REASONS TO BE CHEERFUL
Scientists find new ways to harness natural processes in the fight against environmental disaster
Regarding the looming plastic catastrophe: in a recent paper, scientists at Kew Gardens announced that fungi could be key to winning the battle against plastic waste, not to mention cleaning up radioactive material and producing biodiesel. For instance in 2017, on a rubbish dump in Islamabad, Pakistan, Chinese scientists found a fungus called Aspergillus tubingensis, which produces an enzyme that can break down even super-resilient plastics such as polyester polyurethane, fully digesting it within weeks. The genes that produce this enzyme could be put in marine fungi to help clear plastic in the oceans. Meanwhile, bacteria and even caterpillars are evolving to ‘eat’ plastic; the waxworm, a type of moth caterpillar, consumes polyethylene, one of the toughest and most commonly used varieties. D.Telegraph, 12 Sept; D.Mail, 13+20 Sept 2018.
Professor Tim Bugg at Warwick University has found that a natural glue called lignin, which stiffens plant stems by holding cellulose fibres together, can be turned into a strong, mouldable, biodegradable plastic by genetically tweaking a bacterium called Rhodococcus jostii, which lives in the soil and feeds on lignin. Lignin is a by-product of the papermaking process. D.Telegraph, 5 July 2018.
The masked bee (Hylaeus nubilosus) produces a nesting material that is non-toxic, waterproof, acid-resistant and flame-resistant. Humble Bee, a biotech company in New
Zealand, hopes to reverseengineer the material and massproduce it as an alternative to plastic. The company initially plans to use the material to make outdoor apparel, which often requires toxic chemicals to keep it waterproof. Sunday Telegraph, 19 Aug 2018.
Droughts could be consigned to history by a water harvester that can pull moisture out of the air using solar power. Harvesters can provide 2.8 litres of drinkable water from the air over a 12-hour period in conditions as dry as the Mojave Desert, where the average humidity is around 20 per cent. The device is an open-air chamber containing a lattice-like structure made from zirconium and adipic acid sandwiched between a solar absorption panel and a condenser plate. The zirconium and acid structure traps the water vapour, then sunlight drives it towards the cooler condensing plate, which returns
the vapour to liquid so it can drip into a collector. Two-thirds of the world’s population experience water shortages, yet there is an estimated 13,000 trillion litres in the atmosphere. D.Telegraph, 14 April 2017.
Deep in Oman’s al-Hajar mountain range, geologists have found a potential way to remove carbon dioxide from air and water. An exposed section of the Earth’s mantle, about 200 miles (320km) long, up to 25 miles (40km) wide and several miles thick, contains peridotite, a rock that reacts with carbon to form marble and limestone. About a billion tons of CO2 are held inside each mountain, and more is pulled in every second. If this carbon mineralisation could be harnessed, accelerated and applied inexpensively on a huge scale – admittedly some very big ifs – it could help fight climate change. Smaller deposits of peridotite can be found elsewhere, such as northern California, Papua New Guinea and Albania. And at a geothermal power plant in Iceland an energy company is injecting modest amounts of carbon dioxide into volcanic rock, where it becomes mineralised. 14 April 2017; New York Times, 2 May 2018.
MIT researchers have engineered a bionic plant that can detect explosives and send a warning signal. A paper in the journal Nature Materials explains how to turn plants into bomb-sniffing machines with the help of tiny cylinders of carbon that can detect nitroaromatics – chemical compounds often used in explosives. As the plant absorbs air and groundwater from the environment, the carbon tubes register any nitroaromatics and emit a fluorescent signal. This gets picked up be an infrared camera and relayed to a small computer or smartphone, which then sends an email to the user. “This is a novel demonstration of how we have overcome the plant/human communication barrier,” said paper co-author Michael Strano, a chemical engineer at MIT. Though he and his colleagues worked with spinach plants, “you can apply these techniques with any living plant” to turn them into any kind of sensor, he said. A plant is a better groundwater sensor than pretty much any machine a human can build. The carbon nanosensors can be tailored to detect nitric oxide (a pollutant produced by combustion) as well as hydrogen peroxide, the explosive TNT and sarin gas, used as a chemical weapon. Toronto Star, 5 Nov 2016.