title: Antibacterial metabolites and bacteriolytic enzymes produced by Bacillus pumilus during bacteriolysis of Arthrobacter citreus.
abstract: 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. pumilus in the presence of pasteurized A. citreus is accompanied by an enhanced production of 2,5-diketopiperazines (DKPs). DKPs inhibit bacterial growth, but do not seem to cause bacteriolysis. This study shows that B. pumilus also lyses living cells of A. citreus in co-culture experiments as an intraguild predator, even if the inoculum of B. pumilus is low. In order to characterize the bacteriolytic process, more precisely changes in the extracellular metabolome and proteome have been analyzed under different culture conditions. Besides the known DKPs, a number of different pumilacidins and bacteriolytic enzymes are produced. Two lipopeptides with [M + H](+) = 1008 and [M + H](+) = 1022 were detected and are proposed to be pumilacidin H and I. While the lipopeptides lyse living bacterial cells in lysis test assays, a set of extracellular enzymes degrades the dead cell material. Two of the cell wall hydrolases involved have been identified as N-acetylmuramoyl-L-alanine amidase and beta-N-acetylglucosaminidase. These findings together with electron microscopic and cell growth monitoring during co-culture experiments give a detailed view on the bacteriolytic process.
authors: Institute of Microbiology, Ernst-Moritz-Arndt-University of Greifswald, Friedrich-Ludwig Jahn-Str. 15, 17487, Greifswald, Germany, cb050806@uni-greifswald.de.
authors: Christiane
authors: C
authors: Brack
authors: Annett
authors: A
authors: Mikolasch
authors: Rabea
authors: R
authors: Schlueter
authors: Andreas
authors: A
authors: Otto
authors: Dörte
authors: D
authors: Becher
authors: Uwe
authors: U
authors: Wegner
authors: Dirk
authors: D
authors: Albrecht
authors: Katharina
authors: K
authors: Riedel
authors: Frieder
authors: F
authors: Schauer
mesh_terms: D000118:Acetylglucosaminidase / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000302:isolation & purification / Q000494:pharmacology; D000898:Antibiosis; D001173:Arthrobacter / Q000737:chemistry / Q000187:drug effects*; D001407:Bacillus / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity / Q000648:ultrastructure; D001433:Bacteriolysis; D054659:Diketopiperazines / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D015870:Gene Expression; D055666:Lipopeptides / Q000096:biosynthesis / Q000302:isolation & purification / Q000494:pharmacology; D055442:Metabolome; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D010456:Peptides, Cyclic / Q000096:biosynthesis / Q000302:isolation & purification / Q000494:pharmacology; D020543:Proteome / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D054659:Diketopiperazines; D055666:Lipopeptides; D010456:Peptides, Cyclic; D020543:Proteome; D000118:Acetylglucosaminidase; D009238:N-Acetylmuramoyl-L-alanine Amidase