Write a 6 pages paper on the bacterial specific growth medium. Bacteria can be differentiated based on the enzymes secreted by them. Some enzymes are secreted out by the microorganisms enabling simple biochemical tests. The major exo enzymes present in bacteria are amylases, caseinase, gelatinase (hydrolytic enzymes), oxidase and catalase. Since most of the exoenzymes are hydrolytic enzymes that break down complex substances into simpler molecules, they are used as identifiers for the bacteria. Amylases hydrolyze the starch, gelatinase hydrolyses gelatin and caesinase converts casein into peptides and amino acids. Catalase converts hydrogen peroxide into oxygen and water and oxidases oxidizes dichlorophenol indophenols from colorless to blue or red.
Two plates of starch, casein and TSA media were taken and one set of the plates were inoculated with Bacillus subtilis and the other set of plates were divided into 5 and the four cultures were inoculated and the last section was left as a control. Spread plate technique was used to inoculate the culture and inverted and incubated for 24 – 48 hours at 32 °C.
Pseudomonas aeruginosa was positive for all the enzymes except amylase. Enterococcus fecal was negative for all the tests and concludes that it requires some other distinct methods for identification. Escherichia coli were positive for casinos and catalase enzymes. Staphylococcus aureus was positive for gelatinase and caseinate.
Biochemical tests help to identify the bacteria which are morphologically similar and have similar physical characters. Biochemical tests are based on the exoenzymes synthesized by the bacteria. Bacteria such as Escherichia coli are positive for most of the basic tests and the differentiation between the enterobacteria and other gram positive bacteria is possible only through biochemical tests.