雨巷 戴望舒:探索发现：野生啤酒酵母终被发现

Scientists have tracked down the wild ancestor of the yeast that makes cold-brewing ale possible.

 

科学家们已经找到到使冷酿啤酒成为可能的野生啤酒酵母

THE GIST 

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People have been searching for the wild ancestor of lager yeast for decades. 

　　○ 人们已经花了几十年的时间寻找了野生啤酒酵母。

Scientists finally located the yeast in the forest of the Patagonia region. 

　　○ 科学家们最终在南美巴塔哥尼亚地区的森林里找到了这种酵母。

The find reveals how the first batches of European lager were brewed in cool caves of Bavaria. 

　　○ 这项发现可以揭秘第一批欧洲啤酒是如何在凉爽的巴伐利亚山洞里酿造而成的。

Deep in the forests of South America's Patagonia region, scientists have tracked down the wild ancestor of the yeast that makes cold-brewing ale possible, according to a new study.

　　根据一份新的研究报告，在南美的巴塔哥尼亚地区的森林深处，科学家们已经发现了酵母的野生祖先。这种野生酵母使冷酿啤酒成为可能。

The finding provides the missing piece in a centuries-long tale of beer-drinking, today a $250 billion a year industry, that began with the first batches of European lager brewed in the cool, dank caves of Bavaria.

　　这个发现为持续了一个世纪之久的啤酒传奇补齐了遗失的章节。今天的啤酒业已经是一个年产值2500亿美元的产业。第一批欧洲啤酒诞生于巴伐利亚阴凉潮湿的山洞里。

"People have been hunting for this thing for decades," said Chris Todd Hittinger, a University of Wisconsin-Madison genetics professor and a co-author of the study in the Proceedings of the National Academy of Sciences.

　　“人们已经寻找它几十年了，”克里斯托德·海廷格说。他是威斯康星大学麦迪逊分校的遗传学教授也是承担美国国家科学院这项研究报告的共同作者。

"And now we've found it. It is clearly the missing species. The only thing we can't say is if it also exists elsewhere (in the wild) and hasn't been found."

　　“但现在我们终于找到它了。很显然，这正是（啤酒酿造史）缺少的环节。我们唯一不能确定的是，它还是否还存在于其它仍未被发现的野外环境中。”

Researchers from Portugal, Argentina and the United States teamed up in the hunt for the yeast, now dubbed Saccharomyces eubayanus.

　　来自葡萄牙、阿根廷和美国研究人员组成了团队共同寻找酵母，现在他们给这种酵母起了一个绰号：Saccharomyces eubayanus。

The origin of the the hybrid yeast used for making the popular golden brew has been a persistent mystery.

　　用来酿造普通金色啤酒的混合酵母的起源一直是个谜。

One element -- Saccharomyces cerevisiae, responsible for the warmer temperature fermentation of ale, wine and bread -- was well known.

　　一种成份是Saccharomyces cerevisiae，用于温暖温度下啤酒、葡萄酒和面包的发酵，人们都对这些工艺很熟悉了。

But the other was a puzzle. Scientists at the New University of Lisbon, who pored over 1,000 species of known yeast in European collections in an attempt to find a match, but turned up nothing.

　　但是其它成份还是一团迷雾。里斯本新大学的科学家们试图找到一种匹配酵母，为此他们仔细比对了在欧洲收集的1000多种已知的酵母，但最终一无所获。

They expanded the search to international collaborators, and Diego Libkind of the Institute for Biodiversity and Environment Research (CONICET) in Bariloche, Argentina found a close match for the yeast in Patagonian beech trees.

　　他们寻找国际合作者以扩大搜索的范围。阿根廷巴里洛切生物多样性与环境研究机构（CONICET）的圣地亚哥·利布金德在巴塔哥尼亚的山毛榉树上为已知的酵母找到了接近的匹配物。

The yeast seemed to thrive and spontaneously ferment in the sugar-rich bulbous formations called galls which arise when insects lay eggs on the tree's leaves.

　　这种新酵母似乎在叫做虫瘿的富含糖份的球状形成物里生气勃勃并自然地发酵。虫瘿是昆虫把虫卵产在树叶上时形成的。

"When overmature, they fall all together to the (forest) floor where they often form a thick carpet that has an intense ethanol odor, most probably due to the hard work of our new Saccharomyces eubayanus," said Libkind.

　　利布金德说，“虫瘿过熟时，就会一起掉到下来，在森林的地表经常会覆盖厚厚的一层，并发出非常强烈的乙醇气味。这种气味很大的可能性要归因于我们这种新发现的Saccharomyces eubayanus。”

Researchers at the University of Colorado School of Medicine sequenced the genome of the Patagonian yeast and found it was a near-perfect match to the element used to brew lager.

　　科罗拉多大学医学院的研究人员为巴塔哥尼亚酵母做了基因组排序，并发现它近乎完美地与用于酿造啤酒的成份相匹配。

"It proved to be distinct from every known wild species of yeast, but was 99.5 percent identical to the non-ale yeast portion of the lager genome," said Hittinger.

　　利布金德说，“我们已证实，这种新酵母不同于任何一种已知种类的野生酵母，但是与已知啤酒酵母之外的某种酿造成份的基因组有99.5%的同一性。”

Researchers believe the forest yeast made its way to Bavaria's brewing caves as a stowaway when trade first began across the Atlantic Ocean, perhaps in a piece of wood or in the belly of a fruit fly.

　　研究人员相信，在跨大西洋的贸易开始出现后，这种森林酵母是作为偷渡客，也许是夹在一片木材里、也许是在一只果蝇的肚子里到达巴伐利亚的酿酒山洞的。