Participatory Research to Quantify Microbes in River Water

The public service community lab near Lausanne, Switzerland, Hackuarium, has a long record of developing open science hardware. From ‘DIY’ fluorescence detectors, developed for bacterial biosensor studies, to an accurate and reliable spectrophotometer, a bioreactor, and other tools, Hackuarium members have made and continue to aim to make low cost and reliable tools for anyone to use. An initial Hackuarium project was around water quality, and work around quantitative microbiological measures of water quality began in 2016, using a ‘chromogenic’ gel format on classic petri dishes, with blue colonies highlighting E. coli (the main bioindicator for the presence of raw sewage) and pink colonies showing general coliforms (bacteria mainly of environmental origin). As beta testers for a special format of this system, the R-Card, we were impressed, as these not only reduce plastic use and decrease volumes in comparison to petri dishes, but are also very simple to use. Some early work was published in an open access article (https://doi.org/10.1002/2688-8319.12094) with Github analyses in python, and data accessible for anyone to examine via Zenodo. 

For the Panama GOSH in 2022, a special mini-incubator was developed in collaboration with Harold Tay for the workshop around water quality run then. Now, we report on results of the latest season of water quality work, when we had the opportunity to initiate a participatory research project around river water quality, which had always been a concern. In fact, in previous seasons, river water was only used as a ‘positive control’ for microbial tests, as it was very reliably positive for bioindicators of raw sewage. In collaboration with the ‘Maison de la Rivière’ the project Bacté-Rivières (https://wiki.hackuarium.ch/w/Bacterivieres) was developed; and for this summer’s sampling season, we had around 40 participants involved. With 15 rivers assessed, the mini-incubator was built also as a 3D-printed variant, for more convenient incubations by five of the teams. Finally, 10 years after starting these water quality efforts, we were able to really probe the microbial pollution levels of local rivers, and sensitize the public to this fact. Analyses to correlate results with local weather and other factors will be presented.