If I have a mixture of different bacteria, what is the best way to identify them by biochemical reactions? I mean, does any manual or reference summarize the identification of different bacteria?
If there are mixture of Bacteria first each of them as to be purified based on the colony characteristics. first go for staining like gram, endospore, capsule, acid fast , flagella. Then can go for Biochemical tests like carbohydrate fermentation, nitrate reduction, casein hydrolysis, starch hydrolysis, lipid hydrolysis, gelatin liquefaction, catalase test, beta-galactosidase, oxidase, urease, decarboxylase, IMVIC and growth characteristic like whether the colony is pigmented, mucoid, swarming and size of cell. check for relation of bacteria with oxygen. U can go for serological reaction like agglutination test, flouresecent antibody techniques which are simple. Refer Bergery's manual. Biochemical tests can give around 70-8-% confirmation of type of Bacteria.
You can identify the different Bacteria by number of methods,Morphologically by observing its growth on different selective medias like Eosine methylene blue agar,Mannitol salt agar,Mac Conkey Agar .Grams staining can also be done. To identify bacteria you can perform IMVIC test MRVP test .Sugar fermentation test,Citrate utilization test,Nitrate reduction test,Oxidase and Catalase,and Coagulase tests are the some of biochemical test,s.
well as suggested morphological features are good for a mixture, however for individual confirmation you will need to isolate them and study them using various biochemical methods, better refer Bergey's manual for selection of tests.
If there are mixture of Bacteria first each of them as to be purified based on the colony characteristics. first go for staining like gram, endospore, capsule, acid fast , flagella. Then can go for Biochemical tests like carbohydrate fermentation, nitrate reduction, casein hydrolysis, starch hydrolysis, lipid hydrolysis, gelatin liquefaction, catalase test, beta-galactosidase, oxidase, urease, decarboxylase, IMVIC and growth characteristic like whether the colony is pigmented, mucoid, swarming and size of cell. check for relation of bacteria with oxygen. U can go for serological reaction like agglutination test, flouresecent antibody techniques which are simple. Refer Bergery's manual. Biochemical tests can give around 70-8-% confirmation of type of Bacteria.
Yes, purifying them by isolating on differential and enriched culture plates is the first step. If you are looking into human pathogens alone you could follow Mackie & McCartney practical medical microbiology and if its environmental isolates please follow Bergey's Manual of Systematic Bacteriology for biochemical characterization.
In addition- VITEK 2 | Automated Microbial ID/AST System could be handy.
Have you looked at the Bergey's Manual? It has a lot of biochemical methods that allow you to identify organisms. Here's a flow chart of bacterial identification based on the Bergey's methods:
http://www.uiweb.uidaho.edu/micro_biology/250/IDFlowcharts.pdf
If you deal with medical samples, then try API kits, this is simply the easiest and fastest way to do your job
There are many methods for bacterial identification , maybe this can help
http://www.tgw1916.net/tests.html
observe their morphology under microscope, and continued biochemstry test such as nitrification tet, urease test, levan formation test, etc. compare your result test with bergey's manual..
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