Expression of Rhizobium tropici phytochelatin synthase in Escherichia coli resulted in increased bacterial selenium nano
- PDF / 3,486,002 Bytes
- 13 Pages / 547.087 x 737.008 pts Page_size
- 58 Downloads / 175 Views
RESEARCH PAPER
Expression of Rhizobium tropici phytochelatin synthase in Escherichia coli resulted in increased bacterial selenium nanoparticle synthesis Qunying Yuan Zhigang Xiao
&
Manjula Bomma & Haley Hill &
Received: 4 August 2020 / Accepted: 24 November 2020 # Springer Nature B.V. 2020
Abstract Phytochelatins are the main heavy metal detoxifying peptides found in plants. In the present study, Escherichia coli DH5α cells were transformed with the phytochelatin synthase gene from Rhizobium tropici. The tolerance of these recombinant bacterial cells to heavy metals as well as their capacity to synthesize selenium nanoparticles were explored. The functional studies showed the recombinant E. coli grew faster and achieved a higher cell density after overnight cultivation in comparison with the control cells. In addition, the recombinant E. coli had a higher tolerance to copper, nickel, zinc, and cadmium ions. Importantly, the cells had increased capacity to synthesize selenium nanoparticles. Our results suggested that the phytochelatin synthase gene transformed E. coli DH5α cells can be used to produce selenium nanoparticles in large scale for various applications in nanotechnology and biomedicine. Keywords Selenium nanoparticles . Recombinant Escherichia coli . Phytochelatin synthase . Phytochelatins This article is part of the topical collection on Nanoparticles in Biotechnology and Medicine, Xiaoshan (Sean) Zhu, University of Nevada, Guest Editor Q. Yuan (*) : M. Bomma : H. Hill Department of Biological and Environmental Science, Alabama A&M University, Normal, AL 35762, USA e-mail: [email protected] Z. Xiao Department of Electrical Engineering and Computer Science, Alabama A&M University, Normal, AL, USA
Introduction Nanoparticles have a broad range of diverse applications in various fields of nanotechnology. Microbial synthesis of nanoparticles has been attracting increasing attention due to its simple synthesis process, environmental friendliness, and low cost, compared with the traditional chemical and physical methods. Microbial synthesis of nanoparticles is accomplished using microorganisms such as bacteria, yeast, and fungi. The presence of natural reducing enzymes, intracellular or extracellular reducing reagents, and metal-binding proteins allows the biological systems to convert metal ions into elementary metal and further aggregate to nanomaterials (Lloyd 2003; Singh et al. 2016). One particular group of the metal-reducing and binding peptides, phytochelatins and metallothioneins, play a critical role in protecting the plants and microorganisms from heavy metal and metalloid toxicity (Cobbett and Goldsbrough 2002; Emamverdian et al. 2015; Gupta et al. 2013; Tennstedt et al. 2009; Grill et al. 1987). While metallothioneins are found in animals and prokaryotes, phytochelatins are analogs of metallothioneins in plants. Phytochelatins consist of only three amino acids: Glu, Cys, and Gly and have a general structure of repetitions of the γ-Glu-Cys dipeptide followed by a terminal Gly; (γ-Glu-Cys)n
Data Loading...
