I want to isolate microbes from fermented fish but confused which type of microorganisms should be targeted and what media can be used to isolate them.
According to my opinion for isolation of bacteria from fermented fish you should employ cultivation media for isolation of anaerobic and facultative anaerobic as well as aerobic bacteria, because the structure of microbial concsorcia is during time changing. For example one study showed that in fermented fish in the Phillipines aerobic organisms predominate at the onset of the fermentation followed by the microaerophilic and anaerobic microorganisms at the later stages (please see https://www.ncbi.nlm.nih.gov/books/NBK234688/) . As far as I know there does not exist specific cultivation media for isolation of bacteria from fermented fish. I recommend to employ isolation media for various groups of anaerobic, facultative anaerobic and aerobic bacteria. Because fermented fish could contain except bacteria also yeast and filamentous fungi (please see for example
http://aem.asm.org/content/29/1/106.full.pdf) you should aim also to this microorganisms.