GENETIC AND BIOCHEMICAL STUDIES WITH THIOBACILLUS FERROOXIDANS FOR ENHANCED METAL RECOVERY FROM LEACH PILES AND COAL WASTE.

METALS RECOVERY FROM LEACH PILES AND COAL WASTES (FLY ASH AND BOTTOM ASH FROM BURNING) CAN BE A VALUBLE SOURCE OF STRATEGICALLY IMPORTANT METALS. IN ADDITION, RUNOFF AND LEACHATES FROM COAL WASTES CONTAIN POTENTIALLY TOXIC HEAVY METALS SUCH AS ARSENIC, SELENIUM, CADMIUM, AND MERCURY THAT CAN HAVE DETRIMENTAL EFFECTS ON ANIMAL AND HUMAN POPULATIONSVIA GROUNDWATER CONTAMINATION. THIOBACILLUS FERROOXIDANS CAN BE USED TO LEACH VALUBLE METALS FROM LOW GRADE ORES AND IN A PRETREATMENT PROCESS TO REMOVE TOXIC METALS FROM COAL WASTES. A MAJOR DRAWBACK WITH THIS IDEA IS THAT SOME OF THEMETALS ARE ALSO TOXIC TO THIOBACILLUS FERROOXIDANS. ALTHOUGH STUDIES HAVE BEEN PERFORMED RELATING GROWTH INHIBITION TO HEAVY METAL CONCENTRATION, VERY LITTLE WORK HAS BEEN DIRECTED TOWARDS THE BIOCHEMISTRY AND GENETICS OF METAL RESISTANCE IN THIOBACILLUS FERROOXIDANS. THIS RESEARCH WILL: DETERMINE THE EFFECTS OF TOXIC METALS ON THE COMPONENTS OF THE ORGANISM'S PROTON ELECTROCHEMICAL GRADIENT(I.E., ITS SOURCE OF ENERGY FOR ATP GENERATION); AND ISOLATEMUTANTS OF THIOBACILLUS FERROOXIDANS THAT ARE RESISTANT TO THE TOXIC EFFECTS OF INHIBITORY METALS.