The mutually beneficial relationship between algae and modern corals — which provides algae with shelter, gives coral reefs their colors and supplies both organisms with nutrients — began more than 210 million years ago, according to a new study by an international team of scientists including researchers from Princeton University.
A nitrite-oxidizing enzyme may work in reverse for some microbes in the Antarctic autumn. Marine microorganisms play a major role in cycling elements like carbon and nitrogen throughout the environment. In the nitrogen cycle, some microbes perform an especially important step: the oxidation of nitrite (NO2−) to nitrate (NO3−), the dominant form of biologically available nitrogen in the ocean. Now Kemeny et al. suggest that the enzyme that converts nitrite to nitrate sometimes works in revers