青年人肠道中双歧杆菌的分离及其在发酵羊乳中的应用

Isolation and identification of Bifidobacteria from feces of young volunteers and their application in the fermented goat milk

在对湖北省襄阳地区青年人肠道中双歧杆菌进行分离鉴定的基础上,采用电子舌和电子鼻技术对其在羊乳中的发酵特性进行了评价。结果表明:分离出的20株双歧杆菌菌株,共鉴定为Bifidobacterium longum(长双歧杆菌)、B. breve(短双歧杆菌)、B. bifidum(两歧双歧杆菌)、B.pseudocatenulatum(假链状双歧杆菌)、B. adolescentis(青春双歧杆菌)和B. faecale(粪便双歧杆菌)6个种,其中11株为B. longum(长双歧杆菌)。通过电子舌分析发现,不同双歧杆菌制备的发酵羊乳在后味A(涩味的回味)上的差异最大,极差值为24.52。通过高效液相色谱法分析发现,乳酸和乙酸为双歧杆菌制备发酵羊乳中的主要有机酸。通过电子鼻分析发现,传感器W6S、W1W和W5S对不同双歧杆菌菌株制备发酵羊乳响应值差异较大,其变异值分别为35.56%、23.32%和17.20%。通过主成分分析发现,B. longum HBUAS55095和B. longum HBUAS55100具有良好的羊乳发酵特性。由此可见,B. longum(长双歧杆菌)为襄阳地区青年人肠道中双歧杆菌类群的优势种,且不同双歧杆菌制备的发酵羊乳品质差异主要体现在滋味上。

In this study, the Bifidobacterial strains were isolated and identified from feces of young volunteers recruited from Xiangyang Hubei province, and their fermentation characteristic were evaluated by electronic tongue and electronic nose technologies. The results indicated that 20 Bifidobacterial strains, were identified as Bifidobacterium longum, B. breve, B. bifidum, B. pseudocatenulatum, B.adolescentis and B. faecale, respectively. It was worth mentioning that 11 isolates were identified as B.longum. The testing of electronic tongue indicated that there was greater difference in sourness among fermented goat milk samples with range values of 24.52. The composition of organic acid was determined by High performance liquid chromatography(HPLC) method, and the result shown that lactic acid and acetic acid were majority organic acids in fermented goat milk samples. The testing of electronic nose indicated that the response value of sensor W6S, W1W and W5S were greater differences among fermented goat milk samples with variation value of 35.56%, 23.32% and 17.20%. The result of principal component analysis indicated that the fermented goat milk samples fermented by B. longum HBUAS55095 and B. longum HBUAS55100 with better quality. Thus, B. longum was domain Bifidobacterial species in young volunteers recruited from Xiangyang, and the differences among fermented goat milk fermented by Bifidobacterial strains were major in taste indexes.