engleski

Possible interactions within methanotrophic-heterotrophic community

This work presents the results of the growth kinetics and dynamics of mixed methanotrophic-heterotrophic community growing in batch culture (shake flasks) at the temperatures of 20 and 30*C, under different methane and oxygen tensions. The main objective was to study the interactions between culture members in order to discuss possible significance of these associations in nature. The methanotrophic-heterotrophic community (culture MM1) was enriched from aquifer solids in continuously stirred reactor under a continuous stream of 30-35% methane in air at room temperature (20-23*C). It was characterized as a stable consortium consisting of one methanotroph (type II) and three or four heterotrophs (Henry and Grbić-Galić, 1990). In our experiments, when growing in shake flasks under different methane and oxygen tensions, culture MM1 showed as "tight" association, consisting of one obligate methanotroph with type II intracytoplasmic membranes and four heterotrophic species of different morphological and metabolic capabilities (Hršak and Begonja, 1996). Almost regular appearance of culture members and nearly constant growth and methane oxidation rates under different conditions illustrated that culture MM1 may be structured on the basis of specific relationships between the methanotroph and heterotrophic species. Most of these relationships, including those based on the removal of inhibitory compounds, alterations in the growth constants and the provision of specific nutrients, seem to be beneficial for both the methanotroph and heterotrophs, making the community adaptable to a range of environmental conditions containing methane as only carbon source.

microbial interactions; methanotrophs; heterotrophs

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