What is Purpose of Heat Shocking treatment

·        Mainly two purpose

1.     Elimination of Vegetative cells through thermal destruction.
2.    The activation (or “breaking of dormancy”) of spores inducing them to germinate. 

• This is a well studied effect and certain species (or strains of the same species) seem to be more responsive to the heat shock.
• Perform the heat shocking procedure using a water bath by placing a thermometer in   a test tube.
•  Start the timing when the thermometer reached 80 °C for heat shocking at 80°-85°C. or

           Start the timing when the thermometer reached 95°C for heat shocking at 95°-100°C.

·         Don’t over heat.

Name of the Organisum spores	Heat shocking temepature
Geo bacillus sterao thermophilus	95-100 °C at 15 minutes
Bacillus subtilis spps	80-85 °C at 10 minutes
Bacillus pumpilis	80-85 °C at 10 minutes

         ·         After heat shocking , rapidly cool tubes in a ice bath (0°- 4 °C) .

·         Plates with in 20 minutes after heat shocking using molten SCDA plates. 

		Test Organism			Heat shock**			Incubation
	G. stearothermophilus			95 - 100ºC for 15 minutes			55 - 60ºC for 48 hours*
		B. atrophaeus		80 - 85ºC for 10 minutes			30 - 35ºC for 48 hours
	B. subtilus ‘DSM4181’			95 - 100ºC for 15 minutes			48 - 52ºC for 48 hours
		B. smithii		95 - 100ºC for 15 minutes			48 - 52ºC for 48 hours*
		C. sporogenes		65 - 70ºC for 20 minutes			35 - 39ºC for 48 hours, anaerobic
								conditions
		B. subtilis ‘5230’
		B. pumilus
		B. cereus
				65 - 70ºC for 15ºminutes			30 - 35ºC for 48 hours
		B. subtilis ‘6633’
		B. megaterium
		B. licheniformis

Geobacillus stearothermophilus:

• formaly called Bacillus stearothermophilus.
• 2001 reclassified.
• is a rod-shaped bacteria
• Gram -Positive bacterium.