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At least 685 records · Page 38Linked to original sources
PubMed2006

[The role of the promoter structure in the efficiency of the expression of guanylspecific ribonucleases from Bacillus intermedius and Bacillus pumilus].

Guanylspecific ribonucleases from B. intermedius (binase) and B.pumilus (RNase Bpu) are structural and functional homologues, and their biosynthesis is subjected to the same laws. At the same time, there are essential differences in the expression efficiency of binase and RNase Bpu genes. This was first suggested to be due to differences in nucleotide sequences of promoters of the genes. Therefore, we constructed plasmids changing each different nucleotide in binase promoter for corresponding one from RNase Bpu and vise versa. It was found that the difference in RNase Bpu and binase expression was due to the only nucleotide in RNase Bpu promoter.

Bacillus↗
PubMed1991

Compatibility of Bacillus thuringiensis var. Israelensis and Bacillus sphaericus with the fungal pathogen Lagenidium giganteum (Oomycetes: Lagenidiales).

Larvae of Culex quinquefasciatus were exposed to infection by Lagenidium giganteum and various concentrations of B.t.i. or B. sphaericus. The resulting larval mortalities, percentages of infected dead larvae and percentages of larval body regions containing the fungus were compared. Overall, the effectiveness of Lagenidum giganteum against the larvae was not significantly affected by the presence of B.t.i. or B. sphaericus, and the fungal and bacterial agents were compatible. In experiments using 3-day-old larvae, the extent of growth of the fungus in the infected larvae and the percentage of the larvae infected were related to the concentration of B.t.i. in the range of 0.057-0.456 ITU/ml tested but were not related to the concentration of B. sphaericus in the range of 0.6-4.8 x 10(4) spores/ml. With larvae of various ages treated with a low concentration of B.t.i. (0.114 ITU/ml), exposure to the fungus increased the mortality rate in early but not late instars. After single and multiple applications of B.t.i. and B. sphaericus in the presence of the fungus, followed by drying and reflooding, the fungus persisted and reinfected larvae while the B. sphaericus persisted but the B.t.i. did not.

Animals↗
PubMed1991

[Molecular cloning of alpha-amylase gene from Bacillus megaterium and its expression in Bacillus subtilis].

Using Bacteriophage lambda and plasmid pAT153 and pNQ122 as vectors, alpha-Amylase gene from B. megaterium has been cloned into both hosts of E. coli and B. subtilis. Expression level of the gene is 250 times higher than B. megaterium when it resides in B. subtilis. The enzyme produced by B. subtilis harboring the hybrid plasmid can digest amylase into maltose and maltotriose at first, then turn them to maltose and glucose, as incubation time extended. It also can digest maltotriose to maltose and glucose. As a control, the extracts from the broth of recipient strain have no detectable amylase activities. Therefore the enzyme coded by this gene is defined as saccharifying type alpha-amylase. Its molecular weight is about 58,000 daltons.

Bacillus megaterium↗
PubMedDate not supplied

[Cloning and expression in Bacillus subtilis of the gene for neutral protease of Bacillus brevis].

Plasmids pCB20 and pCB22 were used for cloning and expression of the Bac brevis 7882 neutral protease gene in Bac. subtilis cells. The protease-containing fragments of 13 and 14 kb were cloned in pCB20 plasmid based on replication region of Streptococci plasmid pSM19035. Expression of the gene was shown to take place in Bac. subtilis. Application of vegetative promoters of the previously identified expression unit EU19035 greatly increases the expression of the protease in Bac. subtilis. Bac. subtilis cells, expressing the gene of Bac. brevis neutral protease, do not sporulate, are considerably larger than the cells which do not contain the gene and form multicellular structures.

Bacillus↗
PubMedDate not supplied

[Analysis of the structure of Bacillus brevis neutral proteinase and its biosynthesis in Bacillus subtilis cells].

