Abstract Background The obligate aerobe Azotobacter vinelandii is a model organism for the study of biological nitrogen fixation (BNF). This bacterium regulates the process of BNF through the two component NifL and NifA system. where NifA acts as an activator. while NifL acts as an anti-activator based on various metabolic signals within the cell. https://www.lodiceelpueblo.com/product-category/eye-gels/