Screening of biosurfactant producers from petroleum hydrocarbon contaminated sources in cold marine environments

- It is the first study on marine biosurfactant producers in North Atlantic Canada.
- Fifty-five biosurfactant producers of 8 genera were isolated and characterized.
- The 55 isolates include 1 Alcanivorax, 1 exiguobacterium and 2 halomonas strains.
- Some isolates reduced water surface tension to 28 dyens/cm and/or have E24 >50%.
- Some isolates formed flocculants which facilitate economic production.

An overview of literature about isolating biosurfactant producers from marine sources indicated no such producers have been reported form North Atlantic Canada. Water and sediment samples were taken from petroleum hydrocarbon contaminated coastal and offshore areas in this region. Either n-hexadecane or diesel was used as the sole carbon source for the screening. A modified colony-based oil drop collapsing test was used to cover sessile biosurfactant producers. Fifty-five biosurfactant producers belong to genera of Alcanivorax, Exiguobacterium, Halomonas, Rhodococcus, Bacillus, Acinetobacter, Pseudomonas, and Streptomyces were isolated. The first three genera were established after 1980s with interesting characteristics and limited relevant publications. Some of the 55 isolated strains were found with properties such as greatly reducing surface tension, stabilizing emulsion and producing flocculant. Isolates P6-4P and P1-5P were selected to demonstrate the performance of biosurfactant production, and were found to reduce the surface tension of water to as low as 28 dynes/cm.