Linear Regression
Daryl S. Paulson in Applied Statistical Designs for the Researcher, 2003
A researcher is performing a steam-heat thermal-death curve calculation on a 106 microbial population of Bacillus stearothermophilus, where the steam sterilization temperature is 121°C. Generally, a log10 reexpression is used to linearize the microbial population. In log10 scale, 106 is 6. In this example, assume the microbial population is reduced 1 log10 for every 30 seconds of exposure to steam. This example is presented graphically in Fig. 5. b1 represents the slope of the regression line, which is the rise/run or tangent. This rise is negative because the value is decreasing over exposure time, so b0 represents the value of ŷ when x = 0, which is ŷ = 6 – 0.0333(0) = 6 in this example. For x = 60 seconds, ŷ = 6 – 0.0333(60) = 4.
Distribution and Biological Functions of Pyruvate Carboxylase in Nature
D. B. Keech, J. C. Wallace in Pyruvate Carboxylase, 2018
In yeast grown under conditions of biotin limitation, pyruvate carboxylase activity is low,156,572,573 and the cells contain substantial proportions of the apoenzyme.240,353,357,572 However, the biotin deficiency is not compensated for by an increased amount of pyruvate apocarboxylase.357 Similar results were noted for pyruvate carboxylase in Bacillus stearothermophilus grown under biotin-deficient conditions.161
Natural and physical preservative systems
R. M. Baird, S. F. Bloomfield in Microbial quality assurance in cosmetics, toiletries and non-sterile Pharmaceuticals, 2017
Effects of combined pressure and temperature on Bacillus stearothermophilus spores showed that increasing pressure from 10 to 400 MPa gave the greatest reduction in numbers of surviving spores where the temperature was greater than 60°C (Taki et al. 1990).
Design and evaluation of in situ gel eye drops containing nanoparticles of Gemifloxacin Mesylate
Published in Drug Delivery, 2023
Vishwa J. Kalaria, S. Saisivam, Anas Alshishani, Jameel S. Aljariri Alhesan, Sumit Chakraborty, Mohamed Rahamathulla
The optimized formulation B3 in situ gel formulation containing Gemifloxacin Mesylate Nanoparticles was sterilized in an autoclave. During the sterilization process, a sterile filter paper strip impregnated with spores of Bacillus stearothermophilus as a biological indicator packed in an aluminum foil was also subjected to autoclave sterilization along with optimized formulation . The Biological indicator was transferred aseptically into petriplate containing nutrient agar medium and incubated at 37° C for 24 hrs. The Petriplate did not show any growth of Bacillus stearothermophilus. This proves that autoclave sterilization is proper. Apart from this, the sterilize optimized formulation was also subjected to test for sterility as per Indian Pharmacopeia (2018). The formulation passed the test for sterility proving that there is no microbial contamination.
Molecular regulation of adhesion and biofilm formation in high and low biofilm producers of Bacillus licheniformis using RNA-Seq
Published in Biofouling, 2019
Faizan Ahmed Sadiq, Steve Flint, Hafiz Arbab Sakandar, GuoQing He
The food industry, particularly the dairy industry, is facing challenges due to biofilm formation on the surfaces of processing equipment (Marchand et al. 2012). Bacterial contamination of food due to biofilms costs the food industry millions of dollars annually (Brooks and Flint 2008). Bacillus licheniformis, Geobacillus stearothermophilus and Anoxybacillus flavithermus are the major microbial contaminants in the dairy industry, particularly the milk powder manufacturing industry (Burgess et al. 2010; McHugh et al. 2017). Their widespread prevalence in dairy products is directly related to their ability to form biofilms on food contact surfaces (Sadiq, Flint, Yuan, et al. 2017). Despite the biofilm related issues in the dairy industry, studies have not reported on the molecular determinants of biofilms formation for dairy isolates.
Correlation of Staphylococcus Epidermidis Phenotype and Its Corneal Virulence
Published in Current Eye Research, 2021
Armando R. Caballero, Aihua Tang, Michael Bierdeman, Richard O’Callaghan, Mary Marquart
E coli M15 [pREP4] expressing the recombinant protease was grown in LB media to an OD600 ~ 0.6 and induced with 0.5 mM IPTG overnight. Afterwards, the bacteria were pelleted and the culture supernatant was filtered through a 0.45 µm filter, concentrated and dialyzed. The soluble recombinant protein was purified by affinity chromatography under non-denaturing conditions (TALON Metal Affinity Resin [Clontech Laboratories, Mountain View, CA]) following the manufacturer’s instructions and concentrated. Aliquots of the purified rEsp (200 µl) were incubated with 4 µg of thermolysin from Geobacillus stearothermophilus (Sigma-Aldrich, St. Louis, MO) at 37ºC for 30 minutes to cleave the pro-peptide and the reaction was terminated with EDTA. The activated rEsp was purified away from thermolysin by molecular sieve chromatography.
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