Question

other than rhizobium what other bacteria are observed in the legume root nodules? thank you :)

Answer 1

i found this on wikipedia...but u may want to cross check it once...if i find a better source i will post it....
Many other species of bacteria are able to fix nitrogen (diazotrophs), but few are able to associate intimately with plants and colonize specific structures like Legume nodules. Bacteria that do associate with plants include the actinobacteria Frankia, which form symbiotic root nodules in actinorhizal plants, and several cyanobacteria (Nostoc) associated with aquatic ferns, Cycas and Gunneras. Free-living diazotrophs are often found in the rhizosphere and in the intercellular spaces of several plants including rice and sugarcane, but in this case the lack of a specialized structure results in poor nutrient transfer efficiency compared to legume or actinorhizal nodules.

Answer 2

thank you @shrutipande9 :) its a big help :)