Is Bacillus subtilis resistant to high temperatures?
Bacillus subtilis is a well-studied model organism that is able to form dormant endospores. These spores can survive harsh environmental conditions and therefore are a major concern to the food industry. subtilis that produce spores with very high heat resistance.
What is the thermal death point of Bacillus subtilis?
The thermal resistance values (Z T) of B. subtilis spores are 30°C, 37°C, and 40°C at 60, 80, 100 MPa. The increase in Z T value at higher pressures indicates lower temperature sensitivity.
Why can Bacillus subtilis survive high temperatures?
Spores that form in Bacillus type bacteria provide dormancy at high temperature because enzyme proteins change shape as the spore dehydrates. These tough capsules form in response to adverse conditions such as drought or high temperatures.
What is the Gram reaction of Bacillus subtilis?
Bacillus subtilis is a motile, Gram-positive, rod-shaped bacteria that occurs as short chains, small clumps, or single cells. It is heterotrophic, which means it cannot make its own food and needs to consume from the environment.
Why is B subtilis more resistant to UV light than E coli?
subtilis, are 5 to 50 times more resistant to UV radiation than are the corresponding growing cells. This elevated spore UV resistance is due to: a) the photochemistry of DNA within spores, as UV generates few if any cyclobutane dimers, but rather a photoproduct (Fig.
How do you calculate thermal death time?
Take two nutrient agar plate and divide it into five quadrants. On each quadrant assign time like 0.15 sec, 2 min, 5 min, 15 min. This time will depict at particular temperature for how much time the organism was heated. Now take your sample culture that were heated in different temperatures.
What is thermal death curve?
A thermal death curve for this process is shown below. It is a logarithmic process, meaning that in a given time interval and at a given temperature, the same percentage of the bacterial population will be destroyed regardless of the population present.
Is Bacillus subtilis harmful to humans?
B. subtilis is considered a benign organism as it does not possess traits that cause disease. It is not considered pathogenic or toxigenic to humans, animals, or plants. The potential risk associated with the use of this bacterium in fermentation facilities is low.
What are the characteristics of Bacillus subtilis?
Bacillus subtilis is a spore forming, motile, rod-shaped, Gram-positive, facultative aerobe. It is mostly found in soil and vegetation with an optimal growth temperature from 25-35 degrees Celsius. B. subtilis has the ability to produce and secrete antibiotics.
