PS 8-77
Cultivation of oil degrading microbes and the effect of toxicity on marine ecosystems

Monday, August 10, 2015
Exhibit Hall, Baltimore Convention Center
Julissa L. Hunte, Environmental Science, Spelman College, Atlanta, GA

Oil is one of Earth’s most efficient natural resources and stores the energy generated by ancient photosynthetic activity. Oil does not only serve as a source for fuel, but also as food for microbes. Microbes are bacteria and fungi that can break oil to carbon dioxide and water. Microbes can also be used as a source to clean up oil and can biodegrade up to 90% of some light crude oil. During the Deep Water Horizon Oil Spill in the Gulf of Mexico a large amount of oil went on the shore line having ecological and economic effects. More than 8,000 wildlife species such as birds, sea turtles, and marine animals were injured or dead due to the spill. The objective of this project was to cultivate oil degrading microbes and analyze the effect the toxicity of the degraded sample has on marine ecosystems. During the course of this project oil degrading microbes were cultivated using a Labrenzia bacterial strain and marinobacter ENV1 and EN3 bacterial strains. The effects of the toxicity level of the bacteria degraded water oil mixture on marine ecosystems was also analyzed using rotifers.  


The results of this study differed between all 3 bacterial strains. The Labrenzia bacteria strain degraded the oil with marine broth, but when put in a more realistic marine setting with the use of marine water it was unable to degrade the oil efficiently. The ENV1 and EN3 marinobacter strains were able to degrade oil in both the marine broth and marine water. It took both the ENV1 and EN3 marinobacter strains 15 days to cultivate. Since the Labrenzia strain was not able to degrade oil in marine water it was not tested in the toxicity experiment, but the ENV1 and EN3 strains were and their toxicity levels differed in the rotifer wells. Even though both strains degraded oil in the same amount of days the ENV1 strain was more toxic than the EN3 strain and was more harmful to the ecosystem.