Slashdot Mirror
Bacteria Used To Fix Cracked Concrete
An anonymous reader writes "Researchers at the UK's University of Newcastle have created a new type of bacteria that generates glue to hold together cracks in concrete structures — that means everything from concrete sidewalks to buildings that have been damaged by earthquakes. When the cells have been germinated, they burrow deep into the concrete until they reach the bottom. At this point, the concrete repair process is activated, and the cells split into three types that produce calcium carbonate crystals, act as reinforcing fibers, and produce glue which acts as a binding agent to fill concrete gaps."
I think it's officially "the future".
How can I believe you when you tell me what I don't want to hear?
How is it gonna stop? when they run out of concrete to fill, when they overpopulate and eat all the concrete "cracks" or when they kill all humans and we can't record the moment it stops because there won't be any humans to observe it?
Well, since grey goo is such an abstract concept, they thought they would rather use something more concrete ...
The Tao of math: The numbers you can count are not the real numbers.
I can't come in today, my street has a bad cold.
The spores germinate only in very alkaline environments — concrete has a quite high pH. The article is vague on details, but notes that "[the bacteria] have a built-in self-destruct gene that prevents them from proliferating away from the concrete target."
Now, What Could Possibly Go Wrong and all of that, but the bases are nominally covered.
You do realize that most waste products that can be used as you mentioned contain toxins themselves? Bottom ash and fly ash from coal plants is comparable to nuclear waste.
Supporter of the +1 Over Dramatic mod option. In memory of apk.
What's the acidity of your lungs? Oh, I see. You didn't read the article. Carry on, then.
Gigacrete looks like a better material for building in my opinion. I'll just have bacteria in my yogurt for now.
Nice GigaCrete advert but the bacteria isn't presented as a replacement for concrete or GigaCrete. It's presented as a mechanism to repair existing concrete.
Or are you advocating we raze all existing concrete buildings and tear up all sidewalks?
"When it rains, it pours." --Morton's Salt
I think that whole nanobot grey goo problem is way overhyped. Biological organisms are much more advanced than our technology and they haven't been able to turn all matter into copies of themselves yet, despite their best efforts.
check out the Mp3 Garbler I built!
The bacteria they made in the lab likes the acidity of concrete. What about the mutant bacteria that the bacteria in the crack makes?
It won't survive because it's still in the very alkaline concrete environment? Or as Morbo might put it: EVOLUTION DOES NOT WORK THAT WAY.
They said the binder was 100% non-toxic. which is only a small percentage of the product (as filler is the rest, up to 80%).
To see another example of "green" being a fib, look up AggRite construction/pavement aggregate.
React to the specific PH of the concrete? If only all concrete were the same. Its been in use for several hundred years, and the formula has been constantly evolving.
Remember Monsanto and "roundup ready" seeds? Now imagine a "bio-healing ready" concrete... concrete that is differentiated by a specific compound formula which is standardized for a specific bacteria (of course several grades of the product combo will exist for both quality and usage differences ... which also allow for market segmentation)
All it will take is some enterprising megacorp with the legal muscle to patent this combo (and defend the patents) and you can effectively raised margin on concrete 10x at least.
Anything can be de-commoditized if it provides unique value and a big enough megacorp.
Make sure everyone's vote counts: Verified Voting
This engineered bacterium system was entered into the International Genetically Engineered Machine competition, so there's a lot more information about this project at the team's project page. In particular, there's a more thorough description of the kill switch the team engineered to prevent the spread of this bacterium beyond the target environment, the underlying mechanism being that sucrose must be available in the environment to prevent the bacterium from producing a toxin which kills itself.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
So basically, it had nothing at all do with the topic hand and your comparison "I'll just have bacteria in my yogurt for now" was completely meaningless since no one has suggested building new things with it since that wouldn't work anyway.
Beware the press releases. You'll note that nowhere does the article discuss the strength of Gigacrete. They put up a few random things, but nothing like how much PSI it can withstand. And according to their web site, "GigaCrete manufactures some of the most innovative, functional, high-performance interior finishes on the market". Interior finish != replacement for concrete. Concrete is used as a structural material. It holds up thousands of tons of stuff. GigaCrete is an alternative to plaster. It looks pretty smeared on a wall...that's made of concrete.
Usually when you say that the bacteria 'likes' acidity it means that at least one of the proteins it depends on requires the acidity to function. If there are several proteins that are essential for the bacteria to live, the probability that all of the required mutations would occur becomes reasonably small. Additionally, even if the bacteria are able to mutate in such a way to live outside the concrete, they would be poorly adapted to that environment, and would most likely become food for something else. That's not even considering the likelihood that the food source the bacteria uses in its concrete environment may not be available elsewhere.
tl;dr:
The amount of change necessary to go from a bacteria that thrives in concrete to a bacteria that thrives in the lungs is large enough (under the expected conditions) to be considered insurmountable.
So the assumption, as I read it, is the environment in which the bacteria is deployed is assumed to have a consistent pH level to help it identify that it is in fact, concrete. However anything that also has that pH could potentially be a hospitiable environment.
