孟寧素具有抑制鐮孢菌之能力

Monensin exhibits novel antifungal activity against Fusarium species

"鐮孢菌（Fusarium spp.）具病原性者影響層面廣泛，例如香蕉黃葉病菌F. oxysporum f. sp. cubense遍及大部分香蕉產區，番茄萎凋病菌F. oxysporum f. sp. lycopersici曾於2012年造成印度番茄45%的產量損失，草莓萎凋病菌F. oxysporum f. sp. fragariae於2010年後對臺灣草莓田區危害面積逐年增加，而美商生產的隱形眼鏡藥水曾被鐮孢菌汙染，造成多人感染角膜炎。食安問題、環境的永續性近年來備受重視，國內外皆有許多研究者投入非農藥資材的開發。本研究自多種天然資材中，篩選出對多株鐮孢菌具抑制能力的天然資材孟寧素（monensin）。孟寧素由細菌分泌產生，為一種離子載體，可促進家禽腸胃道吸收、提升免疫力與抑制球蟲症（coccidiosis），可被使用於飼料添加劑。經過最低抑菌濃度（minimum inhibitory concentration, MIC）與最低殺菌濃度（minimum fungicidal concentration, MFC）測試證實，孟寧素對7株來自於植物或人類鐮孢菌之MIC值最低達16μg/mL，抑菌效果屬靜菌作用。孟寧素可抑制鐮孢菌菌絲生長、隔膜生成與產孢構造生成，對F. oxysporum與F. graminearum之抑制效果較佳，但對F.solani則較差。由亞甲基藍染色與DAPI染色，結果顯示經孟寧素處理後之鐮孢菌細胞仍可存活，但細胞核結構受到影響。植物病害防治方面，孟寧素較適合作為保護劑於鐮孢菌入侵植物組織前或於初期感染時施用。若欲使用孟寧素針對人體鐮孢菌進行治療，建議可以添加於眼藥水以防範鐮孢菌於其中滋生。"

"There is a large number of species in genus Fusarium, and the pathogenic ones of this genus have wide influence worldwide. For example, F. oxysporum f. sp. cubense is widespread in banana growing regions; tomato Fusarium wilt caused by F. oxysporum f. sp. lycopersici resulted in 45% yield lost in India in 2012; strawberry Fusarium wilt caused by F. oxysporum f. sp. fragariae has increased its impact on Taiwanese strawberry field since 2010; contact lens solution produced by an American company used to be contaminated with Fusarium species and resulted in numerous people infected, and even resulted in keratitis. Food safety and environmental protection issues have received much attention in recent years, many researchers thus interested to develop nonpesticide materials for controlling of plant diseases. In this study, we discovered monensin, a natural compound, can inhibit multiple Fusarium species. Monensin, an ionophore, can be produced by bacterium, and promote animal gastrointestinal absorption, enhances immunity, inhibits coccidiosis in poultry, and thus serve as feed additive. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration tests showed that monensin is fungistatic but not fungicidal and the MIC values against seven plant or human Fusarium strains can reach 16 μg/mL. Monensin can inhibit the hyphal growth, formation of septa, and production of conidiophore of Fusarium species. Compared with F. solani, monensin has stronger inhibition effect against F. oxysporum, especially F. oxysporum f. sp. lycopersici 4287 and F. graminearum PH-1. Methylene blue and DAPI stains showed that Fusarium cells treated with monensin were still alive but the structure of nuclei was affected. For controlling Fusarium infections on plants, monensin is suitable for protectant that is usually used before pathogen invasion. As for controlling Fusarium infection in humans, monensin can be added in eye drops or contact lens solutions to prevent keratitis."