蜘蛛丝产业化在望

    一些发明者或许会因此进入一些陌生的领域。10年前，美国的研究人员曾经尝试创造“蜘蛛山羊”——它们的乳蛋白基因被加入的蜘蛛DNA改变了。由此产生的山羊乳汁含有蜘蛛丝蛋白质，羊奶挤出来后再提取蜘蛛丝蛋白。然而在这之后，这项任务就变得愈加困难了。

    剑桥大学（the University of Cambridge）生物材料力学教授米歇尔•奥恩表示，到目前为止，如何充分理解这些来自大自然的材料以模仿它们，难倒了不少科学家。“就蜘蛛丝而言，我们能够复制负责制造蜘蛛丝的基因序列，把它转移到别的地方，羊奶的情况也是如此，”她说，“但我们随后必须模仿蜘蛛丝的喷丝头，以便使这些蛋白质形成纤维。这一步相当棘手，是迄今为止的瓶颈之一。”

    资本规模达7.8亿日元的Spiber公司现在每天能够生产1公斤蜘蛛丝蛋白质，而且满怀信心地与一家隶属于丰田汽车（Toyota）的公司组建了一家合资企业，希望实现商业化生产。Spiber公司的纱线蛋白质不是用羊奶、而是用合成微生物制作而成。这家公司正在兴建一家计划于今年年末竣工的试验厂，未来每月将生产100公斤已获得专利、名叫Qmonos Fiber的蜘蛛丝蛋白质。至2015年，Spiber公司还将建造一个旨在进行商业化生产、每年将生产超过10吨蜘蛛丝的试点工厂。

    关山和秀声称：“蜘蛛丝将用来生产超轻、但坚固的汽车零部件和医疗器械。我们想制造发生撞车事故时不会伤害行人的轿车。”蜘蛛丝的拉伸强度和相应的灵活性使它成了制造人工韧带的理想材料。然而，奥恩教授希望我们不要误以为蜘蛛丝比钢铁更坚固。“就拉伸强度而言，蜘蛛丝或许可以与钢铁比较一番。拉伸强度是蜘蛛丝唯一的一个关键属性，”她说，“蜘蛛丝的刚度，也就是它灵活变形的能力，要比钢铁弱很多倍。”

    蜘蛛丝潜在价值巨大，它的市场化无异于一场竞赛，但参与这场竞争的公司并不止Spiber一家。德国公司Amsilk最近就宣布，它也将启动一个在实验室大规模生产蜘蛛丝的试点项目。与此同时，当初那家创造“蜘蛛山羊”的美国公司获得了数百万美元的投资后，现在已经不再从事蜘蛛网业务。当年的那些山羊（目前在犹他州一个大学农场）现在依然在生产蜘蛛蛋白质。但就目前而言，用微生物合成蛋白质这项技术似乎占据了领先地位。（财富中文网）

    译者：任文科

    This can take inventors down some strange avenues. Ten years ago, U.S. researchers came up with the idea of creating "Spider goats" that had their milk genes altered with spider DNA. The resultant animal's milk contained the spider silk protein which was then extracted following milking. After that the task got harder.

    So far, what has held scientists back, says Michelle Oyen, professor of Mechanics of Biological Materials at the University of Cambridge, is understanding the natural materials well enough to mimic them. "In the case of spider silk, we can copy the gene sequences responsible for silk and transfer them elsewhere, as with the goat's milk case," she says. "But we then have to mimic the spider's silk spinneret in order to form the proteins into fibers, and that's tricky and has been one of the limitations to date."

    Spiber, capitalized at 780 million yen, is now capable of producing up to 1 kg of the silk protein a day and is confident enough to form a joint venture with a Toyota (TM) subsidiary to commercialize production. The yarn proteins at Spiber are made by synthetic microorganisms -- not goat's milk. Spiber is currently building a test plant that will produce 100 kg a month of patented spider thread protein, dubbed Qmonos Fiber, by the end of the year. A pilot plant will then be built for commercialization of the yarn by 2015 that will produce over 10 tons silk annually.

    "Applications will include super-light but strong car parts and medical applications," says Sekiyama. "We have an idea for cars that won't hurt pedestrians in crashes." Spider silk's tensile strength but corresponding flexibility could make it ideal for artificial ligaments. One claim, however, that Prof. Oyen wishes to disabuse us of, is that spider silk is stronger than steel. "At best, spider silk might compare to steel when it comes to tensile strength. Tensile strength is only one critical property," she says. "The stiffness of silk, which is its ability to deform elastically when force is applied, is many times less than that of steel."

    Nevertheless, Spiber is not alone in the race to market such a potentially valuable substance. German firm Amsilk recently announced it, too, will start a pilot project to scale up lab production of spider silk. Meanwhile, the American company that originally created the spider goats, after securing millions of dollars in backing, is no longer in the spider web business. The goats, now a Utah university farm, still produce spider proteins. But for the time being, the protein-synthesizing micocrobes seem to have the lead.