Natural Classification of Bacteria

The second edition of Bergey's manual, published in Bergey's honor after his death had a more natural classification. There were over 40 phylums.

Cyanobacteria
A cyan colored bacteria that is photosynthetic and that will usually stain gram negative.

Actinobacteria
Actinobacteria is a new phylum that was developed because DNA evidence suggested that they belonged together. They all had a high guanine and cytosine ratio, and were consistent with gram positive bacteria.

Bacteria that fall into this category are mycobacterium and corynebacterium.

Firmicutes
Firmucutes are gram positive bacteria that have a low G+C ratio.

Staphylococcus, streptococci, bacilli, clostridium tetani, and mycoplasma all fall into this category

Proteobacteria
Proteobacteria are huge group that mostly consist of bacteria that will stain gram negative.

Examples are E. coli, Klebsiella, Neisseria, Rickettsiae.

Chlamydiae
Chlamydiae are gram negative and include the Chlamydia trachomatis, which causes the STD chlamydia. About half the people with gonorrhea also have chamydia.

Spirochetes
Gram negative worm-like bacteria that include Treponema and Borellia.