Replacement of glycine by serine at positions 123 and 124 of phenylalanine dehydrogenases from Bacillus badius and Bacillus sphaericus respectively strikingly decreased enzyme activity toward aromatic amino acids and resulted in an elevation of relative activity toward aliphatic amino acids. The mutant from B. badius preferentially dehydrogenated branched-chain amino acids, while that from B. 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 16S rRNA gene sequences for six strains of Bacillus sphaericus representing five distinct DNA homology groups and one strain of Bacillus fusiformis have been determined. An-oligonucleotide probe based on the area approximately between position 186 and 198 (Escherichia coli numbering) of the 16S rRNA gene of the mosquito pathogen, strain 2362, hybridised to DNA from strains of DNA homology g...

Bacillus sphaericus was used to control Culex pipiens breeding in a water treatment settling basin near Montpellier, France. Four treatments with 4 liters/ha (3.6 lb/acre) of commercially available B. sphaericus formulation (Vectolex) reduced the larval population of Cx. pipiens with 50-600 spores of B. sphaericus/ml recorded in the treated portions of the water plant 14 days following the last...

The 2362 strain of Bacillus sphaericus, which produces a binary toxin highly active against Culex mosquitoes, has been developed recently as a commercial larvicide. It is being used currently in operational mosquito control programs in several countries including Brazil, France, India, and the United States. Laboratory studies have shown that mosquitoes can develop resistance to B. sphaericus, ...

Biolarvicides, based on mosquitocidal toxins of certain strains of Bacillus sphaericus and Bacillus thuringiensis var israelensis H-14 (Bti) are highly effective against mosquito larvae at very low doses and safe to other non-target organisms. During past two decades various biolarvicide formulations produced in India and abroad have been tested at Malaria Research Centre and some formulations ...

In the quest for effective control of mosquitoes, attention has turned increasingly to strains of the bacteria Bacillus sphaericus and Bacillus thuringiensis subsp. israelensis, which produce potent toxins with specific mosquitocidal activities. However, sedimentation of the bacterial spores limits the duration of effective control after field application of these bacilli. We describe here the ...

AIMS To present the pairwise comparison of potential mosquito-pathogenic Bacillus strains based on their SDS-PAGE protein patterns and to evaluate their characteristic toxicity patterns. METHODS AND RESULTS In this work, 20 Bacillus strains were subjected to qualitative toxicity tests against Aedes aegypti and Culex quinquefasciatus larvae. The selected strains were then characterized by SDS-...

The microbial control agents Bacillus thuringiensis (H-14) and B. sphaericus were evaluated in laboratory and field against Psorophora columbiae. Bacillus sphaericus strain 2362 was also tested in the field against Aedes melanimon. Psorophora columbiae was slightly more susceptible than Culex quinquefasciatus to active strains of B. sphaericus. The LC90 for active strains ranged from 0.013 to 0...

A simple chemically defined medium containing sodium acetate (37 or 74 mM) as the only major source of carbon was inoculated with soil from various locations. The bacteria which grew most rapidly at 30 degrees C were almost entirely strains of Bacillus sphaericus and Arthrobacter species. Pasteurization of the soils made the medium selective for B. sphaericus. Several new strains were isolated,...