Could caterpillars save the planet from plastic waste?
Most scientific research follows a logical progression, with one experiment following up on the findings of another. Every now and then, however, serendipity plays a part. Such is the case with a paper just published in Current Biology, which reveals to the world a moth capable of chewing up plastic.
大多数科学研究都是一个逻辑推理的过程，一个研究随着另一个研究的结果而开始。有时，巧合也扮演着一个重要角色。就如在《现代生物》刊登的一篇文章向世人揭示——飞蛾具有消化塑料的能力。
The experiment behind the paper was inspired when Federica Bertocchini, an amateur beekeeper who is also a biologist at Cantabria University, in Spain, noticed caterpillars chewing holes through the wax in some of her hives and lapping up the honey. To identify them, she took some home in a plastic shopping bag. But when, a few hours later, she got around to looking at her captives she found the bag was full of holes and the caterpillars were roaming around her house.
费得里卡·贝托基尼（Federica Bertocchini），一位养蜂爱好者，同时也是意大利的坎塔步里亚大学的一名生物学教授。她因注意到毛虫咀嚼蜂巢的洞口并汲取里面的蜂蜜而受启发进行实验。为了研究这些毛虫，她将一些毛虫放进塑料袋带回家。可是过了几个小时之后，她却发现塑料袋全是小孔，那些毛虫则悠哉地在房间里漫游。
After rounding them up, she identified them as larvae of the greater wax moth, a well-known pest of bee hives. On considering their escape from their shopping-bag prison, though, she wondered whether they might somehow be put to work as garbage-disposal agents.
将这些毛虫聚集起来后，她认为这些毛虫是大蜡螟（属蜜蜂种类）的幼虫。想到它们可以从塑料袋里逃脱，她就想把这些毛虫放进垃圾处理厂会怎么样呢。
Past attempts to use living organisms to get rid of plastics have not gone well. Even the most promising species, a bacterium called Nocardia asteroides, takes more than six months to obliterate a film of plastic a mere half millimetre thick. Judging by the job they had done on her bag, Dr Bertocchini suspected wax-moth caterpillars would perform much better than that.
用微生物化解塑料并没有产生很好的效果。即使是最有希望的诺卡菌都需要花6个多月的时间化解一层薄薄（仅半毫米）的塑料。鉴于这些毛虫在几个小时之内就可以几个小时穿破塑料袋，贝托基尼博士认为它们可以比诺卡菌做得更好。
To test this idea, she teamed up with Paolo Bombelli and Christopher Howe, two biochemists at Cambridge University. Dr Bombelli and Dr Howe pointed out that, like beeswax, many plastics are held together by methylene bridges (structures that consist of one carbon and two hydrogen atoms, with the carbon also linked to two other atoms). Few organisms have enzymes that can break such bridges, which is why these plastics are not normally biodegradable. The team suspected wax moths had cracked the problem.
为了证明这一设想，她联和坎塔步里亚大学的两位生物学教授——保罗·波贝利（Paolo Bombelli）及克里斯托弗·霍斯（Christopher Howe）一起进行实验。他们两个认为就像蜂蜡，许多塑料袋都是由亚甲基桥（结构是一个碳原子和两个氮原子，碳原子还和两个其他原子连接）组成的。很少有微生物具有消化不易被生物降解亚甲基桥的酶。这个团队猜测大蜡螟可以解决这一难题。
One of the most persistent constituents of rubbish dumps is polyethylene, which is composed entirely of methylene bridges linked to one another. So it was on polyethylene that the trio concentrated. When they put wax-moth caterpillars onto the sort of film it had taken Nocardia asteroides half a year to deal with, they found that holes appeared in it within 40 minutes. On closer examination, Dr Bertocchin and her colleagues discovered that their caterpillars each ate an average of 2.2 holes, three millimetres across, every hour, in the plastic film. A follow-up test found that a caterpillar took about 12 hours to consume a milligram of shopping bag. Such bags weigh about three grams, so 100 larvae might, if they spent half their lives eating, consume one in a month.
塑料中最难化解的成分就是全部由亚甲基桥构成的聚乙烯，所以聚乙烯是这个团队关注的焦点。他们把毛虫放进一层薄薄的塑料里，塑料在40分钟以内就会出现小洞，而诺卡菌却要花半年的时间。在进一步的研究中，他们发现每只毛虫平均1小时可以消化2.2个3毫米的洞口。接下来的测验中，他们还发现一只毛虫可以花12小时左右的时间在1毫米薄度，重3克的购物袋上消化一个小洞。所以如果100只幼虫的寿命中有一半是在消化塑料，它们就可以在一个月内消化一个塑料袋。
Whether releasing wax moths on the world’s surplus plastic really is sensible is not yet clear. For one thing, it has not been established whether the caterpillars gain nutritional value from the plastics they eat, as well as being able to digest them. If they do not, their lives as garbage-disposal operatives are likely to be short—and, even if they do, they will need other nutrients to thrive and grow. Another question is the composition of their faeces. If these turn out to be toxic, then there will be little point in pursuing the matter. Regardless of this, though, the discovery that wax-moth larvae can eat plastic is intriguing. Even if the moths themselves are not the answer to the problem of plastic waste, some other animal out there might be.
利用大蜡螟虫消化世界上的塑料污染物是否是理智的？目前还没有确切的答案。原因之一就是目前还没有确认这些幼虫是否可以消化塑料并汲取自身所需的营养。如果不是，那么它们吃了塑料后寿命就会超短；如果是，它们也需要其他营养。还有一个问题是这些毛虫的粪便，如果排放的粪便有毒，那么用它们来消化塑料就没有丝毫的意义。即便如此，大蜡螟幼体可以吃塑料还是值得研究的。就算这些毛虫不能解决塑料污染问题，地球上其他生物也有可能可以。
moth:飞蛾
moth-eaten:被虫蛀的，蛀坏的；过时 的，破旧的
caterpillars:毛虫
serendipity:巧事
hive: 蜂房，蜂群；忙碌的场所，繁华. 的地方
hive sth off into/to sth:把一部分分离出来，卖掉公司的一部分
lap up: 将……卷叠起来；舔食；照单全 收，欣然接受
larva: 幼虫，幼体
obliterate: 毁掉，覆盖，清楚
enzyme: 酶
biodegradable: 可生物降解的
faeces: 粪便
intriguing: 神秘的，有趣的