A novel approach for increasing transformation efficiency in E. coli DH5α cells using silver nanoparticles

Gorantla Nagamani; Swapna Alex; K B Soni; K N Anith; M M Viji; A G Kiran

doi:10.1007/s13205-019-1640-9

A novel approach for increasing transformation efficiency in E. coli DH5α cells using silver nanoparticles

3 Biotech. 2019 Mar;9(3):113. doi: 10.1007/s13205-019-1640-9. Epub 2019 Mar 1.

Authors

Gorantla Nagamani¹, Swapna Alex¹, K B Soni¹, K N Anith², M M Viji³, A G Kiran¹

Affiliations

¹ Department of Plant Biotechnology, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala 695522 India.
² Department of Agricultural Microbiology, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala 695522 India.
³ Department of Plant Physiology, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala 695522 India.

Abstract

The present study is the first report on the application of silver nanoparticles for efficient bacterial transformation. EC50 value of 100 nm silver nanoparticles against E. coli DH5α cells was recorded as 4.49 mg L^-1 in toxicity assay. Competency induction in E. coli DH5α cells by treatment with 100 nm silver nanoparticles at a concentration of 1 mg L^-1 for 60 min and transformation using three plasmid vectors of different sizes, viz. pUC18, pBR322 and pCAMBIA resulted in tenfold increase in the bacterial transformation efficiency, i.e. 8.3 × 10⁴, 8.0 × 10⁴ and 7.9 × 10⁴ cfu ng^-1 of DNA, respectively, even without heat shock compared to the conventional chemical method using 0.1 M calcium chloride (2.3 × 10³ cfu ng^-1 of DNA).

Keywords: Bacterial transformation; Competent cells; Silver nanoparticles; pBR322; pCAMBIA; pUC18 plasmid; β-Galactosidase.