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PubMedDate not supplied

[The biosynthesis of new secretory high-molecular-weight ribonucleases in Bacillus intermedius and Bacillus subtilis].

The investigation of new secretory ribonucleases, the Bacillus intermedius binase II expressed in the recombinant B. subtilis strain 3922 and the native RNase Bsn of B. subtilis, showed that they are synthesized in the growth retardation phase, when inorganic phosphate is exhausted in the medium. The biosynthesis of these ribonucleases was found to be suppressed by the presence of inorganic phosphate in the medium and activated by small amounts of the transcriptional inhibitor actinomycin D. The cultivation media of the producing strains were optimized for the maximum production of the enzymes.

Bacillus↗
PubMed1992

Fate of Bacillus sphaericus and Bacillus thuringiensis serovar israelensis in the aquatic environment.

Bacillus sphaericus spores were suspended in bottles of filtered (0.45 microns) freshwater and seawater under various conditions of temperature, pH and salinity. Heat resistant culturable counts (spores) slowly decreased with time. Spores suspended in dialysis bags submerged in a freshwater pond or in flowing seawater underwent a more rapid drop in heat resistant spore counts than did spores held in bottles. Thus, laboratory studies may overestimate spore longevity in the environment. Spore settling rate was related to the nature of particulate material in the water column. Paraspores (or perhaps spores and toxin) of B. thuringiensis serovar israelensis (B.t.i.) had a greater tendency to adhere to and settle with suspended sediment and fine particulates than did paraspores of B. sphaericus. These observations may at least partially explain the greater persistence of B. sphaericus larvicidal activity in field tests than that of B.t.i..

Animals↗
PubMedDate not supplied

[Growth characteristics of Lactobacillus plantarum, Bacillus subtilis and Bacillus licheniformis at deep cultivation in the monoculture and coculture].

Active growth of some representatives of bacteria of Bacillus genus on earlier optimized nutrient medium for L. plantarum 8R-A3 is shown. Growth characteristics of the studied bacteria at mixed cultivation on this medium have been studied. The increase of their growth activity and accumulation of cell biomass has been determined. Taking into consideration the fact, that the process of obtaining of the studied strain mixed culture was determined by the type of ecological vital strategy of each separate species. B. licheniformis 5514 and L. plantarum 8R-A3 have been related to K-strategists and B. subtilis 5007--to r-strategists.

Bacillus↗
PubMed1991

Field trials with Vectolex (Bacillus sphaericus) and Vectobac (Bacillus thuringiensis (H-14)) against Anopheles gambiae and Culex quinquefasciatus breeding in Zaire.

Under field conditions in Kinshasa, Zaire, an aqueous suspension of Bacillus thuringiensis (H-14), Vectobac (12-AS), lost most of its larvicidal activity at all concentrations after 48 h against Culex quinquefasciatus breeding in polluted gutter water and Anopheles gambiae breeding in clear water irrigation ponds. However, good control of Cx. quinquefasciatus was obtained using a granular formulation of B. sphaericus, Vectolex-G (ABG-6185), at concentrations of 10-30 kg/ha. High concentrations of Vectolex-G gave excellent control of An. gambiae breeding in irrigation ponds. The Vectobac-G was less active against An. gambiae than Vectolex-G, in spite of good dispersion of Vectobac-G particles.

Animals↗
PubMed1977

Dihydrodipicolinate reductases from Bacillus cereus and Bacillus megaterium.

