Project no. 201
Biodegradation of Plasticizers by Marine Bacteria
DTU Bioengineering, Technical University of Denmark
Plasticizers are widely used in the plastics industry to add certain desired characteristics to
plastic such as softness, durability and flexibility. Unfortunately, some of them are toxic to
humans and other forms of life. They have disruptive effects on the endocrine system, which
results in reduced fertility, altered behavior in marine organisms and even changes in the
brain. Furthermore, plasticizers have been linked to diabetes type 2, obesity and cancer.
It is evident that these chemical additives are very harmful to the environment they are in,
and the marine environment is at particular risk since this is where most effluents containing
plasticizers terminate. In relation to this, humans are at even greater risk when eating
seafood affected by plasticizers. Possible bioremediation strategies for removal of these
pollutants from the oceans include biodegradation by marine bacteria. However, only a few
marine bacteria capable of biodegradation of plasticizers have been isolated.
My project presents an approach to identify marine bacteria with biodegradation abilities
towards plasticizers. From known research, I collected the few gene sequences known to be
involved in plasticizer degradation in other bacteria. Via bioinformatic tools, these sequences
were compared to the gene sequence data from bacteria collected on the Galathea 3
expedition, where marine bacteria were collected from all around the globe. This yielded
seven interesting marine bacteria to work with in order to find a bacterium that can be used
for biodegradation of plasticizers in the environment.
RESULTS AND CONCLUSION
Through the bioinformatic screening conducted, I found that especially one bacterium;
Ruegeria mobilis NBRC102038 showed great potential for biodegradation of plasticizers
genomically and should be examined further in future studies. Furthermore, three strains
belonging to one family of bacteria; Rhodobacteraceae, were found to have genomic
potential of biodegrading plasticizers, which aligns with previous research, making this
family of particular interest for bioremediation strategies.
In the future, marine bacteria that can biodegrade plasticizers can be used to clean up these
pollutants from the oceans. This requires more research into R. mobilis and the
Rhodobacteraceae family to reveal if they are suitable for bioremediation of plasticizers
directly in the oceans or if for instance the enzymes should be purified and applied.