Metal resistance in acidophilic microorganisms and its significance for biotechnologies.

Publisher: Springer International Country of Publication: Germany NLM ID: 8406612 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1432-0614 (Electronic) Linking ISSN: 01757598 NLM ISO Abbreviation: Appl Microbiol Biotechnol Subsets: MEDLINE

Original Publication: Berlin ; New York : Springer International, c1984-

Biotechnology*; Acids/*metabolism ; Bacteria/*metabolism ; Metals/*metabolism; Bacteria/genetics

Extremely acidophilic microorganisms have an optimal pH of <3 and are found in all three domains of life. As metals are more soluble at acid pH, acidophiles are often challenged by very high metal concentrations. Acidophiles are metal-tolerant by both intrinsic, passive mechanisms as well as active systems. Passive mechanisms include an internal positive membrane potential that creates a chemiosmotic gradient against which metal cations must move, as well as the formation of metal sulfate complexes reducing the concentration of the free metal ion. Active systems include efflux proteins that pump metals out of the cytoplasm and conversion of the metal to a less toxic form. Acidophiles are exploited in a number of biotechnologies including biomining for sulfide mineral dissolution, biosulfidogenesis to produce sulfide that can selectively precipitate metals from process streams, treatment of acid mine drainage, and bioremediation of acidic metal-contaminated milieux. This review describes how acidophilic microorganisms tolerate extremely high metal concentrations in biotechnological processes and identifies areas of future work that hold promise for improving the efficiency of these applications.

0 (Acids)
0 (Metals)

Date Created: 20140809 Date Completed: 20150515 Latest Revision: 20140915

20240829

10.1007/s00253-014-5982-2

25104030