Bacteria of the Burkholderia cepacia complex are cyanogenic under biofilm and colonial growth conditions.
BACKGROUND
The Burkholderia cepacia complex (Bcc) is a collection of nine genotypically distinct but phenotypically similar species. They show wide ecological diversity and include species that are used for promoting plant growth and bio-control as well species that are opportunistic pathogens of vulnerable patients. Over recent years the Bcc have emerged as problematic pathogens of the CF lung. Pseudomonas aeruginosa is another important CF pathogen. It is able to synthesise hydrogen cyanide (HCN), a potent inhibitor of cellular respiration. We have recently shown that HCN production by P. aeruginosa may have a role in CF pathogenesis. This paper describes an investigation of the ability of bacteria of the Bcc to make HCN.


RESULTS
The genome of Burkholderia cenocepacia has 3 putative HCN synthase encoding (hcnABC) gene clusters. B. cenocepacia and all 9 species of the Bcc complex tested were able to make cyanide at comparable levels to P. aeruginosa, but only when grown surface attached as colonies or during biofilm growth on glass beads. In contrast to P. aeruginosa and other cyanogenic bacteria, cyanide was not detected during planktonic growth of Bcc strains.


CONCLUSIONS
All species in the Bcc are cyanogenic when grown as surface attached colonies or as biofilms.
Ryall
Ben
B
Department of Life Sciences, Division of Biology, Faculty of Natural Sciences, Imperial College London, Sir Alexander Fleming Building, London, SW7 2AZ, UK. ben.ryall00@imperial.ac.uk
Lee
Xiaoyun
X
Zlosnik
James E A
JE
Hoshino
Saiko
S
Williams
Huw D
HD
D000362:Agar; D000595:Amino Acid Sequence; D018441:Biofilms; D042602:Burkholderia cepacia complex / Q000378:metabolism* / Q000502:physiology*; D003470:Culture Media; D016680:Genome, Bacterial; D005898:Glass; D006856:Hydrogen Cyanide / Q000378:metabolism*; D008969:Molecular Sequence Data; D050891:Oxidoreductases Acting on CH-NH2 Group Donors / Q000378:metabolism; D010641:Phenotype; D011550:Pseudomonas aeruginosa / Q000378:metabolism / Q000502:physiology; D016415:Sequence Alignment
D003470:Culture Media; D006856:Hydrogen Cyanide; D000362:Agar; D050891:Oxidoreductases Acting on CH-NH2 Group Donors; C112800:glycine dehydrogenase (cyanide-forming)