科技日报---在城市水道中发现了食用塑料的细菌
2024-11-13 10:40阅读：
题记：令人想不到在城市的污水管道中竟然生活着一种如此神奇的微生物—Comamonas菌，它们的体内可以分泌出一种特殊的酶，可以分解塑料。这对于人类解决塑料污染的大问题来说，真是一个福音！人类无法或很难做到的事情，微小的细菌却能轻而易举地做到，而且很完美，这不能不说它们的智慧和能力。适者生存，微乎其微的细菌在污水管道中找到了自己生存的空间，并能从中寻找到理想的食物，进而得以繁衍生息。关注这些微小的生命吧！它们可以创造奇迹，可以改变人类的生存环境！
Comamonas bacteria live in wastewater, where they break
down plastic waste for food. Credit: Ludmilla
Aristilde/Northwestern University
Comamonas细菌生活在废水中，它们在废水中分解塑料废物作为食物。图片来源：Ludmilla
Aristilde/西北大学
This discovery could pave the way for bioengineered
solutions to tackle plastic waste cleanup.
Researchers have long observed that a common family of
environmental bacteria, Comamonadacae, grow on plastics littered
throughout urban rivers and wastewater systems. But what, exactly,
these Comamonas bacteria are doing has remained a
mystery.
这一发现可能为解决塑料废物清理问题的生物工程解决方案铺平道路。
长期以来，研究人员一直在观察一种常见的环境细菌家族Comamonadacae，它们生长在城市河流和废水系统中随处可见的塑料上。但这些Comamonas细菌究竟在做什么，一直是个谜。
Now, Northwestern University-led researchers have
discovered how cells of a Comamonas bacterium are breaking down
plastic for food. First, they chew the plastic into small pieces,
called nanoplastics. Then, they secrete a specialized enzyme that
breaks down the plastic even further. Finally, the bacteria use a
ring of carbon atoms from the plastic as a food source, the
researchers found.
现在，
西北大学的研究人员发现了一种Comamonas
细菌的细胞是如何分解塑料作为食物的。研究人员发现，首先，它们将塑料咀嚼成小块，称为纳米塑料。然后，它们分泌一种特殊的酶，再进一步分解塑料。最后，细菌利用塑料中的碳原子环作为食物来源。
The discovery opens new possibilities for developing
bacteria-based engineering solutions to help clean up
difficult-to-remove plastic waste, which pollutes drinking water
and harms wildlife.
The study will be published on Thursday (Oct. 3) in the
journal Environmental Science & Technology.
这一发现为开发基于细菌的工程解决方案提供了新的可能性，有助于清理难以清除的塑料垃圾，因为塑料垃圾会污染饮用水并伤害野生动物。
这项研究将于本周四（10月3日）发表在《环境科学与技术》（Environmental
Science & Technology.）杂志上。
“We have systematically shown, for the first time, that a
wastewater bacterium can take a starting plastic material,
deteriorate it, fragment it, break it down, and use it as a source
of carbon,” said Northwestern’s Ludmilla Aristilde, who led the
study. “It is amazing that this bacterium can perform that entire
process, and we identified a key enzyme responsible for breaking
down the plastic materials. This could be optimized and exploited
to help get rid of plastics in the environment.”
“我们首次系统地展示了一种废水细菌可以利用塑料材料，使其变质、碎裂、分解，并将其用作碳源”，领导这项研究的西北大学的路德米拉-阿里斯蒂尔德（Ludmilla
Aristilde）说。“这种细菌竟然能完成整个过程，我们还发现了一种负责分解塑料材料的关键酶。可以优化和利用这种酶，帮助清除环境中的塑料。”
An expert in the dynamics of organics in environmental
processes, Aristilde is an associate professor of environmental
engineering at Northwestern’s McCormick School of Engineering. She
also is a member of the Center for Synthetic Biology, International
Institute for Nanotechnology and Paula M. Trienens Institute for
Sustainability and Energy. The study’s co-first authors are Rebecca
Wilkes, a former Ph.D. student in Aristilde’s lab, and Nanqing
Zhou, a current postdoctoral associate in Aristilde’s lab. Several
former graduate and undergraduate researchers from the Aristilde
Lab also contributed to the work.
阿里斯蒂尔德是环境过程中有机物动力学方面的专家，现任西北大学麦考密克工程学院环境工程副教授。她还是合成生物学中心、国际纳米技术研究所和
Paula M. Trienens
可持续发展与能源研究所的成员。
该研究的共同第一作者是阿里斯蒂尔德实验室的前博士生丽贝卡-威尔克斯（Rebecca
Wilkes）和阿里斯蒂尔德实验室的现任博士后周南清（Nanqing
Zhou）。
阿里斯蒂尔德实验室的几位前研究生和本科生研究员也为这项工作做出了贡献。
The pollution problem
The new study builds on previous research from Aristilde’s
team, which unraveled the mechanisms that enable Comamonas
testosteri to metabolize simple carbons generated from broken down
plants and plastics. In the new research, Aristilde and her team
again looked to C. testosteroni, which grows on polyethylene
terephthalate (PET), a type of plastic commonly used in food
packaging and beverage bottles. Because it does not break down
easily, PET is a major contributor to plastic
pollution.