Dyhydrodipicolinate reductases were purified 100-fold from crude extracts of B. cereus and B. megaterium and their properties were compared with those of the reductase from B. subtilis. The molecular weights of the reductases of B. cereus and B. megaterium were fount to be 155,000 and 150,000, respectively. These reductases were shown to be free of flavin, unlike the B. subtilis enzyme, which contains flavin. Both NADPH and NADH acted as coenzymes for these two reductases. NADPH being three or four times more effective than NADH. The Km values for NADPH and dihydrodipicolinate were 8 micrometer and 62 micrometer, respectively, with B. cereus reductase, and 13 micrometer and 59 micrometer with B. megaterium reductase. The pH optima of the enzymes from B. cereus and B. megaterium were pH 7.4 and 7.2, respectively. The reductases were inhibited by dipicolinate noncompetitively with respect to dihydrodipicolinate and the Ki values were 85 micrometer and 140 micrometer, respectively. Lysine and diaminopimelate were not inhibitory. The properties of the reductases from B. cereus and B. megaterium were similar, but they differed considerably from those of the B. subtilis enzyme. However, all three Bacillus reductases were markedly inhibited by dipicolinate, unlike the enzyme from E. coli.

Bacillus cereus↗
PubMed1989

Effect of Bacillus sphaericus and Bacillus thuringiensis on acid-phosphatase activity of mosquito larvae, Culex pipiens and Aedes caspius.

The use of Bacillus sphaericus and B. thuringiensis H-14 form one of the important group of biological control agent against mosquito larvae. Acid phosphatase enzyme plays a significant role in determining susceptibility of mosquito larvae to both bacterial species. Biochemical assay showed activation in acid phosphatase in Culex pipiens and Aedes caspius treated with B. thuringiensis. Variation in acid phosphatase activity occurred in both mosquitoes treated with B. sphaericus, while there was no change in acid phosphatase activity in A. caspius. An obvious increase in activity in C. pipiens treated with the same bacteria was observed.

Acid Phosphatase↗
PubMed1987

[Integration of the plasmid carrying the genes for tryptophan metabolism of Bacillus mesentericus into the chromosome of Bacillus subtilis].

Integration of several tryptophan operon genes from Bacillus mesentericus into the chromosome of Bac. subtilis was carried out. The genetic material exchange between these two species is usually impossible in the process of transformation, because of poor homology. The integration only took place after the genes of Bac. mesentericus were introduced in Bac. subtilis cells on a hybrid plasmid. Plasmid markers also integrated into the chromosome, together with heterologous DNA. The integration occurred in the region of Bac. subtilis tryptophan operon, which is likely to be due to retained homology between corresponding DNAs. The integration acts occurred during prolonged maintenance of chimeric plasmid in autonomously replicating form. We suggest to designate this phenomenon "retarded homologous recombination".

Bacillus↗
PubMed1983

[Interspecific recombinants of Bacillus thuringiensis x Bacillus cereus].

The possibility of interspecies recombination was shown by using protoplast fusion method. The Bacillus thuringiensis var. galleriae strain 48S Thi Nic Gua Rifr Strr and 56R Gua Rifr, and also Bac. cereus carrying the plasmid pBC16 responsible for resistance to tetracycline (150 mcg/ml) were used. Recombinants were selected on the medium containing rifampicin and tetracycline. They were shown to combine the properties of both parents. The majority of recombinants were resistant to phages Tg4 and Td15 and represented the mean level of sensitivity to phages Tg12, Tg13 and Td14. Examination of the plasmid profiles of recombinants revealed that their resistance to tetracycline was due to the plasmid with mobility analogous to pBC16. It was concluded that the protoplast fusion method can be used to obtain recombinants between relatively remote species of microorganisms.

Bacillus cereus↗
PubMed1980

The crystalline layers in spores of Bacillus cereus and Bacillus thuringiensis studied by freeze-etching and high resolution electron microscopy.

The comparative morphology of spores from Bacillus cereus, B. thuringiensis S-9 (wildtype), B. thuringiensis HB 9-1 (acrystaliferous mutant) and B. finitimus, was studied by the freeze-etching technique. Particular attention was given to the three crystalline layers found in these spores, the pitted layer, the parasporal layer, and the basal layer of the exosporium with lattice constants of 9.2 nm, 5.8 nm and 8.0 nm respectively. The parasporal layers, corresponding to the fraction of Fl of Scherrer and Somerville [18] were found to be membraneous sheets laying between spore and exosporium. Analysis of the isolated exosporium by negative staining and digital image processing revealed a lattice structure belonging to the p 6 hexagonal space group with a repeat of 8.0 nm. The unit cell contains 6 subunits, each 3 nm in diameter, which are centered around a hypothetical channel readily penetrated by the stain.

