P59: Rhodococcus sp. DAP 96253 induced for high levels of NHase and amidase displayed an increased ability to utilize gaseous hydrocarbons such as ethylene or/and propylene gas

Rhodococcus sp. DAP 96253 is Gram-positive, aerobic soil bacteria that belongs to the family Norcardiaceae that have extensive bioconversion and biodegradation capabilities. Rhodococci are capable of degrading many short chain aliphatic and aromatic hydrocarbons, including the compound acrylonitrile by using Nitrile Hydratase (NHase) and Amidase enzymes. Previous literature has shown that cells cultured on a YEMEA Induction media that contains cobalt and urea induces the activity of NHase and Amidase.

Rhodococcal cells used in this study were initially cultured on YEMEA Non-Induced media and YEMEA Induced media (with cofactors cobalt, urea) for 7 days, cultures were harvested, re-suspended in PBS buffer, and wet packed weight of sample was recorded. The Rhodococcal cells were transferred to a biphasic media culture containing Minimal salts media (no carbon source), and 100ml of 99.9% pure propylene or 200ml of 100ppm ethylene/air gas mixture for 3 to 4 days at 30˚C. Cell cultures were harvested and wet packed weight was recorded. YEMEA non-induced cells average gain in total dry weight was ~0.0375g. YEMEA induced cells average gain in total dry weight was ~0.077g. The finding suggest that Rhodococcus cells previously induced for NHase activity on YEMEA plates are far more effective at utilizing ethylene or propylene gas.