microscopy (SCLM) of Q 15 at 5℃ revealed the presence of hydrophobic intracellular electron-transparent inclusions in cells grown on diesel or hexadecane. Following growth on octacosane or diesel at 5℃, Q 15 cells were observed, by scanning electron microscopy or SCLM, to be in direct contact with solid octacosane and with diesel microdroplets, indicating that Q 15 assimilates alkane substrates at low temperature by direct contact with the alkane phase. Genetic analysis of the hydrocarbon-degradative Pseudomonas sp. BI7 (isolated from petroleum-contaminated Arctic soils) revealed that both the alkane (alk) and naphthalene (nah) catabolic pathways, located on separate plasmids, can naturally co-exist in the same bacterium (2). Application of cold-adapted organisms such as Q 15 and BI7 to enhance degradation of specific contaminants and the effects of nutrient amendments (commercial fertilizers) on biodegradation is currently being investigated in contaminated soils from northern Canada.
1. Whyte et al. (1996) Can. J. Microbiol., 42, 99-106.
2. Whyte et al. (1997) Appl. Environ. Microbiol., 63, 3719-3723.
