Selection and Optimization of Bacillus atrophaeus Inoculum Medium and its Effect on Spore Yield and Thermal Resistance.

Autor: Belquis Guizelini, Luciana Vandenberghe, Adriane Medeiros, Ashok Pandey, Carlos Soccol
Zdroj: Applied Biochemistry & Biotechnology; Dec2008, Vol. 151 Issue 2/3, p380-392, 13p
Abstrakt: Abstract   Bacillus atrophaeus’s spores are used as biological indicators to monitor sterilization processes and as a Bacillus anthracis surrogate in the development and validation of biosafety methods. The regular use of biological indicators to evaluate the efficiency of sterilization processes is a legal requirement for health services. However, its high cost hinders its widespread use. Aiming at developing a cost-effective inoculum medium, soybean molasses and nutrient-supplemented vinasse were evaluated for their effectiveness in solid-state fermentation (SSF). In biomass production, the results demonstrated that all tested compositions favor growth by providing the nutritional demands of the microorganism. Optimum casein peptone and soybean molasses concentration (1.0%, 2.5%, or 4.0%) was determined by a 2(2–0) factorial experimental design. The results have showed a positive influence of peptone on biomass production. In order to define peptone final concentration (4.0% or 6.0%), a 22 factorial experimental design was used. An optimized medium containing 4.0% soybean molasses and 4.0% casein peptone was similar in performance to a synthetic control medium (tryptone soy broth) in dry-heat thermal-resistant spore production by SSF. An experiment performed under optimum SSF conditions resulted in 1.9 × 1010 CFU g−1 dry matter with D 160 °C = 5.2 ± 0.2 min. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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