Burkholderia cepacia has attracted attention because of its extraordin
ary degradative abilities and its potential as a pathogen for plants a
nd for humans. This bacterium was formerly considered to belong to the
genus Pseudomonas in the gamma-subclass of the Proteobacteria, but re
cently has been assigned to the beta-subclass based on rrn gene sequen
ce analyses and other key phenotypic characteristics. The B. cepacia g
enome is comprised of multiple chromosomes and is rich in insertion se
quences. These two features may have played a key role in the evolutio
n of novel degradative functions and the unusual adaptability of this
bacterium.