title: A simple bacterial transformation method using magnesium- and calcium-aminoclays.
abstract: An efficient and user-friendly bacterial transformation method by simple spreading cells with aminoclays was demonstrated. Compared to the reported transformation approaches using DNA adsorption or wrapping onto (in)organic fibers, the spontaneously generated clay-coated DNA suprastructures by mixing DNA with aminoclay resulted in transformants in both Gram-negative (Escherichia coli) and Gram-positive cells (Streptococcus mutans). Notably, the wild type S. mutans showed comparable transformation efficiency to that of the E. coli host for recombinant DNA cloning. This is a potentially promising result because other trials such as heat-shock, electroporation, and treatment with sepiolite for introducing DNA into the wild type S. mutans failed. Under defined conditions, the transformation efficiency of E. coli XL1-Blue and S. mutans exhibited ~2 × 10(5) and ~6 × 10(3)CFU/μg of plasmid DNA using magnesium-aminoclay. In contrast, transformation efficiency was higher in S. mutans than that in E. coli XL1-Blue for calcium-aminoclay. It was also confirmed that each plasmid transformed into E. coli and S. mutans was stably maintained and that they expressed the inserted gene encoding the green fluorescent protein during prolonged growth of up to 80 generations.
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Chonnam National University, Gwang-ju 500-757, Republic of Korea.
authors.forename: Hyoung-An
authors.initials: HA
authors.lastname: Choi
authors.forename: Young-Chul
authors.initials: YC
authors.lastname: Lee
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Hyun-Jae
authors.initials: HJ
authors.lastname: Shin
authors.forename: Hyo-Kyung
authors.initials: HK
authors.lastname: Han
authors.forename: Geun-Joong
authors.initials: GJ
authors.lastname: Kim
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D002118:Calcium / Q000737:chemistry*; D000077215:Clay; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D008274:Magnesium / Q000737:chemistry*; D016254:Mutagenesis, Insertional / Q000379:methods*; D010957:Plasmids / Q000235:genetics; D013295:Streptococcus mutans / Q000235:genetics*; D014169:Transformation, Bacterial
chemical_list: D000538:Aluminum Silicates; D004269:DNA, Bacterial; D008274:Magnesium; D002118:Calcium; D000077215:Clay
keywords: Aminoclay; Bacteria; E. coli; S. mutans; Transformation