Measurement of protein-like fluorescence in river and waste water using a handheld spectrophotometer.

Protein-like fluorescence intensity in rivers increases with increasing anthropogenic DOM inputs from sewerage and farm wastes. Here, a portable luminescence spectrophotometer was used to investigate if this technology could be used to provide both field scientists with a rapid pollution monitoring tool and process control engineers with a portable waste water monitoring device, through the measurement of river and waste water tryptophan-like fluorescence from a range of rivers in NE England and from effluents from within two waste water treatment plants. The portable spectrophotometer determined that waste waters and sewerage effluents had the highest tryptophan-like fluorescence intensity, urban streams had an intermediate tryptophan-like fluorescence intensity, and the upstream river samples of good water quality the lowest tryptophan-like fluorescence intensity. Replicate samples demonstrated that fluorescence intensity is reproducible to +/- 20% for low fluorescence, 'clean' river water samples and +/- 5% for urban water and waste waters. Correlations between fluorescence measured by the portable spectrophotometer with a conventional bench machine were 0.91; (Spearman's rho, n = 143), demonstrating that the portable spectrophotometer does correlate with tryptophan-like fluorescence intensity measured using the bench spectrophotometer.

Isolation of a glucosyltransferase from Arabidopsis thaliana active in the metabolism of the persistent pollutant 3,4-dichloroaniline.

The pollutant 3,4-dichloroaniline (DCA) was rapidly detoxified by glucosylation in Arabidopsis thaliana root cultures, with the N-beta-d-glucopyranosyl-DCA exported into the medium. The N-glucosyltransferase (N-GT) responsible for this activity was purified from Arabidopsis suspension cultures and the resulting 50 kDa polypeptide analysed by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) following tryptic digestion. The protein was identified as GT72B1. The GT was cloned and the purified recombinant enzyme shown to be highly active in conjugating DCA and 2,4,5-trichlorophenol, as well as several other chlorinated phenols and anilines, demonstrating both N-GT and O-GT activity. GT72B1 showed little activity towards natural products with the exception of the tyrosine catabolite 4-hydroxyphenylpyruvic acid. Both O-GT and N-GT activities were enhanced in both plants and cultures treated with herbicide safeners, demonstrating the chemical inducibility of this detoxification system in Arabidopsis.