Bioremediation Flashcards
Oily drill cuttings are
Lubricants and ground rock
Oily drill cuttings do not
Biodegrade
Can be tonnes from one drill site
Polluting
Definition of biodegradation
The naturally occurring degrading properties of microorganisms
Definition of bioremediation
The use of biodegradative processes to detoxify or remove pollutants
Biodegradation can be used for
Pollutants in the environment including medicines, pesticides, industry, chemical spills etc.
Targets for bioremediation of oil are
Recalcitrant, toxic, polyaromatic compounds
How many tonnes of petroleum fractions are introduced into the environment per year?
3.4M
Petroleum main routes of entry into environment
Spills/accidents
Natural tar seeps
Landfill (drill cuttings buried)
Bioremediation was used in the
Deepwater Horizon oil spill
Bioremediation microbes must be chosen
For the environment in which they will work e.g cold or warm seas
Alkyltetralins
Most toxic and persistent fraction of oil
Bioremediation is designed around microbes that can process
Alkyltetralins
The ‘Hump’ most toxic, most persistent
Halophiles
Salt loving microbes
Due to the anoxic nature of oily drill cuttings
Degradation is severely reduced
Microbes that digest drill cuttings have to deal with
Anaerobic, halophilic, high pressure and toxic environment
Halophiles are
Extremophiles
Two types of hypersaline environments
- Athalassohaline
2. Thalassohaline
Athalassohaline
e.g. Dead Sea
Enclosed waters
Thalassohaline
Marine waters
Solar salterns can be used
To mine for halophiles
Solar salterns are
Convenient systems for analyzing and interpreting biogeo-chemical trends through salinity gradients or between comparable salinities of different localities
Halophiles are part of
Archaea
The red colour of halophilic archaea is due to
C50 carotenoids
Ancient brine from the Gyda oil field in the North Sea was used
To isolate microbes that could break down oil fractions
Characterisation of microbes was done by
16S RNA analysis
Isolated then phylogenetic analysis
Gyda oil haloarchaea are closely related to
Great Salt Lake archaea (16S)
AlkB
Enzyme important in degradation pathway in archaea
Pseudomonas putida is used as a
Control for the effectiveness of degradation by other bacteria (it has AlkB)
AlkB is responsible for the
Alkane hydroxilase enzyme