survival of the fittest overcoming oxidative stress at the extremes of acid, heat and metal适者生存克服极端的酸氧化应激,热量和金属.pdfVIP

Life 2012, 2, 229-242; doi:10.3390/life2030229 OPEN ACCESS life ISSN 2075-1729 /journal/life Review Survival of the Fittest: Overcoming Oxidative Stress at the Extremes of Acid, Heat and Metal Yukari Maezato and Paul Blum * Beadle Center for Genetics, University of Nebraska, Lincoln, NE 68588-0666, USA; E-Mail: yukarimaezato@ * Author to whom correspondence should be addressed; E-Mail: pblum1@; Tel.: +1-402-472-8969. Received: 4 July 2012; in revised form: 14 August 2012 / Accepted: 17 August 2012 / Published: 23 August 2012 Abstract: The habitat of metal respiring acidothermophilic lithoautotrophs is perhaps the most oxidizing environment yet identified. Geothermal heat, sulfuric acid and transition metals contribute both individually and synergistically under aerobic conditions to create this niche. Sulfuric acid and metals originating from sulfidic ores catalyze oxidative reactions attacking microbial cell surfaces including lipids, proteins and glycosyl groups. Sulfuric acid carbon. Oxidative reactions leading to abstraction of electrons is further impacted by heat through an increase in the proportion of reactant molecules with sufficient energy to react. Collectively these factors and particularly those related to metals must be overcome by thermoacidophilic lithoautotrophs in order for them to survive and proliferate. The necessary mechanisms to achieve this goal are largely un