TY - JOUR
T1 - Toxicant inhibition in activated sludge
T2 - Fractionation of the physiological status of bacteria
AU - Foladori, P.
AU - Bruni, L.
AU - Tamburini, S.
N1 - Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/9/15
Y1 - 2014/9/15
N2 - In wastewater treatment plants the sensitivity of activated sludge to a toxicant depends on the toxicity test chosen, and thus the use of more than one test is suggested. The physiological status of bacteria in response to toxicants was analysed by flow cytometry to distinguish intact, permeabilised, active cells and cells disrupted. Results were compared with respirometry and bioluminescence bioassay (Vibrio fischeri).3,5-Dichlorophenol (DCP) was used as reference xenobiotic. DCP has a strong effect on cellular integrity, causing an increase in permeabilised and disrupted cells. A reduction of 44-80% of intact cells with 6-30. mgDCP/L for 5. h was found. Inhibition of active cells was 25-49%, at 6-30. mgDCP/L for 5. h. The bioluminescence bioassay resulted oversensitive to DCP compared to tests based on activated sludge, while oxygen uptake rate was affected similarly to intact cells measured by flow cytometry. Landfill leachate was tested: a detrimental impact on both cellular integrity and enzymatic activity was observed. Reduction of intact cells and active cells was by 32% and 61% respectively after addition of 50% (v/v) of leachate for 5. h. The flow cytometry analysis proposed here might be widely applicable in the monitoring of various toxicants and in other aquatic biosystems.
AB - In wastewater treatment plants the sensitivity of activated sludge to a toxicant depends on the toxicity test chosen, and thus the use of more than one test is suggested. The physiological status of bacteria in response to toxicants was analysed by flow cytometry to distinguish intact, permeabilised, active cells and cells disrupted. Results were compared with respirometry and bioluminescence bioassay (Vibrio fischeri).3,5-Dichlorophenol (DCP) was used as reference xenobiotic. DCP has a strong effect on cellular integrity, causing an increase in permeabilised and disrupted cells. A reduction of 44-80% of intact cells with 6-30. mgDCP/L for 5. h was found. Inhibition of active cells was 25-49%, at 6-30. mgDCP/L for 5. h. The bioluminescence bioassay resulted oversensitive to DCP compared to tests based on activated sludge, while oxygen uptake rate was affected similarly to intact cells measured by flow cytometry. Landfill leachate was tested: a detrimental impact on both cellular integrity and enzymatic activity was observed. Reduction of intact cells and active cells was by 32% and 61% respectively after addition of 50% (v/v) of leachate for 5. h. The flow cytometry analysis proposed here might be widely applicable in the monitoring of various toxicants and in other aquatic biosystems.
KW - Activated sludge
KW - Bioluminescence bioassay
KW - Flow cytometry
KW - Inhibition
KW - Respirometry
KW - Toxicity
UR - http://www.scopus.com/inward/record.url?scp=84908032537&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2014.09.003
DO - 10.1016/j.jhazmat.2014.09.003
M3 - Article
C2 - 25240645
AN - SCOPUS:84908032537
SN - 0304-3894
VL - 280
SP - 758
EP - 766
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
ER -