Use of L-proline as a nutrient by <i>B. licheniformis</i> DSM 13^T.

<p>The proline catabolic system has been studied in <i>B. subtilis</i> where a high-affinity proline transporter (PutP), two proline catabolic enzymes (PutB-PutC) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080956#B82" target="_blank">82</a>], and a proline-responsive activator protein (PutR) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080956#B83" target="_blank">83</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080956#B84" target="_blank">84</a>] have been functionally studied. (A) This proline catabolic pathway is predicted from the genome sequence to be present in <i>B. licheniformis</i> DSM 13^T as well [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080956#B13" target="_blank">13</a>]. (B) Genetic organization of the <i>put</i> locus of <i>B. licheniformis</i> DSM 13^T. (C) <i>B. licheniformis</i> DSM 13^T cells were grown in SMM with glucose as the carbon source without the addition of a nitrogen (N) source (-) or in the presence of 15 mM (NH₄)₂SO₄ [NH₄⁺, 30 mM L-proline [Pro], or 30 mM glycine betaine [GB], respectively. Growth yields of the cultures were measured after 16 h of incubation at 37 °C in a shaking water bath. (D) <i>B. licheniformis</i> DSM 13^T cells were grown in SMM with (NH₄)₂SO₄ [15 mM] in the absence (-) of a carbon source or in the presence of 27 mM glucose [Gluc], 32.4 mM L-proline [Pro] or 32.4 mM glycine betaine [GB]. Growth yields of the cultures were measured after 16 h of incubation at 37 °C in a shaking water bath. The error bars give the standard deviation of three independently grown cultures.