Polylactic Acid doesn’t sound like a friendly neighborhood chap,
but it is in fact a common plastic. Not only is it biodegradable, it
can be made from renewable resources like sugarcane and corn starch.
The current common technique for producing PLA is both expensive and
complex, involving bacterial fermentation and then chemical
polymerization.
A collaboration between KAIST University (Korea) and LG Chem, led
by professor Sang Yup Lee, has developed a new process which produces
PLA using the same resources. The process is a one-step
direct fermentation, but it utilizes a slightly unsavory, though
common bacterial component: E. coli.
“By developing a strategy which combines metabolic engineering
and enzyme engineering, we've developed an efficient bio-based
one-step production process for PLA and its copolymers. This means
that a developed E. coli strain is now capable of
efficiently producing unnatural polymers, through a one-step
fermentation process,” explains Lee.
“The polyesters and other polymers we use everyday are mostly
derived from fossil oils made through the refinery or chemical
process. The idea of producing polymers from renewable biomass has
attracted much attention due to the increasing concerns of
environmental problems and the limited nature of fossil resources.
PLA is considered a good alternative to petroleum based plastics as
it is both biodegradable and has a low toxicity to humans.”
Though the use of E. coli in the process seems at first
unsettling, the benefits of such a process are readily apparent.
Reduced production cost would allow for greater use of PLA in plastic
products, possible reducing or even replacing the need for many of
the non-biodegradable, petroleum-based products presently in use.
Though it may indeed be a small step, Lee’s team’s research adds
another bio-friendly product to a stack of growing “greener”
products and resources.
The research work is published in the 50th anniversary
of the journal Biotechnology and Bioengineering.