Table 1.

Essential and nonessential B. subtilis genes

	Essential	Nonessential	Total
This study*	150	2,807	2,957
Previous studies†	42	614	656
Prediction‡	79	106	185
Phage genes	0	303	303
Total§	271 (6.6%)	3,830 (94.4%)	4,101

A list of the genes and their classifications can be accessed at http://bacillus.genome.ad.jp. 

^*We included 18 essential genes here that were inactivated in the course of this study and also studied previously. 

^† Carried out in B. subtilis. 

^‡ Full list is presented as Table 3. 

^§ Excluded are four genes that were not studied because of technical reasons (too short for insertional inactivation and too inconveniently placed for chloramphenicol replacement).