目前，国内外对于裙带菜的研究主要集中于其抗氧化、抗肿瘤等活性，而对其内生菌的研究未见报道。本文以青岛海域裙带菜为原材料，对其内生菌进行分离、纯化，共获得7株内生真菌和5株内生细菌，并采用DTNB显色法测定各菌株发酵液抑制乙酰胆碱酯酶活性，筛选出具有活性的菌株，并对活性最高的一株细菌QD-4进行生理生化鉴定和16S rDNA分子生物学鉴定，确定该菌株为芽孢杆菌，命名为Bacillus sp. QD-4。以发酵液的AChE抑制率为活性指标，采用单因素和正交试验对发酵条件进行优化，确定了培养基最佳碳源为5.0%淀粉、最佳氮源为1.0%蛋白胨，最佳发酵条件：发酵时间5 d、接种量8%、培养基初始pH值9.0、培养温度30 ℃。发酵条件经优化后,当发酵液粗浸膏为20 mg/mL时，对AChE抑制率可达到34.02%。

Studies on Undaria pinnatifida to date have mainly focused on its antioxidant, antitumor activities, while no reports are available on the endophytes from Undaria pinnatifida. In this study, fresh U. pinnatifida from Qingdao sea area was used to isolate and purify endophytes. A total of seven strains of endophytic fungi and five strains of endophytic bacteria were isolated, the acetylcholinesterase (AChE) inhibitory activity of each strain was evaluated by the 5,5-dithiobis-2-nitrobenzoic acid (DTNB) method, and active strains were identified. Strain QD-4 showed the highest AChE inhibitory activity and was identified, by physiological-biochemical characteristics and molecular biological techniques (using 16S rDNA sequencing), as Bacillus sp. and named as Bacillus sp. QD-4. The fermentation conditions were optimized using single-factor and orthogonal experiments with the inhibition rate on AChE in the fermentation broth as the activity indicator. The optimum carbon and nitrogen sources were identified as 5% starch and 1% peptone, respectively. The optimum fermentation conditions were as follows: fermentation time, 5 days; quantity of inoculum, 8%; initial substrate pH, 9.0; and culture temperature, 30 ℃. Under these conditions, the highest rate of AChE inhibition was 34.02% when the concentration of crude extract from fermentation broth was 20 mg/ml.

青岛市科技发展计划项目－应用基础研究（13-1-4-199-jch）