Rapidly detect and quantify specific microbial populations and processes involved in Microbiologically Induced Corrosion (MIC).
CENSUS employs a molecular biological tool (MBT) called quantitative polymerase chain reaction (qPCR) for enumeration of specific microorganisms or genes encoding specific biological processes associated with MIC. To elucidate the distribution, abundance, and functional interactions in corrosion-related microbial populations, MI offers CENSUS quantification of total bacteria and a variety of microbes commonly implicated in MIC including sulfate reducing bacteria (SRB), nitrate reducing bacteria (NRB), methanogens, and acid producing acetogens.
Evaluation of the microorganisms present within a system permits project managers to:
- detect MIC bacteria and thereby provide for timely correction of a corrosive condition
- quantify MIC bacteria to determine the appropriate aggressiveness of treatment
- monitor remedial efficacy in a corrosive environment
CENSUS qPCR is an effective dection and enumeration tool for MIC related microorganisms. CENSUS – Bacterial Group Targets for MIC include:
|
Target
|
MI Code
|
Relevance / Data Interpretation
|
|
Total Eubacteria
|
qEBAC
|
MIC is initiated by growth of a biofilm on the material surface. Monitoring total bacteria provides a general measure for evaluating bacterial growth in the system.
|
|
Total Archaea
|
qARC
|
Archaea are another general group of single celled microorganisms which, like bacteria, can initiate and contribute to MIC. Depending upon types and environmental conditions, total archaea can outnumber total bacteria and be a more important factor in MIC.
|
|
Sulfate Reducing Bacteria
|
qAPS
|
Sulfate reducing bacteria (SRB) are the group of microorganism most commonly implicated in the pitting corrosion of various metals. The qAPS CENSUS assay for SRB targets a functional gene involved in sulfate reduction.
|
|
Methanogens
|
qMGN
|
Corrosion rates due to methanogens can be comparable to those of sulfate reducing Desulfovibrio cultures. In addition to directly promoting MIC, some methanogens may also promote growth and activity of other MIC-associated microorganisms including SRB and acetogens.
|
|
Acid Producing Bacteria
|
qAGN
|
Acetogenic bacteria are strict anaerobes that produce acetate from the conversion of H2-CO2, CO, or formate. Hydrogen mediated acetogenesis has been demonstrated in high pressure natural gas pipelines confirming the in situ activity of this bacterial group. Further, the presence of acetic acid is known to exacerbate carbon dioxide corrosion of carbon steel.
|
|
Nitrate Reducing Bacteria
|
qDNF
|
Increasingly, nitrate addition is being used to stimulate growth of nitrate reducing bacteria as a bioexclusion strategy to combat SRB-mediated reservoir souring and MIC. The qDNF assay quantifies target genes encoding enzymes responsible for a key step in biological nitrate reduction.
|
|
Archaeoglobus
|
qARG
|
A specific genus of hyperthermophilic, sulfate reducing archaea implicated in MIC at elevated temperatures.
|
|
Iron Oxidizing Bacteria
|
qFeOB
|
Iron oxidizing bacteria are a group of microorganisms commonly implicated in pitting corrosion on various metals.
|
|
