TESTING OF WATER QUALITY WITH BIOLUMINESCENT E. COLI

THE PRIMARY OBJECTIVE OF THSES STUDIES IS TO DETERMINE THE FEASIBILITY OF USING THE CLONED LUX GENE SYSTEM ISOLATED ON A PLASMID EXPRESSION VECTOR FROM LUMINOUS MARINE BACTERIA AND EXPRESSED IN E. COLI (OR POSSIBLY OTHER BACTERIA) TO DETECT TOXIC SUBSTANCES IN WATER. NUMEROUS TOXIC SUBSTANCESATTENUATE THE LUMINESCENCE FROM MARINE BACTERIA. THIS IS PRESUMABLY DUE TO THE INSERTION OF THE TOXIC MATERIALS INTO THE CELL MEMBRANE AND PARTIAL DISRUPTION OF MEMBRANE- ASSOCIATED PROCESSES. IT IS NOT KNOWN WHETHER THE SAME PROCESSES WILL OCCUR IN E. COLI CARRYING THE GENETIC MATERIALS THAT ENCODES THE POLYPEPTIDES RESPONSIBLE FOR LUMINESCENCE. THERE ARE NUMEROUS ADVANTAGES TO UTILIZATION OF THE CLONED GENE SYSTEM IN E. COLI RATHER THAN IN THE NATIVE ENVIRONMENT: (1) E. COLI IS NOT A MARINE ORGANISM AND DOES NOT REQUIRE ADDITION OF SALT TO THE TEST WATER. (2) THE SYSTEM IN E. COLI IS UNDER READY GENETIC CONTROL. (3) THE SAME GENETIC SYSTEM CAN BE MOVED IN MANY DIFFERENT HOST ORGANISMS TO TEST FOR DIFFERENT SUBSTANCES. LUMIN- ESCENCE ASSAYS ARE BOTH EXQUISITELY SENSITIVE AND FAST. IT IS POSSIBLE TO DETECT THE LUMINESCENCE FROM A SINGLE BACTERIAL CELL WITH STANDARD EQUIPMENT. ADDITION OF LOW LEVELS OF TOXIC SUBSTANCES TO GLOWING CULTURES OF BACTERIA RESULTS IN ATTENUATION OF LIGHT THAT IS APPARENT WITHIN 30 SECONDS. THEREFORE, IF THE ASSAY IS FEASIBLE IN E. COLI OR OTHER NONMARINE BACTERIUM, IT SHOULD BE READILY ADAPTABLE TORAPID, BROAD-SPECTRUM SCREENING OF WATER SUPPLIES FOR TOXIC SUBSTANCES.