學生姓名:
陳威宇
指導教授:
張祐維
學期:
111上
摘 要:
Tea is one of the most popular beverages in the world, and polysaccharides in it are considered to have many physiological activities. This report explores the antibacterial and other activities of polysaccharides in green tea and yerba mate tea. Green tea polysaccharide conjugate (gTPC) is obtained after green tea extraction, gTPC has optimal antibacterial concentrations for E. coli is 1.00 and 4.00 mg/mL for different strain (E. coli DH5α and 25,922). The results of SEM and TEM showed obvious morphological changes, part of the cell wall became blurred, and the leakage of cytoplasmic content were observed. Same experiments showed that outer membrane disruption played a key role in the antibacterial activity of gTPC against E. coli. The permeability of the cell membrane is significantly increasedand appears to be dose dependent. Reactive oxygen species (ROS) production of gTPC-treated E. coli has increased significantly (increased by 26.57 – 38.19 %). The yerba mate polysaccharide extracted from Ilex paraguariensis showed prominent antioxidant activity by DPPH•,ABTS•+ 25 and hydroxyl scavenging activity (IC50 = 1.25 , 0.41, 3.36 mg/ml), presented high antimicrobial activity against several bacterial (Gram-negative bacteria: Enterobacter cloacae, Salmonella enteritidis, and Salmonella typhimurium; Gram positive bacteria: Bacillus cereus, Micrococcus flavus, Staphylococcus aureus, and Listeria monocytogenes) and fungal strains (Aspergillus fumigatus, Aspergillus versicolor, Aspergillus ochraceus, Aspergillus niger, Candida crusei, Penicillium funiculosum, and Penicillium verrucosum var. cyclopium) and no cytotoxic properties of purified yerba mate polysaccharide. This research results will open a new application field (such as antimicrobial packaging, antioxidant food and wound dressing, and so on) of tea polysaccharide.
參考文獻摘要.docx.pdf