Ferric Iron Reduction by Fermentative Strain BS2 Isolated From an Iron-Rich Anoxic Environment (Lake Pavin, France)

A facultatively Fe-reducing strain BS2 related to Clostridium saccarobutylicum was isolated from the anoxic zone of iron-rich Lake Pavin. A comparative study was performed on the growth, fermentative profile and heat production of BS2 on glucose in presence and absence of Fe(III). Fe(III) availability led to an optimization of glucose uptake and higher maintenance of strain BS2 in the growth media. Given the prevailing conditions (e.g., scarcity of metabolizable organic matter) in the anoxic zone of Lake Pavin, Fe(III) reduction by this facultative Fe(III) reducer may confer ecological benefits to strain BS2. Moreover, in presence of Fe(III), there was a modification of the fermentative balance that may influence the terminal-accepting processes in this layer.