Dear Santosh,

When one proceed to isolate degrading (any substrate) microorganisms (MO), the best possle method is enrichment culture technique. General principle of this culture technique is that- you add all the ingredients (as salts as inorganic source) except the substrate 9the only organic source) that you want the MOs to utilize and degrade. this substrate for growth. now the strategies varies depending upon need. this organic substrate may act as sole source of C or N or P, depending upon your design of experiment(s).

In total, a defined artificial mineral medium (MM, which contains known ingredients) act as basal medium containing all ingredients (N source, P source, Micro and micro nutrient source etc.; sometimes vitamins as well) that provides building materials for cells. This MM is used to ensure that, the substrate (organic, lets, say glucose or any other organic compound, this may be your xenobiotic compound as well whose degradation, you want to study) that you are adding in this medium acts as the sole source of C (sometimes may be both C and N, when you use amino acids as it contains both C & N or may be P if the substrate contains bio-available P doner group, such as organophosphate pesticides).

You may read the first volume of Prokaryotes (1990s edition, there are 5 volumes), to learn the basics. You will also get many literature in Annual Rev of microbiology as well. Also follow papers (1980s & early 1990s) from the journal applied & environ microbiology (its free, except last 6 months & available at PubMed Central)

there are many trics in formulation of this mineral medium and the best way to formulate it after you have carried out physical & chemical analysis of your environmental sample from which you are planning to isolate your bacterial strains. 

Hope it helps.

Dr. saha

Please add, that the strategy that i have shared is for heterotrophic bacteria.

thank you 

The answer is quite straightforward. When checking the biodegradation of a compound or mixture there is no cetainty that this compound offers all requirements for the bacteria to grow (which is necessary for biodegradation). Therefor you add a minimal medium. A minimal medium is defined as a medium holding the absolute minimal ingredients for bacterial growth, as to force the bacterial population to use the compound under evaluation as a nutrient source, albeit C, P, N or other element.