Fig. 5.

Effectiveness of T-ZnO and UV to cause damages on a circular plasmid (pUC19) that contains antibiotic resistance genes. Breaks in a circular plasmid DNA will cause change of a circular plasmid into a linear form (with one break), or multiple fragments (with multiple breaks). The total size of pUC19 is 2686 bp. Thus, an undamaged pUC19 (i.e., in its circular form) is expected to show on an electrophoresis gel with a band size smaller than 2.7 kb. When there is a break on the plasmid, the circular plasmid will become a linearized plasmid (i.e. 1 cut) and the size of band on an electrophoresis gel is expected to be around 2.7 kb. (a) Electrophoresis gel of plasmid DNA pUC19 showing breaks of pUC19 before and after photolysis by T-ZnO and/or UV exposure up to 48 h. Control 1 contains plasmid pUC19 without UV exposure (i.e., pUC19 only); control 2 contains plasmid pUC19 and T-ZnO without UV exposure(i.e., pUC19 + T-ZnO); control 3 contains plasmid pUC19 with UV exposure (i.e., pUC19 + UV). Sample contains plasmid pUC19 and T-ZnO with UV exposure (i.e., pUC19 + T-ZnO + UV). Circular plasmid Control without restriction enzyme, linear plasmid for 1 cut with a restriction enzyme NdeI, 2 cuts with NdeI and PciI were used. The expected sizes with 2 cuts are 2 kb and 0.7 kb. (b) The ability of treated plasmids to be uptake by other live microorganisms were estimated using competent E. coli with samples. It is shown as a log scale of transformation efficiency (TE). The TE of plasmids in the sample (i.e., pUC19 + T-ZnO + UV) is determined by counting the transformant CFU of each sample divided by transformant CFU of time zero samples. Each error bar is already shown in the figures.