“…This experimental evidence of thermodynamically feasible acetate oxidation -with Fe(OH) 3 as an electron acceptor -reveals the potential ability of microbes to reduce solid-phase iron which is carried by rivers in the region, using the fermented metabolites produced in oxygen-depleted water. This process would release dissolved bioavailable Fe for utilization by phytoplankton and chemolithotrophic microbes (Segovia-Zavala et al, 2013), and metalloenzymes required for reduction of nitrate and nitrite (Milligan and Harrison, 2000). In support of this working hypothesis, bacterial reduction of solid-phase metals associated with oxidation of acetate has in fact been detected in the Baltic Sea (Berg et al, 2013).…”