Investigating natural product biosynthetic pathways in the microbiomes associated with long-lived aquatic vertebrates

最近人们认识到有益微生物群对延长动物宿主寿命的重要贡献。在我们努力鉴定可能有助于水生动物长寿的关键细菌、代谢物和生物合成基因的过程中，我们最初获得了长寿动物的细菌分离物，如石鳖（寿命40年）和日本岩鱼（寿命90年）。从每个石鳖样品中分离纯化宏基因组。随后的pcr克隆和测序导致在五个石鳖样本中的两个样本的宏基因组中检测到一种生物合成前景良好的细菌。从单个石鳖的不同部位分离出约430株细菌，并进行耐药性检测。结果发现，约109株细菌对某些抗生素具有耐药性，随后对其进行pcr克隆，以检测具有生物合成潜力的菌株。这些鉴别有生物合成潜力的细菌的筛选工作仍在进行中。这是与Joern Piel教授（苏黎世联邦理工学院）的实验室合作，以补充他们在细菌化学方面的工作。利用已知的海绵衍生化合物，我们优化了筛选方案，以测试化合物在生物模型酿酒酵母中刺激寿命延长的能力。这是基于与阳性对照（蛋白酶体刺激化合物）和阴性对照（蛋白酶体抑制剂）相比，用测试化合物处理酵母裂解物后的蛋白酶体活性监测。

It has recently been recognized that the important contribution of beneficial microbiomes to the prolonged lifespan of their animal hosts. In our efforts to identify key bacteria, metabolites and biosynthetic genes that may contribute to the longevity of aquatic animals, we initially obtained bacterial isolates from long-lived animals, such as chitons (lifespan ~40 years) and a Japanese rockfish (lifespan >90 years). We isolated and purified metagenome from each chiton sample. Subsequent PCR-cloning and sequencing led to the detection of a biosynthetically promising bacterium in the metagenome from two of five studied chiton samples. We isolated ~430 bacterial strains from different parts of individual chitons and tested them for antibiotic resistance. It was found that ~109 bacterial strains showing resistance to certain antibiotics, which were subsequently subjected to PCR-cloning to detect strains with biosynthetic potential. These screening efforts to identify biosynthetically promising bacteria are still on going. This is in collaboration with the Lab of Prof. Joern Piel (ETH Zurich) to complement with their work on the bacterial chemistry. Using known sponge-derived compounds, we optimized the screening protocol for testing the ability of compounds to stimulate lifespan extension in the organism model Saccharomyces cerevisiae. This was based on monitoring proteasome activity of yeast lysates after being treated with tested compounds in comparison with the positive control (proteasome-stimulating compounds) and the negative control (proteasome inhibitor).