RESUMO
A comparative investigation of protein expression by two-dimensional gel electrophoresis was conducted between Bacillus subtilis cultures grown in defined medium under aerobic, anaerobic nitrate respiration, or fermentation conditions. Defined medium specific for either nitrate respiration or fermentation allowed distinction between proteins induced by each individual growth process. Our differential protein profiling analysis between aerobic and anaerobic conditions showed that anaerobic fermentation induced at least 44 proteins and nitrate respiration induced at least 19 proteins compared to aerobic controls. Certain proteins were specifically induced during nitrate respiration or fermentation, while others were induced by both anaerobic processes. Eleven proteins induced by nitrate respiration and/or fermentation were identified by peptide mass matching using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Proteins encoded by feuA, hmp, and ytkD were induced by nitrate respiration. Proteins encoded by pyrR, sucD, trpC, and ywjH were induced by fermentation. Proteins encoded by acuB, pdhC, ydjL, and yvyD were induced by nitrate respiration and fermentation. This proteomic analysis has provided a more complete characterization of B. subtilis anaerobic growth and increased our understanding of its metabolic pathways of nitrate respiration and fermentation.
Assuntos
Bacillus subtilis/metabolismo , Proteínas de Bactérias/metabolismo , Nitratos/metabolismo , Proteoma/análise , Bacillus subtilis/química , Proteínas de Bactérias/química , Meios de Cultura/química , Eletroforese em Gel Bidimensional , Fermentação , Regulação Bacteriana da Expressão Gênica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Bacillus subtilis anaerobic respiration and fermentative growth capabilities were compared to two other facultative anaerobes, Bacillus licheniformis and Escherichia coli. In glycerol defined medium, B. subtilis grew with nitrate, but not nitrite or fumarate, while B. licheniformis grew with nitrate or fumarate, but not nitrite. Growth of E. coli occurred in glycerol defined medium with either nitrate, nitrite, or fumarate. In order to grow by fermentation, B. subtilis required both glucose and pyruvate, while B. licheniformis and E. coli were capable of using either glucose or pyruvate.
