title: Cell Surface Display of Four Types of Solanum nigrum Metallothionein on Saccharomyces cerevisiae for Biosorption of Cadmium.
abstract: We displayed four types of Solanum nigrum metallothionein (SMT) for the first time on the surface of Saccharomyces cerevisiae using an α-agglutinin-based display system. The SMT genes were amplified by RT-PCR. The plasmid pYES2 was used to construct the expression vector. Transformed yeast strains were confirmed by PCR amplification and custom sequencing. Surface-expressed metallothioneins were indirectly indicated by the enhanced cadmium sorption capacity. Flame atomic absorption spectrophotometry was used to examine the concentration of Cd(2+) in this study. The transformed yeast strains showed much higher resistance ability to Cd(2+) compared with the control. Strikingly, their Cd(2+) accumulation was almost twice as much as that of the wild-type yeast cells. Furthermore, surface-engineered yeast strains could effectively adsorb ultra-trace cadmium and accumulate Cd(2+) under a wide range of pH levels, from 3 to 7, without disturbing the Cu(2+) and Hg(2+). Four types of surfaceengineered Saccharomyces cerevisiae strains were constructed and they could be used to purify Cd(2+)-contaminated water and adsorb ultra-trace cadmium effectively. The surface-engineered Saccharomyces cerevisiae strains would be useful tools for the bioremediation and biosorption of environmental cadmium contaminants.
authors.affiliation: College of Life Science, Qufu Normal University, Qufu, Shandong 273165, P.R. China.|Department of Biotechnology, Weifang Business Vocational College, Zhucheng, Shandong 262234, P.R. China.
authors.forename: Qinguo
authors.initials: Q
authors.lastname: Wei
authors.affiliation: College of Life Science, Qufu Normal University, Qufu, Shandong 273165, P.R. China.
authors.forename: Honghai
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Life Science, Qufu Normal University, Qufu, Shandong 273165, P.R. China.
authors.forename: Dongge
authors.initials: D
authors.lastname: Guo
authors.affiliation: College of Life Science, Qufu Normal University, Qufu, Shandong 273165, P.R. China.
authors.forename: Shisheng
authors.initials: S
authors.lastname: Ma
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D017343:Genes, Plant; D005818:Genetic Engineering / Q000379:methods; D008668:Metallothionein / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D032324:Solanum nigrum / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D013499:Surface Properties; D014131:Trace Elements / Q000737:chemistry
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D014131:Trace Elements; D002104:Cadmium; D008668:Metallothionein
keywords: Cadmium; Metallothionein; Saccharomyces cerevisiae; Solanum nigrum; Surface display; flame atomic absorption spectrophotometer(FAAS)