Recycling polyethylene terephthalate (PET) plastics is difficult as the hard material is tough to breakdown. For years there’s been research into using bacteria to eat the plastic to help with getting the plastic to reusable state. This year a bacterial enzyme called “PETase” has been found to be highly effective at breaking down this hardened plastic. The enzyme itself comes from a bacteria that was found within a plastic recycling plant (nature always finds a way) which was subsequently modified to be more efficient. This discovery may lead to a healthier use of plastic, but for now the best thing you can do is buy less plastic objects.
They compared the DNA sequence of the PETase gene with that of cutinases from thousands of bacterial species, looking for differences. They then created new versions of PETase, each with one or more of its amino-acid building blocks changed to resemble those of ancestral cutinases.
As many of the differences between PETase and cutinases were, presumably, what allowed PETase to do its job, they expected these new enzymes to digest the plastic less efficiently. To their surprise, however, one of the engineered enzymes (with two amino acids mutated to be more cutinase-like) was able to digest PET about 20% faster than the natural one. That is a modest increase, but one that came about by accident rather than design. This, Dr McGeehan argues, shows there is plenty of scope for further improvement.
A new field of research, that doesn’t even have a proper name yet, is looking into ways we can incorporate biology into our built environment. It turns out the bacteria and germs found in our indoor worlds are vastly different than those found in natural environments. It makes me wonder what are we inadvertently breeding in our workplaces and homes.
As evidence continues to mount against ultrasterilization, scientists are looking for alternatives that nurture, rather than eradicate, microbial communities.
One way is through “bio-active” surfaces, permeable nanostructures with “good” bacteria stitched inside. Built into walls, chairs, carpets, and other indoor fixtures, these living surfaces would continuously secrete beneficial microbes into the indoor environment. In laboratory tests with mice and rats, these bio-active structures have been found to reduce the likelihood of allergic reactions and asthma attacks. “Instead of building new buildings per se, we could just refurbish all the existing buildings in Manhattan or downtown Chicago with bio-active walls or bio-active carpets,” Gilbert says.
The need for a biofuel that can be used in standard automobiles is needed more everyday as the bloody global thirst for oil only increases. Thankfully researchers have engineered a bacteria that can produce a fuel substance that can be used in standard internal combustion engines.
To be used as a mainstream alternative to fossil fuels – desirable because biofuels are carbon-neutral over their lifetime – engines would have to be redesigned, or an extra processing step employed to convert the fuel into a more usable form.
To try to bypass that, John Love from the University of Exeter in the UK and colleagues took genes from the camphor tree, soil bacteria and blue-green algae and spliced them into DNA from Escherichia coli bacteria. When the modified E. coli were fed glucose, the enzymes they produced converted the sugar into fatty acids and then turned these into hydrocarbons that were chemically and structurally identical to those found in commercial fuel.
In the future, oil spills could be partly cleaned up by bacteria that loves to eat all the dangerous goo in oil.
esearchers have discovered a new strain of bacteria that can produce non-toxic, comparatively inexpensive “rhamnolipids,” and effectively help degrade polycyclic aromatic hydrocarbons, or PAHs – environmental pollutants that are one of the most harmful aspects of oil spills.
Because of its unique characteristics, this new bacterial strain could be of considerable value in the long-term cleanup of the massive Gulf Coast oil spill, scientists say.
More research to further reduce costs and scale up production would be needed before its commercial use, they added.
The findings on this new bacterial strain that degrades the PAHs in oil and other hydrocarbons were just published in a professional journal, Biotechnology Advances, by researchers from Oregon State University and two collaborating universities in China. OSU is filing for a patent on the discovery.
“PAHs are a widespread group of toxic, carcinogenic and mutagenic compounds, but also one of the biggest concerns about oil spills,” said Xihou Yin, a research assistant professor in the OSU College of Pharmacy.