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蜂蜜:细菌最大的敌人

Honey: Bacteria's Worst Enemy

Honey.
蜂蜜
You’ve met honey.
你一定见过蜂蜜
It’s that sticky, sweet stuff.
一种黏黏的 甜甜的物质
Basically just slightly liquidy sugar in a plastic bear bottle, right?
基本上就是盛放在熊型塑料罐里稍显液态的糖 是吗?
Wrong!
错!
Honey is a supercharged bacteria-killing powerhouse.
蜂蜜是种超强的杀菌物质
And it’s all down to what those hardworking bees put into it
这种杀菌能力完全归功于勤劳的蜜蜂所产出的物质
from immune proteins to the sugar itself.
包括免疫蛋白和糖分
Since ancient times, honey has been used to prevent wounds from getting infected.
古时候 蜂蜜就被用来防止伤口感染
And these days we use purified and standardized versions of honey
如今 医院使用纯蜂蜜和标准蜂蜜
to fight infections in hospitals.
来对抗感染
Honey has three main tricks for fighting bacteria.
在抗菌方面 蜂蜜具有三大法宝
The first is all that sugar.
其一是蜂蜜所含的糖分
Honey is only about 17% water.
蜂蜜只含有17%的水份
Most–but not all–of what remains is sugar.
其余的几乎都是糖分 虽然不全是
The two main types of sugar in honey are glucose and fructose.
蜂蜜中的糖主要有两种 葡萄糖和果糖
Like all sugars, glucose and fructose are sticky — they attract water.
像其他糖一样 葡萄糖和果糖都很黏——都具有亲水性
Honey is technically a supersaturated solution,
严格来说 蜂蜜是种过饱和溶液
meaning it contains more sugar than would normally dissolve at that temperature.
意味着其含有的糖比相同温度能正常溶解的糖多
That’s why it eventually gets all crystally in the pantry
这就是储藏的蜂蜜会结晶的原因
— over time, the sugar comes out of the solution.
——随着时间推移 糖分会从溶液中析出
Chemically speaking, it’s desperate for water.
从化学角度看 蜂蜜极度缺水
Water can travel across cell membranes from where there’s a higher concentration of
水可以穿过细胞膜 从含水浓度高的地方
water to where there’s a lower concentration.
流向含水浓度低的地方
And there’s a higher concentration of water in a bacterium than in honey.
而细菌的含水浓度高于蜂蜜
Which means that honey will
这就意味着蜂蜜会
suck the juices right out of any bacterium (or mold or fungus) that tries to set up shop.
从那些想要繁殖的细菌(霉菌或真菌)中吸收水分
Plus, there’s isn’t enough water in honey for any microorganisms to live on.
另外 蜂蜜中所含的水不足以供任何微生物存活
So they die, and the honey doesn’t spoil.
所以细菌就会死亡 蜂蜜也不会变质
The second thing
蜂蜜抗菌的第二个法宝是
is that when bees make honey, they throw in an enzyme called glucose oxidase.
蜜蜂酿造蜂蜜时所产生的葡萄糖氧化酶
And bacteria hate glucose oxidase
细菌讨厌葡萄糖氧化酶
because it produces two different compounds.
因为这种酶会产生两种物质
It converts glucose to gluconic acid and hydrogen peroxide.
它会将葡萄糖转化成葡萄糖酸和过氧化氢
Gluconic acid is, you guessed it, an acid.
就像你想的那样 葡萄糖酸是一种酸
It gives honey a pH value of less than 4.
它使蜂蜜的酸碱度小于4
That’s about a thousand times more acidic than the neutral pH of 7
这比中性pH7酸了约一千倍
that most bacteria need to grow.
而大多数细菌需要中性酸碱度来发育
And hydrogen peroxide is very good at killing cells.
而过氧化氢很善于破坏细胞
It destroys the cell walls of bacteria, which breaks them apart.
它能破坏细菌的细胞壁 从而将细菌分解
Glucose oxidase isn’t active in ripe honey–there’s not enough water for it to work properly.
葡萄糖氧化酶在熟蜜中不会发挥作用——因为没有足够的水令它起效
It seems to be there to keep the honey from spoiling while the bees are drying it out.
蜜蜂将蜂蜜脱水似乎是为了防止蜂蜜变质
But if you dilute honey
但是如果将蜂蜜稀释
the glucose oxidase will switch back on and make gluconic acid again.
葡萄糖氧化酶就会再次发挥作用 产生葡萄糖酸
The final thing bees do to make honey antibacterial?
归功于蜜蜂 蜂蜜抗菌的最后一个法宝是
They put antibiotics in it.
它们在蜂蜜中加入了抗生素
Some types of honey contain a protein called bee defensin-1
有些类型的蜂蜜含有一种蛋白 叫做蜜蜂防御素-1
which is exactly what it sounds like.
