Skip to main content
Biology LibreTexts

34: Urea Hydrolysis

  • Page ID
    3666
    \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Learning Objectives

    • Understand the reactions of bacteria in urea broth

    UREA

    Urea can be broken down with the help of the enzyme urease, producing the alkaline product of ammonia plus carbon dioxide. That causes the pH indicator phenol red to turn a beautiful shade of hot pink.

    MATERIALS NEEDED

    • 1 urea broth for unknown bacterium

    THE PROCEDURE

    1. Inoculate the tube of urea broth with your unknown bacterium.
    2. Incubate until next period at optimal temperature, 30º C or 37º C.

    INTERPRETATION

    urea1.png

    1. The alkaline reaction turns the pH indicator to hot pink.
    2. A yellowish color is still a negative reaction, although acidic.
    3. Some bacteria will produce a WEAK reaction, with a bit of pink in the tube. This should be recorded as weak +.
    4. It is a good idea to compare your tube with an uninoculated to make sure that you do not have a weak + result.

    QUESTIONS

    1. Is the end product being tested for an acidic, basic, OR neutral chemical? Name it.
    2. Name the indicator in this medium.

    This page titled 34: Urea Hydrolysis is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Jackie Reynolds.

    • Was this article helpful?