Citation:

Bae, W., W. Chen, A. Mulchandani, AND R. Mehra. ENHANCED BIOACCUMULATION OF HEAVY METAL BY BACTERIA CELLS DISPLAYING SYNTHETIC PHYTOCHELATINS. (R827227). ENVIRONMENTAL FORENSICS. John Wiley & Sons Incorporated, New York, NY, 70(5):518-524, (2000).

Description:

A novel strategy using synthetic phytochelatins is described for the purpose of developing microbial agents for enhanced bioaccumulation of toxic metals. Synthetic genes encoding for several metal-chelating phytochelatin analogs (Glu-Cys)_nGly (EC8 (n = 8), EC11 (n = 11), and EC20 (n = 20)) were synthesized, linked to a lpp-ompA fusion gene, and displayed on the surface of E. coli. For comparison, EC20 was also expressed periplasmically as a fusion with the maltose-binding protein (MBP-EC20). Purified MBP-EC20 was shown to accumulate more Cd²⁺ per peptide than typical mammalian metallothioneins with a stoichiometry of 10 Cd²⁺/peptide. Cells displaying synthetic phytochelatins exhibited chain-length dependent increase in metal accumulation. For example, 18 nmoles of Cd²⁺/mg dry cells were accumulated by cells displaying EC8, whereas cells exhibiting EC20 accumulated a maximum of 60 nmoles of Cd²⁺/mg dry cells. Moreover, cells with surface-expressed EC20 accumulated twice the amount of Cd²⁺ as cells expressing EC20 periplasmically. The ability to genetically engineer ECs with precisely defined chain length could provide an attractive strategy for developing high-affinity bioadsorbents suitable for heavy metal removal. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 70: 518-524, 2000.

Record Details:

Record Type:DOCUMENT( JOURNAL/ PEER REVIEWED JOURNAL)

Product Published Date:01/01/2000

Record Last Revised:12/22/2005

Record ID: 68744

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Document IDs:

EPA Number :R827227