A putative porin gene of Burkholderia sp. NK8 involved in chemotaxis toward β-ketoadipate

Abstract

Burkholderia sp. NK8 can utilize 3-chlorobenzoate (3CB) as a sole source of carbon because it has a megaplasmid (pNK8) that carries the gene cluster (tfdT-CDEF) encoding chlorocatechol-degrading enzymes. The expression of tfdT-CDEF is induced by 3CB. In this study, we found that NK8 cells were attracted to 3CB and its degradation products, 3- and 4-chlorocatechol, and β-ketoadipate. Capillary assays revealed that a pNK8-eliminated strain (NK82) was defective in chemotaxis toward β-ketoadipate. The introduction of a plasmid carrying a putative outer membrane porin gene, which we name ompNK8, into strain NK82 restored chemotaxis toward β-ketoadipate. RT-PCR analyses demonstrated that the transcription of the ompNK8 gene was enhanced in the presence of 3CB.

Transcriptome differences between Cupriavidus necator NH9 grown with 3-chlorobenzoate and that grown with benzoate

“…The chemotactic behavior of strain NH9 towards aromatic compounds was tested in semi-solid agar plate assays [71]. For these assays, 100 ml NH9 cell culture in the early stationary phase (O.D.…”

Complete Genome Sequence of Caballeronia sp. Strain NK8 (MAFF311271), a Chlorobenzoate-Degrading Bacterium

“…NK8 can degrade 3-chlorobenzoate (3CB), an intermediate of polychlorinated biphenyls, via the chlorocatechol ortho -cleavage pathway encoded by the tfdCDEF genes ( 2 ). We previously demonstrated that NK8 cells are motile and exhibit chemotaxis toward 3CB and its degradation products ( 3 ).…”

“…The genes for the conversion of 3CB to 3- and 4-chlorocatechols ( cbeABCD ) were located on pNK81. The tfdCDEF genes (NK8_82450 to NK8_82480) ( 2 ) were on pNK84 along with the putative DNA relaxase gene traI (NK8_85450) ( 3 ), suggesting that the tfdCDEF genes were acquired by horizontal transfer. The genus Caballeronia has recently been divided from the genus Burkholderia ( 11 ).…”

“…The analysis of two-way average nucleotide identity (ANI) using an ANI calculator ( http://enve-omics.ce.gatech.edu/ani ) revealed that Caballeronia pedi LMG 29323 (NCBI BioProject accession number PRJEB12492 ) was the closest to NK8 among the type strains of Caballeronia , with an identity of 94.85%, which was slightly lower than the ANI cutoff value generally accepted for species delineation (95 to 96%) ( 13 , 14 ). Furthermore, while NK8 showed chemotaxis ( 3 ), LMG 29323 was described as nonmotile by Peeters et al ( 15 ). These findings suggest that NK8 represents a new species of the genus Caballeronia .…”