Phenetic and Molecular Diversity of Nitrogen Fixating Plant Growth Promoting Azotobacter Isolated from Semiarid Regions of India

Table 2

Qualitative and quantitative estimation of nitrogen fixation by Azotobacter strains.

Isolates	N2 fixation using NFMM with BTB	N2 fixed (mg g^-1 sucrose)	ARA (nmol C2H4 mg protein^−1 hr^−1)
Azo1	Positive
Azo2	Positive
Azo3	Positive
Azo4	Positive
Azo5	Positive
Azo6	Negative
Azo7	Positive
Azo8	Positive
Azo9	Positive
Azo10	Positive
Azo11	Positive
Azo12	Negative
Azo13	Positive
Azo14	Positive
Azo15	Positive
Azo16	Negative
Azo17	Positive
Azo18	Positive
Azo19	Positive
Azo20	Positive
Azo21	Positive
Azo22	Negative
Azo23	Positive
Azo24	Positive
CD at 5%	—	0.748152188	17.03123459
CV%	—	4.695825426	7.468182458

. Positive Azotobacter strains produced a blue color zone on the medium indicating the nitrogen fixation; using micro-Kjeldhal method; acetylene reduction assay.