Isolation of a Urea Degrading Bacteria :: Biology

Isolation of a urea Degrading BacteriaIntroductionUrea was the first organic chemical to be synthetically produced1,previously it was thought that only living creatures could produceorganic compounds Urea is naturally produced by the kidneys as wastefrom the degradation of amino acids. It is because of this that ureais commonly found in soils and is a useful nutrient source forbacteria that are able to put on it, such as, Helicobacter pylori,Klebsiella pneumonia, all species of Proteus and Micrococcus luteus.These bacteria degrade urea in a reaction catalysed by the ureaseenzyme, CO(NH2)2 + H2O CO2 + 2NH3. this process benefits the bacteriain several ways. The bacteria use the ammonia that is produced forrespiration, the products also raise the pH of the environment. Thispromotes the growth of umteen urea degrading bacteria and inhibitscompetition from many other bacterial species.M. luteus is commonly found on mammalian skin and it is unusual for amember of the natural human flor a to degrade urea. It is believed thatM. luteus has this ability as an evolutionary hangover from its lifein its ancestral soil habitat. In this environment urea is readilyavailable and the ability to degrade it is a distinct advantage. Asthe species evolved to live on skin the trait remained, as it had nonegative effect on survivability.Micrococcus is a genus within the family Micrococcaceae family. With the useof 16s RNA in bacterial taxonomy the genus has recently been revised2.The genus now includes three species, M. luteus, M. lylae and M.antarcticus3. M. luteus is a common yellow gram-positive coccus androughly 0.5-2.0mm in diameter. Cells step to the fore in pairs, tetrads andirregular clusters but never in chains.4Method of Isolation* Isolate a variety of beingnesss from soil and skin.By taking examples from four divergent sources (three skin and onesoil) the chance of urea degrading bacteria being present wasincreased.* Culture in nutrient broth.This allowed all isolat ed microbes to grow.* Plate sample onto urea plates.On these plates urea was the only nutrient available, this meant thatany bacteria that grew could degrade urea.* Perform urease test.Isolated bacteria are grown in a broth containing phosphate buffer,yeast extract, 2% urea and phenol red. An agar slope of the medium isheavily inoculated and incubated at 370c for at least four hours. Ifthe organism only has low urease activity the phosphate buffer willneutralise the NH3 produced. A red colour indicates that NH3 has beenproduced and the result is positive5.* Perform Gram stain.This is the most chief(prenominal) stain in bacteriology and differentiatesbetween gram positive and gram-negative cell walls, which indicates