万物简史 第432期:小生物的世界(3)

 Bacteria do it all the time without fuss, and thank goodness, for no larger organism could survive without the nitrogen they pass on. 而细菌一直在不慌不忙地干这件事。谢天谢地，要是没有它们来传送氮，大的生物就活不下去。

Above all, microbes continue to provide us with the air we breathe and to keep the atmosphere stable. 尤其重要的是，细菌们不断为我们提供我们所呼吸的空气并使大气保持稳定。

Microbes, including the modern versions of cyanobacteria, supply the greater part of the planet's breathable oxygen. 包括现代型的藻青菌在内的细菌，提供了地球上供呼吸用的大部分氧。

Algae¹ and other tiny organisms bubbling away in the sea blow out about 150 billion kilos of the stuff every year. 海藻和海里的其他微生物每年大约吐出1500亿立方公里那种气体。

And they are amazingly prolific². 而且，细菌的繁殖力极强。

The more frantic³ among them can yield a new generation in less than ten minutes; 其中劲头大的在不到10分钟里便能产生新的一代；

Clostridium perfringens, the disagreeable little organism that causes gangrene, can reproduce in nine minutes. 那种引起坏疽的讨厌的小生物“产气荚膜梭菌”在9分钟里就可以繁殖，接着又马上开始分裂。

At such a rate, a single bacterium⁴ could theoretically produce more offspring in two days than there are protons in the universe. 以这种速度，从理论上说，一个细菌两天内产生后代比宇宙里的质子还多。

"Given an adequate supply of nutrients⁵, a single bacterial⁶ cell can generate 280,000 billion individuals in a single day," “要是给予充分的营养，一个细菌细胞在一天之内可以产生280万亿个个体，”

according to the Belgian biochemist and Nobel laureate Christian⁷ de Duve. 据比利时生物化学家、诺贝尔奖获得者克里斯琴·德迪夫说。

In the same period, a human cell can just about manage a single division. 而在同样的时间里，人的细胞大约只能分裂一次。

About once every million divisions, they produce a mutant. 大约每分裂100万闪，便会产生一个突变体。

Usually this is bad luck for the mutant—change is always risky⁸ for an organism, 这对突变体来说通常是很不幸的，对生物来说，变化总是蕴藏着危险，

but just occasionally the new bacterium is endowed with some accidental advantage, 只是偶然的情况下，一个新的细菌会碰巧具有某种优势，

such as the ability to elude⁹ or shrug¹⁰ off an attack of antibiotics¹¹. 比如摆脱或抵御抗生素的能力。

1 algae   

n.水藻，海藻

参考例句：

• Most algae live in water.多数藻类生长在水中。
• Algae grow and spread quickly in the lake.湖中水藻滋蔓。

2 prolific   

adj.丰富的，大量的；多产的，富有创造力的

参考例句：

• She is a prolific writer of novels and short stories.她是一位多产的作家，写了很多小说和短篇故事。
• The last few pages of the document are prolific of mistakes.这个文件的最后几页错误很多。

3 frantic   

adj.狂乱的，错乱的，激昂的

参考例句：

• I've had a frantic rush to get my work done.我急急忙忙地赶完工作。
• He made frantic dash for the departing train.他发疯似地冲向正开出的火车。

4 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

5 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

6 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

7 Christian   

adj.基督教徒的；n.基督教徒

参考例句：

• They always addressed each other by their Christian name.他们总是以教名互相称呼。
• His mother is a sincere Christian.他母亲是个虔诚的基督教徒。

8 risky   

adj.有风险的，冒险的

参考例句：

• It may be risky but we will chance it anyhow.这可能有危险，但我们无论如何要冒一冒险。
• He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。

9 elude   

v.躲避，困惑

参考例句：

• If you chase it,it will elude you.如果你追逐着它， 它会躲避你。
• I had dared and baffled his fury.I must elude his sorrow.我曾经面对过他的愤怒，并且把它挫败了；现在我必须躲避他的悲哀。

10 shrug   

v.耸肩(表示怀疑、冷漠、不知等)

参考例句：

• With a shrug,he went out of the room.他耸一下肩，走出了房间。
• I admire the way she is able to shrug off unfair criticism.我很佩服她能对错误的批评意见不予理会。

11 antibiotics   

n.（用作复数）抗生素；（用作单数）抗生物质的研究；抗生素，抗菌素( antibiotic的名词复数 )

参考例句：

• the discovery of antibiotics in the 20th century 20世纪抗生素的发现
• The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。