MiDAS: Field Guide to the Microbes of Activated Sludge and Anaerobic Digesters
MiDAS (Microbial Database for Activated Sludge) is a central collaborative workspace available to researchers and wastewater treatment practitioners to facilitate a better understanding of the microbial ecology of the engineered ecosystems of activated sludge plants, anaerobic digesters, and related wastewater treatment systems. The ambition of the field guide is to summarize all the knowledge about the physiology and ecology of the important microorganisms present in these systems. Integral to this goal is the ability to link an organism’s name with its putative function.
We have developed the MiDAS taxonomy (available for download), which is a manual curation of the 16S rRNA gene sequence-based SILVA taxonomy that proposes a name for all genus-level taxa observed to be abundant by large-scale amplicon sequencing of communities of full-scale activated sludge wastewater treatment plants and their associated anaerobic digesters. The goal is to provide a common taxonomy for the field that will provide a solid foundation for the study of microbial ecology of systems related to wastewater treatment, nutrient recovery and bioenergy production. The taxonomy can be used to classify unknown sequences, and the online MiDAS field guide links the identity to a referenced summary of their in situ metabolism, morphotype, and distribution in these systems. The recent incorporation of abundance information of individual genera in the influent wastewater, activated sludge, and anaerobic digesters additionally allows an assessment of immigration on population structure.
Recently we have launched the MiDAS Global Database project, where we collect samples from diverse wastewater treatment systems and anaerobic digesters across the world (check who has already joined us). Our aim is to encompass as much as possible of the microbial diversity present in these ecosystems across the world by applying novel high throughput sequencing technologies and to expand our MiDAS database, ultimately creating a universal guide to the field.