Eubacteria are the true bacteria, which lack a nucleus and membrane-bound organelles like mitochondria, chloroplast, etc. Bacteria are cosmopolitan. They can survive almost everywhere, including the bottom of oceans, our month, acidic and alkaline environment, hot springs, puddles, on glaciers, surface water, soil, foodstuffs, petroleum, rubbish, manure, the surface of plants, the surface of animals, body cavities, intestinal tracts of animals, etc.