4 replies to this topic

[muncher]

Good day everyone!

 

I just want to know the difference between those kind of organism.

At which temperature you will subjected to heat treatment for micro analysis, and incubation temp?

 

Thank you in advance

[EagleEye]

You would have found that with a simple Google search

Thermophilic : Bacteria those thrive at 50-110 C growing conditions and this needs for their optimum growth.

Thermoduric : those bacteria which withstand higher temperatures that actually not suitable for their optimal growth. In pasteurized foods, this has significances.


Mesophilic : these bacteria needs moderate temperature range. Most pathogens are included in this group. The temperature range, say 20 - 40 C.

The incubation temperatures can vary in accordance the target organism. Though, normally mesophilic organisms are incubated at 36-37 C.

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[liberator]

to add to EagleEyes comments,

 

Phillic/Phile - means "loving" so thermophiles "love" or grow well at high temperatures. The actual temperatures that need to be considered could depend on your customer requirements and what your products are used for and what temperatures are of concern with your manufacturing process. In the dairy industry we're concerned about organism that can grow around the 50-60°C range.

 

Thermoduric - they endure high temperatures - they don't love it but can survive short times of exposure to high temperatures.

 

Mesophilic  (Meso - middle/modeate)  these microbes are what are typically counted/tested for under the "standard plate count"(SPC) aka - "total plate count" (TPC) test methodology - which is typically incubated at 30°for 72 hours.

 

Thermophiles are processed using the same test methodology as for SPC but the difference is that they are incubated at 55°C for 48 hours.

 

Thermodurics are tested by exposing the sample to a high temperature eg 63°C for 30 mins (pasteurization) rapidly cooled and then, plated out and treated like a SPC test - i.e. 30°C for 72 hours.

[Tony-C]

Hi muncher,

 

In fresh dairy Psychrotrophic bacteria are also important:

 

Psychrotrophic bacteria are of particular concern to the dairy industry. [22] Most are killed by pasteurization; however, they can be present in milk as post-pasteurization contaminants due to less than adequate sanitation practices. According to the Food Science Department at Cornell University, psychrotrophs are bacteria capable of growth at temperatures at or less than 7 °C (44.6 °F).

https://en.wikipedia...ki/Psychrophile

 

Kind regards,

 

Tony

[muncher]

Thank you very much Sir for all the answers! 

 

Regards,

Edited by muncher, 18 March 2019 - 07:05 AM.