| The symbiotic nitrogen fixing bacterium from legume | | | | 3-5%hydrogen peroxide were removed by washing |
| nodules. Nitrogen fixation is mediated by two microbial | | | | the nodules in sterile water for several time. Then the |
| systems: free living microbe like the other symbiotic | | | | nodules were transformed to the plates containing |
| forms like in the former type. The organisms produce | | | | 70% ethyl alcohol for 3minutes and then washed with |
| thick walls, there by producing a dormant cyst that is | | | | sterile water.Then nodules were crashed by using |
| resistant to drying and ultraviolet radiations. The latter | | | | mortar and pestle.The dilution were plated using hofer's |
| type establishes a mutually beneficial association with | | | | alkaline medium. The medium was allow to settle and |
| the plant roots and produces nodules on infected roots. | | | | plates were incubated at room temperature. |
| A root nodule bacterium can be isolated from root | | | | Nodules from the root of leguminous plant were |
| nodules of leguminous plants by crushing the nodules | | | | collected.The nodules were washed with sterile |
| and inoculating for hofer's alkaline medium which is | | | | water.The nodules were placed on a clean slide and |
| specific for its isolation. Hofer's alkaline medium medium | | | | crushed by pressing another slide over it. A thin smear |
| has the dye congo red which distinguishes organism | | | | was made by sliding the slides one over the |
| cells from some colonies by adsorbing the dye. | | | | other.Smear was allowed to dry and heat fixed.The |
| Plants having will developed nodules were collected. | | | | smear was stained with ethylene blue for 30 |
| The large pink nodules were separated from the roots | | | | seconds.The slides were washed with running water |
| and used for isolation of organism.The microorganisms | | | | and air dry, the slide was observed for the presence |
| on the surface of the nodules should be removed by | | | | of typical bacteria of various |
| surface sterilization with either 1%mercury chloride or | | | | configuration.White,smooth colonies were observed. |