Isolation and characterization of hydrocarbon degrading bacteria from environmental habitats in western New York state

Katarina Malatova

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TD192.5 .M35 2005


Screening of hydrocarbon degrading microorganisms isolated from three habitats in Western New York State by selective enrichment technique, resulted in the collection of 20 distinct species. All strains were cultivated in liquid media with crude oil as a sole carbon and energy source. Bacterial strains capable of degrading hydrocarbons belong to the genera Serratia marcescens, Acinetobacter baumannii and Pseudomonas sp. Carbon dioxide evolution experiments were used as the major indicator of microbial degradation of oil in biometric flasks. The measurements of CO2 evolution rates have shown to effectively evaluate the biodegradation rates by providing significant data within a short period. The chemical composition of the residual oil was determined by gas-chromatographic techniques. The results indicate that the highest accumulation of carbon dioxide and the highest degradation efficiency of medium chain alkanes were observed on Leepershank crude oil, whereas degradation of Mexican crude oil with a composition of higher saturated and substituted hydrocarbons was prolonged. Additionally, biodegradation of Smakover oil was significantly reduced due to a high content of aromatic and cyclic hydrocarbons. Noticeable formation of solubilizing agents was observed by GR1 (not yet identified clone) and Serratia marcescens. The results also suggest that the application of bacterial consortiums containing combinations of two isolated strains enhanced the degradation of Mexican crude oil and also lead to a successful utilization of complex organic industrial waste. The bacterial mixture of GR1 clone and Acinetobacter baumannii demonstrated the highest growth and CO2 evolution on both substrates among all tested bacterial blends.