NUCLEIC-ACID ANALYTICAL APPROACHES IN BIOREMEDIATION - SITE ASSESSMENT AND CHARACTERIZATION

Bioremediation, the removal of environmental pollutants by living orga nisms, has become a viable and promising means of restoring contaminat ed sites. Gene probing techniques have enhanced our ability to assess the efficacy of microbial-based remediation efforts. DNA probes target ing specific genetic sequences, i.e. those genes responsible for the d egradative ability of the microorganism, can be used to characterize a contaminated site throughout the bioremediation program to determine overall community structure and catabolic activity. To do so, however, requires efficient techniques for recovering nucleic acids from envir onmental sites as well as methods for generating probes to the specifi c genetic sequences desired. This review discusses procedures for isol ating DNA, messenger RNA, and ribosomal RNA from environmental samples , the utilization of polymerase chain reactions to construct gene prob es, and hybridization methods to genetically match the probe to the en vironmental sample. The use of these methods and advancement of techni ques at several bioremediation sites is also presented along with typi cal problems and limitations encountered. The first case study involve s monitoring the effects of nutrient addition to stimulate microbial d egradation of chlorinated solvents at the DOE Westinghouse Savannah Ri ver Site. The next case study describes the bioremediation of chlorina ted solvents and low levels of BTEX at Dover Air Force Base, Delaware. The final study is a field-scale natural attenuation project currentl y underway at Columbus Air Force Base, Mississippi. (C) 1998 Elsevier Science B.V.