TY - JOUR
T1 - In situ microscopy as a tool for the monitoring of filamentous bacteria
T2 - A case study in an industrial activated sludge system dominated by M. parvicella
AU - Dunkel, Thiemo
AU - Dias, Philipe Ambrozio
AU - De León Gallegos, Erika Lizette
AU - Tacke, Viola
AU - Schielke, Andreas
AU - Hesse, Tobias
AU - Fajado, Diego Andrés Sierra
AU - Suhr, Hajo
AU - Wiedemann, Philipp
AU - Denecke, Martin
N1 - Publisher Copyright:
© IWA Publishing 2016.
PY - 2016/3
Y1 - 2016/3
N2 - The present study demonstrates the application of in situ microscopy for monitoring the growth of filamentous bacteria which can induce disturbances in an industrial activated sludge process. An in situ microscope (ISM) is immersed directly into samples of activated sludge with Microthrix parvicella as dominating species. Without needing further preparatory steps, the automatic evaluation of the ISM-images generates two signals: the number of individual filaments per image (ISM-filament counting) and the total extended filament length (TEFL) per image (ISM-online TEFL). In this first version of the image-processing algorithm, closely spaced crossing filament-segments or filaments within bulk material are not detected. The signals show highly linear correlation both with the standard filament index and the TEFL. Correlations were further substantiated by comparison with real-time polymerase chain reaction (real-time PCR) measurements of M. parvicella and of the diluted sludge volume index. In this case study, in situ microscopy proved to be a suitable tool for straightforward online-monitoring of filamentous bacteria in activated sludge systems. With future adaptation of the system to different filament morphologies, including cross-linking filaments, bundles, and attached growth, the system will be applicable to other wastewater treatment plants.
AB - The present study demonstrates the application of in situ microscopy for monitoring the growth of filamentous bacteria which can induce disturbances in an industrial activated sludge process. An in situ microscope (ISM) is immersed directly into samples of activated sludge with Microthrix parvicella as dominating species. Without needing further preparatory steps, the automatic evaluation of the ISM-images generates two signals: the number of individual filaments per image (ISM-filament counting) and the total extended filament length (TEFL) per image (ISM-online TEFL). In this first version of the image-processing algorithm, closely spaced crossing filament-segments or filaments within bulk material are not detected. The signals show highly linear correlation both with the standard filament index and the TEFL. Correlations were further substantiated by comparison with real-time polymerase chain reaction (real-time PCR) measurements of M. parvicella and of the diluted sludge volume index. In this case study, in situ microscopy proved to be a suitable tool for straightforward online-monitoring of filamentous bacteria in activated sludge systems. With future adaptation of the system to different filament morphologies, including cross-linking filaments, bundles, and attached growth, the system will be applicable to other wastewater treatment plants.
KW - Filament index
KW - Image analysis
KW - In situ microscope
KW - Light microscopy
KW - Total extended filament length
UR - http://www.scopus.com/inward/record.url?scp=84961734437&partnerID=8YFLogxK
U2 - 10.2166/wst.2015.612
DO - 10.2166/wst.2015.612
M3 - Article
C2 - 27003073
AN - SCOPUS:84961734437
SN - 0273-1223
VL - 73
SP - 1333
EP - 1340
JO - Water Science and Technology
JF - Water Science and Technology
IS - 6
ER -
