Bacteriology and Infectious Diseases

Biography

Biography: Vanessa Jackson

Abstract

Polycyclic Aromatic Hydrocarbons have been shown to be carcinogenic, teratogenic and mutagenic. PAHs can enter environmental matrices via natural and anthropogenic sources from agricultural and industrial activities. The aim of this study was to isolate and identify potential PAH-degrading microorganisms from the Diep- and Plankenburg Rivers, Western Cape, South Africa. Water and sediment samples were collected monthly over a six month period at six sampling points (three sampling points along each of the Rivers) and kept on ice at 4ºC during transport. For phenotypic identification, standard cultivation on various general and selective media, including Nutrient and Aeromonas isolation agars, as well as Pseudomonas-isolation Agar Base, amongst others, were employed. Each isolate was screened for PAH degradation (acenaphthene, fluorene) using shaking flasks prior to isolation and identification. After screening and cultivation, nineteen isolates were selected and molecularly identified using 16S rRNA extraction followed by primer-specific PCR amplification. The predominant species identified included Raoutella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila. Raoutella ornithinolytica was isolated from most of the media utilised, including Pseudomonas Agar Base supplemented with CFC and Pseudomonas Agar Base supplemented with CN, while Aeromonas hydrophila grew on all culture media except Pseudomonas Agar Base. Raoutella ornithinolytica is a member of the Enterobacteriaceae while Aeromonas sp. closely resembles Enterobacteriaceae, which could account for its growth on most media. Bacterial species that display tolerance to these compounds could have great beneficial effects in the area of bioremediation of PAH-contaminated sites.