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 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 color of the bacterial growth comes from pigments within its cells. The slime formed around the bacteria provides it with a relatively high level of protection from external threats. Like other species in its genus, pink algae is a methane consuming bacterium. It has an affinity for the matrix of PVC plastics, and will attach