Comparative nitrogen fixation by mesophilic (HTS) vis-à-vis thermotolerant mutants (HTR) of Azotobacter chroococcum at high temperature and their effect on cotton biomass

Abstract

Introduction and objective: The amount of nitrogen fixed by Azotobacter varied from 0.02-0.25 KgN/ha/d and has been reported to be variable with various physiological and environmental factors. The nitrogen fixation by mesophilic soil isolates and their analogue resistant mutants of Azotobacter chroococcum was compared with their thermotolerant mutants at three different temperatures (30oC, 37oC, 42oC).