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组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，我们最初从长寿动物中获得了细菌分离株，如石鳖（寿命约40年）和日本岩鱼（寿命>90年）。我们从每个石鳖样品中分离和纯化宏基因组。随后的PCR克隆和测序导致检测的生物合成有前途的细菌的宏基因组从两个研究的五个石鳖样品。我们从各个石鳖的不同部位分离出约430种细菌菌株，并对其进行了抗生素耐药性测试。发现约109种细菌菌株对某些抗生素显示出耐药性，随后对其进行PCR克隆以检测具有生物合成潜力的菌株。这些筛选工作，以确定生物合成有前途的细菌仍在继续。这是与Joern Piel教授（ETH苏黎世）的实验室合作，以补充他们在细菌化学方面的工作。使用已知的海绵衍生化合物，我们优化了筛选方案，用于测试化合物在生物体模型酿酒酵母（Saccharomyces cerevisiae）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，监测用测试化合物处理后酵母裂解物的蛋白酶体活性。

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).