PH-DEPENDENT ACTIVATION OF THE ALTERNATIVE TRANSCRIPTIONAL FACTOR SIGMA(B) IN BACILLUS-SUBTILIS

The expression of the sigB gene of Bacillus subtilis was analysed in r esponse to a mild acid shock. This gene is subject to sigma(B-)depende nt regulation. It has been found that the expression of sigB is induce d as part of the acid tolerant response. In that respect sigB is simil ar to the previously described gene gsiB which is also a member of the sigma(B) regulon. Through this induction, the sigma(B) regulon provid es protection against acid shock. Besides its protective role against acid shock, no other general function could be directly associated wit h the sigma(B) regulon. An acidification of the cytoplasmic environmen t induces synthesis of general stress proteins in B. subtilis. (C) 199 8 Federation of European Microbiological Societies. Published by Elsev ier Science B.V. All rights reserved.