Microbial analysis of soil and groundwater from a gasworks site and comparison with a sequenced biological reactive barrier remediation process.
OBJECTIVE
To investigate the distribution of a polymicrobial community of biodegradative bacteria in (i) soil and groundwater at a former manufactured gas plant (FMGP) site and (ii) in a novel SEquential REactive BARrier (SEREBAR) bioremediation process designed to bioremediate the contaminated groundwater.


RESULTS
Culture-dependent and culture-independent analyses using denaturing gradient gel electrophoresis (DGGE) and polymerase chain reaction (PCR) for the detection of 16S ribosomal RNA gene and naphthalene dioxygenase (NDO) genes of free-living (planktonic groundwater) and attached (soil biofilm) samples from across the site and from the SEREBAR process was applied. Naphthalene arising from groundwater was effectively degraded early in the process and the microbiological analysis indicated a dominant role for Pseudomonas and Comamonas in its degradation. The microbial communities appeared highly complex and diverse across both the sites and in the SEREBAR process. An increased population of naphthalene degraders was associated with naphthalene removal.


CONCLUSIONS
The distribution of micro-organisms in general and naphthalene degraders across the site was highly heterogeneous. Comparisons made between areas contaminated with polycyclic aromatic hydrocarbons (PAH) and those not contaminated, revealed differences in the microbial community profile. The likelihood of noncultured bacteria being dominant in mediating naphthalene removal was evident.


CONCLUSIONS
This work further emphasizes the importance of both traditional and molecular-based tools in determining the microbial ecology of contaminated sites and highlights the role of noncultured bacteria in the process.
Ferguson
A S
AS
QUESTOR Centre and EERC School of Planning Architechture and Civil Engineering, David Keir Building, The Queen's University of Belfast, Belfast, UK.
Huang
W E
WE
Lawson
K A
KA
Doherty
R
R
Gibert
O
O
Dickson
K W
KW
Whiteley
A S
AS
Kulakov
L A
LA
Thompson
I P
IP
Kalin
R M
RM
Larkin
M J
MJ
D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D001673:Biodegradation, Environmental; D017753:Ecosystem; D011084:Polycyclic Aromatic Hydrocarbons; D016133:Polymerase Chain Reaction; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D014871:Water Microbiology
D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants