Scientists crack sustainable plastics puzzle

A team of South Korean scientists have produced the polymers used in conventional plastics through bio-engineering processes, in a breakthrough that promises to significantly cut the cost of so-called bioplastics.

The technique could allow the production of environmentally friendly plastics that are fundamentally the same as conventional plastics, but are biodegradable and do not use oil during their manufacture.

The research focused on polylactic acid (PLA), a bio-based polymer which can be used as an alternative to petroleum-based polymers to produce plastic.

"The polyesters and other polymers we use everyday are mostly derived from fossil oils made through the refinery or chemical process," professor Sang Yup Lee, who led the research, said in a statement.

"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," he added.

Until now, PLA has been produced in a two-step fermentation and chemical process of polymerisation, which is both complex and expensive.

However, the team used a metabolically engineered strain of E.coli to develop a one-stage process for creating PLA.

"By developing a strategy which combines metabolic engineering and enzyme engineering, we'e developed an efficient bio-based one-step production process for PLA and its copolymers," said Lee, adding that as a result, a developed E.coli strain is now capable of efficiently producing polymers in large amounts through a one-step fermentation process.

The research team from KAIST University in Seoul and the Korean chemical company LG Chem published their findings in the 50th edition of the Biotechnology and Bioengineering journal.