Bioproducts Offer Greener Alternatives

Applications include car parts and building materials

Nicole Pinto, left, and Atsuko Negishi

For Nicole Pinto, a graduate student in the Department of Integrative Biology, and Amar Mohanty, a professor in the Department of Plant Agriculture, the Government of Canada’s recent announcement of support for the expanding biomaterials market in southern Ontario is a positive step towards reducing our dependence on petroleum-based materials.

Pinto draws out vimentin – a human intermediate filament – from bacteria, which she hopes could be used as the building blocks for future biodegradable textiles. Her painstaking work purifying and concentrating the vimentin takes hours to produce about 20 mL, enough to fill 15 test tubes and, she says, the minimum amount required to form fibres large enough to test for tensile strength. From this filament she hopes to produce fibres with strength comparable to steel or Kevlar.

“Under specific temperature conditions, the vimentin proteins are able to self-assemble into filaments of 10 nanometers in diameter that can be attached end to end to make longer strands,” Pinto explains. “Using the self-assembled filaments, I am then able to produce larger fibres.” Later, she stretches the film out as much as she can without breaking the fibres.

Pinto’s colleague, Atsuko Negishi, a research associate in the Department of Integrative Biology, has been exploring the potential for making stronger fibres using proteins from hagfish-slime thread.

“I’ve always been interested in what happens at the microscale and how molecules interact,” Negishi says. “I am inspired by nature’s own sustainable processes and I’d like to help minimize the human footprint on the planet.”

Pinto and Negishi believe biomaterials could be useful in the medical field and the way forward is to study nature for answers. “It’s exciting to think that once the fibres are spun or woven into biocompatible and biodegradable textiles, they can be used for specific things like sutures and patches,” Pinto says. “In time, I hope they will become increasingly economically viable for production on an industrial scale.”

Mohanty has been studying natural materials for industrial purposes since the 1980s. At that time, bioplastics were extremely costly – almost 20 times the cost of petroleum-based plastics. Bioplastics are easily broken down by micro-organisms under appropriate conditions and are considered biodegradable.

When the University’s Bioproducts Discovery and Development Centre (BDDC) opened in 2008, Mohanty was appointed the Premier’s Research Chair in Biomaterials and Transportation and director of the BDDC. The centre produces biomaterials as possible substitutes for non-renewable materials in a variety of manufacturing sectors.

“Such biomaterials can be used for everything from green building structures and car parts to new biodegradable plastic wrap or packaging, and the crops that produce them are completely renewable,” says Mohanty.

Under Mohanty’s directorship, researchers at the BDDC develop biomaterials containing 25 to 100 per cent biobased content. They aim to develop new biomaterials with as much biobased content as possible, while improving cost and performance.

“Agricultural residues such as corn cobs, oat hull, wheat straw and soybean stalks can be incorporated into manufactured products in place of petrochemicals,” says Mohanty. “In addition to agricultural residues, the co-products and byproducts from biofuel industries were undervalued in the past. Today, turning them into bioproducts results in more environmentally friendly and competitive bio-resin based industrial products that can benefit farmers and consumers, as well as the economy.”

In addition to agricultural residues, Mohanty sees a strong future for local grasses such as switch grass, miscanthus, and co-products and byproducts from biofuel industries, including cereal byproducts of the distillation process. Material like distillers’ dried grains with solubles; lignin, a chemical compound derived from wood; and crude glycerol, a form of glycerin often used in pharmaceuticals, have potential for use in value-added industrial products.

“Marginal lands that are not viable for agriculture can be put to better use in the development of biomaterials,” says Mohanty. “We cannot deny that we need food and we need fuel. It is vital we manage our renewable resources to help us get both in a sustainable manner. For example, the corn now going to the development of bioplastics as a sustainable alternative to oil-based plastics amounts to around 0.1 per cent of global supply, which in my opinion does not significantly impact the food chain.”

Mohanty says the BDDC has succeeded in translating innovation into practical applications and the current challenge is to engineer Ontario-grown green products that are cost competitive in the marketplace.

“Biomaterials are still in their infancy mainly because of their comparatively higher cost, and in certain cases there is limited supply chain and technology available. That explains why people are currently more interested in hybrid products than ever before. Companies are moving towards a better balance of the environment versus cost and I believe gradually over time some products will be 100 per cent bio-based.

“To me, the progress made in the development of biodiesel – a vegetable oil or animal fat based diesel fuel – is remarkable,” says Mohanty. “Thanks to technological advancements, biofuels can be made from non-food agricultural residues.

“Substituting biomaterials for petro-based materials in manufacturing processes reduces greenhouse gas emissions, which improves the situation for the environment and for society both in the short- and long-term.”