Question: How are they planning on accounting for a non-lab environment where everything from moisture, temperature, hell even lighting apparently, can influence the pH of the target location? Based on respitory infection the pH in a lung is hardly consistent in that scenario and as many have jested, the side walk could have a cold. The point is if they are pinning the identification based on the pH I fail to see this as viable in uses outside of a controlled lab. Bridge work going on in Nov with snow and sleet I fail to see a consistent pH for this to work on any credible level. Just more theortical lab work that will get a bit of grant money and that is about it. With construction workers dealing with a lot of concrete dust during repairs the pH is one hurdle for the bacteria. As for phsyical contaminates, respitory contaminates could be lunch for this stuff. I doubt there is a lethal risk, but having to throw someone on sick leave because they have a mild infection of this stuff is more economic risk then anything. pH to me seems a tad bit flaky as a marker for concrete. Even from what the article mentions, it requires too much of a controleld environment to be usseful. The number of things that could have similar pH seems rather high, the non-concrete contaminates... potential predators\competitors... It might work great in a lab... but in the real world? I'm doubtful.
-=[ Who Is John Galt? ]=-
Absolute worst case scenario is a grey goo outbreak being treated basically like a fire (which, when you think about it is the ultimate grey goo machine). There's a limit to how much energy is available for replication, and there's a limit on how efficient you can make your replication (at some level, the replicating nanobots will be literally tearing apart and putting back together materials). Fighting the grey goo only involves tearing about the replicators, not necessarily wasting energy putting the pieces back together into something useful.
In other words, it should be trivial to design a nanobot that tears apart the self-replicators but doesn't waste energy by making copies of itself. This nanobot would be manufactured a head of time and stored for future use, or manufactured in specialist facilities (even in a mobile truck if necessary) that provide the energy input necessary for their production. As long as your facilities have more energy available than the self-replicators do, you'll win out eventually. And the replicators will only have about as much energy available as a fire can produce.
Also, the concrete repair activity is produced by upregulation of genes natural to Bacillus subtilis, not by anything transgenic. The upregulation of these genes presents an energy cost to the engineered bacterium while providing no benefit- if these bacteria mutate, it is more likely to be towards the wild phenotype. In addition, the team responsible has added a kill switch which tells the bacteria to commit suicide if sucrose is not present.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
One has an immune system, and the other looks like concrete.
How would you know? You didn't even read the damn thing, as is apparent from your questions, some of which are addressed in the damn article in the first place.
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
There are three principal parts to the filler produced by these bacteria. First, the bacterium naturally produces calcium carbonate as a byproduct of breaking down urea as a nitrogen source; this activity has been greatly increased in the engineered bacterium. The second part is a "glue" made from levan, a polysaccharide that the bacterium is able to produce from sucrose; this activity is also natural, but highly upregulated in the engineered bacterium. The final part is the bacterial cells themselves; the cells are made long and threadlike by expressing a protein that halts cell division, and these filamentous cells act as reinforcing fibers. In practical usage, a solution of nutrients (including sucrose in particular) would need to be sprayed along with the bacterial spores in order for them to display this concrete-filling activity. This information comes from here.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
I had the same thought... wouldn't bottom ash be essentially "distillate of everything toxic left behind by the burn process"...??
As to the other fillers... what makes concrete strong isn't just the binder, it's also (perhaps mostly) the character of the filler. Organics decompose over time. Now what.. you've got binder and decomposition products, but no filler. Explain to me how that retains its structural strength and integrity? Not only that, but with varied fillers, how do you achieve predictable structural strength?
As to the case you cite, how about this:
http://caselaw.findlaw.com/pa-superior-court/1175891.html
Reusing waste products is great, but let's not kid ourselves that they're suitable substitutes for everything else.
~REZ~ #43301. Who'd fake being me anyway?
If you've ever tried to pump glue into a crack in concrete, you'll quickly figure that out. It's somewhere between messy and inadequate as a repair method, and certainly doesn't get into the smaller cracks, let alone the microcracks. The idea here is to have the glue self-extend, filling the air pockets and microcracks that no glue with sufficient surface tension to stick could ever manage.
However I think where this will become a more useful technique is for fixing the kinds of surface cracks that ail structures exposed to repeated wet/freeze/thaw cycles -- the typical winter climate for the east slope of the Rocky Mountains. Mount Rushmore would seem to be a good candidate, since seasonal surface cracking is what's causing damage.
Concrete roads that suffer similar winter freeze/thaw damage could also benefit -- instead of trying to patch the road one crack at a time (usually an exercise in futility, culminating in yawning potholes), or having to dig up and replace the concrete (an extremely expensive job), just wash it with a slurry of this bacteria. That could even eliminate most of the seasonal damage, by filling the microcracks that are where freeze damage starts.
Imagine if your state and local highway departments could reduce their budgets by simply needing to do less repair on concrete-based roads. Even if you don't believe in reducing taxes when need is reduced, it would free up that budget to use elsewhere.
~REZ~ #43301. Who'd fake being me anyway?
That depends. How many highly alkali environments are there in nature? (Answer: Very few)
Solids do not have pH. You can't have a pH without a solvent. The alkali environment present in concrete does not exist within humans...or any animal or plant I'm aware of.
Evolution doesn't work that way. There has to be selection pressure. Bacteria that live in concrete but thrive in a lower pH would be selected against - the "thrive in high pH" would outcompete them.
You can't make this assessment without knowing the pH of the pH range of the bacteria, the pH range of the concrete, and knowing how common that pH range is in nature.
The problem, with bullet wound is...[dirt].
Another problem with bullet wounds is emergency room doctors who believe the myth of "hydrostatic shock" damage and chop out a core of tissue around the bullet's path (as if it were a linear cancer), rather than treating it properly by cleaning and closing the wound (as if it were any other puncture-and-displacement trauma).
Yo, Docs! Even if the bullet somehow WAS traveling faster than the speed of sound in flesh (like about mach 4.4) shock waves aren't any big deal for soft tissue. Think Lithotripter.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
We are the gray goo.
What doesn't kill you only delays the inevitable