title: Rapid fluorescence-based measurement of toxicity in anaerobic digestion.
abstract: A rapid fluorescence measurement based on resazurin reduction was developed and applied for the detection of toxicants/inhibitors to anaerobic digestion metabolism. By initially using a pure facultative anaerobic strain, Enterococcus faecalis as a model organism, this technique proved to be fast and sensitive when detecting the model toxicant, pentachlorophenol (PCP). The technique revealed significant metabolic changes in Enterococcus faecalis with a PCP spike ranging from 0.05 to 100 mg/L, and could detect PCP's toxicity to E. faecalis at a concentration of only 0.05 mg/L in 8 min. Furthermore, by extending this technique to a mixed anaerobic sludge, not only could the effect of 0.05-100 mg/L PCP be determined on anaerobic digestion metabolism within 10 min, but also its rate of biogas production. These results suggest that a resazurin-based fluorescence measurement can potentially be incorporated into a microfluidic system to develop a biosensor for the real-time monitoring, control and early warning of toxicant/inhibitor loads in the influent to an anaerobic digestion system.
authors.affiliation: Nanyang Environment & Water Research Institute, Advanced Environmental Biotechnology Centre, Nanyang Technological University, 637141, Singapore.
authors.forename: Jian Lin
authors.initials: JL
authors.lastname: Chen
authors.affiliation: School of Materials Science & Engineering, College of Engineering, Nanyang Technological University, 637141, Singapore.
authors.forename: Raphael
authors.initials: R
authors.lastname: Ortiz
authors.affiliation: Nanyang Environment & Water Research Institute, Advanced Environmental Biotechnology Centre, Nanyang Technological University, 637141, Singapore.
authors.forename: Yeyuan
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: School of Materials Science & Engineering, College of Engineering, Nanyang Technological University, 637141, Singapore. Electronic address: wjsteele@ntu.edu.sg.
authors.forename: Terry W J
authors.initials: TW
authors.lastname: Steele
authors.affiliation: Nanyang Environment & Water Research Institute, Advanced Environmental Biotechnology Centre, Nanyang Technological University, 637141, Singapore; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK. Electronic address: d.stuckey@imperial.ac.uk.
authors.forename: David C
authors.initials: DC
authors.lastname: Stuckey
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D013293:Enterococcus faecalis / Q000187:drug effects*; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000633:toxicity*; D005453:Fluorescence; D007202:Indicators and Reagents / Q000737:chemistry*; D010078:Oxazines / Q000737:chemistry*; D010416:Pentachlorophenol / Q000633:toxicity*; D012722:Sewage / Q000009:adverse effects*; D014966:Xanthenes / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D007202:Indicators and Reagents; D010078:Oxazines; D012722:Sewage; D014966:Xanthenes; C005843:resazurin; D010416:Pentachlorophenol
keywords: Anaerobic digestion; Biosensor; Pentachlorophenol; Resazurin; Toxicity