"Long before it's in the papers"
August 03, 2010

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Scientists make plastic without using fossil fuels

Nov. 24, 2009
Courtesy Wiley - Blackwell jorunals
and World Science staff

Sci­en­tists say they have man­aged to make plas­tics through “bio-en­gi­neer­ing” rath­er than through the use of fos­sil fu­els that con­trib­ute to glob­al warm­ing.

The find­ings are pub­lished in two pa­pers in the jour­nal Bi­o­tech­nol­ogy and Bi­o­en­gi­neer­ing to mark the jour­nal’s 50th an­ni­ver­sa­ry.

Poly­mers are mo­le­cules found in eve­ry­day life in the form of plas­tics and rub­bers. The re­search­ers, from Ko­rea Ad­vanced In­sti­tute of Sci­ence and Tech­nol­o­gy and Ko­re­an chem­i­cal com­pa­ny LG Chem, fo­cused their re­search on poly­lac­tic ac­id, a bi­o­log­ic­ally-based pol­y­mer.

“The polyesters and oth­er pol­y­mers we use eve­ry­day are mostly de­rived from fos­sil oils made through the re­fin­ery or chem­i­cal pro­cess,” said In­sti­tute re­searcher Sang Yup Lee. Poly­lac­tic ac­id “is con­sid­ered a good al­ter­na­tive to petroleum-based plas­tics as it is both bi­o­de­grad­able and has a low tox­icity to hu­mans.”

Un­til now the pol­y­mer had been pro­duced in a com­plex, costly two-step chem­i­cal pro­cess, he added. Lee’s team de­vel­oped a one-stage pro­cess in which en­gi­neered E. coli bac­te­ria pro­duced poly­lac­tic ac­id and as­so­ci­at­ed pol­y­mers through fer­menta­t­ion, a met­a­bol­ic pro­cess.

“This means that a de­vel­oped E. coli strain is now ca­pa­ble of ef­fi­ciently pro­duc­ing un­nat­u­ral pol­y­mers, through a one-step fer­menta­t­ion pro­cess,” he said.

“Global warm­ing and oth­er en­vi­ron­men­tal prob­lems are urg­ing us to de­vel­op sus­tain­a­ble pro­cesses based on re­new­able re­sources,” added Lee. “This new strat­e­gy should be gen­er­ally use­ful for de­vel­oping oth­er en­gi­neered or­gan­isms ca­pa­ble of pro­duc­ing var­i­ous un­nat­u­ral pol­y­mers by di­rect fer­menta­t­ion from re­new­able re­sources.”

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South Korean scientists say they have managed to make plastics through “bio-engineering” rather than through the use of fossil fuels that contribute to global warming. The findings are published in two papers in the journal Biotechnology and Bioengineering to mark the journal’s 50th anniversary. Polymers are molecules found in everyday life in the form of plastics and rubbers. The team, from Korea Advanced Institute of Science and Technology and Korean chemical company LG Chem, focused their research on polylactic acid, a biologically-based polymer. “The polyesters and other polymers we use everyday are mostly derived from fossil oils made through the refinery or chemical process,” said Institute researcher Sang Yup Lee. Polylactic acid “is considered a good alternative to petroleum-based plastics as it is both biodegradable and has a low toxicity to humans.” Until now the polymer had been produced in a complex, costly two-step chemical process, he added. Lee’s team developed a one-stage process which engineered E.coli bacteria produce polylactic acid and associated polymers through fermentation, a metabolic process. “This means that a developed E. coli strain is now capable of efficiently producing unnatural polymers, through a one-step fermentation process,” he said. Fermentation is a metabolic process carried out by certain bacteria. “Global warming and other environmental problems are urging us to develop sustainable processes based on renewable resources,” added Lee. “This new strategy should be generally useful for developing other engineered organisms capable of producing various unnatural polymers by direct fermentation from renewable resources”.