FEMS Microbiology Ecology, 01/2012, Vol.79(1), pp.167-175
B urkholderia is a physiologically and ecologically diverse genus that occurs commonly in assemblages of soil and rhizosphere bacteria. Although B urkholderia is known for its heterotrophic versatility, we demonstrate that 14 distinct environmental isolates oxidized carbon monoxide (CO) and possessed the gene encoding the catalytic subunit of form I CO dehydrogenase ( coxL ). DNA from a B urkholderia isolate obtained from a passalid beetle also contained coxL as do the genomic sequences of species H160 and Ch1-1. Isolates were able to consume CO at concentrations ranging from 100 ppm (vol/vol) to sub-ambient (〈 60 ppb (vol/vol)). High concentrations of pyruvate inhibited CO uptake (〉 2.5 mM), but mixotrophic consumption of CO and pyruvate occurred when initial pyruvate concentrations were lower ( c . 400 μM). With the exception of an isolate most closely related to B urkholderia cepacia , all CO-oxidizing isolates examined were members of a nonpathogenic clade and were most closely related to B urkholderia species, B. caledonica , B. fungorum , B. oxiphila , B. mimosarum , B. nodosa , B. sacchari , B. bryophila , B. ferrariae , B. ginsengesoli , and B. unamae . However, none of these type strains oxidized CO or contained coxL based on results from PCR analyses. Collectively, these results demonstrate that the presence of CO oxidation within members of the B urkholderia genus is variable but it is most commonly found among rhizosphere inhabitants that are not closely related to B . cepacia .
〈Kwd〉〈Italic〉B〈/Italic〉〈Italic〉Urkholderia〈/Italic〉〈/Kwd〉 ; Carbon Monoxide ; 〈Kwd〉〈Italic〉Coxl〈/Italic〉〈/Kwd〉;
FEMS Microbiology Ecology