Advanced experimental analysis of controls on microbial Fe(III) oxide reduction. 1998 annual progress report

Technical Report · Mon Jun 01 04:00:00 EDT 1998

DOI:https://doi.org/10.2172/13478· OSTI ID:13478

Roden, E E; Urrutia, M M

'Understanding factors which control the long-term survival and activity of Fe(III)-reducing bacteria (FeRB) in subsurface sedimentary environments is important for predicting their ability to serve as agents for bioremediation of organic and inorganic contaminants. This project seeks to refine the authors quantitative understanding of microbiological and geochemical controls on bacterial Fe(III) oxide reduction and growth of FeRB, using laboratory reactor systems which mimic to varying degrees the physical and chemical conditions of subsurface sedimentary environments. Methods for studying microbial Fe(III) oxide reduction and FeRB growth in experimental systems which incorporate advective aqueous phase flux are being developed for this purpose. These methodologies, together with an accumulating database on the kinetics of Fe(III) reduction and bacterial growth with various synthetic and natural Fe(III) oxide minerals, will be applicable to experimental and modeling studies of subsurface contaminant transformations directly coupled to or influenced by bacterial Fe(III) oxide reduction and FeRB activity. This report summarizes research accomplished after approximately 1.5 yr of a 3-yr project. A central hypothesis of the research is that advective elimination of the primary end-product of Fe(III) oxide reduction, Fe(II), will enhance the rate and extent of microbial Fe(III) oxide reduction in open experimental systems. This hypothesis is based on previous studies in the laboratory which demonstrated that association of evolved Fe(II) with oxide and FeRB cell surfaces (via adsorption or surface precipitation) is a primary cause for cessation of Fe(III) oxide reduction activity in batch culture experiments. Semicontinuous culturing was adopted as a first approach to test this basic hypothesis. Synthetic goethite or natural Fe(III) oxide-rich subsoils were used as Fe(III) sources, with the Fe(III)-reducing bacterium Shewanella alga as the test organism.'

• Research Organization: Univ. of Alabama, Tuscaloosa, AL (US)
• Sponsoring Organization: USDOE Office of Environmental Management (EM), Office of Science and Risk Policy
• OSTI ID: 13478
• Report Number(s): EMSP-55164--98; ON: DE00013478
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
BIOGEOCHEMISTRY
Biogeochemistry
PROGRESS REPORT
Progress Report
REMEDIAL ACTION
Remedial Action