Azotobacter—A Natural Resource for Bioremediation of Toxic Pesticides in Soil Ecosystems

Pesticides and chemical fertilizer reaching the soil in significant quantities have direct effect on soil microbiological activities, environmental pollution, and health hazards. Number of soil-borne bacteria has the ability to break down pesticides into simpler nontoxic compounds. Among them, plant growth-promoting rhizobacteria (PGPR) are best bio-inoculant bacterial species and have more influence on physiological and structural traits of soil properties. Among PGPR group, Azotobacter are one of the important genera studied over the decades because of its nitrogen fixation, used as a biofertilizer and produces array of growth-promoting substances and helps to replace chemical fertilizer for the sustainable agriculture production. Azotobacter species, viz., Azotobacter vinelandii, Azotobacter tropicalis, Azotobacter armeniacus, Azotobacter salinestris, and Azotobacter chroococcum showed 90%–100% degradation of three prominent pesticides such as pendimethalin, chlorpyrifos, and carbendazim. Azotobacter species also showed resistant to different pesticides and able to grow under stress conditions. Hence, usage of Azotobacter will help in organic farming for improving soil nutrients and also to remove hazardous chemicals from food chain. Thus, it clearly demonstrates that Azotobacter is not only natural habitant but they are also natural bioremediator.