Bioremediation of petroleum hydrocarbons in the marine environment
Student name: Ms Aditi Sengupta
Guide: Dr S Ramakrishnan
Year of completion: 2010
Host Organisation: The Energy and Resources Institute (TERI)
Supervisor (Host Organisation): Dr Priyangshu M. Sarma
Abstract: Every year, roughly 1,300,000 tonnes of petroleum are discharged into the sea. Large scale
production, use, transport and disposal of petroleum has made it a major contaminant in the marine
environment. Although petroleum hydrocarbons have been reported to be degraded by
microorganisms such as bacteria, fungi, yeast and microalgae in the marine, freshwater and soil
ecosystems, bioremediation aims to increase the rate of this natural biodegradation. This study
aimed at successfully obtaining isolates that would have the potential to degrade petroleum
hydrocarbons in the marine environment. Two bacterial isolates and one putative yeast isolate were
identified from TERI’s culture collection, that were able to degrade crude paraffinic oil. Partial
sequencing of 16S rRNA gene of the two bacterial isolates showed 99% homology to Bacillus spp.
The mixed culture containing three isolates was reported to show 47% degradation capacity
following total petroleum degradation experiments. All isolates were tested individually for their oil
degradation capacity. The individual isolates showed far less degradation efficiency. The mixed
culture was tested for its potential to degrade individual aliphatic and aromatic compounds and
showed 81.89% degradation of heptadecane and 99.71% degradation of naphthalene. Degradation
of individual compounds by individual isolates showed a similar degradation profile amongst the
Bacilli strains. However, the putative yeast isolate showed lesser degradation efficiency of aromatic
compounds. The isolates identified in this work can be used to augment bioremediation of petroleum
hydrocarbons in the marine environment by customizing the bioremediation parameters to local
conditions.
Keywords: Bioremediation, Bacillus spp., consortia, marine environment, petroleum hydrocarbons
