These engineered organisms have been released into the environment at several locations worldwide.
Considerable controversy surrounds such releases.
In addition to engineered organisms, microbial cocktails can also be created to clean some environmental problems. These typically consist of a group of microbes that serve various breakdown functions for complex pollutants. For instance, it is not uncommon for restaurants that use large amounts of grease to have grease digester units installed in sewage lines. These are essentially larger containers where microbial cocktails are added to breakdown the greases to smaller components that are less toxic to the environment.