Characterization of Diverse Hydrocarbon-Degrading Bacteria Isolated from Indonesian Seawater

Seawater sampled from the Semarang port in Indonesia was streaked onto inorganic-medium plates coated with weathered crude oil, and 153 strains were isolated. Analyses of 16S rRNA gene sequences identified 67 different phylotypes affiliated with Alphaproteobacteria (111 strains/44 phylotypes), Gammaproteobacteria (8/8) and Actinobacteria (34/15). The organisms represented by 36 phylotypes could transform petroleum components in pure cultures. Many of them were affiliated with genera yet unrelated to hydrocarbon degradation. Strains unaffiliated with known genera were also obtained. Results suggest that many as-yet-unknown hydrocarbon-degrading bacteria are present in tropical marine environments.