The vast majority of single-use plastic bottles end up in landfills or the ocean

絕大多數一次性塑料瓶最終都會被送往垃圾填埋場或海洋。

where they'll take at least 450 years to break down completely.

在那裡，它們至少需要450年才能完全分解。

Now though, scientists have created a new “super enzyme” that can decompose plastic faster than ever before,

不過現在，科學家們創造了一種新的 "超級酶"，可以比以往更快地分解塑膠。

and it could revolutionize recycling.

而且它可能會徹底改變回收的方式。

Not all plastic is the same; there are actually several materials that fall under the term.

並不是所有的塑膠都是一樣的，其實有好幾種材料都屬於這個範疇。

The plastic most disposable bottles are made out of is polyethylene terephthalate, or PET.

大多數一次性塑料瓶的材質是聚對苯二甲酸乙二醇酯，即PET。

As a material, PET is ideal for carbonated beverages because it doesn't explode from the pressure

作為一種材料，PET是碳酸飲料的理想材料，因為它不會因壓力而爆炸。

while still keeping soft drinks fizzy.

同時還能保持軟飲料的活力。

PET is recyclable, but typical methods used today involve melting down products of all different colors,

PET是可以回收利用的，但目前使用的典型方法是熔化所有不同顏色的產品。

resulting in a gray or black plastic that's not very appealing to consumers or as durable.

導致灰色或黑色的塑膠，對消費者的吸引力不大，也不耐用。

It's also cheaper to use new PET instead of the recycled variety.

使用新的PET而不是回收的品種也更便宜。

So, scientists are looking at ways to break PET into its component parts,

所以，科學家們正在研究如何將PET分解成其組成部分。

allowing recycling plants to make products indistinguishable from virgin PET by ignoring dyes and eliminating the need for sorting.

允許回收工廠通過忽略染料和消除分揀的需要，使產品與原生PET難以區分。

Decomposing the plastic would also avoid some environmental issues of melting it down.

分解塑膠也可以避免一些融化塑膠的環境問題。

One alternative uses enzymes that target the bonds in the material, and amazingly...

一種替代方法是使用針對材料中的鍵的酶，令人驚奇的是... ...

scientists have discovered some of these enzymes naturally occur in bacteria.

科學家們發現其中一些酶自然存在於細菌中。

That's right, there are microorganisms that have the ability to decompose plastic.

沒錯，有一些微生物具有分解塑膠的能力。

The bacteria that breaks down PET the fastest out of any we've discovered so far were discovered in a waste site in Japan in 2016.

在我們目前發現的所有細菌中，分解PET最快的細菌是2016年在日本的一個垃圾場發現的。

They can eat through low-quality plastic in about 6 weeks,

它們可以在6周左右的時間內吃完低質量的塑膠。

though highly crystalized PET like the kind found in bottles takes longer to break down.

雖然像瓶子裡的那種高結晶的PET需要更長的時間來分解。

So, scientists searched for a way to pick up where nature has started.

於是，科學家們尋找到了一種方法，來拾取大自然的起點。

First they experimented with variations of the enzyme the bacteria make called PETase.

首先，他們用細菌製造的名為PET酶的變體進行實驗。

One lab engineered version was found to break down PET about 20% faster than the naturally occurring variety.

其中一種實驗室工程版本被發現比天然存在的品種分解PET快20%。

Okay, off to a good start.

好了，開了個好頭。

But the same Japanese bacterium has another trick to further break down PET, a second enzyme called MHETase.

但同樣的日本細菌還有另一招可以進一步分解PET，第二種酶叫MHET酶。

MHETase takes a product PETase creates, mono(2-hydroxyethyl) terephthalate,

MHET酶將PET酶產生的產物--單(2-羥乙基)對苯二甲酸酯。

and further cuts it up into terephthalic acid and ethylene glycol.

並進一步將其切割成對苯二甲酸和乙二醇。

I may have been practicing that sentence all day in the mirror.

