Lab-grown Meats Will Help to Address Climate Change

The protein sector is at a crossroads. On the one hand, global demand for animal protein has never been higher. On the other, meat and dairy already have an outsized hoofprint on the world’s farmlands. And with the climate crisis devastating natural and agricultural resources, we know the Earth’s ecosystems cannot support an expanded traditional agricultural sectorPlant-based protein has experienced rapid growth but is dwarfed by the size of the global meat protein market.

Enter cellular agriculture. Every day brings news of new venture capital funding, adding over US$9.7 billion in global investments. Cellular agriculture encompasses a raft of technologies and approaches that manufacture food and other products normally sourced from plants and animals including: dairy proteins, egg proteins, chocolate, honey, red meat, poultry, seafood, leather, silk and ingredients including sweeteners and flavourings. Cellular agriculture entered the public eye in 2013 when tissue engineering researcher Mark Post produced the first test-tube burger. This prototype cost hundreds of thousands of dollars but today, the same patty can be made for about 10 euros, or $15. In the past two years, dozens of companies have sprung up in Singapore, Israel and California to develop consumer products almost biologically identical to those traditionally sourced from plants and animals.

A few products are already in restaurants and on supermarket shelves. The cellular agriculture dairy company Perfect Day brews dairy proteins in bioreactors using yeast, much like a craft brewer produces beer. One of the largest plant-based food companies, Impossible Foods, uses cellular derived soy heme in its signature burger. Their Whoppers are for sale at Burger King and they have just raised a further US$500 million in investment capital to scale up production. The food-tech startup Eat Just mixes chicken proteins produced through cellular agriculture with plant-based ingredients to create an analogue to a chicken nugget.

Some current cellular agriculture technologies involve animal-based inputs such as stem cells and growth media. These products are not necessarily vegetarian, and so may not be universally accepted by consumers for cultural, religious or dietary reasons. That said, there is a huge potential to reduce water consumption, energy use, land use and greenhouse gases. While there are debates as the extent of the hoped-for environmental benefits, optimists are betting on the fact that carefully designed bioreactors using renewable energy will be more sustainable than a lot of the world’s livestock systems.

https://theconversation.com/

How To Recycle Plastic Infinitely And Reduce Plastic Pollution

The scientists who re-engineered the plastic-eating enzyme PETase have now created an enzymecocktail’ which can digest plastic up to six times faster. A second enzyme, found in the same rubbish dwelling bacterium that lives on a diet of plastic bottles, has been combined with PETase to speed up the breakdown of plasticPETase breaks down polyethylene terephthalate (PET) back into its building blocks, creating an opportunity to recycle plastic infinitely and reduce plastic pollution and the greenhouse gases driving climate change. PET is the most common thermoplastic, used to make single-use drinks bottles, clothing and carpets and it takes hundreds of years to break down in the environment, but PETase can shorten this time to days.

The team was co-led by the scientists who engineered PETaseProfessor John McGeehan, Director of the Centre for Enzyme Innovation (CEI) at the University of Portsmouth in UK, and Dr Gregg Beckham, Senior Research Fellow at the National Renewable Energy Laboratory (NREL) in the US. “Gregg and I were chatting about how PETase attacks the surface of the plastics and MHETase chops things up further, so it seemed natural to see if we could use them together, mimicking what happens in nature,” said  Professor McGeehan

Our first experiments showed that they did indeed work better together, so we decided to try to physically link them, like two Pac-men joined by a piece of string. “It took a great deal of work on both sides of the Atlantic, but it was worth the effort – we were delighted to see that our new chimeric enzyme is up to three times faster than the naturally evolved separate enzymes, opening new avenues for further improvements.

The initial discovery set up the prospect of a revolution in plastic recycling, creating a potential low-energy solution to tackle plastic waste. The team engineered the natural PETase enzyme in the laboratory to be around 20 percent faster at breaking down PET. Now, the same trans-Atlantic team have combined PETase and its ‘partner’, a second enzyme called MHETase, to generate much bigger improvements: simply mixing PETase with MHETase doubled the speed of PET breakdown, and engineering a connection between the two enzymes to create a ‘super-enzyme’, increased this activity by a further three times.

