The appearance of microbially-mediated foam is a recognized problem in activated sludge plants and is often correlated with warmer temperatures and an over abundance of fats, oils and nutrients1 2 . The main causative microorganisms belong to the actinomycete group of bacteria, in particular to the genus Nocardia3 . In recent years, similar foaming events have taken place on the shores of the Sunshine Coast, Queensland, Australia after heavy rain and flooding events during the summer season. A preliminary study conducted by University of the Sunshine Coast isolated actinomycetes from foaming coastal seawater, finding that Nocardia were particularly common. Local beaches have been reported to be exposed to oil and nutrient pollution brought to the coastal sea water with flood and storm waters. This pollution constitutes a nutrient base for these microorganisms.
Exposure to oil presents a risk to the coastal and marine environment. Low boiling point hydrocarbons in oil are toxic and are an immediate threat to marine organisms by acting as a solvent for cellular fats and membranes, while those with a higher boiling point form slicks and block the exchange of water and water soluble nutrients4 5 . In the past, beaches were considered resilient to oil spills and easy to rehabilitate with a combination of mechanically removing oil contaminated sand and allowing natural processes to re-profile the beach, but this has since been otherwise disproven6 .
This research study investigated the oil degradative abilities of nocardiae isolated from foaming coastal waters between 2003 and 2012. Research results revealed the presence of an alkane biodegrading alkane monooxygenase gene in these isolates. Molecular sequencing studies also confirmed that the isolates belonged to the genus Nocardia. Bioremediation using close relatives of the native isolates has been in practice overseas via bioaugmentation. These findings could be utilized in bio-clean up processes to maintain pristine conditions of coastal beaches.