Distinctive heat-shock response of bioleaching microorganism Acidithiobacillus ferrooxidans observed using genome-wide microarray

Temperature plays an important role in the heap bioleaching. The maldistribution of ventilation in the heap leads to local hyperthermia, which does exert a tremendous stress on bioleaching microbes. In this study, the genome-wide expression profiles of Acidithiobacillus ferrooxidans at 40°C were detected using the microarray. The results showed that some classic proteases like Lon and small heat-shock proteins were not induced, and heat-inducible membrane proteins were suggested to be under the control of σ^E. Moreover, expression changes of energy metabolism are noteworthy, which is different from that in heterotrophic bacteria upon heat stress. The induced enzymes catalyzed the central carbon metabolism pathway that might mainly provide precursors of amino acids for protein synthesis. These results will deepen the understanding of the mechanisms of heat-shock response on autotrophic bacteria.