In the root nodules of leguminous plants Rhizobium (a nitrogen fixing bacteria) lives in symbiotic association. Yeast helps in alcohol production not in bio-gas (by methanogenic bacteria). Myxomycetes (slime moulds) do not cause ringworm disease, it is caused by Microsporum audouini fungus. Mycorrhizae a mutualistic relationship between some soil fungi with the roots of higher plants. The higher plants provide the fungi with carbohydrates and in return the fungi provide the plants minerals (especially phosphorus) which the plants cannot absorb from soil.