height, root length, total biomass production and total chlorophyll content of leaves. Yield of bacterized plants were increased by 10 to 49% compared to uninoculated control plants. Brinjal sapling raised through seed bacterization by the strain BS2 showed a significantly reduced wilt syndrome of brinjal caused by Rhizoctonia solani. Control of wilt disease by the bacterium was clue to the production of antibiotic-like substances, whereas plant growth-promotion was due to the activity of hydrogen cyanide. Root colonization study confirmed that the introduced bacteria colonized the roots and occupied 23-25% of total aerobic bacteria, which was confirmed using dual antibiotic (nalidixic acid and streptomycin sulphate) resistant mutant strain. The results obtained through this investigation suggested the potentiality of the strain BS2 to be used as a plant growth promoter and suppressor of wilt pathogen.

Response of Java citronella (Cymbopogon winterianus Jowitt) to toxic heavy metal cadmium.

Cadmium at 200 mg kg-1 soil and above concentrations was fatal as growth was inhibited ultimately leading to death of Java citronella (Cymbopogon winterianus Jowitt.). The surviving plants at 50 and 100 mg kg-1 treatments also exhibited pronounced retardation of growth and biomass yield. There was considerable reduction in the level of essential oil in herbage and oil quality deteriorated. Cadmium accumulation profile showed that highest accumulation was in root, followed by stem, leaf sheath and leaf. Very high accumulation in root for higher doses appeared to be the reason for fatality.

Protease from Sporosarcina sp. RRLJ 1.

Protease was isolated from Sporosarcina RRLJ1 which was collected from acid tea (Camellia sinensis) plantations. It showed potential for production of the enzyme for commercial purposes. The study revealed that optimum pH for growth of the organism was 6.5-7 and supplement of casein (1%) in the medium was required for production of protease. Enzyme production and enzyme activity was maximum in 72 hr old broth culture. Maximum activity of the enzyme was found at pH 6.5.