MORPHOLOGICAL AND BIOCHEMICAL CHARACTERIZATION OF BACILLUS SUBTILIS ISOLATED FROM RHIZOSPHERE OF SUGARBEET.

Bacillus subtilis is a gram positive, endospore-forming bacteria play a major role in biocontrol and PGPR activities. Eighteen rhizosphere soil samples of healthy sugarbeet plants were collected from sugarbeet crop grown at Amritsar, Punjab (10), Baramati, Maharashtra (6), Lucknow, Uttar Pradesh (1) and Dharwad, Karnataka (1). Soil samples were collected from different spots in each sampling field and pooled them to get a composite soil sample. The pooled samples were placed in sterile polythene bags, labelled, brought to the laboratory of the Department of Plant Pathology, U.A.S., Dharwad, Karnataka, India and stored in a refrigerator at 4°C before using for isolation of bioagents. Rhizosphere soil samples collected from different sugarbeet fields of India were used for isolation of bioagents. With respect to morphological characters, all the B. subtilis isolates were Gram positive and rod-shaped, produced endospores and with respect to colony characters, they were cream to white coloured, circular to irregular shape and having irregular or ragged colony edge. All the B. subtilis isolates produced green coloured colonies on HiCromeTM Bacillus Agar (HIMEDIA) medium. Regarding biochemical characterization, all the isolates showed positive reaction to starch hydrolysis, gelatin liquefaction, casein hydrolysis, VP (Voges-Proskauer) test, citrate test, catalase test, phosphate solubilization and there was no growth of B. subtilis isolates at 55°C temperature. [ABSTRACT FROM AUTHOR]