Biodegradation Research at Bangor
under Peter Williams
The School of Biological Sciences (SBS) at Bangor has one of the longest
standing continuous research records in Europe on the microbial catabolism
of aromatic compounds, going back to 1952 when one of the major pioneers
in the field, Professor W.Charles Evans FRS,
was appointed to the newly formed Chair of Agricultural Biochemistry.
Current research on aromatic catabolism is concentrated within the
group of Professor Peter Williams who, after graduating with a B.A. in
Chemistry and a D.Phil. from the University of Oxford, was originally appointed
as a lecturer in Bangor in 1966 by Charles Evans. Evans' research on the
pathways of microbial degradation of aromatics was the inspiration for
a total change of research direction from physical biochemistry to microbial
Research in the two laboratories ran in parallel until Evans'
retirement in 1979 although, whereas in the latter stages of his career
Evans was more interested in the pathways of anaerobic degradation, research
in Williams' laboratory turned towards the genetics and molecular biology
of aerobic processes following their discovery of the TOL plasmid in 1974.
Since then the research has encompassed a wide range of substrates, of
pathways and of microbial degraders. Perhaps more importantly, it has spanned
one of the most exciting periods in biological research, the development
of DNA-based molecular biology. In the 1970s research in biodegradation
was able to encompass only the elucidation of the metabolic pathways and,
to a lesser extent, the characterization of the enzymes. Today the developments
in molecular biology have enabled the current explosion in the depth of
investigation to the level of gene sequences, regulatory complexity, horizontal
gene transfer etc. A substantial part of research in Bangor has concentrated
on plasmid-encoded catabolism in Pseudomonas particularly involving
the TOL plasmids. These are a group of large plasmids (from 100-300 kb)
encoding the degradation of the monocylclic aromatic hydrocarbons toluene
and m- and p-xylenes. The archetype of this group is the
117 kb plasmid pWW0 from P.putida mt-2 which was first identified
in Bangor. Its xyl genes, encoding the catabolism of the hydrocarbons,
span some 25 kb, are organised in two operons and their expression is controlled
by two regulatory genes, xylS and xylR. The complete xyl genes are arguably are the best studied of any long catabolic pathway and
the TOL plasmids, in particular pWW0, have been the subject of a considerable
body of literature.
The group's current research interests focus on the molecular biology
and biochemistry of the degradation of toluene, xylenes, naphthalene, nitro-substituted
aromatics and aromatic esters by a range of bacteria including fluorescent Pseudomonas spp., Ralstonia spp., Acinetobacter spp., acidophiles and
bacteria from Antarctica.
A recent collaboration with Dr.
D. B. Johnson in the Bangor
Acidophile Research Team has characterized a novel class of acidophilic
bacterial degraders which might be able to participate in a process to
clean up mixed industrial wastes containing both organic and toxic inorganic
In particular we are interested in the genes encoding the catabolic
functions, their organisation and their regulation. Knowledge of these
enables us to understand better how bacteria can rapidly evolve the ability
to degrade xenobiotic compounds (i.e. those of non-biological origin).
It also enables genetic manipulation of the pathways either to allow the
use of bacteria for accumulation of fine chemicals or for maximising bioremediative
processes for pollution control.
Currently Peter Williams is in the second year of a five-year term as
an Editor of Applied and Environmental Microbiology
and handles many of the submitted papers on biodegradation and also
papers on microbial molecular biology, ecology and enzymology. To make
contact on any topic related to papers you have submitted and which I am
handling, please make contact via firstname.lastname@example.org
where your enquiry will be handled by myself or Sally Wells, my very
capable Editorial Assistant.
Go to this link for a more general overview
of the role of microbes as the most effective environmental clean-up agents
and some general reading.