[The role of 2-C-methylerythritol-2,4-cyclopyrophosphate in the resuscitation of the "nonculturable" forms of Mycobacterium smegmatis].

2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate (MEC), an intermediate of the biosynthesis of isoprenoid compounds in bacteria, was found to be capable of exerting a resuscitating effect on resting Mycobacterium smegmatis cells. The introduction of an additional copy of the ispE gene encoding cytidyl-methylerythritol kinase, an enzyme involved in MEC synthesis in M. smegmatis, resulted in the emergence of a capacity for spontaneous reactivation of "nonculturable" M. smegmatis cells, which is not characteristic of the wild-type cells of this species. The involvement of MEC in the transition from the "nonculturable" state to the state of active growth is indicative of a previously unknown function of MEC, assumed to consist in regulation of the bacterial genome activity.