Growth characteristics and metabolic activities of the methanotrophic-heterotrophic groundwater community.

Abstract

In this work the growth characteristics and metabolic activities of the methanotrophic-heterotrophic groundwater community (culture MM1) as well as of individual community members were studied. When growing in shake flasks, under various methane and oxygen tensions, culture MM1 revealed the capability of a stable association consisting of one obligate methanotroph with type II intracytoplasmic membranes as the dominant strain, and four or five heterotrophs of different morphological, physiological and metabolic characteristics. Coexistence of different populations and the stability of culture MM1 under various conditions suggested that complex relationships may exist between the community members. Most of these relationships seem to be beneficial for both the methanotroph and heterotrophs, making the community adaptable to a range of environmental conditions containing methane as the only carbon source. Furthermore, faster and more complete transformation of 2-[4-(sulphophenyl)]decane (2C10LAS) by the community than by any of the community members alone, illustrates the role and importance of methanotrophic-heterotrophic interactions in combined metabolic attack on complex linear alkylbenzenesulphonates molecules.