Bacteria came in 1977 when Carl Woese recognised that archaea have a separate line of evolutionary descent from bacteria. This new phylogenetic taxonomy depended on the sequencing of 16S ribosomal RNA, and divided prokaryotes into two evolutionary domains, as part of the three-domain system. 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
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