Oxygen Flux As an Indicator of Physiological Stress in Fathead Minnow (Pimephales promelas) Embryos: A Real-Time Biomonitoring System of Water Quality

Abstract

The detection of harmful chemicals and biological agents in real time is a critical need for protecting freshwater ecosystems. We studied the real-time effects of five environmental contaminants with differing modes of action (atrazine, cadmium chloride, pentachlorophenol, malathion, and potassium cyanide) on respiratory oxygen consumption in 2-day postfertilization fathead minnow (Pimephales promelas) eggs. Our objective was to assess the sensitivity of fathead minnow eggs using the self-referencing micro-optrode technique to detect instantaneous changes in oxygen consumption after brief exposures to low concentrations of contaminants. Oxygen consumption data indicated that the technique is indeed sensitive enough to reliably detect physiological alterations induced by four of the five contaminants. After 2 h of exposure, we identified significant increases in oxygen consumption upon exposure to pentachlorophenol (100 and 1000 microg/L), cadmium chloride (0.0002 and 0.002 microg/L), and atrazine (150 microg/L). In contrast, we observed a significant decrease in oxygen flux after exposuresto potassium cyanide (44 and 66 microg/L) and atrazine (1500 microg/L). No effects were detected after exposures to malathion (200 and 340 microg/L). Our work is the first step in development of a new technique for physiologically coupled biomonitoring as a sensitive and reliable tool for the detection of environmental toxicants.

A self-referencing biosensor for real-time monitoring of physiological ATP transport in plant systems

“…nitric oxide, indole acetic acid), and biomolecules (e.g. glucose, glutamate and lactate) Porterfield, 2011, 2013;McLamore et al, 2010;McLamore et al, 2010Porterfield, 2007;Shi et al, 2011;Gilliham et al, 2006;Land et al, 1999;Sanchez et al, 2008;Zuberi et al, 2008;Dey and Raj, 2010;Borgens, 1984).…”

Self-referencing optrodes for measuring spatially resolved, real-time metabolic oxygen flux in plant systems

“…Among various designs in literature, optrodes utilizing fluorescence lifetime-based spectroscopy are preferred, due to less noise, drift, and elimination of calibration shifts associated with photobleaching (Wolfbeis 2004;Borisov and Wolfbeis 2008;). SR lifetime-based optrodes have been used for non-invasively quantifying real-time respiration in various biomedical and environmental applications Sanchez et al 2008;). However, to date the technique has not been demonstrated in detail for plant science applications.…”

Mouse and human islets survive and function after coating by biosilicification

“…Timeresolved metabolic flux was measured in single islets by oscillating an oxygen biosensor perpendicular to the islet/coating surface. This technique, known as self-referencing, converts concentration sensors into dynamic biophysical flux sensors for quantifying real-time cellular transport (26,31,36,39). Analyte flux is calculated using Fick's first law of diffusion (25) by continuously recording differential concentration (⌬C) while oscillating the microsensor between two locations separated by a fixed excursion distance (⌬X).…”