Bacteria Bacteria Bacteria (; common noun bacteria, singular bacterium) are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only about half of the
Pink algae pink algae. All visible pink algae must be manually removed from a pool. A dose of algicide, followed by a shock treatment is also necessary to destroy the bacteria. The pool filter must be run constantly until the water is clear and halogen or peroxide levels are normal, then the filter must be chemically cleaned. Pink algae Pink algae is a growth of pink, slimey bacterial matter which can sometimes occur in pools and sometimes in laboratory tubings. The title is a misnomer, because, as noted before, pink algae is actually caused by a bacterium, in the genus methylobacterium. The