How to distinguish the substance is nutrition or growth hormon - (Sep/28/2009 )

Now we are testing some substance on medium for growth microbacterial. We want to know how to distinguish (or demonstrate) that the substance have role of nutrition or Growth Hormon. Because both of them (Nutrition or Growth Hormon) help microbacterial growth. Thank

blackpencil75 on Sep 28 2009, 12:02 AM said:

well you could radiolable your substrate and feed it to the bug. if you find radioactive atoms being incoperated into the cells protein/wall etc then you know the compound is being used as nutritional substrate.

alternatively, you can try looking at the growth response of the bacterium. Ideally a hormone should give a growth response in small quantities (pM to nM range) while a nutritional substrate should continue giving a growth response in the uM to mM range. Although you could have a poor growth hormone, so a week response.

Maybe pencil could tell us more - what is the substance or its origin.

adding to what mr blue said, you could formulate medium in which the substance was the sole source of C or N. For the "hormone" - use highly dilute levels in medium that supports growth and note growth promotion v. control.