Landfills produce methane—which can be valuable as an energy source. But scientists haven’t known why landfills make so much methane. The solid waste in landfills is typically at a pH that’s considered too [--1--] to host methanogens, methane-producing microbes.

So scientists did [--2--], literally, to investigate. They found a particularly [--3--] methanogen called named Methanosarcina barkeri, or just M. barkeri, that can survive at low pH levels.

M. barkeri eats the acids and produces some methane. At the same time, it raises the pH level in the area around it. The less-acidic environment that results becomes a better host for other methanogens. As liquid [--4--] the landfill, it carries higher pH materials and the methanogens living among them to other areas of the landfill.

M. barkeri repeats this cycle, making the landfill environment even more methanogen-friendly. The research was published in the journal Applied and Environmental Microbiology.

M. barkeri not only produces methane that could be [--5--]—the microbes also make the whole trash mound more compact. The finding could help in the development of ways to accelerate the process. Leading to more methane collection and more room for waste without more landfills.
【視聽版科學(xué)小組榮譽(yù)出品】
acidic some digging hearty leaches through harvested for fuel
產(chǎn)甲烷菌:我的規(guī)則我做主 科學(xué)家們一直不明白為什么垃圾填埋場(chǎng)可以產(chǎn)生那么多沼氣(一種很有價(jià)值的能源). 而且垃圾堆里的固體廢料是一種典型的PH值極低的物質(zhì)[注1], 可以生產(chǎn)甲烷的微生物產(chǎn)甲烷菌無(wú)法在這種強(qiáng)酸環(huán)境中生存. 于是科學(xué)家們跑到垃圾填埋場(chǎng)去刨刨挖挖,說(shuō)好聽點(diǎn),去做調(diào)查. 于是他們發(fā)現(xiàn)了一種精力旺盛的產(chǎn)甲烷菌---巴氏甲烷八疊球菌(簡(jiǎn)稱巴氏M.)可以在強(qiáng)酸環(huán)境中存活. 巴氏M. 嗜酸并制造一些甲烷. 同時(shí), 它會(huì)中和它的周邊區(qū)域. 而酸性越弱的環(huán)境對(duì)其他普通的產(chǎn)甲烷菌的寄居越有利. 當(dāng)液體物質(zhì)流過(guò)垃圾堆時(shí)會(huì)帶來(lái)一些PH值較高的物質(zhì)和在其他垃圾堆寄居的產(chǎn)甲烷菌. 巴氏M. 將垃圾場(chǎng)的環(huán)境變得更適合產(chǎn)甲烷菌居住并重復(fù)這種生態(tài)循環(huán). 該研究發(fā)表在<應(yīng)用與環(huán)境微生物學(xué)>期刊上. 巴氏M.不僅制造可以用作燃料的甲烷,還可以將整個(gè)垃圾堆變得更容易分解. 此項(xiàng)發(fā)現(xiàn)有助于加速垃圾處理過(guò)程, 收集到更多的甲烷,并且減小垃圾的占地面積.