title: Isolation of a novel yeast strain Candida digboiensis TERI ASN6 capable of degrading petroleum hydrocarbons in acidic conditions.
abstract: A novel yeast species Candida digboiensis TERI ASN6 was isolated from soil samples contaminated with acidic oily sludge (pH 1-3) from the Digboi refinery (Northeast India). The strain TERI ASN6 could degrade 73% of the total petroleum hydrocarbons present in the medium at pH 3 in a week. This strain presents a dimorphic behaviour and showed mycelia morphology when grown under stressed conditions such as low pH and in a medium containing petroleum hydrocarbons. The C. digboiensis strain could efficiently degrade the aliphatic and aromatic fractions of the acidic oily sludge at pH 3 as confirmed by gas chromatography. During the growth of TERI ASN6 in dibenzothiophene (DBT), DBT-sulfone and biphenyl-2-ol were detected. An active cytochrome P450 system, implicated in hydrocarbon oxidation, was also detected in this yeast using degenerated primers based on its conserved regions. This yeast is a potential candidate for petroleum bioremediation treatment of hydrocarbon contaminated acidic soils. Its physiological behaviour allows the strain to work efficiently where other hydrocarbon-degrading bacteria may not survive.
authors.affiliation: The Energy and Resources Institute (TERI), Darbari Seth Block, India Habitat Centre, New Delhi, India.
authors.forename: Nitu
authors.initials: N
authors.lastname: Sood
authors.forename: Banwari
authors.initials: B
authors.lastname: Lal
mesh_terms: D001673:Biodegradation, Environmental; D001713:Biphenyl Compounds / Q000032:analysis; D002175:Candida / Q000302:isolation & purification / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D006838:Hydrocarbons / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010578:Petroleum / Q000378:metabolism*; D010802:Phylogeny; D012722:Sewage / Q000382:microbiology; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013876:Thiophenes
chemical_list: D001713:Biphenyl Compounds; D006838:Hydrocarbons; D010578:Petroleum; D012722:Sewage; D012989:Soil Pollutants; D013876:Thiophenes; C058517:dibenzothiophene 5-oxide; D003577:Cytochrome P-450 Enzyme System