不同发酵茶中优势真菌的分离鉴定及产消化酶活性比较

The activities of digestive enzymes of fungi isolated from different fermented teas

目的分离鉴定云南普洱茶、广州小青柑、广西六堡茶和湖南熙茯茶中的主要真菌,并探讨其产消化酶活性。方法采用平板涂布法分离不同发酵茶中的真菌,通过其ITS序列进行分子鉴定;利用平板透明圈法测定不同真菌的产淀粉酶、蛋白酶、纤维素酶和脂肪酶活性。结果从4种发酵茶中共分离出8种真菌,其中,在云南普洱茶中分离出2种真菌,分别为篮状菌(Talaromyces.sp.)和T.variabilis;广州小青柑中分离出3种真菌,分别为阿曲霉(Aspergillus amstelodami)、烟曲霉(A.fumigatus)和绳状篮状菌(T.funiculosus);广西六堡茶中分离出2种真菌,分别为黑曲霉(A.niger)和冠突曲霉(A.cristatus);湖南熙茯茶中仅分离出谢瓦曲霉(A.chevalieri)。其中Talaromyces.sp.、T.variabilis、A.niger、A.amstelodami、A.fumigatus、T.funiculosus有产纤维素酶活性,Talaromyces.sp.、T.variabilis、A.cristatus、A.fumigatus、T.funiculosus有产淀粉酶活性,Talaromyces.sp.、T.variabilis、A.niger、A.fumigatus、T.funiculosus有产蛋白酶活性,A.niger有产脂肪酶活性。在8种真菌中,T.variabilis、烟曲霉和绳状篮状菌可同时产纤维素酶、淀粉酶和蛋白酶;黑曲霉能同时产纤维素酶、蛋白酶和脂肪酶;冠突曲霉仅有产淀粉酶活性;阿曲霉仅有产纤维素酶活性。通过比较不同真菌的产酶活性表明,烟曲霉的产蛋白酶活性能力最强;Talaromyces sp.的产纤维酶活性能力最强;Talaromyces.sp.和绳状篮状菌的产淀粉酶活性最强。结论发酵茶的真菌以曲霉菌属Aspergillus、散囊菌属Eurotium和篮状菌属Talaromyces为主,多数真菌具有产消化酶活性,这些酶可能在茶叶发酵过程中起重要作用,并影响发酵茶叶的品质。

Objective To isolate dominant fungi from Yunnan Pu-erh tea,Guangzhou Xiao Qinggan tea,Guangxi Liubao tea and Hu′nan Xifu tea and compare the activities of the digestive enzymes of the fungi.Methods The fungi were isolated and purified from the fermented teas using spread-plate method and identified using ITS sequence analysis.The activities of fungal amylase,protease,cellulase and lipase were determined using transparent circle method,and compared using the ratio of hydrolysis circle to colony diameter.Results Eight fungi were isolated from 4kinds of fermented tea.Talaromyces sp.and T.variabilis were isolated from Pu-erh tea;Aspergillus amstelodami,A.fumigatus and T.funiculosus were isolated from Guangzhou Xiao Qinggan tae;A.Nigerand A.cristatus were isolated from Gangxi Liubao tea;A.cahevalieri was isolated from Hu′nan Xifu tea.Among them,Talaromyces sp.,T.variabilis,A.Niger,A.mstelodami,A.fumigatus and A.funiculosus produced cellulase;Talaromyces.sp.,T.variabilis,A.cristatus,A.fumigatus and T.funiculosus produced amylase;Talaromyces sp.,T.variabilis,A.niger,A.fumigatus and T.funiculosus produced protease;A.Niger produced lipase.T.variabilis,A.fumigatus and T.funiculosus produced cellulase,amylase and protease simultaneously;A.Niger produced cellulase,protease and lipase simultaneously;A.cristatus produced only amylase,and A.amstelodami only cellulase.A.fumigatus had the strongest protease activity in the 8fungi;Talaromyces sp.had the strongest cellulase activity;Talaromyces sp.and T.funiculosus had the strongest amylase activity.Conclusion Aspergillus,Eurotiumand Talaromyces are the main fungi in the 4kinds of tea.7fungi can produce digestive enzymes which may play an important role in tea fermentation and affect the quality of different fermented teas.