[Participation of nitrifying bacteria in the disintegration of serpentinous ultrabasic rock]

Nitrifying bacteria were found to be widely distributed among the products of the weathering crust of ultrabasite rocks. Nitrosospira briensis and Nitrobacter winogradskyi involved in the first and second phases of nitrification, respectively, were detected and isolated as pure cultures. In experiments conducted with a pure culture of Nitrosospira briensis, a correlation was established between degradation of serpentinite by this culture and an increase in the content of nitrites in the growth medium. The presence of nitrogen compounds in the deposits, as well as wide distribution of nitrifying bacteria, suggests that this bacterial group along with other, in particular, heterotrophic microorganisms participates in weathering of serpentinized ultrabasite rocks, leaching of elements, and formation of the weathering crust.