The macrocyclic peptide antibiotic micrococcin P(1) is secreted by the food-borne bacterium Staphylococcus equorum WS 2733 and inhibits Listeria monocytogenes on soft cheese.
Staphylococcus equorum WS 2733 was found to produce a substance exhibiting a bacteriostatic effect on a variety of gram-positive bacteria. The metabolite was purified to homogeneity by ammonium sulfate precipitation and semipreparative reversed-phase high-performance liquid chromatography. Electrospray mass spectrometry confirmed the high purity of the compound and revealed a molecular mass of 1,143 Da. By two-dimensional nuclear magnetic resonance spectroscopy the substance was identified as micrococcin P(1) which is a macrocyclic peptide antibiotic that has not yet been reported for the genus Staphylococcus. A total of 95 out of 95 Listeria strains and 130 out of 135 other gram-positive bacteria were inhibited by this substance, while none of 37 gram-negative bacteria were affected. The antilisterial potential of this food-grade strain as a protective starter culture was evaluated by its in situ application in cheese-ripening experiments under laboratory conditions. A remarkable growth reduction of Listeria monocytogenes could be achieved compared to control cheese ripened with a nonbacteriocinogenic type strain of Staphylococcus equorum. In order to prove that inhibition was due to micrococcin P(1), a micrococcin-deficient mutant was constructed which did not inhibit L. monocytogenes in cheese-ripening experiments.
Carnio
M C
MC
Institut für Mikrobiologie, FML Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
Höltzel
A
A
Rudolf
M
M
Henle
T
T
Jung
G
G
Scherer
S
S
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D001430:Bacteriocins; D002611:Cheese / Q000382:microbiology*; D005516:Food Microbiology; D008401:Gas Chromatography-Mass Spectrometry; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides; D013210:Staphylococcus / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D010455:Peptides; C009779:micrococcin