While experts are developing 'greener' alternative fuel sources, a group of undergrads are creating a more natural one.
当专家们还在研发更环保的燃料时，一群在校生已经开始制作一种天然的燃料。
The team is working towards producing a biofuel that uses human and animal excretion, with the hopes of replacing harmful gasoline, diesel and jet fuel that dominate the market.
这个研究小组正在用人和动物的排泄物生产生物燃料。他们希望以此替代目前占据市场主导地位但却有害的汽油、柴油和喷气燃料。
By engineering Bacillus subtilis, researchers are able to break down proteins and transform the left over material into alcohol biofuels and ammonia.
通过对枯草杆菌进行处理，研究者们成功地分离了蛋白质，把排泄物转化为酒精生物燃料和氨气。
The US produces over 1 billion tons of animal and human waste every year, which does nothing but sit in an aerobically compost giving off harmful emissions.
美国每年产生超过10亿吨的动物和人类排泄物。它们原本没有任何用处，只能堆在耗氧肥料中释放有害气体。

David Wernick, a PhD candidate who graduated from the University of California, and his colleagues 'were struck by all the waste that is literally going to waste' and realized the material may have potential as a renewable fuel source, reports the University of California.
大卫·韦尼克是毕业于加州大学的博士生。据加州大学报道，有一天，他和同事们灵机一动，想到这些被浪费掉的排泄物或许可以转化为可再生燃料。
'We're working with anything such as agricultural waste like manure, municipal waste like sewage, plant matter, cellulosic matter and even carbon dioxide out of the atmosphere,' said Wernick in a video discussing the research.
韦尼克在某个视频中讨论了这项研究：“我们正在不断地实验。肥料之类的农业废弃物，污水等城市垃圾，还有植物、纤维素，甚至是空气中的二氧化碳，我们都不放过。”
Wernick explained that the world is dominated by gasoline, diesel and jet fuel as the main transportation fuels.
韦尼克解释说，汽油、柴油和喷气燃料这些主要的交通燃料目前在世界上占据主导地位。
In 2014, the US consumed 375 million gallons of gasoline every day for the entire year, according to the US Energy Information Administration.
据美国能源情报署数据，2014年，美国每天消耗3.75亿加仑的汽油。
Gasoline isn't just a toxic and highly flammable liquid it also produces vapors that pollute our air.
汽油不仅是有毒、易燃液体，它还会释放气体，污染空气。
Burning this liquid releases carbon dioxide into the atmosphere – the biggest culprit of climate change.
燃烧汽油会向大气排放二氧化碳，这也是如今气候变化的罪魁祸首。
And diesel and jet fuel do their part in polluting the air with polyaromatic hydrocarbons and nitrous oxides.
柴油和航空煤油使用过程中会释放多环芳烃和氮氧化物，同样会污染大气。