A Comparison of Microbial Hydrocarbon Degraders Based On the Source of the Contaminant in Alaska

Abstract

The overall objective of this study was to compare microbial hydrocarbon degraders based on their source of contaminant. The research involved enrichment of a single bacterial isolate from each of five hydrocarbon-contaminated soils collected at different sites in Alaska. After the strains were isolated from each source, they were compared to one another using various diagnostic tests. Forty-seven binary biochemical tests were performed. Of these only eighteen tests were discriminatory. These discriminatory tests were used for further statistical analysis. SYSTAT 5.1 was used to perform numerical cluster analyses which produced dendrograms showing normalized percent disagreement between responses to the tests for any two isolates. Complete linkage was used to produce a correlation matrix. This showed the probability that two isolates will give the same responses to the diagnostic tests when sampling from a random population. Although isolated from very different climatic regions in Alaska, I found that a statistically significant correlation exists between the bacterial growth and the source of the contaminant. From this it appears that the specific contaminant may provide a selective pressure for similar phenotypic bacterial growth.