title: Antibacterial property and mechanism of a novel Pu-erh tea nanofibrous membrane.
abstract: Pu-erh tea is made via a natural fermentation process. In this study, Pu-erh tea was used as a raw material for nanomaterials preparation and as an antibacterial agent. Antibacterial activities on Escherichia coli of Pu-erh tea, Pu-erh tea powder (PTP) of different sizes, and Pu-erh tea residual powder were firstly determined, respectively. With polyvinyl alcohol as the carrier, through an electrospinning technique, different kinds of nanofibrous membranes were obtained from the extract of Pu-erh tea and nano-PTP (NPTP), and their antibacterial properties and mechanism against E. coli were evaluated. The results showed better antibacterial activity with smaller PTP particles, the nano-sized particles had the best effects, and the MIC of NPTP was 13.5 mg/mL. When NPTP was in nanofibrous membranes, the antibacterial activity decreased slightly, but increased with modification by ZnO. Pu-erh tea in nanofibrous membranes damaged the E. coli cell membranes and caused leakage of K(+) and enzymes. What is more is that damage of the cell walls led to the leakage of fluorescent proteins from enhanced green fluorescence protein-expressing E. coli. These results indicate that the Pu-erh tea nanofibrous membranes had good antibacterial activities against E. coli, which may provide a promising application of novel antibacterial materials.
authors.affiliation: School of Life Sciences and Technology, Tongji University, Shanghai, People's Republic of China.
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Su
authors.forename: Chenlu
authors.initials: C
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Li
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D015169:Colony Count, Microbial; D004798:Enzymes / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D057139:Nanofibers; D010539:Permeability / Q000187:drug effects; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D013662:Tea / Q000737:chemistry*; D015034:Zinc Oxide / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004798:Enzymes; D010936:Plant Extracts; D013662:Tea; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D011188:Potassium; D015034:Zinc Oxide