macro close up of nitrogen fixing bacteria actively converting nitrogen in a biological process

macro close up nitrogen fixing bacteria converting biological process microbiology biochemistry cycle cellular respiration enzymes nitrogenase fixation soil fertility plant growth symbiotic relationship root nodules agriculture nitrites nitrates denitrification ammonification ecosystem biogeochemical rhizobium leguminous plants fertilizers crop yield photosynthesis oxygen atmosphere nutrient cycling bacterial colonies agricultural productivity environmental sustainability agronomy health microscopic organisms