Sporogenous bacteria

It is only the spore that can tolerate high temperatures and immediately the spore germinates it can be killed with moderate heat treatment. The spores can be made to germinate by subjecting them to a low, non-lethal heat (70oC) and if a secondary heat treatment at 75-80°C is then applied the bacteria cannot survive it. This kind of double heat treatment has been documented under the term "Tyndallisation", but there are many unknown factors relating to the degree of germination, how high the temperature must be and how much time must elapse between the heat treatments. The effect of various biochemical components (germinators) that can be added to increase germination is also being studied. To study the germination of spores, methods will be used that look at changes to the spores' heat tolerance, optical density and light refraction. This will be investigated with various equipment for heat treatment, spectrophotometer and phase contrast microscopy.