Vol. 12, Issue 12 (2023)

Author(s):
A Mounica, CT Kumbhar, VA Jiotode and SV Deshmukh

Abstract:
The current investigation was carried out with the aim to study the variability in Azotobacter species pertaining to physio-morphological characteristics and nitrogen fixing ability. It revealed that, among 50 different isolates obtained from the soil samples of Maharashtra, 11 isolates belonged to A. beijerinckii and remaining 39 isolates belonged to A. paspali. The isolates PN 7, PN 8, AH 1 (A. paspali) and PN 2 (A. beijerinckii) were found to be fixing nitrogen greater than 30 mg / g of sucrose, whereas the isolates ST 6, AH 6, AH 18, AH 7, AH 9, AH 17 (A. paspali) and AH 20 (A. beijerinckii) were fixing atmospheric nitrogen lesser than 10 mg / g of sucrose consumed. Both the species Azotobacter beijerinckii and Azotobacter paspali had shown similar results in Gram staining reaction, catalase and oxidase test, indole formation, gelatin liquefaction, carbon source utilization test but showed variation in morphological, cultural characteristics, motility test, starch hydrolysis test and nitrogen fixing efficiency.