微生物群落有工作记忆，可以把它们变成活的计算机

Collections of bacteria known as biofilms can store memories of exposure to light, providing intriguing parallels to the way neurons process memories in our brains. This doesn't mean you need to be nice to bacteria lest they harbor a grudge, but it may prove useful for neuroscience research and making biological computers.

被称为生物膜的细菌群可以储存暴露在光下的记忆，这与我们大脑中神经元处理记忆的方式有有趣的相似之处。这并不意味着你必须善待细菌，以免它们怀恨在心，但它可能对神经科学研究和制造生物计算机有用。

Recent discoveries by Professor Gürol Süel of the University of California San Diego have helped promote renewed respect for bacteria, demonstrating they can communicate with each other in colonies using ion channels and even support each to share resources. Süel and others have also demonstrated bacteria can remember certain events, changing their response to circumstances based on what they have experienced previously.

加州大学圣地亚哥分校的Gurol Suel教授最近的发现帮助促进了对细菌的重新尊重，证明细菌可以通过离子通道在群体中相互交流，甚至支持彼此共享资源。Suel和其他人也证明了细菌可以记住某些事件，根据它们之前的经历改变它们对环境的反应。

Süel brings these two discoveries together in Cell Systems. Blue light has been found to alter the flux through cells' ion channels, so Süel's team spread Bacillus subtilis on a growth medium and illuminated them for five seconds with a fluorescent lamp. Using a mask of the University's logo, some of the bacteria were protected from the light, while others were fully exposed. Even hours later, the responses of the bacteria varied depending on whether they were shaded or not, with the exposed bacteria having more potential to transport potassium through their membranes.

Suel在细胞系统中把这两个发现结合在一起。人们发现蓝光会改变细胞离子通道的通量，所以Suel的研究小组将枯草芽孢杆菌(Bacillus subtilis)传播到生长培养基上，用荧光灯照射它们五秒钟。利用该大学标志的面具，一些细菌被保护起来不受光照，而另一些则完全暴露在阳光下。即使在数小时后，细菌的反应也会根据它们是否被遮蔽而有所不同，暴露在阳光下的细菌更有可能通过细胞膜运输钾。

Stephen Luntz

"When we perturbed these bacteria with light they remembered and responded differently from that point on," Süel said in a statement.

Suel在一份声明中说:“当我们用光线干扰这些细菌时，它们的记忆和反应从那时起就不同了。”

When potassium availability was cycled on and off, the light-exposed bacteria produced the exact opposite response to those that had been shaded, closing their potassium channels when their counterparts were opening them. Feeding the bacteria glutamine restored them to their usual state. The researchers hope to put this to use, turning bacteria into a model for neurons.

当钾的有效性循环时，暴露在阳光下的细菌产生的反应与那些被遮荫的细菌完全相反，当它们的对手打开钾离子通道时，它们却关闭了钾离子通道。给细菌喂食谷氨酰胺使它们恢复到正常状态。研究人员希望利用这一点，把细菌变成神经元的模型。

“For the first time we can directly visualize which cells have the memory,” Süel added. “That's something we can't visualize in the human brain."

“我们第一次可以直接看到哪些细胞有记忆，”Suel补充道。“这是我们无法在人脑中想象出来的东西。”

With suitable masks, bacteria could be turned into a circuit board, with some light-primed and others not, turning bacterial communities into a sort of computer. The team also found longer light exposures produced greater changes to membrane potential, suggesting outcomes could be more nuanced than simply whether a bacteria was primed or not. If varying intensity or wavelength of light produce different sorts of priming, then even more sophisticated devices may be possible.

有了合适的掩模，细菌可以变成电路板，有些可以发光，有些则不能，把细菌群落变成某种电脑。研究小组还发现，长时间的光照会对细胞膜电位产生更大的变化，这表明结果可能比简单地判断细菌是否受到了刺激更微妙。如果不同强度或波长的光产生不同种类的启动，那么更复杂的设备可能成为可能。

"Bacteria are the dominant form of life on this planet," Süel said. "Being able to write memory into a bacterial system and do it in a complex way is one of the first requirements for being able to do computations using bacterial communities."

“细菌是这个星球上的主要生命形式，”Suel说。“能够将内存写入细菌系统并以一种复杂的方式进行操作，是使用细菌群落进行计算的首要要求之一。”