**2. The emerging** *B. subtilis* **host**

*B. subtilis* has emerged as an appropriate host to supplement the use of BACs from *E. coli* (Itaya, 2009). Our favorite cloning host, *B. subtilis* 168, yet unfamiliar to many researchers, is a Gram-positive firmicute bacterium. It grows as rapidly and in the same media as *E. coli*. Consequently, many protocols used with *E. coli* can be used with *B. subtilis.* However, features inherent in *B. subtilis* facilitate natural transformation, in addition, the bacterium forms endospores that survive for extraordinarily long periods. *E. coli* lacks these features.
