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|Title:||Implementation guidance for determining suitability of microorganisms for explosives degradation|
Installation Restoration Research Program (U.S.)
Fredrickson, Herbert L.
Ringelberg, David B.
Perkins, Edward J.
Polymerase Chain Reaction (PCR)
|Publisher:||Environmental Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
Abstract: This report pulls together past and recently completed research efforts conducted for the 6.1 basic work unit on “Microbiology and Degradation of Explosives.” Results are summarized in the form of guidance on the isolation and physiological, biochemical, genetic, and environmental characterization of explosives-degrading microorganisms. Primary emphasis is placed on those microorganisms degrading 2,4,6-trinitrotoluene (TNT) and 2,4- and 2,6-dinitrotoluene (2,4- and 2,6-DNT), but microorganisms degrading hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX or cyclonite), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) are also considered. The first section describes methods used to determine the presence and characteristics of explosives degradation. Topics covered include a method for screening soils for the presence of explosives-degrading activity, application of radiorespirometry to assess the ability of the microorganisms to degrade explosives to 14-CO2 and other products, and extraction and identification of explosives and explosives degradation products in samples from soil and water slurries incubated with explosives. The second section examines procedures used to evaluate the physiological, biochemical, and genetic properties of explosives-degrading microorganisms. Here, procedures used for isolation of these microorganisms are described and the application of modern lipid and nucleic acid technologies for identification of microbial isolates are presented. This section also summarizes the use of physiological and genetic properties to determine the degradation pathways utilized by microbial isolates and groups of isolates. The third section discusses microbial and environmental restrictions on explosives degradation. Particular emphasis is placed on relating microbial activity and composition to function in situ and assessing environmental considerations for explosives-degrading microorganisms, with an emphasis on (A.) basic processes relevant to microbial addition, (B.) modification of the soil environment to favor addition of explosives-degrading microorganisms, (C.) assessment of bioavailability, and (D.) determination of limiting factors under ex-situ conditions. The third section also considers the enhancement of microbial activity through use of forced molecular evolution versus use of mass culture and addition of native microbial species. The last section considers practical application of the basic procedures developed in the 6.1 work unit to line-funded and reimbursable biotreatment projects at the 6.2 level. Biotreatment scenarios examined include natural attenuation, rhizosphere-enhanced phytoremediation, and bioslurry treatment.
|Appears in Collections:||Miscellaneous Paper|