Bacteria: Polystyrene Foam

Another species of bacterium, Pseudomonas putida, naturally found in soil, has been modified in a bioreactor to consume styrene. Actually, they remove the pollutants and converts the styrene into the plastic polymer PHA (polyhydroyalkanoates). PHA can be used as a biodegradable plastic in the use of eating utensils, and have a wide range of industrial and commercial uses such as medical implants or scaffolds for tissue engineering. The process starts by heating up styrene foam and converting it into styrene oil and then feed to the bacteria. PHA is heat, grease, and oil resistant and biodegrades in soil and water. But, if it is sent to a landfill, it will most-likely fossilize under the compressed layers of garbage and dirt.

Sources:

http://en.wikipedia.org/wiki/Biodegradable_plastics
http://en.wikipedia.org/wiki/Bioplastics