就和字面意思一样
Bee defensin-1 defends bees.
蜜蜂防御素-1能保护蜜蜂
It’s part of their immune system and protects them from certain bacteria
这种抗生素是蜜蜂免疫系统的一部分 能够帮助蜜蜂抵抗某些细菌
including ones that could cause nasty diseases inside the hive.
包括一些能在蜂巢引发严重疾病的细菌
It’s produced in a gland that bees use to make honey
这种抗生素是由蜜蜂生产蜂蜜的一种腺体分泌的
so it makes sense that some of it would make it into the finished product.
所以一些蜂蜜中会含有它就说的通了
And while scientists aren’t sure how much of the protein is really in honey
虽然科学家不确定这种抗生素在蜂蜜中的含量
it sort of makes sense that bees would use it to protect their food.
但可以理解 蜜蜂用它来保护它们的食物
Another antibacterial compound sometimes found in honey is methylglyoxal.
有时会在蜂蜜中发现另一种抗菌素 甲基胶醇
Methylglyoxal is a small organic molecule that forms in honey
它是蜂蜜中形成的有机小分子
from a compound in the nectar of certain flowers.
来自于某些花蜜中的一种化合物
There’s an especially large amount of methylglyoxal in manuka honey
麦卢卡蜂蜜含有特别多的甲基胶醇
a honey made from a New Zealand flower.
它是一种产自新西兰花的蜂蜜
This honey is so good at killing bacteria that it’s actually used in hospitals.
这种蜂蜜长于杀菌 医院经常会用到
There’s one bacterium that has honey’s number–but only sort of.
只有一种细菌可以抵抗蜂蜜——但也只是稍微抵抗
It’s the type of bacteria that that causes botulism.
那就是能够引发肉毒杆菌症的细菌
The bacteria start out as spores, which are very hard to kill.
这种细菌起初是孢子形态 很难被杀灭
They’re already dried out, so honey’s water-sucking properties don’t kill them,
孢子形态下细菌已经是脱水状态 所以蜂蜜吸水的特性杀不了它们
and because the spores aren’t growing
而且因为孢子并不生长
they aren’t affected by the acidity or the antibiotic compounds.
所以它们不受酸或抗生素的影响
The really dangerous part of the bacteria
这种细菌真正危险的地方在于
is the botulinum toxin they produce when they grow into mature bacteria.
它们发育成熟时所产生的肉毒杆菌毒素
Less than a hundred nanograms — that’s billionths of a gram — is enough to kill an adult.
不到100纳克——1克的十亿分之一—— 的肉毒杆菌毒素就可以杀死一个成年人
About 10% of honeys have some botulinum spores in them.
大约10%的蜂蜜中含有肉毒杆菌孢子
But since the spores in honey aren’t growing and making toxin
但是蜂蜜中的孢子不会成长和制造毒素
they’re harmless to healthy adults.
所以它们对健康的成人没有危害
Our immune systems intercept the spores before they can start growing inside of us.
在孢子进入我们身体开始发育之前 我们的免疫系统会将这些孢子拦截消灭
But the immune systems of infants
但是婴幼儿的免疫系统
aren’t always able to kill those spores before they start growing.
不能总是在孢子发育前将其消灭
So, in rare cases, the bacteria can germinate and start producing toxin.
所以在少有的案例里 这些细菌会发育并开始产生毒素
That’s why it’s not safe to give honey to infants under one year old,
这就是为什么给一岁以下的婴儿喂食蜂蜜并不安全
but the rest of us don’t need to worry about it.
但其余的人都不必担心这种危害
So the next time you’re looking for something sweet,
所以下次你想吃甜食的时候
go ahead — eat some of bacteria’s worst enemy.
来点细菌最大的敌人吧
Thanks for watching this episode of SciShow
感谢收看本期科学秀
which was brought to you by our patrons on Patreon.
本期节目由Patreon上的赞助商资助播出
Thank you, so much, to all of those people.
非常感谢所有的赞助者
If you want to be one of those people you can go to patreon.com/scishow.
如果你想赞助我们 可以访问patreon.com/scishow
And if you just want to keep getting smarter with us
如果你想和我们一起收获知识
you can go to youtube.com/scishow and subscribe!
可以访问youtube.com/scishow并订阅哦!

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视频概述

本视频主要介绍了蜂蜜抗菌的三大法宝以及一岁一下的婴儿为什么不适合吃蜂蜜

听录译者

收集自网络

翻译译者

小柴胡

审核员

审核员TOP

视频来源

https://www.youtube.com/watch?v=7FlzHiURdTs

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