Klebsiella sp.NIAB-I: A new diazotroph, associated with roots of kallar grass from saline sodic soils

Abstract

A nitrogen fixing organism containing a plasmid has been isolated from the rhizosphere fraction ofLeptochloa fusca (L) Kunth (kallar grass) growing on saline soils in the Punjab area. This bacterium can grow aerobically in a medium containing 1M NaCl and can fix nitrogen efficiently under microaerobic conditions on semi-solid medium with glucose or sucrose as a carbon source. Maximum N2-fixation in batch cultures occurred with 100 mM NaCl at pH 8.0 and 35°C. DNA hybridization and analysis of the protein pattern were carried out to establish its taxonomic position. On the basis of protein electrophoretic pattern, physiological characteristics, DNA relatedness, and better growth in the presence of high NaCl concentration, we regard this strain as a new species ofKlebsiella.