A) Rhizobium
B) Azotobactor
C) Clostridium
D) Streptomyces
Correct Answer: A
Solution :
Rhizobium is nitrogen fixing bacterial symbiont of leguminous roots. It fixes the atmospheric nitrogen \[({{N}_{2}})\] into nitrate as to make the soil \[{{N}_{2}}\] rich. Symbiotic nitrogen fixation requires co-operation of nod genes of legume and nod, nif, fix gene clusters of bacteria. Azotobacter is a free living nitrogen fixing bacteria. It is a saprotrophic bacteria that perform nitrogen fixation under aerobic conditions. Clostridium is anaerobic free living saprotrophic bacteria that fixes nitrogen under anaerobic condition. Streptomyces is most common bacterium from which maximum antibiotics have been reported. Streptomycin was first isolated by I Waksman from Streptomyces griseus. It is effective against both Gram \[\text{+ve}\]and \[-\text{ve}\] bacteria. This antibiotic is generally used against TB maningitis, pneumonia. Streptomyces has not been found any role to play in \[{{\text{N}}_{\text{2}}}\]fixation.You need to login to perform this action.
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