Identification of genetic markers correlating with degradation of different hydrocarbons

A method was developed with the objective to monitor the microbial changes in a bioreactor during biodegradation of a well-defined mixture of hydrocarbons. The defined slurry consisted of water, sand, nutrients and several different hydrocarbons. The slurry was inoculated with minute amounts of microorganisms originating from oil-sludge from an oil-refinery. Temperature, pH, redox-potential, supply of O-2 and CO2-production were continuously monitored. Chemical analyses were performed on both the off-gas and the slurry-phase. A rapid, convenient method for simultaneous preparation of total DNA and RNA from the bioslurry was developed. Random amplified polymorphic DNA (RAPD) analysis was performed over time, on both the complex mixture of DNA that was prepared from the bioslurry, and on the cDNA derived from the reverse transcriptase (RT) synthesis of total RNA. The RAPD products were analyzed by capillary electrophoreses (CE). The reproducibility of the procedure was investigated. A correlation between the genetic fingerprint and the chemical fingerprint over time was made from partial least square (PLS) analysis. Four different DNA and RNA fragments correlated to degradation of eight different hydrocarbons.