Ever since the discovery of the first Bacillus thuringiensis strain capable of killing mosquito larvae, namely, B. thuringiensis var israelensis, there are several reports from different parts of the world about the occurrence of mosquitocidal strains belonging to different subspecies/serotypes numbering thirty-six. The main sources of these wild type strains are soils/sediments, plants, animal...

Bacillus thuringiensis subsp. tenebrionis DSM-2803 has been studied extensively and spore/crystal mixtures of this strain are used widely in commercial products to control coleopteran pests. The endochitinase chiA Btt gene of B. thuringiensis subsp. tenebrionis DSM-2803 was cloned and expressed in Escherichia coli. The recombinant 6x-histidine tagged protein (rChiA Btt, ~74 kDa), was purified b...

A total of 128 Bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in Denmark were characterized. Of these strains, 39% (50/128) were classified as Bacillus thuringiensis on the basis of their content of cry genes determined by PCR or crystal proteins visualized by microscopy. Random amplified polymorphic DNA analysis and plasmid profiling indicated t...

J. Econ. Entomol. 88(5): 1113-1119 (1995) ABSTRACT Field and laboratory tests were done to determine effects of application technology, plant age, Bacillus thuringiensis (Berliner) subspecies, and rate of application on mortality of 2 populations of diamondback moth, Plutella xylostella (L.). One population was susceptible (Geneva 88) and the other (Loxa b) was resistant to Bacillus tlwringiens...

Bacillus thuringiensis serovar medellin strain 163-131 and Bacillus thuringiensis serovar jegathesan (B.t.jeg.) strain 367 are very toxic to mosquito larvae. However, they are 10 times less toxic than Bacillus thuringiensis var. israelensis (B.t.i.) to mosquito larvae under laboratory conditions. Lyophilized powders were produced from these strains and their toxicities were compared to that of ...

We report here the 6,512,057-bp draft genome sequence of Bacillus thuringiensis subsp. aizawai HD133. This strain contains at least 6 cry genes and 13 candidate biosynthetic gene clusters.

The effect of sunlight on the efficacy and persistence of an experimental tablet formulation based on Bacillus thuringiensis sorovar. israelensis (C4P1) was evaluated against Aedes aegypti larvae under simulated field conditions. The initial mortality ranged from 93 to 100%, and the residual activity (> or = 70% mortality) recorded in containers exposed to sunlight or shade were, respectively, ...

Using the shuttle vector pBU4, the mosquitocidal toxin gene mtx1 from Bacillus sphaericus strain SSII-1 was introduced into an acrystalliferous strain of B. thuringiensis both individually and in combination with the accessory protein gene p20 and the cytolytic protein gene cyt1Aa from B. thuringiensis subsp. israelensis. Bioassay results indicated that the recombinants B-pMT4(Mtx1) and B-pMT9(...

Three members of the δ-endotoxin group of toxins expressed by Bacillus thuringiensis subsp. israelensis, Cyt2Ba, Cry4Aa and Cry11A, were individually expressed in recombinant acrystalliferous B. thuringiensis strains for in vitro evaluation of their toxic activities against insect and mammalian cell lines. Both Cry4Aa and Cry11A toxins, activated with either trypsin or Spodoptera frugiperda gas...

Solubilized crystals of Bacillus thuringiensis var. israelensis were 7000 times less toxic to Aedes aegypti larvae than intact crystals, presumably because mosquito larvae are filter feeders and selectively concentrate particles while excluding water and soluble molecules. A procedure is described whereby soluble toxins are adsorbed to 0.8-micrometer latex beads, with retention of toxicity. The...