The study is published in the journal Proceedings of the National Academy of Sciences of the United States of America.

https://www.port.ac.uk/

New Concrete Incorporates And Reduces Carbon Dioxide Emissions

Concrete surrounds us in our cities and stretches across the land in a vast network of highways. It’s so ubiquitous that most of us take it for granted, but many aren’t aware that concrete’s key ingredient, ordinary portland cement, is a major producer of greenhouse gases. Each year, manufacturers produce around 5 billion tons of portland cement — the gray powder that mixes with water to form the “glue” that holds concrete together. That’s nearly three-quarters of a ton for every person on Earth. For every ton of cement produced, the process creates approximately a ton of carbon dioxide, all of which accounts for roughly 7 percent of the world’s carbon dioxide emissions. And with demand increasing every year — especially in the developing world, which uses much more portland cement than the U.S. does — scientists are determined to lessen the growing environmental impact of portland cement production.

One of those scientists is Gaurav Sant of the California NanoSystems Institute at UCLA, who recently completed research that could eventually lead to methods of cement production that give off no carbon dioxide, the gas that composes 82 percent of greenhouse gases. Sant, an associate professor of civil and environmental engineering and UCLA’s Edward K. and Linda L. Rice professor of materials science, found that carbon dioxide released during cement manufacture could be captured and reused.

For every ton of cement produced, the process creates approximately a ton of carbon dioxide, all of which accounts for roughly 7 percent of the world’s carbon dioxide emissions.

The reason we have been able to sustain global development has been our ability to produce portland cement at the volumes we have, and we will need to continue to do so,” Sant said. “But the carbon dioxide released into the atmosphere creates significant environmental stress. So it raises the question of whether we can reuse that carbon dioxide to produce a building material.

During cement manufacturing, there are two steps responsible for carbon emissions. One is calcination, when limestone, the raw material most used to produce cement, is heated to about 750 degrees Celsius. That process separates limestone into a corrosive, unstable solidcalcium oxide, or lime — and carbon dioxide gas. When lime is combined with water, a process called slaking, it forms a more stable compound called calcium hydroxide.

And the major compound in portland cement is tricalcium silicate, which hardens like stone when it is combined with water. Tricalcium silicate is produced by combining lime with siliceous sand and heating the mixture to 1,500 degrees Celsius. Of the total carbon dioxide emitted in cement manufacturing, 65 percent is released when the limestone is calcined and 35 percent is given off by the fuel burned to heat the tricalcium silicate compound.

But Sant and his team showed that the carbon dioxide given off during calcination can be captured and recombined with calcium hydroxide to recreate limestone — creating a cycle in which no carbon dioxide is released into the air. In addition, about 50 percent less heat is needed throughout the production cycle, since no additional heat is required to ensure the formation of tricalcium silicate.

The study is published in the journal Industrial and Engineering Chemistry Research.

Source: https://newsroom.ucla.edu/

Cut emissions to avert catastrophic sea-level rise

Scientists behind a landmark study of the links between oceans, glaciers, ice caps and the climate delivered a stark warning to the world: slash emissions or watch cities vanish under rising seas, rivers run dry and marine life collapse. Days after millions of young people demanded an end to the fossil-fuel era in protests around the globe, a new report by a U.N.-backed panel of experts found that radical action may yet avert some of the worst possible outcomes of global warming. But the study was clear that allowing carbon emissions to continue rising would upset the balance of the geophysical systems governing oceans and the frozen regions of the Earth so profoundly that nobody would escape untouched.

We are in a race between two factors, one is the capacity of humans and ecosystems to adapt, the other is the speed of impact of climate change. This report…indicates we may be losing in this race. We need to take immediate and drastic action to cut emissions right now,” IPCC Chair Hoesung Lee said at the presentation of the report in Monaco.

Finalised in a marathon 27-hour session of talks in Monaco between authors and representatives of governments, the report was the culmination of two years’ efforts by the U.N.-backed Intergovernmental Panel on Climate Change (IPCC). Compiled by more than 100 authors who crunched 7,000 academic papers, the study documents the implications of warm, fast-melting ice sheets in Greenland and Antarctica and shrinking glaciers for more than 1.3 billion people living in low-lying or high-mountain regions.

The report projects that sea levels could rise by one meter (3.3 feet) by 2100 — ten times the rate in the 20th century — if emissions keep climbing. The rise could exceed five meters by 2300. In the Himalayas, glaciers feeding ten rivers, including the Ganges and Yangtze, could shrink dramatically if emissions do not fall, hitting water supplies across a swathe of Asia. Thawing permafrost in places like Alaska and Siberia could release vast quantities of greenhouse gases, potentially unleashing feedback loops driving faster warming.