Bacillus stearothermophilus processing

Biological indicators (Bis) for use in thermal, chemical or radiation sterilization processes consist of standardized bacterial spore preparations which are usually in the form either of suspensions in water or culture medium or of spores dried on paper, aluminium or plastic carriers. As with chentical indicators, they are usually placed in dummy packs located at strategic sites in the sterilizer. Alternatively, for gaseous sterihzation these may also be placed within a tubular hehx (Line-Pickerill) device. After the sterilization process, the aqueous suspensions or spores on carriers are aseptically transferred to an appropriate nutrient medium which is then incubated and periodically examined for signs of growth. Spores of Bacillus stearothermophilus in sealed ampoules of cultrrre medium are used for steam sterilization morritoring, and these may be incubated directly at 55°C this eliminates the need for an aseptic transfer. 

Perform microbiological challenge studies to determine the degree of process lethality provided by the sterilization cycle. The microorganisms most frequently utilized to challenge steam sterilizer cycles are Bacillus stearothermophilus and ATCC 7953. The Kaye validator equipped with 12 (minimum) thermocouples and biological indicators (10 ) shall be positioned in the detected cool points of the chamber and condenser. After the sterilization cycle is complete, the B.I s are recovered and subjected to microbiological test procedures. 

K. Bartsch, R. Schneider, and A. Schulz, Stereospecific production of the herbidde phosphinothridn (glufosinate) purification of aspartate transaminase from Bacillus stearothermophilus, cloning of the corresponding gene, aspC, and application in a coupled transaminase process, Appl. 

Fig. 2a-c. Growth of Bacillus stearothermophilus PV72 in continuous culture on a synthetic medium containing glucose (8 gH) as the sole carbon and energy source. The dissolved oxygen concentration was controlled at 50 % and the dilution rate was 0.3 h-1. As derived from the measured process variables, variant formation started at about 15-16 h after inoculation. Shown are the measures for a Respiration activity b External and internal reduction state (redox potential and culture fluorescence) c Cell density (Reprinted from J. Biotechnol. 54, K.C. Schuster et al., p. 19,1997, with permission from Elsevier Science)... 

To sterilize the plant, a certain amount of H2O2 is injected and pumped off. This process is repeated a few times. Table 7 shows D values of Bacillus stearothermophilus at different temperatures of the plant and the H2O2 concentration applied. At low temperatures the concentration can be small, but the D values are long. At high temperatures the D values become very small, but the concentration has to be high because more and more H2O2 decomposes at higher temperatures. (The D value... 

Perform microbiological challenge studies to determine the degree of process lethality provided by the sterilization cycle. The microorganisms most frequently utilized to challenge steam sterilization cycles are Bacillus Stearothermophilus and Clostridium Sporogenes of 106 population. 

Rajan, S., Pandrangi, S., Balasubramaniam, V.M., and Yousef, A.E. 2006b. Inactivation of Bacillus stearothermophilus spores in egg patties by pressure-assisted thermal processing. Lebensmittel-Wissenschaft und-Technologie 39 844-851. 

Dry heat is generally used at 180°C for a period of two hours for the sterilisation of glassware, metal instruments and thermostable products. Spore strips of Bacillus stearothermophilus may be placed in the oven as a biological sensor, and removed for culturing at the end of the heating period. Growth indicates that the sterilisation process was inadequate, whilst no growth shows a suitable temperature was maintained for the requisite time. 

CGTase is rather rough, and the nature of CGTase from varied source is different. For example, the preparation process and a-CD yield can be different depending on the source of a- CGTase from B. macerans or Bacillus stearothermophilus in the preparation of a-CD. Therefore, on the classification of CGTase, the source of the bacteria must be taken into consideration. 

For foods it is desired to kill essentially all the spores of Clostridium botulinum, which produces a toxin that is a deadly poison. Complete sterility with respect to this spore is the purpose of thermal processing. Since Cl. botulinum is so dangerous and often difficult to use, other spores, such as Bacillus stearothermophilus, which is a non-pathogenic organism of similar heat resistance, are often used for testing the heat-treating processes (A2, Cl). 

The pulping process in a paper mill is performed at temperatures of65-80 °C atpH 9-12. Xylanases (EC 3.2.1.32 endo-1,3-P-xylanase) from some thermophilic bacilli were found to be compliant with these conditions (Gat et al. 1994), and the xylanase from Bacillus stearothermophilus T6 was developed and tested on a large scale (Lundgren et al. 1994). This enzyme shows activity at high temperature (60-70 °C) and... 

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