Metal reducers and reduction targets : A short survey about the distribution of dissimilatory metal reducers and the multitude of terminal electron acceptors
The longer we study the processes of microbial metal reduction the more we see the diversity within the processes. There are model organisms that are widely used to study the biochemistry of microbial metal respiration, but these strains are only the tip of the iceberg in terms of phylogenetic diversity. Dissimilatory metal reducers are highly abundant and widespread within the tree of life. Interestingly, the phylogenetic diversity seems to be mirrored by a biochemical diversity, which we are just beginning to assess. Diversity can also be seen in the terminal electron acceptors that can be used. Certainly, iron and manganese are the most influential environmental metallic electron acceptors and were therefore covered in the first chapter of this book. Nevertheless, other metals can serve as respiratory electron acceptors as well. These metals are mostly toxic and their reduction might not only be of respiratory purpose but also a detoxification process. Interestingly, in the past years, reduction of these alternative metallic electron acceptors became more and more an applied process for bioremediation, metal enrichment, and catalyst production. Therefore, this chapter deals with diversity and highlights phylogenetic diversity as well as the diversity within the usable metallic electron acceptors.