Volume No. 3 Issue No.: 3 Page No.: 654-662 Jan-Mar 2009

 

ELUCIDATION OF PETROLEUM HYDROCARBON DEGRADATION BY Burkholderia cepacia (ES1) IN MODEL SYSTEMS AND EFFECT OF NONIONIC CHEMICAL SURFACTANTS

 

Sagarika Mohanty and Suparna Mukherji*

Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai (INDIA)

 

Received on : October 16, 2008

 

ABSTRACT

 

Two key factors have a significant impact on bioremediation of petroleum hydrocarbon contamination, i.e., the microbial cultures present and measures used for enhancement of bioavailability. This work reports petroleum hydrocarbon degrading potential of Burkhloderia cepacia (ES1) isolated and enriched from Arabian sea sediment using diesel as the sole substrate. The ability of the organism to utilize different hydrocarbon group types as sole carbon source was studied by applying them as single substrates, binary mixtures and complex mixtures. Further, a synthetic non-aqueous phase liquid (NAPL) representing a model for petroleum fractions such as, diesel, was prepared and extent of degradation of the NAPL was determined in the absence and presence of three nonionic surfactants, Triton-X 100, Igepal CA 630 and Tween 80. Culture growth and degradation rate studies were also conducted using Triton X-100. B.cepacia (ES1) did not utilize the polynuclear aromatic hydrocarbons and its growth was inhibited when equimolar naphthalene and n-hexadecane were present. However, its growth was not hindered by the presence of naphthalene (mole fraction (?) = 0.125) in the model NAPL. The overall loss over 60 hrs increased from 33.8% without surfactant to 82.7%, 62.2% and 37.2% in presence of Triton X-100, Igepal CA 630 and Tween 80, respectively. Surfactants favored the utilization of aliphatics present in the NAPL. The biotic loss increased from 26.5% to 74.4% in the presence of Triton X-100 over 168 hrs.

 

Keywords : Burkholderia cepacia, Petroleum hydrocarbons, Surfactants, NAPLs

 

 

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