Allan. A. Yousten

Learn More
Bacillus thuringiensis serovar, thuringiensis (HD-2) demonstrated antibacterial activity against 48 of 56 strains of B. thuringiensis and against some other Gram-positive species but not against Gram-negative species. The antibacterial activity was not inducible by mitomycin C or by ultraviolet irradiation, and additional activity was not liberated from(More)
Using the vector pGEM-4-blue, a 4,251-base-pair DNA fragment containing the gene for the surface (S)-layer protein of Bacillus sphaericus 2362 was cloned into Escherichia coli. Determination of the nucleotide sequence indicated an open reading frame (ORF) coding for a protein of 1,176 amino acids with a molecular size of 125 kilodaltons (kDa). A protein of(More)
The protein surface layers on the cell walls of mosquito-pathogenic and nonpathogenic Bacillus sphaericus strains were studied by structural, biochemical, and serological methods. The surface structure of two representative insect-pathogenic strains had the form of a delicate linear array with a repeat interval of 5 nm. This was distinctly different from(More)
Almost complete 16S rRNA gene sequences were generated for the type strains of the obligate insect pathogens Bacillus lentimorbus and Bacillus popilliae and a second strain of Bacillus popilliae (NRRL B-4081) received as 'Bacillus popilliae var. melolonthae'. A phylogenetic tree was constructed which grouped these strains into a well defined subcluster(More)
Bacillus sphaericus 2362 is pathogenic for mosquito larvae and is being considered for large-scale production as a larvicide. The inability of the bacteria to metabolize carbohydrates requires that they be grown on proteinaceous media. This bacterium was found to be unable to transport glucose or sucrose into the cell, and it lacked glucokinase and(More)
Using larvae of the mosquito Culex pipiens var. quinquefasciatus as a bioassay system, we have verified an earlier proposal that pathogenicity of Bacillus sphaericus SSII-1 is a toxin-mediated rather than an infectious process. Chloroform or ultraviolet-light treatments that decreased the viable count of SSII-1 cells by 4 or 5 logs did not significantly(More)
A selective medium (BATS), which contains arginine as the sole carbon and nitrogen source and which also contains streptomycin, allowed growth of 18 mosquito-pathogenic strains of Bacillus sphaericus. It inhibited the growth of 68% of the nonpathogenic B. sphaericus strains tested as well as other Bacillus spp. and aquatic bacteria.
Bacillus sphaericus 2297, growing from a boiled, relatively nontoxic spore inoculum, increased about 30-fold in toxicity for mosquito larvae during early exponential growth but showed an approximately 1,000-fold toxicity increase during the late-exponential phase, as spores began to appear in the culture. The development of spores in the bacterial cells was(More)
Elimination of Bacillus sphaericus spores ingested by midge larvae, snails, and oysters was most rapid among midge larvae. Spores remained in oysters up to 21 days and in snails up to 49 days. Viable spores were recovered in snail and oyster feces for these same periods. There was no indication of actively growing B. sphaericus in the animals. Passage(More)
Eleven bacteriophages were isolated using mosquito pathogenic strains of B. sphaericus as hosts. The phage morphology and host range on five DNA homology groups including 16 mosquito pathogenic and 32 non-pathogenic strains were determined. the same bacterial strains were studied serologically for their flagellar agglutination by antisera representing eight(More)