Nitrogen fixing ability, protein content and variation in pH values of Azotobacter in liquid and carrier based cultures at different intervals

Abstract

The study was performed at Commercial Biofertilizer Production Centre, Deptt. of Soil Science & Agril. Chemistry, JNKVV, Jabalpur comprising total 17 treatment combinations: two different types of (liquid and carrier based cultures of Azotobacter) individually maintained at different physical conditions of temperatures viz., 4oC (refrigeration), 20, 30, and 40 oC and subjected to different chemical inducers or stressors viz., no chemical, n-butanol, β-hydroxy butyrate and calcium deficiency. Every treatment was replicated thrice under randomized block design. The treatments were tested under both in vitro laboratory condition and pot experimentation with chilli crop (cv. Jawahar Mirch 283). Nitrogen fixing ability of liquid and carrier based Azotobacter cultures was measure at sixth month growth intervals. The different nitrogen fixing ability of Azotobacter cultures ranged from 3.12 to 4.81 mg/unit wt sucrose consumed with the treatment combinations of carrier based culture alongwith Ca-deficiency and liquid based cultures at 30oC, respectively. The value of 3.79 mg/unit wt sucrose consumed was the average nitrogen fixing ability of Azotobacter cultures. The variation in pH values of different cultures at the different intervals ranged from 5.28 to 7.20 with treatment combinations of carrier based culture along with Ca-deficiency and liquid culture maintained at 30oC, respectively with an overall average pH value 6.21.