The ability of some thermo-alkalophilic Bacillus species to fix nitrogen, isolated from Madinah Munawwarah Soils, Saudi Arabia

Abstract EN

Trials were made to detect the presence of Thermoalkalophilic that has ability to nitrogen fixation, in certain soils at Madinah Munawwarah province, Saudi Arabia.

Soil samples were obtained from two different localities, and they were chemically analyzed.

The microorganisms used were Bacillus alvei, B.

brevis, B.

meg-aterium, B.

circulans, and B.

pumilus, and they prefer to grow at high temperature 60ºC in media adjusted at pH 10.

The result shows that these isolations have the ability to fix nitrogen.

The biomass and the nitrogenase activity after 24 h at 60ºC were : (Bacillus alvei, 1.5 µg/ml; B.

brevis, 1.9 µg/ml; B.

megaterium, 1.4 µg/ml; B.

circulans, 1.6 µg/ml; and B.

pumilus, 1.3 µg/ml).