龜山島為座落於宜蘭外海的火山島，南端的熱泉系統有高溫、低酸鹼值以及高二氧化碳與硫化氫濃 度的環境。此極端環境下被報導有多種動物棲息，真菌相關研究卻缺乏，然而在最近研究中皆顯示 此類環境中確有真菌生存。本整合型計畫總目標為了解龜山島海底熱泉之微生物生態系統，海洋真 菌為本子計畫之首要目標。海洋真菌可分解有機物質，在海洋環境為重要的生態角色。本子計畫目 的為：（1)以培養以及分子生物（高通量定序取得rRNA基因序列)的方法調查海底熱泉附近的真菌或 類真菌生物多樣性；（2)分離出之真菌建立菌種庫；（3)研究此處真菌對溫度及酸鹼值的生長反應；（4) 從菌種庫中篩選可產生具醫藥價值之生物活性化合物的菌株；（5)研究分離出的類真菌生物其脂肪酸 組成，可能具有應用於食品產業的潛力。監控真菌多樣性的變化可做為龜山島海洋棲地保育一項指 標，研究此處真菌的生理學可更加了解環境因子如何對其生存產生影響，如壓力環境下的分解者群 落健康。本整合型計畫囊括其他主要海中生物，可提供未來對於此處的環境評估及永續發展的基本 資訊。海洋絲狀真菌及類真菌生物可產生抗細菌或瘧疾之生物活性化合物、或豐富的多元不飽和脂 肪酸，因此棲地的生態保護對海洋資源的發展及應用相當重要。 Kueishan Island is a volcanic island lying outside Yilan County, which has a shallow underwater hydrothermal system at the southern part of the island. This system comprises unique physical and chemical characteristics, including high temperature, low pH, and high carbon dioxide and hydrogen sulfide concentrations. Conditions are extreme, but many macro-organisms have been reported near the vent system including a fish, a crab, a mussel, a sea anemone, a snail, a sipunculid worm, an algae and zooplanktons. No or little information on microorganisms, including bacteria, archaea and fungi, has been reported, although fungi including filamentous forms and yeasts are known to inhabit high temperature and low pH environments, such as deepsea hydrothermal vents. The goal of the overall project is to understand the ecology of organisms associated with the hydrothermal system at Kueishan Island for sustainability and this sub-project is the first proposed study of marine fungi at this site. Marine fungi not only can grow in sea water, but also play an important ecological role as degraders of organic materials in marine environment. The objectives of this sub-project are to: (1) investigate the diversity of fungi/fungus-like organisms in sediment, sea water and organic materials near the hydrothermal vent over time using cultural and molecular (sequencing of rRNA gene cluster, high throughput sequencing) approaches, (2) set up a culture collection of fungi isolated in (1), (3) study growth response of fungi isolated in (1) to varying temperature and pH (4) exploit bioactive secondary metabolites from fungi in (2) which may be of pharmaceutical significance, and (5) study the fatty acid profile of fungus-like organisms in (2) which may be of use in food industry. The total diversity of fungi in various substrates using culture-dependent and independent approaches at Kueishan Island will provide basic but key information of fungal diversity and any change to this diversity can be monitored in the future for marine habitat conservation at Kueishan Island. The physiological study of the isolated fungi will enhance our understanding on the individual and combined effects of change of environmental factors (temperature, pH) on their survival, i.e. health of the degrader community in the system under stress. The results of the overall study, which include all major groups of organisms in the sea, i.e. animals, bacteria, archaea, fungi, will give a balanced view on the ecosystem of hydrothermal vent at Kueishan Island, therefore, will form baseline information for future environmental assessment and sustainability of this site. Marine fungi (filamentous forms) are known to produce bioactive compounds through secondary metabolism and many are known to exhibit anti-bacterial or anti-malarial activity. Fungus-like organisms (thraustochytrids) are prolific polyunsaturated fatty acid (DHA, EPA) producers, which are of great commercial value. These organisms will be isolated, kept at the culture collection at National Taiwan Ocean University and screened for bioactive secondary metabolites and polyunsaturated fatty acids, respectively. Fungal conservation is essential as fungi isolated from substrates at Kueishan Island might produce useful substances (natural products, saturated and unsaturated fatty acids) which are beneficial to human health.