TRANSFORMATION STUDIES WITH THIOBACILLUS FERROOXIDANS AS A PREREQUISITE FOR STRAIN IMPROVEMENT FOR STRATEGIC METALS RECOVERY

ESTIMATES THAT SUGGEST THAT METALLIC ORE DEPOSITS ARE BEING DEPLETED THOUGH THE REQUIREMENT FOR METALS (ESPECIALLY STRATEGICALLY IMPORTANT ONES) ARE INCREASING. TOXIC-METAL RICH WASTE OCCURS IN SEVERAL INDUSTRIAL PROCESSES, AND ORGANISMS SUCH AS THIOBACILLUS FERROOXIDANS COULD BE USED TO DETOXIFY THIS WASTE. OUR ABILITY TO TAKE FULL ADVANTAGE OF THE VALUE OF MICROBIAL WASTE METAL MANAGEMENT IS HAMPEREDBY OUR LACK OF KNOWLEDGE ABOUT THE GENETICS AND BIOCHEMISTRYOF T.FERROOXIDANS. TO DATE, THERE ARE NO PUBLISHED PROCEDURES FOR THE GENETIC TRANSFORMATION OF THE ORGANISM. TRANSFORMATION WILL PERMIT SPECIFIC MODIFICATIONS TO BE MADETO T.FERROOXIDANS FOR THE PURPOSE OF IMPROVING ITS METAL PURIFYING CAPACITY. THE RESEARCHERS WILL USE CELLS GROWN ATPH5 AND PLASMIDS CONFERRING KANAMYCIN RESISTANCE TO PERFORM TRANSFORMATION OF THE ORGANISM (PH5 IS A COMPROMISE BETWEEN THE PH FOR GROWTH AT WHICH DNA IS UNSTABLE AND PH8, THE OPTIMUM FOR MOST TRANSFORMATIONS BUT WHERE T.FERROOXIDANS ISINACTIVE). THEY ALREADY POSSESS KANAMYCIN SENSITIVE AND RESISTANT STRAINS THAT WERE OBTAINED FROM CULTURES GROWN AT PH5 ON SULFUR-CONTAINING MEDIUM.