Self-Destructing Bacteria Create Better Biofuels 139
MikeChino writes "Researchers at Arizona State University have genetically engineered cyanobacteria to dissolve from the inside out, making it easy to access the high-energy fats and biofuel byproducts located within. To do this they combined the bacteria's genes with genes from the bacteriaphage — a so-called 'mortal enemy' of bacteria that cause it to explode. Cyanobacteria have a higher yield potential than most biofuels currently being used, and this new strain eliminates the need for costly and energy intensive processing steps."
more details (Score:5, Informative)
Re:Biofuels are the future. (Score:2, Informative)
Not necessarily. You can take non-arable land, such as a desert, add sewage waste and bacteria, and VIOLA! biofuel. Or unused coastline, add fast-growing kelp and a lot of sunlight, regular harvests, and, again VOILA! biofuel. Both examples do not detract from current land use, and the coastline kelp forests may attract wildlife. That is not saying that arable land might be used for biofuel production...unless you tightly regulate the production, this will eventually happen if the profit from the sale of biofuel exceeds profit from the sale of food (which I can see happening), but it also give nations that have little industry or resources, but a lot of coastline, a viable industry.
Thanks, clearer how it works now (Score:3, Informative)
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Bioethanol [feeddistiller.com] Feed @ Feed Distiller [feeddistiller.com]
Wrong (Score:5, Informative)
No, the 11% max. figure is for just turning sun's energy into hydrocarbons. If you want to generate electricity out of it, like in a bio-mass power plant, the thermodynamic losses would be on top of that so the efficiency would be considerably lower.
BacteriOphage (Score:3, Informative)
It's properly spelled bacteriophage [wikipedia.org]--which are viruses of bacteria. These viruses make bacteria 'explode' so that newly replicated virions are released into the environment.
Re:Evolution, suckers.... (Score:2, Informative)
At low levels of nutrients they will stop reproducing hence when the solution is saturated of bio-fuel bacteria the self-destruction gene can be triggered and the fuel harvested. This way there ought to be no selective pressure to neutralise the self-destruction.
Re:Biofuels are the future. (Score:3, Informative)
No it doesn't. Most plants only operate at 1-2% photosynthetic efficiency, the most efficient crops maybe at 7%, and the theoretical maximum is 11% [wikipedia.org].
Compare that to solar cells which have 15-20%, in the laboratory even 40% efficiency. The advantage of photosynthesis is not efficiency, but price and resiliency, with the "cells" manufacturing themselves.
We should also look at the overall efficiency including the end use. Combustion to produce mechanical energy is going to be less efficient than for electricity to mechanical energy, but we also need to take into account the losses from electricity storage/retrieval. And there's the matter of losses related to weight differences. Regenerative braking can reduce those some, but heavy batteries are still quite a burden. Not taking manufacturing into account it would seem that both schemes are carbon neutral since the carbon taken from the air by the plants is given back during combustion.
Solar cell and battery production are both expensive, but solar cells may be better used to capture energy in a residential environment. I don't know if residential biofuel production could become viable.
Availability of land may be an issue for any type of solar energy capture, so it makes sense to look at using residential space too.
It seems that for many communities wastewater/sewage treatment is becoming very costly. I've had periods where I paid more for sewer fees than my combined electricity and natural gas costs. I would hope that some methods could be developed to get some biofuel, hydrogen or electricity out of the process of breaking the waste down into something environmentally friendly. Considering that the waste is contaminated with medications (not just pills dumped in the toilet, but what passes through people), it's probably better to be using sewer sludge for biofuel production than for food-crop fertilizer. I was concerned when I found out that a great deal of Los Angeles sludge goes to the central California valley area for use as fertilizer. Although I have read/heard that people are being discouraged from dumping extra medications down the toilet, I've never heard anything about the contamination from drugs people consume. I believe that the drug levels are significant. If meth users can get high from drinking the piss of other meth users, other drugs people take are likely to be present in significant amounts too.
Re:Evolution, suckers.... (Score:3, Informative)
There is a VERY strong evolutionary pressure against the mutants though, those colonies will be disinfected and re-seeded with the non-mutant form.
It won't be a problem for the same reason we don't have a big problem with yeasts and yogurt cultures mutating harmfully.
Re:Evolution, suckers.... (Score:4, Informative)
A loss of function mutation in a yeast used for brewing or a yogurt culture would be a big problem, just not as sensational as a kill the consumer mutation. Yet maintenance and selective breeding of cultures has been manageable for centuries now.
By the time the survival aspect of the modification can come into play, the bacteria are already at a dead end. They are in the batch that is being processed to fuel. The survivors of the nickle treatment will be destroyed just as surely as those that didn't mutate. Yields will be monitored. A tank whose yield declines will be sterilized and re-seeded. Culture sources with poor yields will be destroyed and replaced by others that have bred true (or at least haven't mutated in a way we don't like), just like yeast cultures. Those that produce bad beer are destroyed.
Yes, they mutate a lot. Most of the mutations are a disadvantage. Of the remainder, most don't matter at all. Those that prove harmful to the purpose we culture them for are destroyed batch by batch. The very few that prove beneficial to our purposes are propagated.
In many ways, culturing for fuel production is easier. Unlike foods, we don't care if it has an "off" taste, just that it burns well after processing.
Consider, a brewing yeast that mutates so that it can oxidize alcohol for energy will find plentiful food as the others die out. By the end of the fermentation process they will easily dominate. However, they will produce nasty tasting beer. If the mutation happens in the culture rather than in the vat, the whole culture is discarded.