Stories tagged bacteria

Researchers at Penn State have found a new species of bacteria in Greenland. Big whip – as long as it stays away from me, who cares? Well, this organism is ultra-small (I know what you’re thinking – aren’t bacteria pretty, um, small to begin with? Yeah, but these are super-duper small). It has also survived for 120 thousand years trapped without oxygen under two miles of ice. It may help scientists look for life on cold planets and moons elsewhere in our Solar System. (Which I think is a proper noun and therefore should be capitalized, though I may be mistaken.)

Jun
20
2008

For decades, scientists have been growing microbes in their labs and watching them evolve new traits. Most of the changes tend to be simple things, like an increase in size or growth rate.

But Dr. Richard Lenski of Michigan State University (just 2 miles from my house!) recently witnessed a major evolutionary leap--as it was happening. Twenty years ago, he took a colony of E. coli, a common bacteria, and split it into 12 identical populations. He’s been watching ever since to see if the strains evolve in different directions.

A few years ago, one of them did. One of his study strains suddenly evolved the ability to eat citrate, a molecule found in citrus fruits. No other E. coli in the world can do this, not even the other strains in Dr. Lenski’s lab. Even given several extra years and thousands of extra generations, the other strains are still citrate-averse. What’s more, the bacteria evolved this mutation entirely on their own, without any prodding or genetic manipulation from the researchers.

Lenski had saved frozen reference samples of all of his strains at regular intervals. Going back and growing new cultures from these samples, he again finds that only those from one strain ever evolve the citrate-eating habit – and only those sample less than about 10 years old. Lenski figures that some mutation happened around that time in one strain – and one strain only – that would later lead to citrate eating. He and his lab are now working on figuring out exactly what that mutation is.

Jun
19
2008

It's an important job I've got for you...: That's right: pump my gas. I'm not getting out of the car.
It's an important job I've got for you...: That's right: pump my gas. I'm not getting out of the car.Courtesy thefiveten77
Using microorganisms to do our dirty work is all the rage these days. And, you know, they deserve it—they’ve spent so much time making us sick that they’re due for a little bit of productive action (and don’t bring up gut microbes, water treatment, or natural decomposition. I’m just not interested in anything that contradicts me).

It’s encouraging, then, to see that scientists in California have genetically engineered microorganisms (like yeast and strains of e. coli that eat organic garbage and poop crude oil. Is “poop” the right verb? It is? It’s exactly the right verb? Oh, good.

Currently the process requires a lot of equipment for a pretty small output. A room-sized computer and fermenting machine produces about a barrel of oil a week—America consumes about 143 million barrels of oil each week. And, at the moment, the process isn’t super cheap.

However, the scientists involved are hopeful that the necessary equipment can be shrunk, and the product can be produced more efficiently. With a commercial-scale facility (planned construction in 2011), using Brazilian sugarcane as feedstock (not the best crop, but that’s another post), oil could be produced at a cost of about $50 a barrel. Not bad, compared to the current price of oil hovering around $140 a barrel.

The process should be carbon neutral or negative too. That is to say, the CO2 produced by burning the fuel produced should be less than that pulled from the air by the feedstock materials.

It’s all very interesting, but I’m afraid that this sort of technology is forcing biotechnology away from its true purpose—microorganisms working for us in the very literal sense. The day e. coli wanders out into my yard and mows my lawn is the day I’ll get excited. Otherwise, what’s the point?

It is important to remember that not all microbes make you sick. In fact many are even helpful. Click here for a New York times article that summarizes recent findings or go to the original scientific article in
Genome Research about human skin microbes. Finally you can learn more about gut microbe research at Washington University here.

Why do microbes always get such a bad reputation?

May
14
2008

Sometimes the old ways are best: New-fangled antibacterial soap doesn’t work any better than plain soap, but contains chemicals that may harm the environment.
Sometimes the old ways are best: New-fangled antibacterial soap doesn’t work any better than plain soap, but contains chemicals that may harm the environment.Courtesy Brandon Cirillo

Seriously. Epulopiscium notwithstanding, it does no good, and it may do harm.

Soaps marketed as “antibacterial” contain the chemical triclosan. Numerous studies have shown that soap with tricolsan is no better at killing bacteria than regular soap. Besides, most of the diseases people wash their hands to avoid are actually caused by viruses – antibacterial agents have no effect on them. (Plain old soap and water does.)

The triclosan gets into the water supply, where it may harm the environment. Some studies suggest it might form toxic compounds. Others indicate that some germs become immune to triclosan over time.

The negative side-effects have not been totally proven, but why take the chance? There is no benefit to using antibacterial soap, so we’re all better off using the regular stuff.

May
14
2008

Join the fight!: Grimace is doing his part.
Join the fight!: Grimace is doing his part.Courtesy GiantGinko
Okay…I don’t want to alarm anyone, but I think it’s important that you’re all made aware of this threat before it’s too late. I mean, like, we didn’t used to be afraid of that little ball of goo until it became the blob, and now we’re in deep, deep fudge. That kind of thing.

Okay, so…ugh, why do I have to do this? Just prepare yourself, get a fresh pair of pants ready, and please, please don’t panic. Not yet. That could be dangerous.

