Researchers studied the bacteria in a cold spring sediment in Xinjiang, China. They analyzed 241 bacterial clones and found 86 different types, belonging to 11 phyla. The most common bacteria were Acidobacteria and Proteobacteria. Many of the bacteria were not previously known and some were related to nitrogen-fixing and nitrite-oxidizing bacteria. This shows that the bacteria in the sediment are very diverse and may include many unknown groups.