污染问题
这项新研究建立在阿里斯蒂尔德团队以前的研究基础之上，以前的研究揭示了Comamonas
testosteri代谢植物和塑料分解产生的单质碳的机制。在新的研究中，阿里斯蒂尔德和她的团队再次研究了C.
testosteroni，它生长在聚对苯二甲酸乙二醇酯（PET）上，这是一种常用于食品包装和饮料瓶的塑料。由于聚对苯二甲酸乙二醇酯不易分解，因此是造成塑料污染的主要原因。
“It’s important to note that PET plastics represent 12% of
total global plastics usage,” Aristilde said. “And it accounts for
up to 50% of microplastics in wastewaters.”
'必须指出的是，PET
塑料占全球塑料总用量的12%，'Aristilde
说，'而且它它在废水中的微塑料中所占的比例高达50%。'
Innate ability to degrade plastics
To better understand how C. testosteroni interacts with
and feeds on the plastic, Aristilde and her team used multiple
theoretical and experimental approaches. First, they took bacterium
— isolated from wastewater — and grew it on PET films and pellets.
Then, they used advanced microscopy to observe how the surface of
the plastic material changed over time. Next, they examined the
water around the bacteria, searching for evidence of plastic broken
down into smaller nano-sized pieces. And, finally, the researchers
looked inside the bacteria to pinpoint tools the bacteria used to
help degrade the PET.
降解塑料的天生能力
为了更好地了解C.
testosteroni是如何与塑料相互作用并以塑料为食的，Aristilde和她的团队采用了多种理论和实验方法。首先，他们从废水中分离出细菌，并将其培养在
PET
薄膜和颗粒上。然后，他们使用先进的显微镜观察塑料材料表面随时间的变化。接着，他们检查了细菌周围的水，寻找塑料被分解成更小的纳米级碎片的证据。最后，研究人员观察了细菌内部，以确定细菌用来帮助降解
PET 的工具。
“In the presence of the bacterium, the microplastics were
broken down into tiny nanoparticles of plastics,” Aristilde said.
“We found that the wastewater bacterium has an innate ability to
degrade plastic all the way down to monomers, small building blocks
which join together to form polymers. These small units are a
bioavailable source of carbon that bacteria can use for
growth.”
'在细菌存在的情况下，微塑料被分解成微小的纳米塑料颗粒，'Aristilde
说。'我们发现，废水细菌有一种与生俱来的能力，可以将塑料降解为单体，即连接在一起形成聚合物的小构件。这些小单元是生物可用的碳源，细菌可以利用它们进行生长。'
After confirming that C. testosteroni, indeed, can break
down plastics, Aristilde next wanted to learn how. Through omics
techniques that can measure all enzymes inside the cell, her team
discovered one specific enzyme the bacterium expressed when exposed
to PET plastics. To further explore this enzyme’s role, Aristilde
asked collaborators at Oak Ridge National Laboratory in Tennessee
to prepare bacterial cells without the abilities to express the
enzyme. Remarkably, without that enzyme, the bacteria’s ability to
degrade plastic was lost or significantly
diminished.
在确认C.
testosteroni确实能够分解塑料后，Aristilde接下来想了解如何分解。
通过可以测量细胞内所有酶的组学技术，她的团队发现了该细菌在接触
PET
塑料时表达的一种特定酶。为了进一步探索这种酶的作用，阿里斯蒂尔德请田纳西州橡树岭国家实验室的合作者制备了没有表达这种酶能力的细菌细胞。值得注意的是，如果没有这种酶，细菌降解塑料的能力就会丧失或大大降低。
How plastics change in water
Although Aristilde imagines this discovery potentially
could be harnessed for environmental solutions, she also says this
new knowledge can help people better understand how plastics evolve
in wastewater.
塑料在水中的变化
尽管阿里斯蒂尔德认为这一发现有可能被用于环境解决方案，但她也表示，这一新知识可以帮助人们更好地了解塑料是如何在废水中演变的。
“Wastewater is a huge reservoir of microplastics and
nanoplastics,” Aristilde said. “Most people think nanoplastics
enter wastewater treatment plants as nanoplastics. But we’re
showing that nanoplastics can be formed during wastewater treatment
through microbial activity. That’s something we need to pay
attention to as our society tries to understand the behavior of
plastics throughout its journey from wastewater to receiving rivers
and lakes.”
'废水是微塑料和纳米塑料的巨大宝库，'Aristilde
说。'大多数人认为纳米塑料是以纳米塑料的形式进入废水处理厂的。但我们的研究表明，纳米塑料可以在废水处理过程中通过微生物的活动形成。当我们的社会试图了解塑料从废水到接收河流和湖泊的整个过程中的行为时，我们需要关注这一点。'
