Alternative Carbon Assimilation Pathways in Methane-utilizing Bacteria

Abstract

SUMMARY: An examination of three species of methane-utilizing bacteria has shown (Lawrence, Kemp & Quayle, 1970) that the bacteria use one of two pathways of carbon assimilation, the serine pathway (Heptinstall & Quayle, 1970) or the ribose phosphate cycle of formaldehyde fixation (Kemp & Quayle, 1967). The isolation of many new types of methane-utilizing bacteria by Whittenbury, Phillips & Wilkinson (1970) has made possible an extension of these studies, and this paper reports the results of an examination of eight of the new isolates. The examination is based on the distribution of two key enzymes, each of which appears to be specifically involved in one of the assimilation pathways, namely hydroxypyruvate reductase (serine pathway) and hexose phosphate synthetase (ribose phosphate cycle).