摘要： 採後病害（postharvest disease）之防治，已逐漸朝向使用微生物製劑取代化學藥劑。本研究由環境中分離並篩選拮抗酵母菌，測試其對番石榴採後病害之防治效果。本研究篩選9株具有抑制番石榴瘡痂病菌菌絲生長之拮抗酵母菌，於溫度測試結果顯示，6株酵母菌可生長於4℃，3株酵母菌可生長於44℃，其中以TCY20菌株可生長之溫度範圍最大，可生長於0℃－44℃。而於番石榴果實上進行瘡痂病之防治試驗，結果顯示處理TCY12菌株後可達71.0%之防治率，而TCY70菌株與TCY14菌株分別具67.0%與56.0%的防治率，此3株菌株經由分子生物學鑑定，於LSU rDNA序列片段比對，與Aureobasidium pullulans具有100%之相似度。A. pullulans為黑酵母菌，結果顯示其對番石榴採後病害之防治潛力，未來將持續進行防治試驗及進行量產發酵配方評估。Biological control using microbial agents has been used as an alternative approach to chemical fungicides for managing postharvest diseases. This study aims to isolate and screen antagonistic yeasts from the environment, and evaluate the efficacy of the antagonistic yeasts on controlling postharvest diseases of guava. There are 9 isolates showing strong ability to inhibit the mycelium growth of Pestalotiopsis sp. PDS1-2. Among the 9 isolates, there are 6 isolates can grow at 4℃, and 3 isolates can grow at 44℃. Especially, isolate TCY20 can grow in the range from 0℃ to 44℃. In vivo test on the guava, inhibition rate of isolate TCY12 is 71.0%, TCY70 is 67.0% and TCY14 is 56.0%. The LSU rDNA sequences of isolate TCY12, TCY14, and TCY70 show 100% identity with Aureobasidium pullulans, a is black yeast species. It is expect that the black yeasts TCY12, TCY14 and TCY70 have the potential to control postharvest diseases in the future.