字幕列表 影片播放 列印英文字幕 Most of the UK's energy is derived from non-renewable sources, ok. However, there are plenty of renewable options available to us. The sun is going to continue shining for billions of years. The wind and the tide are not going anywhere, as far as we know. And there is also another form of energy being produced all the time, all around us, which you might not be aware of. And it's methane (CH4). So the combustion of methane can produce large amounts of energy. It's quite popular in India. In the UK it has not gained a foothold. So where does this energy supposed to come from? These guys. Cows get most of the blame for the production of methane but it is actually the microbial communities inside it's digestive tract which are responsible. That process will continue even after the faeces has left the cow and if one were to retrieve a sample of that and place it into an air-tight container, with the appropriate artificial medium, the methane production process would continue, as you can see here. Let's take a closer look at the sample under the microscope to get a picture of what is exactly going on. The intestine of a cow is a very nutrient-rich environment and this allows for the existence of hundreds to thousands of different species. As you can see here in this image, this complexity is completely overwhelming. We can't actually do anything with these bio cells, we have to focus in on our core interest, which is the methane producers known as methanogens. So if we want to isolate these guys and study them further, we have to take some very special precautions. Methanogens are incredibly sensitive organisms. Even a tiny amount of oxygen will kill them. So here you can see my colleague working in an anaerobic chamber where all the oxygen has been removed. This is what a methanogen monoculture looks like after we have successfully isolated it from its natural community. So, of course, these guys are responsible for all the methane production in a cow but they don't do it alone. They rely on an extensive network of other bacteria in a food web. This is where the real science begins, you see, because now that we have our monoculture we can mix and match different players from that food web with this guy to find out: what does a stable community look like; what are the properties of an efficient community; what does a weak community look like? And these design principles can be used to tell us all sorts of things about how nature works. Alright, so thank you very much for listening. Have a great day.
B1 中級 如何用細菌製造生物燃料 (How to make biofuel from bacteria) 131 17 Cheng-Hong Liu 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字