我可能一整天都在對著鏡子練習這句話。

These are the building blocks of PET and returning it to this state could mean the same plastic could be recycled endlessly,

這些都是PET的構件，將其恢復到這種狀態可能意味著同樣的塑膠可以被無休止地回收利用。

cutting down on the need to make more from petroleum.

減少從石油中製造更多的東西；

When researchers used their mutant PETase and MHETase together, they found it broke down plastic

當研究人員將他們的突變體PET酶和MHET酶一起使用時，他們發現它可以分解塑膠

twice as fast as PETase alone.

是單獨PET酶的兩倍。

But the real gains came when they synthesized a link between the two enzymes, in a way that almost looks like they're holding hands.

但真正的收穫來自於他們合成了兩種酶之間的鏈接，這種方式看起來幾乎就像他們在牽手。

With their powers literally combined, they sliced through PET six times faster than PETase alone.

他們的力量完全結合在一起，他們切開PET的速度是PETase單獨的六倍。

You may be wondering why the bacteria don't pull off this same trick themselves?

你可能想知道為什麼細菌自己不使出同樣的招數？

While the two separate enzymes are made within the same bacterium,

雖然這兩種獨立的酶是在同一細菌內製造的。

the combined super enzyme is just too large for their little molecular machinery to produce.

合併後的超級酶對他們的小分子機器來說，實在是太大了，無法生產。

So thank you for the nudge in the right direction, little guys, we'll take it from here.

所以，謝謝你的推敲，小夥伴們，我們會從這裡開始。

Of course, this doesn't mean the end of plastic waste as we know it,

當然，這並不意味著我們所知的塑膠垃圾的終結。

the researchers note even with the increased speed over PETase alone

研究人員注意到，即使比PET酶單獨提高了速度。

this new super enzyme is still not fast enough yet to be commercially viable.

這種新的超級酶的速度仍然不夠快，還沒有商業化。

They're going to have to find other ways of speeding the process up if we're going to close the loop on plastic products.

如果我們要關閉塑料產品的循環，他們將不得不找到其他方法來加快這個過程。

Even if scientists one day make a bacterial enzyme that just obliterates plastic waste,

即使有一天科學家們製造出了一種細菌酶，只是消滅了塑膠垃圾。

there's still a major piece missing: us.

還缺少一個重要的環節：我們。

Fewer than 30% of bottles used in the US are recycled, and that rate is much lower in places that don't incentivize it.

在美國使用的瓶子中，只有不到30%的瓶子被回收，而在不鼓勵回收的地方，這個比例要低得多。

We have to get better at keeping plastic out of the environment and getting it somewhere where it can be reused.

我們必須更好地將塑膠排除在環境之外，並將其送到可以再利用的地方。

Simply making sure what you use finds its way to a recycling facility can be a big help.

只要確保你使用的東西能被送到回收設施，就能幫上大忙。

Develop good recycling habits and if commercial-grade plastic-munching bacteria ever do arrive

養成良好的回收習慣，如果有一天，商業級的食塑菌真的來了。

we can be sure they have plenty to chew on.

我們可以肯定他們有很多東西可以嚼。

While some bacteria have PET slicing enzymes originally meant to break down leaves,

而有些細菌的PET切片酶原本是用來分解樹葉的。

the bacteria discovered in Japan appear to have evolved PETase as a response to plastic waste.

在日本發現的細菌似乎已經進化出PET酶，作為對塑膠垃圾的反應。

Plastic waste is a major problem that we are tackling from all sides, so how close are we to reinventing plastic itself?

塑膠垃圾是我們從各方面著手解決的重大問題，那麼我們離重塑塑膠本身還有多遠？

Check out our video on that here. Thanks for watching, don't forget to subscribe, and I'll see you next time on Seeker.

點擊這裡查看我們的視頻。感謝您的觀看，別忘了訂閱，我們下期《求是》再見。