Work

Bacteria Metabolically Engineered for Enhanced Phytochelatin Production and Cadmium Accumulation

Year: 2007

Type: article

Abstract: Phytochelatins (PCs) with good binding affinities for a wide range of heavy metals were exploited to develop microbial sorbents for cadmium removal. PC synthase from Schizosaccharomyces pombe (SpPCS) was overexpressed in Escherichia coli, resulting in PC synthesis and 7.5-times-higher Cd accumulation. The coexpression of a variant gamma-glutamylcysteine synthetase desensitized to feedback inhibition (GshI) increased the supply of the PC precursor glutathione, resulting in further increases of 10- and 2-fold in PC production and Cd accumulation, respectively. A Cd transporter, MntA, was expressed with SpPCS and GshI to improve Cd uptake, resulting in a further 1.5-fold increase in Cd accumulation. The level of Cd accumulation in this recombinant E. coli strain (31.6 micromol/g [dry weight] of cells) was more than 25-fold higher than that in the control strain.

Source: Applied and Environmental Microbiology

DOI: 10.1128/aem.01237-07

Authors: Seung Hyun Kang, Shailendra Singh, Jae-Young Kim, Wonkyu Lee, Ashok Mulchandani, Wilfred Chen

Institution: University of California, Riverside

Language: English

Topic: Adsorption and biosorption for pollutant removal

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

Open Access status: green

Funder: National Science Foundation

Awards: NTE: Innovative Technologies for Heavy Metals Removal by Tunable Biopolymers with Customized Properties (TSE03-N, PHASE II), Collaborative Research: Metabolic Engineering of Saccharomyces cerevisiae for Enhanced Accumulation of Arsenic