The moderately halophilic bacterium Halomonas maura is a free‐living diazotroph

Halomonas maura is a moderately halophilic bacterium which lives in saline soils and synthesises an exopolysaccharide known as mauran. Strain S-31 T grew in a nitrogen-free medium under an N2 atmosphere; the acetylene reduction assay proved positive under specific conditions. We identified the nifH gene in this strain by using degenerate oligonucleotides designed from highly preserved gene sequences obtained from the alignment of a large number of nifH sequences from different microorganisms. Our results lead us to conclude that H. maura is capable of fixing nitrogen under microaerobic conditions. 2005 Published by Elsevier B.V. on behalf of the Federation of European Microbiological Societies.