Korean Lichen Research Institute, Sunchon National University, Sunchon, 540-742, Republic of Korea.
J Microbiol. 2011 Feb;49(1):66-70. doi: 10.1007/s12275-011-0289-9. Epub 2011 Mar 3.
The present study was conducted to evaluate the antibacterial activity of lichen-forming fungi (LFF) against Helicobacter pylori, and to optimize the culture conditions of LFF for maximum production of natural antibiotics against H. pylori. To accomplish this, a screening assay was first conducted among 19 species of LFF. The extract of Nephromopsis pallescens (KOLRI-040516) exhibited the strongest anti-ff. pylori activity. Bioautograghic TLC and HPLC analysis identified usnic acid as the main antibacterial substance produced by JV. pallescens. The growth of JV. pallescens and production of antibacterial substances produced by the fungus were then investigated under several culture conditions including the culture media, initial medium pHs, incubation temperatures, and the degree of aeration. The results indicated that culture in MY medium with an initial pH of 6.0, a temperature of 15°C and a low degree of aeration supported the largest usnic acid production of the fungus (16.4 ug usnic acid/g dry biomass). Especially, aeration was found to be an important factor that affect both growth and usnic acid production of N. pallescens.
本研究旨在评估地衣真菌（LFF）对幽门螺杆菌的抗菌活性，并优化 LFF 的培养条件，以最大限度地生产天然抗生素来对抗 H. pylori。为了实现这一目标，首先对 19 种地衣真菌进行了筛选试验。Nephromopsis pallescens（KOLRI-040516）的提取物表现出最强的抗 ff. pylori 活性。生物自显影 TLC 和 HPLC 分析表明，熊果酸是 N. pallescens 产生的主要抗菌物质。然后，在几种培养条件下（包括培养基、初始培养基 pH 值、培养温度和通气程度）研究了 N. pallescens 的生长和抗菌物质的产生。结果表明，在初始 pH 值为 6.0、温度为 15°C 和低通气度的 MY 培养基中培养，有利于真菌产生最大量的熊果酸（16.4 ug 熊果酸/g 干生物质）。特别是，通气被发现是影响 N. pallescens 生长和熊果酸产生的重要因素。
