Antibacterial metabolites and bacteriolytic enzymes produced by Bacillus pumilus during bacteriolysis of Arthrobacter citreus.

The marine isolate Bacillus pumilus SBUG 1800 is able to lyse living cells of Arthrobacter citreus on solid media as well as pasteurized A. citreus cells in liquid mineral salt medium. The cultivation of B.

2,5-Diketopiperazines produced by Bacillus pumilus during bacteriolysis of Arthrobacter citreus.

We report the detection by gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry analyses of the secreted 2,5-diketopiperazines (DKPs) cyclo(-Ala-Pro), cyclo(-Gly-Pro), cyclo(-Val-Pro), cyclo(-Ile-Pro), cyclo(-Leu-Pro), cyclo(-Pro-Pro), cyclo(-HyP-Pro), cyclo(-Met-Pro), and cyclo(-Phe-Pro) produced by Bacillus pumilus. The study focuses on a marine isolate and a laboratory test strain of B. pumilus with capabilities to lyse pregrown living cell lawns of different bacterial species, among them Arthrobacter citreus.