Formic hydrogenlyase induction as a basis for the Eijkman fecal coliform concept.

Many Enterobacter species recovered from a relatively unpolluted freshwater stream had the capacity to produce gas from glucose, lactose, and formate at 44.5 C. Composition of the evolved gas was shown to be CO(2) and H(2), which suggested that the enzyme system formic hydrogenlyase functions as the basis for the Eijkman fecal coliform concept. It is postulated that there are at least two different and distinct biochemical types of Enterobacter in the natural aquatic environment: one that lacks an active formic hydrogenlyase at 44.5 C and is associated with the intestinal tract of man and certain animals, and another which possesses the active enzyme at the elevated temperature and is found in soil or on vegetation free from fecal pollution.