Highly Selective and Rapid Arsenic Removal by Metabolically Engineered Escherichia coli Expressing Fucus vesiculosus Metallothionein

Department of Chemical and Environmental Engineering, and Cell Molecular & Developmental Biology program, University of California, Riverside CA 92521

^* To whom correspondence should be addressed. Email: wilfred{at}engr.ucr.edu.

	Abstract

An arsenic-chelating metallothionein (fMT) from an arsenic tolerant marine alga Fucus vesiculosus was expressed in Escherichia coli resulting in 36- & 26-fold higher As(V) and As(III) binding, respectively. Co-expression of an As(III)-specific transporter GlpF with fMT further improved the arsenic accumulation and offered high selectivity towards As. Resting E. coli cells co-expressing fMT and GlpF completely removed trace amounts (35 ppb) of As(III) within 20 min, providing a promising technology to comply with the newly US-EPA recommended As limit of 10 ppb.