Bacillus cereus↗
PubMed1993

Field trials of Bacillus thuringiensis H-14 and Bacillus sphaericus (strain 2362) formulations against Anopheles arabiensis in the central highlands of Madagascar.

Malaria is highly endemic and unstable in the central Highlands plateau of Madagascar. The infection is seasonally transmitted by Anopheles funestus and An. arabiensis. The latter species is abundant especially in rice-growing areas. The field efficacies of commercial formulations of Bacillus thuringiensis H-14 and B. sphaericus (strain 2362) were assessed against An. arabiensis in 5 types of larval habitats. The granular formulation of B. thuringiensis (Vectobac GR) provided very good control in small ponds and rainwater ditches. In ricefields complete larval control was achieved with Vectobac GR and the flowable concentrate (Vectobac 12AS) at 2.5 kg/ha and 0.6 liter/ha, respectively. The granular formulation of B. sphaericus (ABG 6185) showed activity similar to that of Vectobac GR in small pools and ricefields. ABG 6185 was less effective in rainwater ditches where it gave satisfactory control at rates not lower than 6 kg/ha.

Animals↗
PubMedDate not supplied

[Effect of Bacillus intermedius RNAases with various catalytic activity on multiplication of Escherichia coli and Bacillus subtilis].

The effect of the Bacillus intermedius ribonuclease and its mutant forms derived by site-specific mutagenesis on the growth of gram-positive and gram-negative bacteria was studied. Both catalytically active and catalytically inactive (mutant) ribonucleases stimulated bacterial growth, the extent of stimulation correlating with the catalytic activity of the enzymes. It was suggested that the biological activity of exogenous ribonucleases is mainly due to their catalytic activity.

Bacillus↗
PubMed1998

[Structure of teichoic acids from marine microorganisms Bacillus subtilis and Bacillus licheniformis].

Teichoic acids from the cell walls of marine bacilli Bacillus subtilis CMM (Collection of Marine Microorganisms) 234 (R-1) and B. licheniformis CMM 454 (1-1G-2) were isolated and characterized. These teichoic acids were found to have identical structures and are composed of the glucose, ribitol, and phosphoric acid residues. On the basis of 13C NMR and 31P NMR spectra of the teichoic acids and the products of their dephosphorylation, we established the following structure for the biopolymer: poly[-->5)-4-O-beta-D-glucopyranosylribitol-(1-phospho].

Bacillus↗
PubMed1987

Processing of Bacillus subtilis succinate dehydrogenase and cytochrome b-558 polypeptides. Lack of covalently bound flavin in the Bacillus enzyme expressed in Escherichia coli.

The DNA sequence of the Bacillus subtilis sdh operon coding for the two succinate dehydrogenase subunits and cytochrome b-558 (the membrane anchor protein) has recently been established. We have now determined the extent of N-terminal processing of each polypeptide by radiosequence analysis. At the same time, direct evidence for the correctness of the predicted reading frames has been obtained. The cytochrome showed a ragged N-terminus, with forms lacking one residue, and is inserted across the membrane without an N-terminal leader-peptide. Covalently bound flavin was not detectable in B. subtilis succinate dehydrogenase expressed in Escherichia coli despite normal N-terminal processing of the apoprotein. This provides an explanation to why the succinate dehydrogenase synthesized in E. coli is not functional and demonstrates that host-specific factors regulate the coenzyme attachment.

Amino Acid Sequence↗
PubMed1995

Dissociation constants and thermal stability of complexes of Bacillus intermedius RNase and the protein inhibitor of Bacillus amyloliquefaciens RNase.

