Canary in the coliform mine : exploring the industrial application limits of a microbial respiration alarm system
Date
2021-03-04
Journal Title
Journal ISSN
Volume Title
Publisher
Public Library of Science
Abstract
Fundamental ecological principles of ecosystem-level respiration are extensively applied in
greenhouse gas and elemental cycle studies. A laboratory system termed CEMS (Carbon Dioxide
Evolution Measurement System), developed to explore microbial biofilm growth and metabolic
responses, was evaluated as an early-warning system for microbial disturbances in industrial
settings: in (a) potable water system contamination, and (b) bioreactor inhibition. Respiration was
detected as CO₂ production, rather than O₂ consumption, including aerobic and anaerobic metabolism.
Design, thresholds, and benefits of the remote CO₂ monitoring technology were described. Headspace
CO₂ correlated with contamination levels, as well as chemical (R² > 0.83–0.96) and microbiological
water quality indicators (R² > 0.78–0.88). Detection thresholds were limiting factors in monitoring
drinking water to national and inter- national standards (0 CFU/100 mL fecal coliforms) in both
open- (>1500 CFU/mL) and closed-loop CO₂ measuring regimes (>100 CFU/100 mL). However, closed-loop
detection thresholds allow for the detection of significant contamination events, and monitoring
less stringent systems such as irrigation water (<100 CFU/mL). Whole-system respiration was
effectively harnessed as an early-warning system in bioreactor performance monitoring.
Models were used to deconvolute biological CO₂ fluctuations from chemical CO₂ dynamics, to optimize
this real-time, sustainable, low-waste technology, facilitating timeous responses
to biological disturbances in bioreactors.
Description
CITATION: Stone, W., et al. 2021. Canary in the coliform mine : exploring the industrial application limits of a microbial respiration alarm system. PLoS ONE
16(3):e0247910, doi:10.1371/journal.pone.0247910.
The original publication is available at https://journals.plos.org/plosone/
Publication of this article was funded by the Stellenbosch University Open Access Fund
The original publication is available at https://journals.plos.org/plosone/
Publication of this article was funded by the Stellenbosch University Open Access Fund
Keywords
Coliform monitoring, Microbial respiration -- Measurement, Carbon Dioxide Evolution Measurement System, Microbial contamination
Citation
Stone, W., et al. 2021. Canary in the coliform mine : exploring the industrial application limits of a microbial respiration alarm system. PLoS ONE
16(3):e0247910, doi:10.1371/journal.pone.0247910