Plants generate their energy from sunlight via photosynthesis, however many crops have a photosynthetic glitch, which costs them a significant amount of energy that could be used for growth. This glitch has been shortened using careful engineering by researchers from the University of Illinois and US Department of Agriculture’s Agricultural Research Service, to generate plants with a 40% increase in productivity in real-world conditions.
Tobacco seedlings. Image: Claire Benjamin/RIPE project
During photosynthesis, carbon dioxide (CO2) and water are converted into sugars by the enzyme Rubisco, which is fuelled by energy from sunlight. Rubisco is the planets most abundant protein, but its efficiency has resulted in an oxygen-rich atmosphere, and it cannot reliably distinguish between CO2 and oxygen (O2). Approximately 20% of the time, O2 is grabbed by Rubisco instead of CO2, and then converted into a compound which is toxic to plants. This compound can be recycled through a process known as photorespiration.
The research team. Image: Claire Benjamin/RIPE project
In this study, alternate routes for the process have been engineered, allowing the plant to save resources better utilised for growth. The scientists generated three alternate routes using different sets of promoters and genes, which were then stress tested in 1,700 individual plants to find the best performers.
Cellular agriculture involves making food from cell cultures in bioreactors. The products are chemically identical to meat and dairy products, and it’s claimed they have the same taste and texture.
The technology is an attractive option because it would reduce the world’s reliance on livestock, which is unsustainable, and would have potential knock-on benefits of lower greenhouse gas emissions, and reduced water, land, and energy usage than traditional farming.
IndieBio helps biotechnology start-ups. Since 2014, it has funded several new US-based businesses in cellular agriculture: Perfect Day, formerly Muufri, makes milk from cell culture; Clara Foods is developing a way to make egg whites from cell culture; and Memphis Meats is focusing on animal-free meat using tissue engineering.
Growth is driven by the clear benefits this technology can offer, says Ron Sigeta, IndieBio’s Chief Scientific Officer. ‘It takes 144 gallons of water to make a gallon of milk or 53 gallons of water to make an egg. Cellular agriculture products don’t require such large water supplies, or large tracts of land, or produce the same level of greenhouse gas emissions.’
Salmonella bacteria are not present in cell-cultured milk so there is no risk of infection. Image: Wikimedia Commons
Food safety is also a significant issue. ‘Cellular agriculture makes products in an entirely controlled environment so it’s a source of food we can understand with a transparency that is simply not possible now,’ says Sigeta. For example, raw, unpasteurised milk can carry bacteria, such as salmonella, which is not a problem for Perfect Day’s milk as there are no bacteria-carrying animals are involved.
So how does it work?
Cellular agriculture products can be acellular – made of organic molecules like proteins and fats – or cellular – made of living or once-living cells.
Meat industry critics argue that it is not sustainable and lab-grown meat is the future. Video: Eater
Acellular products are made without using microbes like yeast or similar bacteria. Scientists alter the yeast by inserting the gene responsible for making the desired protein. Since all cells read the same genetic code, the yeast, now carrying recombinant DNA, makes the protein molecularly identical to the protein an animal makes.
Other products like meat and leather are produced by a cellular approach. Using tissue engineering techniques muscle, fat or skin cells can be assembled on a scaffold with nutrients. The cells can be grown in large quantities and then combined to make the product.
The first cultured beef patty was made in 2013. Image: Public Domain Pictures
Mark Post at Maastricht University, the Netherlands, made the first cultured beef hamburger in 2013 using established tissue engineering methods to grow cow muscle cells. The process, however, was expensive and time-consuming, but his team has been working on improvements.
‘We are focusing on hamburgers because our process results in small tissues that are large enough for minced meat applications, which accounts for half of the meat market. To make a steak, one would need to impose a larger 3D structure to the cells to grow in.
‘It is very important that such a structure contains a channel system to perfuse the nutrients and oxygen through to the developing tissue and to remove waste as a result of metabolic activity. This technology is being developed, but is not yet ready for large scale production.’
Surveys have shown that the public are behind genetically engineered meat alternatives. Image: Ben Amstutz@Flickr
Commercial challenges include finding a cost-effective medium for cell nutrition developing a bioreactor for industrial scale production. Public perception may also be a challenge: Will people buy synthetically engineered food?
A recent crowdfunding campaign shows the global massive support for the idea of clean meat, says Koby Barak, SuperMeat’s chief operating officer and co-founder. However, he believes these will be overcome shortly, and it will not be long before companies see ‘massive funding’ in this field and the creation of clean meat factories worldwide.