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A recombinant Bacillus subtilis strain containing a plasmid encoding a luxAB fusion, which gave bioluminescence upon addition of an exogenous long-chain aldehyde as substrate for the endogenous luciferase enzyme, was used as test organism. Its populations were treated with 300 MPa for 20 min, or 600 MPa for 20 min at around room temperature, and this treatment is foreseen as a quality-friendly, non-thermal pasteurisation of foods. Besides the estimation of viable cell counts, the extent of pressure-induced germination and post-process development were investigated by phase-contrast microscopy, turbidimetry and luminometry. Increased heat sensitivity of pressurized spore populations was observed both by viable cell counting during a linearly programmed elevation of temperature and a simultaneous differential scanning calorimetry. This was related to pressure-induced germination of spores, although a small fraction remained ungerminated. The luciferase pool built into the spores during their formation seemed to have withstood pressurization. Spore germination was accompanied by the emergence of bioluminescence which also indicated sensitively the characteristic changes of metabolic activity running parallel with the development of untreated cell populations and that of the survivors of the hydrostatic pressure treatments when the cells were incubated in a nutrient broth.
therapy. Then, if there is no need to pay attention to its safety while taking CUR or if there is any clause that we have to follow when it comes to drug combination? Bacillus subtilis ( B. subtilis ), which is commonly found in soil and
A bioluminescent derivative of Bacillus subtilis containing a plasmid encoding a luxAB fusion under control of a vegetative promoter and gives bioluminescence upon addition of an exogenous long-chain aldehyde has been used as test organism. Its spore populations have been produced and their heat- and radiation survival curves established. Heat-sensitization effect of pre-irradiation of spores was proven not only by colony counting but also with differential scanning calorimetry. Under a linearly programmed temperature increase, the heat destruction of spores surviving 2.5 kGy gamma irradiation resulted in at a few centigrade lower temperature than that of untreated spores. Heat denaturation endotherms in the DSC-thermogram of irradiated spores were shifted to lower temperatures as well. Comparative turbidimetric, luminometric and phase-contrast microscopic studies of untreated, heat-treated and irradiated spore populations showed that the kinetics of germination and the light emission during germination of radiation-inactivated spores were the same as those of untreated spores, revealing that the pre-formed luciferase enzyme packaged into the spores during sporulation remained intact after an irradiation dose causing 90% decrease in number of colony forming spores. Therefore, in contrast to heat-treated spores, the initial bioluminescence reading upon germination of irradiated spores does not reflect the viable count of their population.
purification of chitinase from Bacillus subtilis . World J. Exp. Biosci. 1 , 5 – 9 . 6. Galeazzi , M. A. M. , Sgarbieri , V. C. , Constantides , S. M. ( 1981 ) Isolation
., Schanck, K., Colson, C. (1993) Purification and preliminary characterization of the extracellular lipase of Bacillus subtilis 168, an extremely basic pH-tolerant enzyme. Eur. J. Biochem. 216 , 155
Bacillus subtilis is one of the most important producers of diverse antimicrobial compounds. This bacterium grows and produces antibiotics on different substrates. The increase of the antibiotics yield can be achieved by changing the conditions of cultivation and the composition of the culture media. In this study, response surface methodology was used for optimization of glycerol, sodium nitrite, and phosphate content in media for production of antibiotics effective against Staphylococcus aureus. As biosynthesis strain Bacillus subtilis ATCC 6633 was used. The developed model predicts that the maximum inhibition zone radius (38.08 mm) against Staphylococcus aureus and minimal amount of residual nutrients (glycerol 1.75 g l−1, nitrogen 0.21 g l−1, phosphorus 0.18 g l−1) are achieved, when the initial content of glycerol, sodium nitrite, and phosphate are 49.99 g l−1, 1.00 g l−1, and 5.00 g l−1, respectively.
Bacillus subtilis natto is a potential source of fructooligosaccharides (FOS), which can be obtained by fermentation and may stimulate the growth of beneficial microorganisms in the colon representing a strategy to manipulate the intestinal microbiota acting as a prebiotic compound. The present study focuses on the ability of Lactobacillus ssp. strains to utilize FOS as a sole energy source. The results showed that FOS was equally good as glucose to provide energy source. The highest prebiotic activity score was obtained with Lactobacillus plantarum ATCC 14917 grown on FOS (0.526), followed by Lactobacillus casei (LC-1) (0.222). The lowest score was for Lactobacillus paracasei ATCC 27092 (−0.051). The results suggests that specific combinations of probiotic (L. plantarum ATCC 14917 and L. casei (LC-1)) and prebiotic (FOS) could be used as synbiotics in dairy and other foods.
The main purpose of this study was to determine optimum conditions for culture of a test microbe Bacillus subtilis (ATCC 6633) which enabled us to establish its use for direct bioautography. The viability of the bacteria on TLC plates was measured on the basis of their adenosine-5′-triphosphate (ATP) content as determined by bioluminescent luciferin/luciferase assay, the data being referred to values for total bacterial protein. In the first experiments, we used a ‘20-h’ culture of B. subtilis prepared by dilution of an optical density ( OD ) ≫ 0.4 culture to furnish a culture of OD = 0.4 (Method A). Later, on the basis of our optimization experiments we found that a ‘5–9-h’ broth culture of B. subtilis was suitable. Under these conditions the bacteria remained in the log phase ( OD = 0.2–0.4) for 5–9 h (Method B) in immersion bacterial suspension. Because the test bacteria were in the log phase a much shorter incubation time (4–8 h) was sufficient for TLC plates instead of the original 18 h in a previous study. One advantage of this method, in addition to the shorter incubation time, is that we can use TLC plates coated with adsorbents other than silica.
The effect of four rhizobacterial strains on the severity of spot blotch disease caused by cochliobolus sativus was evaluated for two growing seasons under rainfed conditions. Three barley genotypes were used as host plant. All strains reduced C. sativus severity, with effect more pronounced when Pseudomonas putida BTP1 and Bacillus subtilis Bs2508 were used. The disease reduction was up to 56% in Arabi Abiad / P. putida BTP1. The grain yield was not obviously affected by the presence of the rhizobacteria, except some signifitive increase in season 2. Raising the resistance by soaking seed with rhizobacterial strains might be of ultimate value in agriculture.
The changes of cell surface hydrophilicity in Bacillus subtilis were analyzed in response to oxygen-limitation, heat shock, salt stress, pH-shock, phosphate- and carbon-limitation. Although cell surface hydrophilicity varied during growth phases, an increase of surface hydrophilicity was observed under several of these stress conditions. An observed drop in intracellular GTP and/or ATP may be an element of the signal transduction pathway leading to an increase in surface hydrophilicity in response to environmental stresses. Attachment of cells to soil particles under salt stress conditions is strongly influenced by the degS/degU two-component system, which thereby provides a mechanism for the bacteria to escape from the hostile environment.
