In order to survive in complex and interesting environments in the wild, bacteria have a whole arsenal of chemical products that they make within the cell. These chemicals are used for signalling, defence and communication between bacterial cells. One particular group of these chemicals is called the polyketide group, which I have a particular fondness for as I studied polyketides for my degree project. Several antibiotics are polyketides, so they are useful things for bacteria to have.
Polyketides don’t just exist in bacteria, they are also present in plants, fungi, protists and even some animals. They are most commonly found in organisms that are sharing mutualistic relationships, such as colonies of sponges, and the symbiotic bacteria of insects. This may be due to their usefulness as a signalling molecule. In particular lichenised fungi, i.e fungi sharing a relationship with algae or green-bacteria (cyanobacteria) contained a large number of polyketides. When examined closer however, it was found that only 10% of these were related to plant polyketides, the rest were more unique.