A bacterium called Ralstonia sp. PHS1 can break down harmful chemicals found in gasoline like benzene, toluene, and xylene. When these chemicals are mixed together, the bacterium can still break them down, but some are harder to break down than others. Benzene is the easiest, while p-xylene is the hardest. The bacterium can even break down xylene types that it doesn't use for growth. Mixing different chemicals together can slow down the breakdown process, but adding growth chemicals can speed it up. This bacterium is unique in how it breaks down these harmful chemicals compared to other bacteria.