Verbreitung methanotropher Bakterien

Abstract

This paper reports on the investigations of the distribution of the methanotrophic bacteria in various environments and geographic zones. In the most of about 1000 samples investigated by us obligately methanotrophic bacteria were found. More than 300 pure cultures were isolated, among them strains of all five groups of methanotrophs described by Whittenbury et al. (1970). There were great differences in their distribution patterns in several habitats. The occurrence of methanotrophic bacteria even in acidophilic peat bog lakes and in salt-lakes shows the great ecological amplitude of this group of organisms. Experiences with the use and the interpretation of the MPN-method for the enumeration of methanotrophic bacteria are presented. The results of the quantitative investigations enlarge the knowledge about the distribution of these organisms in various natural and artifical habitats and confirm their high frequency in the nature. The greatest densities of cells are found in sewage, but only small numbers of cells in the open water and sandy sediments of Baltic Sea and in salt-lakes. Generally the frequency of the methanotrophic bacteria was closely related to the concentration of methane, respectively, to the rate of methane release in the habitat. The high numbers of cells in the aerobic layers of sediments are an indication of the great activity of the aerobic methane oxidation in these zones.