Bacteria Break Down Waste, Build Bioplastics
The same type of bacteria that help break down paper mill waste could also become an increasingly viable source of environmentally friendly biopolymers that can be used to make bioplastics, glues, and composite building materials.WSU Professor Mike Wolcott has teamed with fellow WSU Professor and Agricultural Research Center scientist Jinwen Zhang, and other scientists and engineers at the WSU Wood Materials Engineering Laboratory, University of California-Davis, and the Idaho National Engineering Lab to focus on a class of naturally occurring bacteria that produce and store polyhydroxyalkanoates (PHAs) which are chain-like molecules, called polymers, that are found in plastics, glues, wood, plants, and even in mussel shells. “Polymers are what bind the fibers together in wood or plants or plastics,” Wolcott explained. “Until now, the plastics we’ve been using have been petroleum based. We could reduce our dependence on international oil if we could make the way we produce PHAs more cost effective and find new uses for a less-pure version of them.”
Firms in the U.S., China, and Brazil have commercially produced PHAs using fermentation techniques for many years. But, Wolcott said, the current process is expensive both financially and environmentally.
“Commercially produced PHAs are fairly expensive when used in their purest form,” he said. “The bacteria feed-stock is expensive because it is raised on glucose, and the chemicals used to extract the polymer from the bacteria are expensive and not very environmentally friendly.”
Wolcott’s research group is attacking both challenges. They are exploiting the fact that the same types of bacte-ria that are being grown commercially for PHAs are also used by paper mills in their water reuse sites to convert phosphates into phosphorous. “The production of PHAs by those bacteria has been fairly low,” he said. “One challenge is to find the right environmental conditions at the wastewater treatment site to enhance production—we are trying to get these guys as fat as possible. By regulating the treatment process, we can substantially increase the amount of PHAs produced, in addition to reducing the phosphates to a very low level.” Wolcott also has developed composite materials that can utilize a simple centrifuge process for extracting the PHAs into a crude form. This physical process is much less damaging to the environment and much less expensive than the chemical extraction process currently used. When used in building materials, the composites can provide a substantial market for the crude PHAs.
The result of the group’s work?A more plentiful supply of crude PHAs.
Wolcott’s team is also working on finding new uses for less-pure PHAs. He has received grants from both the National Science Foundation and the U.S. Department of Energy to pursue production of PHAs and new compos-ite materials made with PHAs. Some of those materials include new building materials that potentially could replace wood or traditional plastics. “We are working with the Navy, for example, on new materials for docks, piers, and bridges,” Wolcott said.
Hanford Site Provides Entomological Window to History
In 1943, the U.S. government claimed and fenced 525
square miles in the Columbia Basin for construction of
the Hanford Reservation. But that site was home to much
more than a Department of Energy (DOE) nuclear facility.
Over the past 12 years, WSU entomology Professor
Richard Zack and his graduate students have uncovered
on the site at least 223 insect species new to the state and
43 insect species new to science. “And those numbers will
certainly increase,” Zack said.
In 1994, when clean-up efforts at Hanford began, the
Nature Conservancy and other organizations asked that
the site be kept as an environmental study area, and
DOE agreed. Zack won a grant to inventory insects living
on the site; to compare them with insects living off the
site; and finally, to investigate insect interaction between
species and with their environment at Hanford. That work
is just now winding down.
“This is land that has not changed much since the first
Europeans discovered it centuries ago,” he said. “Outside
of that fence erected in 1943, however, the land has
changed tremendously with irrigation and urbanization.
The site provides a window to history, a look at what
this Columbia Basin area was like before we started to
change it.”
Zack and his students collected more than 3,600 species
of arthropods, mostly insects. Of those, approximately
1,800 have been identified by different scientists throughout
the world. The remainder still are in the process of
being identified.
Zack says there were no startling discoveries, rather, there
was reaffirmation of some basic entomological tenets.
“What we found—and we knew this going in—was that
insects, especially, are very much tied to certain habitat
requirements,” he said. For example, because of a lack
of disturbance, the desert floor is covered with a crust
of lichens, mosses, and algae. “There are a lot of insects
specifically associated with that crust that you won’t
find outside the site … We’re talking about insects that
probably 100, 150, 200 years ago would have been very
common in this area.”
He said, considering the business conducted on the site,
the Hanford land is “a very pristine environment.”
The administration of President Bill Clinton agreed.
In June 2000, Clinton established the Hanford Reach
National Monument, which includes the 51-mile long
“Hanford Reach,” the last free-flowing, non-tidal stretch
of the Columbia River, as well as other tracts of land. The
proclamation establishing the monument specifically cites
Zack’s work on insect populations. “Such rich and diverse
insect populations are important to supporting the fauna
in the monument,” it says.
Mike Wolcott of the Wood Materials Engineering Lab.
Hanford Entomological Find
Heading using the h3tag
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