Amino acid sequence of neutral metalloprotease from Bac. brevis has been compared with that of Bac. amyloloquefaciens, Bac. cereus, Bac. subtilis, Bac. stearothermophilis, Bac. thermoproteolyticus (thermolysine). A sequence region from N-40 to N-1 with a significant degree of homology allowed to predict the processing site of the propart of Bac. brevis enzyme. The sequence comparison allows to put Bac. brevis enzyme within the evolutionary branch of enzymes, which includes thermolysin and proteases of Bac. cereus and Bac. stearothermophilus. Using automated Edman degradation the N-terminal sequence of Bac. brevis protease has been determined. It does not differ from the sequence predicted from the nucleotide sequence of the gene. It was shown that, when Bac. brevis gene coding for thermostable protease is expressed on a plasmid vector in Bac. subtilis cells at 37 degrees C, enzyme forms possessing low activity are secreted. The enzyme may be significantly activated without an additional cleavage or processing and the activation includes numerous conformation transition states of the protein molecule.

Amino Acid Sequence↗
PubMed1990

Antibacteriophage action on the larvicidal activity of Bacillus thuringiensis H-14 and Bacillus sphaericus against Culex pipiens.

An organically polluted mosquito breeding water was tested for the presence of bacteriophages which could inhibit the larvicidal activity of B. thuringiensis H-14 and B. sphaericus. More than one bacteriophage were isolated which could inhibit the tested bacteria. The sensitivity of the two bacterial species to 12 antibiotics was tested. Two of them, showed no antibacterial action, were selected and considered as antivirus agents in the bacteriophage assays; namely, Amoxycillin and Co-Trimoxazole. Results indicated their antivirus activity as the addition of the antibiotics to the isolated phages could permit normal bacterial growth as well as persistence of larvicidal activity against Culex pipiens larvae.

Animals↗
PubMed1986

[Fusion of Bacillus subtilis and Bacillus licheniformis protoplasts. The mapping of the mutations leading to the supersynthesis of riboflavin in interspecies hybrids].

As a result of fusion of the protoplasts of B. subtilis and B. licheniformis the majority of the prototrophic hybrids, as well as the auxotrophs with the Thi-Hom-phenotype or the Thi-phenotype acquired capacity for over-production of riboflavin lacking in the initial parent strains. When grown on the minimal Spizizen medium with aeration at 37 degrees C the auxotrophic recombinants accumulated 10-60 micrograms/ml of riboflavin for 2 days, while the prototrophic recombinants accumulated up to 90 micrograms/ml of riboflavin. The respective figures for their cultivation in the sucrose fermentation medium were 100-330 and 600 micrograms/ml. For mapping 3 random variants of them with different phenotypes, i.e. SL-7 (prototroph), SL-15 Thi-and SL-52 Thi-Hom-were used. Localization of the mutation on the chromosome of B. subtilis was based on transformation experiments with three marker crossing, where hybrid strains SL-7, S1-15 and SL-52 were used as the DNA donor and strain lys-rib-of B. subtilis was used as the recipient. The analysis showed that the required mutation designated as R1 was localized on the chromosome of B. subtilis in the regulatory region rib0 of the riboflavin operon.

Bacillus↗
PubMed1985

[Fusion of Bacillus subtilis and Bacillus licheniformis protoplasts. Interspecies recombination resulting from protoplast fusion].

Recombinants between B. subtilis and B. licheniformis were prepared by fusion of the bacterial protoplasts. Genetically marked strains SB25 trp C hisH and 168 ade-met-leu- of B. subtilis and 1001 ura-thr- and 1001 met- of B. licheniformis were used as the parent strains. The recombinants were selected with the indirect method followed by analysis of their nutrient requirements and cultural and morphological features. All the hybrids acquired the specific properties of B. subtilis. Apparently, their formation was based on the whole chromosome of B. subtilis and recombination of separate fragments of B. licheniformis with it. Hybrids with prototrophic properties with respect to one, two or three markers of the initial strains were detected independent of the genotype of the B. subtilis parent strains. Moreover, the protoplast fusion resulted in formation of hybrids which were prototrophic with respect to the amino acid markers of B. subtilis and deficient with respect to homoserine and thiamine or only thiamine, whereas the initial strains were not auxotrophic with respect to homoserine and thiamine. Thi-Hom- and a number of the prototrophic recombinants were characterized by the capacity for increased synthesis of riboflavin lacking in the initial cultures. Homologous and heterologous transformation appeared to be possible in the recombinants of the Thi-Hom- phenotype, while transformation of the initial strain SB25 by the intergenocytic markers was possible in reciprocal crossings. It is concluded that contrary to transformation of isolated DNA, protoplast fusion may result in formation of interspecies recombinants of B. subtilis and B. licheniformis with respect to different operones of amino acid synthesis.

Bacillus↗