Moving from scientific journals to even a Netflix special, microbiomes have been a popular topic in the news. Most popular articles discuss the human digestive tract microbiome which is one of the key factors in keeping us healthy. Just like the digestive tract, the wastewater treatment plant houses a diverse microbial community with many important players both good and bad.

What is a wastewater microbiome?

Take a sample of MLSS from a wastewater treatment plant and you will find thousands of microbial species. While MLSS is mostly bacteria, you also find protozoa, fungi, and archaea in smaller amounts depending upon the local conditions. The term microbiome is used to describe this community of microbes living in the system. This community fluctuates based on influent composition, environmental conditions, and how we run the biological treatment system. Monitoring allows operators to make adjustments to keep the biomass within a good range. One of the recent tools for monitoring includes identifying and quantifying the microbial workers in the system – which gives direct information what is working in the system to treat influent.

Monitoring the wastewater microbiome

Every test on the system including MLSS/MLVSS, MCRT, F/M, SV30/SVI, microscopic exam, and DO/OUR give data on the biomass health. Most are measures of physical properties with advanced testing being more on metabolic outputs (OUR, ATP, Nutrient conversions). Over the past decade, Aster Bio started using molecular (DNA based) testing tools to bio-prospect for interesting cultures used in bioremediation projects. Improvements in the technology have allowed Aster Bio to introduce molecular testing as a tool for optimizing system operation. By knowing what is growing in your system and tracking key organisms, you have valuable information for keeping the system at high efficiency. The most common tests include:

  • Microbial Community Analysis

    A total microbial census detailing what is growing in the system including details on their function. For wastewater, we usually run the kingdom bacteria. For anaerobic digesters where we see vital archaea populations, we also evaluate archaeal populations.

  • qPCR 

    A rapid, quantitative test that looks for specific genetic sequences in a sample. qPCR is useful for systems where we know key organisms both good and bad and benefit from a test that gives very fast data turnaround. qPCR is fast but you only get information on the sequences that you are testing. So, having the correct primers is key for running an accurate test.