A novel medium for the isolation of N-acylhomoserine lactone-degrading bacteria

Abstract

A novel chemically defined medium, named KG medium, supplemented with N-3-oxo-hexanoylhomoserine lactone (3-oxo-C6-HSL), an acylhomoserine lactone (AHL) used as signalling molecules in Gram-negative bacterial cell-to-cell communication, as the sole source of carbon and nitrogen, was designed and successfully used for the enrichment and isolation of AHL-degrading bacteria. A 3-oxo-C6-HSL-degrading bacterium, 13sw7, was isolated from sewage after six enrichment transfers in the 3-oxo-C6-HSL-containing KG medium. On the basis of the almost complete 16S ribosomal DNA sequence, isolate 13sw7 was clustered with unculturable beta-proteobacteria. This study indicates that the AHL-containing KG medium is effective in isolating AHL-degrading bacteria, including those previously considered unculturable, from environmental sources. To the best of our knowledge, this is the first documentation of the isolation of an AHL-degrading proteobacterium from sewage.

Rapid degradation of N-3-oxo-acylhomoserine lactones by a Bacillus cereus isolate from Malaysian rainforest soil

“…All bacteria were routinely cultured in Luria-Bertani (LB) medium at 28°C except E. coli strains, which were grown at 37°C. KG medium for enrichment and isolation of B. cereus KM1S was prepared according to Chan et al (2009). When necessary, growth media were supplemented with 100 lg tetracycline/ml.…”

“…Enrichment and isolation of QQ bacteria was according to Chan et al (2009). Briefly, 1 g of soil sample was added to 3 ml of KG medium supplemented with 0.3 g ammonium chloride/l and 50 lg 3-oxo-C6-HSL/ml (Sigma-Aldrich) as the sole nitrogen and carbon sources, respectively.…”

“…In this paper, we report the isolation of Bacillus cereus strain KM1S from a Malaysian rainforest soil sample. This isolate was selected by using a chemically defined medium supplemented with N-3-oxo-hexanoyl homoserine lactone (3-oxo-C6-HSL) as described previously (Chan et al 2009). B. cereus KM1S was able to degrade rapidly 3-oxo-C6-HSL and N-3-oxo-octanoyl homoserine lactone (3-oxo-C8-HSL) in vitro.…”

Genome Sequence of Roseomonas sp. Strain B5, a Quorum-Quenching N -Acylhomoserine Lactone-Degrading Bacterium Isolated from Malaysian Tropical Soil

“…Here, we present the draft genome of Roseomonas sp. strain B5, a quorum-quenching bacterium isolated from Malaysian tropical soil enriched using a published method (4). We sequenced the whole genome of Roseomonas sp.…”

Genome Sequence of Dyella japonica Strain A8, a Quorum-Quenching Bacterium That Degrades N -Acylhomoserine Lactones, Isolated from Malaysian Tropical Soil

“…In 2007, a patient who received long-term hemodialysis was infected by this environmental soil bacterium (7). In this study, Dyella japonica strain A8 was isolated using a published method (3). Quorum quenching represents a novel anti-infective therapy measure (5), but such activity has not been reported in any member of the Dyella genus.…”