Pantothenate, an essential vitamin for animals and humans, can be synthesized by plants and many microbes, such as Bacillus subtilis. Although the pantothenate used for animal feed and other purposes is normally produced by chemical synthesis, this talk will discuss the genetic engineering of a laboratory strain of B. subtilis for the production of D-pantothenate by fermentation. Normally, B. subtilis produces only small amounts of pantothenate, just sufficient for its own needs. Through a series of genetic engineering steps, we have greatly increased the amount of pantothenate secreted by B. subtilis in a fermentor to levels (>80 g/l) such that a commercially feasible alternative to chemical synthesis of the vitamin has been developed. This talk will describe the B. subtilis genes that have been found thus far to be important for the synthesis of pantothenate and the methods we have used to deregulate and increase their expression. These genes include not only pan genes directly involved in pantothenate biosynthesis, but also isoleucine/valine (ilv) biosynthesis genes and serine (ser) and glycine (gly) biosynthesis genes involved in the synthesis of substrates for pantothenate biosynthesis. This work also led to the discovery of a novel pantothenate kinase. This enzyme, which we named CoaX, had no homology to any known pantothenate kinase; however, homologs of this gene can be found in a number of bacterial species, including some that lack a homologue to the well known bacterial CoaA pantothenate kinase, and that are troublesome human pathogens, such as Pseudomonas aeruginosa and Helicobacter pylori.