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Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers

Evaporative cooling towers to dissipate excess process heat are essential installations in a variety of industries. The constantly moist environment enables substantial microbial growth, causing both operative challenges (e.g., biocorrosion) as well as health risks due to the potential aerosolizatio...

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Autores principales: Toman, Stepan, Kiilerich, Bruno, Marshall, Ian P.G., Koren, Klaus
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7665125/
https://www.ncbi.nlm.nih.gov/pubmed/33182471
http://dx.doi.org/10.3390/s20216398
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author Toman, Stepan
Kiilerich, Bruno
Marshall, Ian P.G.
Koren, Klaus
author_facet Toman, Stepan
Kiilerich, Bruno
Marshall, Ian P.G.
Koren, Klaus
author_sort Toman, Stepan
collection PubMed
description Evaporative cooling towers to dissipate excess process heat are essential installations in a variety of industries. The constantly moist environment enables substantial microbial growth, causing both operative challenges (e.g., biocorrosion) as well as health risks due to the potential aerosolization of pathogens. Currently, bacterial levels are monitored using rather slow and infrequent sampling and cultivation approaches. In this study, we describe the use of metabolic activity, namely oxygen respiration, as an alternative measure of bacterial load within cooling tower waters. This method is based on optical oxygen sensors that enable an accurate measurement of oxygen consumption within a closed volume. We show that oxygen consumption correlates with currently used cultivation-based methods (R(2) = 0.9648). The limit of detection (LOD) for respiration-based bacterial quantification was found to be equal to 1.16 × 10(4) colony forming units (CFU)/mL. Contrary to the cultivation method, this approach enables faster assessment of the bacterial load with a measurement time of just 30 min compared to 48 h needed for cultivation-based measurements. Furthermore, this approach has the potential to be integrated and automated. Therefore, this method could contribute to more robust and reliable monitoring of bacterial contamination within cooling towers and subsequently increase operational stability and reduce health risks.
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spelling pubmed-76651252020-11-14 Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers Toman, Stepan Kiilerich, Bruno Marshall, Ian P.G. Koren, Klaus Sensors (Basel) Letter Evaporative cooling towers to dissipate excess process heat are essential installations in a variety of industries. The constantly moist environment enables substantial microbial growth, causing both operative challenges (e.g., biocorrosion) as well as health risks due to the potential aerosolization of pathogens. Currently, bacterial levels are monitored using rather slow and infrequent sampling and cultivation approaches. In this study, we describe the use of metabolic activity, namely oxygen respiration, as an alternative measure of bacterial load within cooling tower waters. This method is based on optical oxygen sensors that enable an accurate measurement of oxygen consumption within a closed volume. We show that oxygen consumption correlates with currently used cultivation-based methods (R(2) = 0.9648). The limit of detection (LOD) for respiration-based bacterial quantification was found to be equal to 1.16 × 10(4) colony forming units (CFU)/mL. Contrary to the cultivation method, this approach enables faster assessment of the bacterial load with a measurement time of just 30 min compared to 48 h needed for cultivation-based measurements. Furthermore, this approach has the potential to be integrated and automated. Therefore, this method could contribute to more robust and reliable monitoring of bacterial contamination within cooling towers and subsequently increase operational stability and reduce health risks. MDPI 2020-11-09 /pmc/articles/PMC7665125/ /pubmed/33182471 http://dx.doi.org/10.3390/s20216398 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Letter
Toman, Stepan
Kiilerich, Bruno
Marshall, Ian P.G.
Koren, Klaus
Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers
title Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers
title_full Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers
title_fullStr Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers
title_full_unstemmed Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers
title_short Bacterial Respiration Used as a Proxy to Evaluate the Bacterial Load in Cooling Towers
title_sort bacterial respiration used as a proxy to evaluate the bacterial load in cooling towers
topic Letter
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7665125/
https://www.ncbi.nlm.nih.gov/pubmed/33182471
http://dx.doi.org/10.3390/s20216398
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