Biodiversity of keratinophilic fungi in Taiwan

嗜角質真菌是一群以角質為養份來源的真菌，在自然界中，它們可以分解動物的毛髮、羽毛、蹄甲、皮膚角質碎屑等角質物質。這些角質的主要成份是α-keratin，為具有雙硫鍵的堅固蛋白質，在自然界不會自行分解消失。嗜角質真菌具有分解這類物質的能力，使碳、氮、硫等元素重回大自然的循環。這類真菌存在於土壤、動物、及人類身上；在分類學上，則集中於爪甲團囊菌目(Onygenales)中。此屬共有約6科41屬的真菌，其中包括重要的人類及動物致病真菌。本研究透過動物毛皮及土壤，調查嗜角質真菌在台灣的多樣性。我們共取得563件樣本，其中包括動物樣本523件，土壤樣本40件。動物來源包括狗、貓、兔、鼠、及蝙蝠。分離純化之真菌總計334株，其中140株屬Onygenales，5株為Arachnomycetales。Onygenales的菌株分屬3科9屬30種，Arachnomycetales 的菌株1科1屬2種；其中多為台灣新紀錄種，另一部份尚待鑑定描述。本研究樣本採集地點雖集中於台灣北部及東部，卻已呈現高度的菌種多樣性。Keratinophilic fungi are a special group of fungi using keratin as their nutrient source. They can degrade a variety of keratinous substances such as hairs, feathers, horn, skin debris, which are composed mainly of α-keratin. Due to the strong disulfide bond, constituents of keratinous substances can be degraded into carbon, nitrogen and sulfur only by keratinophilic fungi, which make recycling of these substances in the ecosystem possible. Most of keratinophilic fungi belong to Onygenales (Ascomycota, Pezizomycotina, Eurotiomycetes, Onygenales), which is composed of about six families and 41 genera, including many important pathogenic fungi of humans and animals. The aim of this study is to survey the biodiversity of keratinophic fungi in Taiwan. We collected 563 samples, including 523 animal fur coat samples from dogs, cats, rabbits, rats, and bats, and 40 soil samples. Among the 334 strains isolated, 140 belong to Onygenales, which can be categorized into three families, nine genera and 30 species. Five Arachnomycetalean fungi can be categorized to one family, one genus and two species. Most of them are new to Taiwan. There are also several new species to be described. A fairly high diversity is revealed in the current study despite that the samples were mainly collected from northern and eastern Taiwan and more collecting needs to be made elsewhere in Taiwan.目 錄 口試委員審定書 i 誌謝 ii 目錄 iii 中文摘要 1 英文摘要 2 第一章 緒論 3 1.1. Onygenales 9 1.1.1. Onygenaceae Berk. 11 1.1.1.1. Chrysosporium Corda 11 1.1.1.2. Aphanoascus Zukal 16 1.1.1.3. Malbranchea Sacc. 18 1.1.1.4. Auxarthron G.F. Orr & Kuehn 19 1.1.1.5. Amauroascus J. Schrot. 20 1.1.1.6. Spiromastix Kuehn & G.F. Orr 21 1.1.1.7. Uncinocarpus Sigler & G.F. Orr 22 1.1.1.8. Neoarachnotheca Ulfig, Cano & Guarro 22 1.1.1.9. Neogymnomyces G.F. Orr. 22 1.1.2. Arthrodermataceae Currah 23 1.1.2.1. Arthroderma Curr. & Berk.. 23 1.1.3. Gymnoascaceae Baran. 25 1.1.3.1. Gymnoascus Baranetzky 25 1.2. Arachnomycetales Gibas, Sigler & Currah 26 1.2.1. Arachnomyces Massee & E.S. Salmon 26 1.3. 嗜角質真菌之研究概況 27 1.3.1. 國外的研究 27 1.3.1.1. 土壤中的嗜角質真菌 27 1.3.1.2. 動物身上的嗜角質真菌 27 1.3.2. 本國的嗜角質真菌調查概況 28 1.3.2.1. 土壤中的嗜角質真菌 28 1.3.2.2. 動物身上的嗜角質真菌 29 1.4. 研究目的 30 第二章 研究方法與材料 31 2.1. 樣本採集及培養 31 2.1.1. 動物皮毛樣本 31 2.1.2. 土壤樣本 31 2.2. 菌株純化及鑑定 32 2.2.1. 動物毛皮樣本 32 2.2.2. 土壤樣本 32 2.2.3. 菌株鑑定 33 2.3. 交配實驗 33 2.4. 分子研究 33 2.4.1. 培養菌絲 33 2.4.2. 萃取DNA 34 2.4.3. 聚合酶鏈結反應 34 2.4.3.1. ITS1-5.8S-ITS2區段 34 2.4.3.1.1. PCR引子 34 2.4.3.1.2. PCR條件 34 2.4.3.2. large subunit rDNA D1/D2 gene區段 35 2.4.3.2.1. PCR引子 35 2.4.3.2.2. PCR條件 35 2.4.4. 純化 35 2.4.5. 定序 35 2.4.6. 分子親緣關係分析 35 2.5. 電子顯微鏡 36 第三章 結果 37 3.1. Taxonomy 39 3.2. Onygenales 44 3.2.1. Description for taxa of Onygenaceae 44 Amauroascus queenslandicus 44 Aphanoascus durus 45 Aphanoascus fluvialis 45 Aphanoascus foetidus 46 Aphanoascus hispanicus 47 Aphanoascus orissae 48 Aphanoascus terreus 49 Aphanoascus verrucosus 50 Aphanoascus sp. 50 Chrysosporium articulatum 51 Chrysosporium lobatum 52 Auxarthron chlamydosporum 53 Auxarthron filamentosum 53 Auxarthron pseudoreticulatum 54 Neoarachnotheca keratinophila 54 Neogymnomyces sp. nov. 55 Spiromastix warcupii 56 Uncinocarpus reesii 57 3.2.2. Description for taxa of Arthrodermataceae 58 Arthroderma ciferii 58 Arthroderma corniculatum 58 Arthroderma curreyi 59 Arthroderma fulvum 59 Arthroderma gypseum 60 Arthroderma incurvatum 61 Arthroderma otae 62 Arthroderma tuberculatum 62 Arthroderma vanbreuseghemii 63 3.2.3. Description for taxa of Gymnoascaceae 65 Gymnascus hyalinosporus 65 Gymnoascus petalosporus 66 Gymnoascus udagawae 66 3.3. Arachnomycetales 68 3.3.1. Description for taxa of Arachnomycetaceae 68 Arachnomyces gracilis 68 Arachnomyces kanei 68 Arachnomyces sp.1 68 Arachnomyces sp.2 69 3.4. Taxa of uncertain taxonomic status 70 第四章 討論 72 參考文獻 7