| Summary: | Microorganisms used for the biohydrometallurgical extraction of metals from minerals
must be able to survive high levels of metal and oxidative stress found in bioleaching environments.
The Acidihalobacter genus consists of four species of halotolerant, iron–sulfur-oxidizing acidophiles that
are unique in their ability to tolerate chloride and acid stress while simultaneously bioleaching minerals.
This paper uses bioinformatic tools to predict the genes and mechanisms used by Acidihalobacter
members in their defense against a wide range of metals and oxidative stress. Analysis revealed the
presence of multiple conserved mechanisms of metal tolerance. Ac. yilgarnensis F5T, the only member
of this genus that oxidizes the mineral chalcopyrite, contained a 39.9 Kb gene cluster consisting
of 40 genes encoding mobile elements and an array of proteins with direct functions in copper
resistance. The analysis also revealed multiple strategies that the Acidihalobacter members can use to
tolerate high levels of oxidative stress. Three of the Acidihalobacter genomes were found to contain
genes encoding catalases, which are not common to acidophilic microorganisms. Of particular
interest was a rubrerythrin genomic cluster containing genes that have a polyphyletic origin of
stress-related functions.
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