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Plastic From Algae | Earth Wise

June 9, 2020 By EarthWise Leave a Comment

Many researchers consider algae to be one of the best renewable resources for replacing fossil fuels and even as a food source. The green microalgae Nannochloropsis salina is already a common source of omega-3 fatty acids that are sold as dietary supplements. As a result, that algae strain is already grown on a large scale for the production of omega-3 products.

A group of researchers at UC San Diego has developed a way to make use of the waste stream from that production to create plastics and other useful products. Currently, when the algae is processed to extract the omega-3 oil, leftover oils comprising more than 70% of the starting material are either thrown away or burned.

The UCSD team has developed a process to purify and convert this waste stream into azelaic acid, which is a building block for flexible polyurethanes. These materials have all kinds of commercial applications from flip-flops and running shoe soles to mattresses and yoga mats.

By analogy to the use of animals by native American tribes, the researchers wanted to “use the whole buffalo” in their solution for algae processing waste and therefore figured out how to convert heptanoic acid – another substance in the algae waste stream – into a food flavoring and fragrance. The flavoring molecule is valued at over $500 per kilogram.

The work, published in the journal Green Chemistry, demonstrates that an algae-source waste stream has both the practical and economic potential to support production of polyurethanes. The team is already working with shoe companies to commercialize the technology. With mounting concern over petroleum-based plastic waste, renewable plastic made from algae is an attractive alternative.

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Researchers Turn Algae Leftovers into Renewable Products with Flare

Photo, posted November 8, 2006, courtesy of Adam Moore via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Foods of the Future? | Earth Wise

March 27, 2020 By EarthWise Leave a Comment

In a world where many go hungry in the context of rapidly changing environments, many experts contend that alternative food sources will be necessary to solve global food security problems. So-called novel food sources are central to this conversation, defined as foods with no history of consumption in a region – or perhaps anywhere.

Three popular examples are lab-grown meat, insect farming, and seaweed aquaculture. Each of these offer opportunities as well as challenges.

Lab-grown meat can refer to actual animal tissues raised in vats as well as the increasingly common cultured plant products made to resemble meat. Lab-grown meat faces push back from the livestock industry that contends it should not be labeled as any kind of meat. While results to date are positive, barriers still remain including concerns over product taste, healthiness, and cost. And while less land- and water-intensive than conventional livestock, cultured meat production is still energy intensive.

Insects do form a significant part of diets across the globe but have yet to be embraced in any substantial way in western cultures. Nutritionally, numerous species of insects are rich in key proteins, micronutrients, and minerals. But the “yuck factor” is a big barrier to cross.

Seaweed is a long-established part of many East Asian diets and has many potential dietary uses. Several selectively bred varieties of seaweed supply a range of valuable nutrients. Growing seaweed does not tax freshwater and terrestrial resources. But intensively cultivated seaweeds would have potential negative effects on local marine ecosystems.

There is no single solution to complex issues like food security. Novel foods may very well form part of the solution to a growing food crisis.

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Insects, seaweed and lab-grown meat could be the foods of the future

Photo, posted March 12, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Controlling Malaria Without Chemicals

August 28, 2019 By EarthWise Leave a Comment

Nearly half of the world’s population lives in areas vulnerable to malaria. The disease kills roughly 450,000 people each year, most of them children and pregnant women. Malaria is spread by Anopheles mosquitoes and, over time, the mosquitoes have been developing resistance to the chemical insecticides that are used to control them. In addition, there is great concern about the toxic side effects of the chemicals used on the mosquitoes.

About 30 years ago, scientists identified a type of bacteria that kills Anopheles, but the mechanism was not understood. As a result, the bacteria could not be replicated or used as an alternative to chemical insecticides.

But now, an international research team, headed by researchers at UC Riverside, has identified the neurotoxin produced by the bacteria and has determined how it kills Anopheles. The work is described in a paper published in Nature Communications.

It took the team 10 years to achieve a breakthrough in understanding the bacteria. Modern gene sequencing techniques were the key.

While many neurotoxins target vertebrates and are highly toxic to humans, the neurotoxin that kills Anopheles mosquitoes does not affect humans, vertebrates, fish, or even other insects. Known as PMP1, the substance is not even toxic to mice when given by direct injection.

The team has applied for a patent on this discovery and hopes to find partners to help them develop the bacteria-based insecticide.

There is a high likelihood that PMP1 actually evolved to kill the Anopheles mosquito. This finding opens the door to new avenues of research into other environmentally friendly insecticides that would be targeted at other disease-spreading pests.

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Controlling deadly malaria without chemicals

Photo, posted June 9, 2018, courtesy of Mario Yardanov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plant-Based Jet Fuels

May 9, 2019 By EarthWise Leave a Comment

The global aviation industry uses a whole lot of fuel: more than 5 million barrels a day. It is an incredibly energy-intensive industry and almost all of its energy comes from petroleum-based fuels.

While other large energy sectors such as electric power, ground transportation and commercial buildings have well-defined pathways to adopting renewable energy sources, the aviation industry does not have such a straightforward way to make a transition to sustainability. Electrifying planes using batteries or fuel cells is very challenging for a number of reasons, notably the weight restrictions on aircraft. So liquid biofuels as replacements for petroleum-based fuels remain the most promising approach.

A new study at the Lawrence Berkeley National Laboratory concludes that sustainable plant-based biofuels could provide a competitive alternative to conventional petroleum fuels if current development and scale-up initiatives are successful.

Multidisciplinary teams based at the Department of Energy’s Joint BioEnergy Institute are focused on optimizing each stage of the bio-jet fuel production process. This includes bioengineering ideal source plants and developing methods for efficiently isolating the carbohydrates in non-food biomass that bacteria can digest and bioconvert into fuel molecules.

The critical issue is cost. The theoretical cost of bio-jet fuel has come down dramatically in recent years but is still around $16 a gallon. The cost of standard jet fuel is about $2.50 a gallon. So, the real challenge is bridging that gap.

Reducing the cost of the fuel could come both from the material and process improvements that are underway as well as by finding ways to turn the leftover lignin residuals from the bioconversion process into valuable chemicals.

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Bright Skies for Plant-Based Jet Fuels

Photo, posted March 28, 2009, courtesy of Yasuhiro Chatani via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bursting The Carbon Bubble

July 25, 2018 By EarthWise Leave a Comment

One way or another, the fossil fuel industry seems to be destined to shrink away. A combination of technological advances and climate policies are going to drastically reduce the global demand for fossil fuels over the course of time. New research shows that the demise of the fossil fuel industry will have profound consequences.

Oman’s Rocks

June 13, 2018 By EarthWise Leave a Comment

There is growing interest in the idea of capturing and storing carbon dioxide. Reducing the amount of it we are putting into the atmosphere is essential for limiting the effects of climate change, but even eliminating emissions entirely is not enough because the CO2 already there stays in the atmosphere for decades or more.

[Read more…] about Oman’s Rocks