Genus names capitalization

Genus names, as formal names, should be capitalized and italicized. Species should not be capitalized, but they should be italicized. Genus names are spelled out in full at first mention and abbreviated thereafter. 

The second word in the name of a microorganism is the species name and is not capitalized. There may be several species with the same genus name, for example, Bacillus subtilis, B. albus, and B. coagulans. Note that when the same genus name is repeated several times, it is abbreviated... 

Do not capitalize genus names used as common nouns except at the beginning of a sentence or in a title or heading. 

Always capitalize genus names, but never capitalize species names, in titles and headings. 

Always capitalize genus names as formal names, but never capitalize species names, even in titles. Do not capitalize the abbreviation for species, singular or plural (sp. and spp., respectively). 

Always capitalize kingdom, phylum, class, order, family, and genus taxonomic names, as well as names of cultivars. Subclassifications follow the same presentation as the main category. 

Notes 1. Restriction endonucleases are named by italicized three-letter codes of which the first capital letter denoting the genus of the organism of origin and die next two letters are an abbreviation of the particular species. Tlie following capital letter and number codes represent the strain and sequence as die enzymes are... 

The Latin genus-species" unit is always written in italics the name of the genus always takes a capital initial letter, whereas the name of the species never does (e.g., Homo sapiens). 

---