Diversity of Bacillus thuringiensis in the rice field soils of different ecologies in India

Abstract

Diversity of the Bacillus thuringiensis (Bt) in the rice fi eld soils of different ecologies viz. the island (Port Blair), the Himalayan (Srinagar), brackish water (Mahe) and coastal mesophilic (Mangalore) habitats was analyzed by phenotypic characterization of 5, 66, 14 and 54 Bt isolates, respectively. The Bt isolates produced either monotypic (bipyramidal or spherical) or heterotypic (polymorphic-bipyramidal or bipyramidal-rhomboidal) crystals. The organisms were generally resistant to the penicillin group of antibiotics, tolerated 5-12% NaCl and 0.5M Na-acetate. The Bt isolates contained 1-5 plasmids of 0.89-58.61 kbp sizes. The plasmid profi les had no correlation with crystal morphology or salt tolerance of different bacteria. Each soil was inhabited by different types of Bt. Two Bt strains of Mangalore and one strain each of the other places were phenotypically similar. One Bt strain each of Port Blair and Srinagar was different from all other strains.

Population dynamics of soil bacteria in some areas of Midnapore coastal belt, West Bengal, India

“…The determination of soil microbes is based on enumeration of laboratory culture of the isolates and also on 16S rDNA sequence analysis of the microbes (Seckbach 2000; Satyanarayana et al 2005). Various works have been done on soil microbial diversity in different regions of India (Das and Dangar 2007, 2008; Chatterjee et al 2007) but no such work on bacterial diversity has yet been done in the coastal areas of Digha, West Bengal, India. Coastal zone is the transitional zone between the terrestrial land and sea which are indeed unique places in our global geography, so various physical and topological parameters of the coastal areas should be maintainedd and observe periodically (Visalatchi and Raj Chandar 2012).…”

Distribution of <i>cry</i> and <i>cyt</i> Genes among Indigenous <i>Bacillus thuringiensis</i> Isolates with Mosquitocidal Activity

“…The presence of the Cyt toxin synergizes and delays or prevents the development of resistance to Cry toxins by functioning as a Cry-membrane bound receptor [10]. However, information on the diversity and distribution of cry and cyt genes among mosquitocidal B. thuringiensis isolates from southern part of India is negligible [13,14]. Hence, the present study was envisaged to analyze the distribution of the cry and cyt genes of indigenous mosquitocidal B. thuringiensis isolates.…”

INSECTICIDAL PROPERTIES of Bacillus thuringiensis var. israelensis. I. THE ACTIVITY SPECTRUM OF A LARVICIDAL PREPARATION BASED ON INDUSTRIAL STRAIN 7-1/23A

“…Бактерии группы thuringiensis образуют споры, продуцируют кристаллические эндотоксины (7), термостабильный экзотоксин (8), другие белки и соединения с инсектицидными и антифунгальными свойствами (9)(10)(11), а некоторые проявляют ростостимулирующий эффект (12,13). Бактерии B. thuringiensis обнаружены в Европе, Северной Америке, на Ближнем Востоке, Индии, Японии (14)(15)(16). По объемам производства ведущее место отводится препаратам на основе Bt (17)(18)(19), доля которых на рынке биопестицидов превышает 60 %.…”