DNA Analysis of Anaerobic Digestion Systems



Anaerobic Digestion DNA Analysis

Anaerobic digestion is a microbial process that relies on the presence of many different types of microbes to produce renewable energy and decompose wastewater sludge, biosolids, food and other organic waste. With Microbe Detectives’ Anaerobic Digestion DNA Analysis, one can attain an intimate understanding of their system’s microbial community, develop best practices and optimize performance.

Challenges with Anaerobic Digestion

Anaerobic digestion relies on the presence of many different types of microbes to work. The microbial community that makes up a specific digester’s microbiome (the combination of all types of microbes in the digester) will be influenced by operational and design conditions, such as SRT, mixing, operating temperature and pH, feedstocks, and chemical addition. The microbial community in turn will affect digester outcomes such as COD removal and biogas production. However, archaeal microbes essential to anaerobic digestion are not identifiable with field microscopes nor other standard test methods.

Advancements in Molecular Test Methods

Advancements in molecular methods (i.e., DNA analysis) have opened a new window to the microbial world of water. Our 2.0 DNA Analysis identifies and quantifies nearly all bacteria and archaea that are important in anaerobic digestion using 16S rRNA amplicon sequencing and qPCR. To attain higher resolution methanogen data, we offer mcrA gene DNA amplicon sequencing. The mcrA gene is specific to methanogens and enables more detailed data. We also identify and quantify eukaryotic organisms such as Protists (Protozoa, Amoeba, Algae) and Fungi for anaerobic digestion systems requiring diagnostics on higher life forms. 

Key Benefits of Anaerobic Digestion DNA Analysis

Know who’s there, how many, and what they are doing

Identify and quantify nearly all microbes important in anaerobic digestion.

  • Hydrolytic Bacteria Clostridium, Variovorax, Methanoculleus, Janthinobacterium, and Syntrophus convert raw feedstocks into smaller organic molecules that can be used by other microbial groups.
  • Acetogenic Bacteria Acetivibrio, Anaerobaculum, Anaerovirgula, Butyrivibrio, Clostridium, Coprothermobacter, Garciella, Gelria, Paludibacter, Propionicicella, Streptococcus, Syntrophomonas, Syntrophorhabdus, and Tissierella metabolize certain sugars (such as xylose or glucose), carbon dioxide or hydrogen to produce acetate.
  • Syntrophs can be Hydrolytic or Acetogenic. Aminobacterium, Geobacter, Smithella, Syntrophobacter, Syntrophorhabdus, and Syntrophus are syntrophs that decompose a variety of organic materials (usually fatty acids, alcohols and aromatic compounds) to produce acetate and H2, the primary food relied on by methanogens.
  • Methanogenic Archaea include aceticlastic and hydrogenoclastic methanogens. Aceticlastic methanogens Methanobrevibacter, Methanomicrobium, Methanosaeta, and Methanosarcina, metabolize acetate to produce methane biogas. Hydrogenoclastic methanogens Methanobacterium, Methanoculleus, Methanomethylovorans, Methanomethylovorans, Methanomicrobiales, Methanoregula, Methanosphaerula, Methanospirillum, Methanothermobacter, Methanothermus, and Methanothermus metabolise hydrogen to produce methane biogas.

Discover answers to questions and problems that you have been unable to solve

Use DNA analysis to quantify impacts of changes in feedstocks, system design, operating practices, or treatment, on anaerobic digestion performance.

Increase Biogas or high-purity Renewable Natural Gas (RNG) production by 10 – 30%+

Improving biogas production in a one-million gallon reactor by 5-10% can offset up to $200,000 annually in power costs when used for onsite power (Ling, A. 2020). RNG produced from an anaerobic digester sized for a municipality serving 50,000 residents is enough biofuel to power 32 transit buses, eliminating 2,745 metric tons of annual carbon emissions.

Mitigate risks of upset conditions, odor and foaming problems

As biological diversity increases an anaerobic digestion process is more resilient and less susceptible to upsets. Biological Diversity is quantified using Shannon’s Diversity Index. Odor and foaming associated microbes are also identified and quantified.

Key findings of the 2017 Anaerobic Digestion Study

View key findings presented by the Principal Investigator Dr. Alison Ling in the video below.

Dr. Alison Ling

Biogas Study: Summary & Key Findings (60 minutes) by Dr. Alison Ling, Barr Engineering
Panel Moderator: Jeremy Cramer, Senior Process Specialist, Donohue & Associates
Autumn Fisher, Superintendent, City of Fond du Lac
Chris Lefebvre, Wastewater Superintendent, Stevens Point, Wisconsin
Nick Menninga, General Manager, Downers Grove Sanitary District
Kamlesh Patel, Senior Environmental Research Scientist, MWRD of Greater Chicago

Anaerobic Digestion Systems Analyzed by Microbe Detectives

Municipal, industrial, food processing, agricultural and landfills.

Example DNA Analysis Dashboards for Anaerobic Digestion

Data is presented in tables to provide details. Dashboards show how Anaerobic Digestion processes change over time, and how they compare to other similar processes. Below are a few examples.

otu's biodiversity
fermentation acetogenesis
methane producing

Your Microbiome Analyst will provide guidance on the DNA analysis methods that will meet your needs and objectives.

Tracking Anaerobic Digester Performance using Next Generation DNA Sequencing

Autumn Fisher, City of Fond du Lac

[We use Microbe Detectives’ DNA analysis for] looking at our digester operations and looking at our methanogen populations and starting to get a better idea [of performance], because we do have a co-digestion program, we accept high-strength waste. How are those different substrates affecting our populations of methanogens within our digesters? Is it good? it is bad? What kind of changes have been made to our digestion that could affect our methane production? We have a biogas generator on site as well, so we’re utilizing that biogas. The biogas very important to us. If we can do anything to promote better biogas production that’s going to be helpful to us for energy [production]. So is [DNA Analysis] giving you more insight that you didn’t have prior? Absolutely, there’s a lot that we’ve been able to look at and quantify that we wouldn’t have been able to otherwise.
performance study anaerobic digesters 2017

2017 Performance Comparison of Biogas Anaerobic Digesters Report

2017 comparative study of biogas anaerobic digesters based on DNA sequencing of samples collected. Includes the DNA sequencing results of each sample, grouped and analyzed for each digester included in the study, and each digester type. Survey data is included to augment DNA testing. Includes pdf version available for immediate download after purchase (64 pages).