Metals and metalloids in photosynthetic bacteria: interactions, resistance and putative homeostasis revealed by genome analysis.

Microbial metabolism of metals and metalloids has been a topic of interest since the early seventies when it was recognized that bacteria are involved in the transformation of metal compounds in the environment. For this reason, bacterial processing of inorganic compounds has been reviewed several times over the past decade. However, this is the first time that the metal(loid)s metabolism of photosynthetic bacteria has been considered in detail as compared to non-phototrophs. Another aspect touched on for the first time in this chapter is the analysis of genomes of representative phototrophs in an attempt to reveal common or unique features of the interactions of these bacteria with metal(loid)s. This work not only identified new genes linked to metal resistance, but also contributed to unify the nomenclature used among the genomes of different photosynthetic species. Based on our analysis, similarities and differences can be used more efficiently in future work as new ‘preys’ that have been either hypothesized or described generically in the past have also been uncovered.