Binase, the extracellular ribonuclease of Bacillus intermedius, is inhibited by barstar, the natural protein inhibitor of the homologous RNase, barnase, of B. intermedius. The dissociation constants of the binase complexes with barstar and its double Cys40,82Ala mutant are about 10(-12) M, only 5 to 43 times higher than those of the barnase-barstar complex. As with barnase, the denaturation temperature of binase is raised dramatically in the complex. Calorimetric studies of the formation and stability of the binase-barstar complex show that the binase reaction with barstar is qualitatively similar to that of barnase but some significant quantitative differences are reported.

Bacillus↗
PubMed1995

Bacillus amyloliquefaciens possesses a second type I signal peptidase with extensive sequence similarity to other Bacillus SPases.

A second sipS2(BA) gene was PCR cloned from Bacillus amyloliquefaciens. The deduced aa sequence is similar to those of the SPases of B. subtilis, B. amyloliquefaciens, and B. licheniformis and the domain structure of the gene has been preserved. A low level of monocistronic gene transcription could be shown using Northern analysis. The sipS2(BA) gene was mapped to a region downstream of an E. coli fruA gene homologue and shown to express a 21 kDa protein in Escherichia coli.

Amino Acid Sequence↗
PubMed1990

Analytical methods for Bacillus cereus and other Bacillus species.

Bacillus cereus can give rise to two distinct forms of foodborne disease, the emetic and the diarrhoeal syndromes. The emetic syndrome is believed to be associated with an emetic toxin pre-formed in food. Cooked rice is the most common vehicle, and the symptoms are similar to those of Staphylococcus aureus intoxication. The diarrhoeal type is caused by an enterotoxin and the symptoms generally parallel those of the Clostridium perfringens food poisoning. The heat resistance of B. cereus spores and the non-fastidious nature of the organism facilitates its survival and/or growth in a wide variety of foods. This review describes analytical methods available for the isolation, identification, and enumeration of the organism, in addition to details about biological and immunological methods for toxin assay. Data are also presented concerning the incidence and epidemiology of B. cereus food poisoning around the world, and especially in Japan.

Bacillus cereus↗
PubMed2006

Emetic toxin-producing strains of Bacillus cereus show distinct characteristics within the Bacillus cereus group.

One hundred representative strains of Bacillus cereus were selected from a total collection of 372 B. cereus strains using two typing methods (RAPD and FT-IR) to investigate if emetic toxin-producing hazardous B. cereus strains possess characteristic growth and heat resistance profiles. The strains were classified into three groups: emetic toxin (cereulide)-producing strains (n=17), strains connected to diarrheal foodborne outbreaks (n=40) and food-environment strains (n=43), these latter not producing the emetic toxin. Our study revealed a shift in growth limits towards higher temperatures for the emetic strains, regardless of their origin. None of the emetic toxin-producing strains were able to grow below 10 degrees Celsius. In contrast, 11% (9 food-environment strains) out of the 83 non-emetic toxin-producing strains were able to grow at 4 degrees Celsius and 49% at 7 degrees Celsius (28 diarrheal and 13 food-environment strains). non-emetic toxin-producing strains. All emetic toxin-producing strains were able to grow at 48 degrees Celsius, but only 39% (16 diarrheal and 16 food-environment strains) of the non-emetic toxin-producing strains grew at this temperature. Spores from the emetic toxin-producing strains showed, on average, a higher heat resistance at 90 degrees Celsius and a lower germination, particularly at 7 degrees Celsius, than spores from the other strains. No difference between the three groups in their growth kinetics at 24 degrees Celsius, 37 degrees Celsius, and pH 5.0, 7.0, and 8.0 was observed. Our survey shows that emetic toxin-producing strains of B. cereus have distinct characteristics, which could have important implication for the risk assessment of the emetic type of B. cereus caused food poisoning. For instance, emetic strains still represent a special risk in heat-processed foods or preheated foods that are kept warm (in restaurants and cafeterias), but should not pose a risk in refrigerated foods.

Bacillus cereus↗