Environmental and Synthetic Sulphydryl Group Inhibitors: Effects on Bioluminescence and Respiration in Vibrio fischeri

Abstract

Elemental sulphur (as S0 and S8) is abundant in anaerobic sediments and soil, and is highly toxic in the Vibrio fischeri bioluminescence test. This mode of S0 action remains uncertain. The objective of this research was the analysis of the toxic effects of S0 on bioluminescence and respiration in V. fischeri, in joint action with N-ethylmaleimide (NEM) or 2,4-dithio-DL-threitol (DTT), which are –SH group inhibiting and maintaining synthetic agents, respectively. Non-toxic DTT immediately protected cell bioluminescence against S0 inhibition at low (5.5ppb) and high (55ppb) concentrations of S0, whilst restoration of the inhibitory effect of S0 took up to 30 minutes. NEM (62.5ppb) diminished cell bioluminescence by up to 50% after 5 minutes, but after 60 minutes, the inhibition reached 100%. DTT restored the bioluminescence function inhibited in vivo and in vitro by S0 and NEM. Enhancement of cell respiration by up to 20% and 33% was observed at 2.2ppm of S0 and 36.8ppm of 2,4-dinitrophenol (2,4-DNP; an uncoupler of oxidative phosphorylation), respectively; whilst NEM (3.1ppm) caused a reduction of up to 40%. This comparative analysis confirmed that S0 has multiple modes of action — it acts as both an –SH group inhibitor and an uncoupler of oxidative phosphorylation in V. fischeri cells.

Wastewater and Landfill Leachate Testing: Acute Toxicity Biotest Results Evaluation

“…Ecotoxicological reseach of toxicants, WW and ll in lithuania. Ecotoxicity investigations of various individual toxicants or their mixtures, WW, LLs were undertaken with standard aquatic organisms of different phylogenetic levels (bacterium, crustacean, algae, fish (četkauskaitė, Bražėnaitė 2004;Kalcienė, četkauskaitė 2007); and ontogenetic stages (fish embryos, larvae, adults) (Kazlauskienė, Vosylienė 2008;Svecevičius 2006;Vosylienė et al 2010;Svecevičius, Kazlauskienė 2011;Montvydienė et al 2014). Chemical analysis and biotest battery data based ecotoxicological evaluations of municipal WW from regional WW treatment plants of Lithuania cities were implemented in 2007 and 2010 (Manusadžianas et al 2010;COHIBA 2012).…”