Microbes involved in dissimilatory nitrate reduction in the human large intestine

Nitrate-limited batch cultures, incorporating 20 different fermentation sub strates and inoculated with human faeces, mainly selected for the growth of enterobacteria. The microbial diversity involved was determined by a combi nation of phenotypic and genotypic procedures. Continuous culture with lact ate as the sole electron donor selected for similar micro-organisms, but wh en antibiotics were incorporated to inhibit Escherichia coli and lactate wa s replaced with choline, there was a wider microbial diversity recovered. C lostridium ramosum and Bacteroides vulgatus were then isolated as well as e nterobacteriaceae. (C) 2000 Federation of European Microbiological Societie s. Published by Elsevier Science B.V. All rights reserved.