Effect of organic matter on nitrogenase metal cofactors homeostasis in Azotobacter vinelandii under diazotrophic conditions. Issue 1 (7th January 2016)

• Record Type: Journal Article
• Authors: Jouogo Noumsi, Christelle; Pourhassan, Nina; Darnajoux, Romain; Deicke, Michael; Wichard, Thomas; Burrus, Vincent; Bellenger, Jean‐Philippe
• Is Part Of: Environmental microbiology reports. Volume 8:Issue 1(2016:Feb.)
• Page Start: 76
• Page End: 84
• Publication Date: 2016-01-07
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; Electronic journals; 579.17
• DOI: 10.1111/1758-2229.12353
• Languages: English
• ISSNs: 1758-2229

Abstract

Summary: Biological nitrogen fixation can be catalysed by three isozymes of nitrogenase: molybdenum (Mo)‐nitrogenase, vanadium (V)‐nitrogenase and iron‐only (Fe)‐nitrogenase. The activity of these isozymes strongly depends on their metal cofactors, molybdenum, vanadium and iron, and their bioavailability in ecosystems. Here, we show how metal bioavailability can be affected by the presence of tannic acid (organic matter), and the subsequent consequences on diazotrophic growth of the soil bacterium A zotobacter vinelandii . In the presence of tannic acids, A . vinelandii produces a higher amount of metallophores, which coincides with an active, regulated and concomitant acquisition of molybdenum and vanadium under cellular conditions that are usually considered not molybdenum limiting. The associated nitrogenase genes exhibit decreased nifD expression and increased vnfD expression. Thus, in limiting bioavailable metal conditions, A . vinelandii takes advantage of its nitrogenase diversity to ensure optimal diazotrophic growth.