| The Antarctic bacterial isolate Sphingomonas paucimobilis ANT 17 has the ability to degrade crude oil in cold and growth-limiting environments. ANT 17 grows at temperatures from 1°C to 35°C. The optimum pH for growth of ANT 17 is near 6.4 at 22°C, but at colder temperatures the optimum pH is less defined. Seventy-five aromatic and non-aromatic substrates were incubated with ANT 17, and the majority served as growth or cometabolic substrates. For example, phenanthrene was mineralized to CO2, but fluoranthene and pyrene were partially oxidized. ANT 17 grew on and degraded the aromatic fraction of several crude oils and a refined oil product under cold and nutrient-limiting conditions, but did not grow on the saturate fraction. Molecular studies revealed that ANT 17 was phenotypically stable and plasmidless, suggesting that the genes required for aromatic degradation are chromosomal. ANT 17 may be a good model for studying cold climate bioremediation, due to its broad aromatic substrate range and ability to grow at cold temperatures. |
