Changes in protein synthesis during the adaptation of Bacillus subtilis toanaerobic growth conditions

After a shift of Bacillus subtilis from aerobic to anaerobic growth conditi ons, nitrate ammonification and various fermentative processes replace oxyg en-dependent respiration. Cell-free extracts prepared from wild-type a. sub tilis and from mutants of the regulatory loci fnr and resDE grown under aer obic and various anaerobic conditions were compared by two-dimensional gel electrophoresis. Proteins involved in the adaptation process were identifie d by their N-terminal sequence. Induction of cytoplasmic lactate dehydrogen ase (LctE) synthesis under anaerobic fermentative conditions was dependent on fnr and resDE. Anaerobic nitrate repression of LctE formation required f nr-mediated expression of narGHJI, encoding respiratory nitrate reductase, Anaerobic induction of the flavohaemoglobin Hmp required resDE and nitrite. The general anaerobic induction of ywfl, encoding a protein of unknown Ine general anaerobic induction or ywfl, encoding a protien or unknown functio n, was modulated by resDE and fnr, The ywfl gene shares its upstream region with the pta gene, encoding the fermentative enzyme acetyl-CoA:orthophosph ate acetyltransferase. Anaerobic repression of the synthesis of a potential membrane-associated NADH dehydrogenase (YjlD, Ndh), and anaerobic inductio n of fructose-1,6-bisphosphate aldolase (FbaA) and dehydrolipoamide dehydro genase (PhdD, Lpd) formation, did not require fnr or resDE participation. S ynthesis of glycerol kinase (GlpK) was decreased under anaerobic conditions . Finally, the effect of anaerobic stress induced by the immediate shift fr om aerobic to strictly anaerobic conditions was analysed. The induction of various systems for the utilization of alternative carbon sources such as i nositol (lolA, lolC, lolH, loll), melibiose (MelA) and 6-phospho-alpha-gluc osides (GlvA) indicated a catabolite-response-like stress reaction.