Crystals in Bacillus thuringiensis are usually formed in the mother cell compartment during sporulation and are separated from the spores after mother cell lysis. In a few strains, crystals are produced inside the exosporium and are associated with the spores after sporulation. This special phenotype, named 'spore crystal association' (SCA), typically occurs in B. thuringiensis subsp. finitimus...

Bacillus thuringiensis is the most effective microbial control agent for controlling numerous species from different insect orders. The main threat for the long term use of B. thuringiensis in pest control is the ability of insects to develop resistance. Thus, the identification of insect genes involved in conferring resistance is of paramount importance. A colony of Spodoptera exigua (Lepidopt...

In this study, we present the selection and the characterization of Bacillus thuringiensis (Bt) strains with respect to their cry/cyt gene content and toxicity evaluation toward one of the most important polyphagous lepidopteran pest, Helicoverpa armigera. Fifty-six Bt isolates were obtained from 10 different regions of northwestern Himalayas, recording a total B. thuringiensis index of 0.62. S...

Integrative plasmids were constructed to enable integration of foreign DNA into the chromosome of Bacillus sphaericus 2297 by in vivo recombination. Integration of the aphA3 kanamycin resistance gene by a two-step procedure demonstrated that this strategy was applicable with antibiotic resistance selection. Hybridization experiments evidenced two copies of the operon encoding the binary toxin f...

The Bacillus cereus group includes eight species: anthracis, B. cereus, cytotoxicus, mycoides, pseudomycoides, thuringiensis, weihenstephanensis and toyonensis, which are highly related at the phylogenetic level. In this work, we performed isolation characterization of a novel sp. strain exhibiting parasporal crystals with insecticidal activity that was initially classified as thuringiensis str...

Bacillus thuringiensis was isolated from 36 of 50 residue samples obtained from an animal feed mill (a stored-product environment). Of 710 selected colonies having Bacillus cereus-B. thuringiensis morphology isolated from the samples, 477 were classified as B. thuringiensis because of production of parasporal delta-endotoxin crystals. There was a diverse population of B. thuringiensis, as revea...

Caenopores are antimicrobial and pore-forming polypeptides in Caenorhabditis elegans belonging to the saposin-like protein superfamily and are considered important elements of the nematode's intestinal immune system. In the present study, we demonstrate that, unlike the other members of the multifarious gene family (spps) coding for caenopores, spp-12 is expressed exclusively in two pharyngeal ...

Resistance to the microbial insecticide Bacillus thuringiensis Berliner has evolved in field populations of diamondback moth, Plutella xylostella (L.), in Hawaii. Three field populations that had been treated repeatedly with commercial formulations of the sporecrystal protein complex of B. thuringiensis subsp. kurstaki developed significant resistance to it. The LC50 of the most resistant popul...

Bacillus thuringiensis is the most widely used bacterial bio-insecticide, and most insecticidal crystal protein-coding genes are located on plasmids. Most strains of B. thuringiensis harbor numerous diverse plasmids, although the plasmid copy numbers (PCNs) of all native plasmids in this host and the corresponding total plasmid DNA amount remains unknown. In this study, we determined the PCNs o...

The two predominant polypeptides of the Bacillus thuringiensis subsp. thompsoni crystal are encoded by the cry40 and cry34 genes. These crystal protein genes are located in an operon. Western analysis (immunoblotting) demonstrated that the operon promoter activity was located in the region upstream of the cry40 gene. The Cry34 protein was expressed only when the upstream promoter region was pre...