Comparison of indigenous and exogenous microbial populations during slurry phase biodegradation of long-term hydrocarbon-contaminated soil.
In this study, a number of slurry-phase strategies were trialled over a 42 day period in order to determine the efficacy of bioremediation for long-term hydrocarbon-contaminated soil (145 g kg(-1) C(10)-C(40)). The addition of activated sludge and nutrients to slurries (bioaugmentation) resulted in enhanced hydrocarbon removal (51.6 ± 8.5 %) compared to treatments receiving only nutrients (enhanced natural attenuation [ENA]; 41.3 ± 6.4 %) or no amendments (natural attenuation; no significant hydrocarbon removal, P < 0.01). This data suggests that the microbial community in the activated sludge inoculum contributed to the enhanced removal of hydrocarbons in ENA slurries. Microbial diversity in slurries was monitored using DGGE with dominant bands excised and sequenced for identification. Applying the different bioremediation strategies resulted in the formation of four distinct community clusters associated with the activated sludge (inoculum), bioaugmentation strategy at day 0, bioaugmentation strategy at weeks 2-6 and slurries with autoclaved sludge and nutrient additions (bioaugmentation negative control). While hydrocarbon-degrading bacteria genera (e.g. Aquabacterium and Haliscomenobacter) were associated with the hydrocarbon-contaminated soil, bioaugmentation of soil slurries with activated sludge resulted in the introduction of bacteria associated with hydrocarbon degradation (Burkholderiales order and Klebsiella genera) which presumably contributed to the enhanced efficacy for this slurry strategy.
School of Biological Sciences, Flinders University of South Australia, Adelaide, Australia.
Arturo
A
Aburto-Medina
Eric M
EM
Adetutu
Sam
S
Aleer
John
J
Weber
Sayali S
SS
Patil
Petra J
PJ
Sheppard
Andrew S
AS
Ball
Albert L
AL
Juhasz
D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D044822:Biodiversity; D019149:Bioreactors / Q000382:microbiology; D004275:DNA, Ribosomal / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D005798:Genes, Bacterial / Q000235:genetics; D006838:Hydrocarbons / Q000378:metabolism*; D010802:Phylogeny; D025341:Principal Component Analysis; D012722:Sewage / Q000382:microbiology*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013997:Time Factors
D004275:DNA, Ribosomal; D006838:Hydrocarbons; D012722:Sewage; D012989:Soil Pollutants