There is…somewhere, like, out there…a bacteria that is literally a million times bigger than other bacteria. Do you understand what this means? Do you understand what “literally” means? It doesn’t mean, “I’m literally going to starve to death if I don’t get that pizza!” It means for real. For really real. And do you know what “a million” means? Of course you do. It’s like, if you had to fight another guy and his ninety nine friends, and then had to fight nine hundred and ninety nine more groups just like his, and then fight just as many people nine more times—you’d be fighting a million guys. Could you win a fight like that? No, try again, you couldn’t. So what chance do we stand against this gargantuan bacteria? You know that bacteria have no emotions, right? They’ll eat you and your new puppy, and then eat, like, a pumpkin, and they wouldn’t feel any worse about you and your lousy puppy than they would about the dumb pumpkin.

Oh, this is the worst.

Okay, okay, I was the one who said we shouldn’t panic. So let’s look at this beast rationally—maybe we can find a weakness.

What do we know? Well, the monstrosity in question, of the epulopiscium genus, is a million times the size of an E. coli bacterium. A million times bigger. That means that epulopiscium is, let’s see…about the size of a grain of salt. If you, for instance, were for some reason one-hundredth the size of a grain of salt, epulopiscium would be a hundred times bigger than you. A hundred times bigger than you! What else? Well, it seems that the bacteria only live in the stomachs of surgeonfish, in the area of Australia’s Great Barrier Reef. That’s where they live for now—the surgeonfish lives in a symbiotic relationship with epulopiscium, so there’s no reason to assume that it will keep its horrible buddy under wraps.

How can we fight this thing? Guns? What good would bullets do against something like this? Nuclear weapons? Only as a last resort. But what if… What if we could turn epulopiscium’s own size against it, like we did with King Kong when we shot him off that building?

Let’s see…Normally bacteria have to be itty-bitty because they haven’t got the specialized organelles to move nutrients around, and their DNA—of which there are only a hundred or so copies—isn’t bound in nuclei; basically their Schmidt is all over the place, so they have to be tiny to keep things working. It seems, however, that the epulopiscium is unique in that it has thousands of copies of its genome incorporated into its cell membrane. That way, if anything remarkable happens in the cell, DNA will be right there to react quickly, locally producing RNA or whatever proteins are necessary for the situation.

So that means we need to destroy its fancy DNA, and then its own bulk will bring the epulopiscium down! And what can damage DNA? Electromagnetic radiation! We need to start dumping radioactive waste into the waters of the Great Barrier Reef immediately! Stat! Ionize their fancy little DNA!

Get to it, Buzzketeers. This will be a modern-day David and Goliath story.

Apr
30
2008

Will wonders never cease?: A hypochondriac surfer...
Will wonders never cease?: A hypochondriac surfer...Courtesy Rickydavid
Ironic, isn’t it? Silver kills werewolves, werewolves hate silver…and yet these ancient enemies are more alike than they ever knew.

As we all know, materials start to get a little crazy when they approach the nano scale. Try as I might to crush bacteria to death with my silverware (beats washing it), silver on the flatware scale is not a very effective antimicrobial material.

When you get down to the nano scale, however, where silver particles are just a few billionths of a meter, it’s no longer like chasing down flagellates with a spoon. Really, nothing is quite like chasing down flagellates with a spoon, but all comparison is lost in the case of nano-silver.

It has been known for years now that nanoparticles of silver are able destroy harmful bacteria. The nanoparticles generate unique chemicals, known as “highly reactive oxygen species,” which inhibit the growth of bacteria. This is great, because we all hate those harmful bacteria. Nano-silver, for instance, is already found in certain fabrics to destroy odor-causing bacteria, and some high-tech washing machines generate tiny particles of silver for essentially the same reason.

Unfortunately, it’s becoming clear that these glittery little assassins may be the enemy of all bacteria, harmful and helpful.

It’s like this: we’d all love werewolves if they just spent their days tearing apart mummies, because mummies are gross and dangerous. But when werewolves start ripping into other more beneficial monsters, like Frankensteins, well, then they tend to lose favor. Frankensteins may be gross, but they have good hearts.

These tiny silver particles, according to researchers at the University of Missouri, have been ripping into Frankensteins. It’s been observed that nano-silver kills off beneficial, benign bacteria, like that used for wastewater treatment. As consumer use of nano-incorporating products increases, so to will the amount of artificial nano particles in the waste stream. Eventually this could kill off vital microbial species in rivers, streams, and lakes, as well as those used in wastewater treatment. There may be indirect consequences as well—for instance, the “sludge” byproduct of wastewater treatment is frequently used as land-application fertilizer. If silver nanoparticles accumulate in high enough levels in this sludge, they could end up seriously damaging the soil we use to grow our food crops.

This isn’t to say that we should necessarily halt our use of nano products, but it’s a reminder of how little we still know about nanotechnology. While we’ve had hundreds of years to learn to learn the ins and outs of deal with werewolves, nanotechnology is still pretty mysterious.

The University of Missouri will soon be launching a second study to determine the levels at which silver nanoparticles become toxic, and to exactly what extent they harm microbes in wastewater.

New research published in Science reported bacteria can survive by eating antibiotics as a food source. This finding goes a step further than resistance. For a good summary read a blog on The Scientist website.

Have you ever wondered what antibiotic resistance really means? And who is resistant to those drugs? For a very good explanation read the blog entry Drug Resistance, Explained in the New York Times. I enjoyed the History of Medicine at the end too.

Did you find this explanation helpful? Did you learn anything that surprised you?

Listen to this interesting story about TB on National Public Radio.