ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Whole-cell optical biosensor for mercury – operational conditions in saline water

Andrey Solovyev, Gabriela Kuncova, and Katerina Demnerova

Institute of Chemical Process Fundamentals ASCR, Rozvojová 135, 165 00 Prague 6, Czech Republic

E-mail: kuncova@icpf.cas.cz

Abstract: The present study demonstrates the influences of chlorides, fluorides and bromides of potassium and sodium on the growth and Hg²⁺-induced bioluminescence of bioreporter Escherichia coli ARL1. In a Luria-Bertani medium (LB), cell growth was inhibited by concentrations of sodium and potassium fluorides above 0.2 mol L⁻¹. The addition of NaCl increased cell tolerance to the toxic effects of fluorides and bromides. Lag periods of 10 h and more were observed for cultivations in LB without NaCl and with halides (NaCl, KCl, NaBr, KBr, NaF and KF) at concentrations lower than 0.06 mol L⁻¹. In a phosphate buffer (PB), the bioluminescence of E. coli ARL1, induced with HgCl₂, was increased by the addition of NaCl, KCl, NaBr, KBr, NaF and KF (concentration of 0-0.25 mol L⁻¹). In a saline phosphate buffer (PBS), the maxima of induced bioluminescence declined to 50 %, in the case of NaF (0.12 mol L⁻¹), and to zero for KF. An addition of tryptone to the induction medium increased induced light emission ten-fold. Concentrated artificial sea water (ASW) (70-100 % ASW) inhibited bioluminescence induction. The new detection assay with E. coli ARL1 made possible the detection of 0.57 μg L⁻¹ of HgCl₂ in double-diluted artificial sea water (25 % ASW).

Keywords: mercury detection assay – bioluminescent bioreporter – sea water – E. coli ARL1 – wholecell biosensor

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0009

Chemical Papers 69 (1) 183–191 (2015)