Articles of Significant Interest Selected from This Issue by the Editors

摘要

Comparably inert substrates, such as ketones, phenols, or some aromatic hydrocarbons, are activated in the absence of molecular oxygen by energy-expensive carboxylation reactions. Acosta et al. (p. 62286235) determined that the sulfate-reducing bacterium Desulfococcus biacutus activates acetone by a carbonylation reaction with carbon monoxide as cosubstrate, thus forming a reactive aldehyde derivative at a comparably low level of ATP expenditure. To date, carbon monoxide was known as a cosubstrate only in the well-described carbon monoxide dehydrogenase/acetyl coenzyme A (acetyl-CoA) synthase reaction, the key enzyme of homoacetogenic bacteria. This novel metabolic concept may be applicable also for anaerobic activation of other comparably inert substrates.Many proteobacteria employ quorum sensing to regulate pathogenesis by timing production of the virulence factors important in successful establishment of disease. Using a proteomics-based approach, Ramachandran and Stevens (p. 62446252) have newly identified genes that are regulated by the quorum-sensing regulator EsaR in the wilt disease maize pathogen Pantoea stewartii. Directly regulated genes within the regulon were characterized using electrophoretic mobility shift assays (EMSA) and DNA footprinting analysis. This study broadens our knowledge of quorum-sensing-controlled targets in this vector-borne plant pathogen and highlights the global nature of the quorum-sensing response in P. stewartii. .