Multiple choice Example of non symbiotic is Azolla Rhizobium BGA Bradyrahzobium Reveal answer Fill a bubble to check yourself C Correct answer Explanation While Rhizobium and Bradyrhizobium are obligate symbiotic nitrogen fixers, and Azolla forms an obligate symbiosis with Anabaena, many Blue-Green Algae (BGA) can fix nitrogen in a free-living, non-symbiotic state.