Abstract
In this study, the metallothionein gene of Candida albicans (C. albicans) was assembled by polymerase chain reaction (PCR), inserted into pUC19 vector, and further transformed into Escherichia coli (E. coli) DH5α cells. The capacity of these recombinant E. coli DH5α cells to synthesize silver nanoparticles was examined. Our results demonstrated that the expression of C. albicans metallothionein in E. coli promoted the bacterial tolerance to metal ions and increased yield of silver nanoparticle synthesis. The compositional and morphological analysis of the silver nanoparticles revealed that silver nanoparticles synthesized by the engineered E. coli cells are around 20 nm in size, and spherical in shape. Importantly, the silver nanoparticles produced by the engineered cells were more homogeneous in shape and size than those produced by bacteria lack of the C. albicans metallothionein. Our study provided preliminary information for further development of the engineered E. coli as a platform for large-scale production of uniform nanoparticles for various applications in nanotechnology.
Highlights
Nanoparticles (NPs) have been explored for a wide range of applications, including biosensors and chemical sensors, bioimaging, catalysis, optics, electronics, drug delivery, and energy [1].The conventional chemical or physical methods for the production of nanoscale materials depend on the utilization of toxic stabilizing and capping agents, which pose risks to the environment and human health [2]
Eight oligonucleotides covering the full length of C. albicans MT gene were designed to synthesize the gene by polymerase chain reaction (PCR) followed the procedure described in reference 19
Once we revealed that the C. albicans MT protein was expressed in E. coli, we continue to explore whether its expression can facilitate bacterial growth, as well as metal NP biosynthesis
Summary
Nanoparticles (NPs) have been explored for a wide range of applications, including biosensors and chemical sensors, bioimaging, catalysis, optics, electronics, drug delivery, and energy [1].The conventional chemical or physical methods for the production of nanoscale materials depend on the utilization of toxic stabilizing and capping agents, which pose risks to the environment and human health [2]. MTs are found in all eukaryotes, as well as some prokaryotes, and play an important role in intracellular metal distribution, accumulation, as well as protection of cells against heavy metal toxicity and oxidative stress [5,6]. Studies showed that MTs are involved in the detoxification of several metals, including zinc, mercury, copper and cadmium in microorganisms [5,6,8]. Due to their important role in metal reduction and high metal binding affinity, Materials 2019, 12, 4180; doi:10.3390/ma12244180 www.mdpi.com/journal/materials
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
