Plastic food
Massachusetts Institute of Technology, is designing a way to
harvest plastic from the fronds of oil palm trees.
A consortium of Malaysian scientists, working with the Massachusetts Institute of Technology, is designing a way to harvest plastic from the fronds of oil palm trees - a process that could lead to food packaging being produced from a primary food source.
Why the fronds? Because getting it in the oil would confuse, not to mention scare, entire populations of consumers. And fronds have so far been a low-value part of the tree.
"In theory, all it needs are rain and sunshine," said Ruslan Abdullah, associate professor of plant genetics at Universiti Kebangsaan Malaysia's School of BioSciences and Biotechnology.
In reality, it's more workable than earlier attempts at getting bacteria to produce biodegradable plastic although it borrows genes from the same source.
"Plants don't readily produce plastic but some bacteria do," said Ruslan. "We've implanted those bacterial genes into oil palm. The plants are about six months old. In about a year, we should see this plastic."
Ruslan and his team of researchers implanted the two plastic-making genes from the bacteria Ralstonia eutropha. That's genetic engineering.
But to get bioplastic, it's metabolic engineering at work: active amino acids from one of those genes piggyback on a series of biochemical reactions that normally take place within the tree, and trick the frond's cells into storing the bioplastic.
Ruslan's assignment - part of the five-year multi-agency Malaysia-MIT Biotechnology Partnership Programme - is to park those genes in the right place.
"We want plastic in the leaves," said Ruslan, "we don't want it in the oil or anywhere else. There are good reasons for that."
Palm oil is good as it is. To install plastic into it - even if it's edible like those funny sweet wrappers - would stir up a stinging psychological hornet's nest that may shatter palm oil's well-entrenched position in the food market.
Oil palm fronds, on the other hand, are low-value and traditionally go into compost, animal feed and to a smaller degree, biomass fuel.
Still, the most powerful driver in this is the prospect that the world will run out of petroleum - the traditional source of plastic - in less than 50 years. For over a decade now, scientists have been desperately hunting for alternatives because no matter what social engineers have tried, people won't give up plastic.
"Petroleum-sourced plastic is made of non-degradable polyethylene," said Ruslan. "That's always been a problem. Bioplastic is made of carbon, oxygen and hydrogen, the stuff the earth is made of. And if it grows on trees, then it would be renewable."
Evolution theorists think polymer-filled cell walls might be a reservoir of food when it's scarce, like human bodies store fat, or possibly, a fortress impenetrable to viruses and other invaders.
That's what prompted the first attempts at making bioplastic. But in factories, getting bacteria to do it is expensive because the microbes needed a rich diet of sugars, starches and fats, pampering in the right environment plus a process to crack those cell walls to extrude bioplastic.
Already, British and US scientists have turned to getting plants like canola and rapeseed to produce bioplastic, also by implanting a gene from a plastic-making bacterium. But some plants have forseeable problems: after harvesting the useful part (oilseed or whatever), you need to chop the plant down to process for bioplastic. Then you plant again. Would that be expensive?
With oil palm, the tree stays, usually for more than two decades. The fruit is taken for the oil people. The fronds, which fall off and get cleared every day in any case, present little change to existing plantation practice.
No matter how exciting all this sounds, the bridge between bioplastic in oil palm fronds and actual usefulness has not been built yet. Will it be a viable process?
At the Malaysian Palm Oil Board - co-ordinator of the Malaysia-MIT collaboration - researchers are investigating this issue.
"It's exciting but still very early days," says Ruslan. "We're likely to see the real picture in about 5 years. The combined body of research will show us what to expect."
