Dry, arid and remote farming regions are vulnerable to water shortages, but scientists are working on a promising new solution.
As scientists have searched for solutions, an alternative water supply has been hiding in plain sight: Water vapor in the atmosphere. It is abundant, available, and endlessly renewable, just waiting for the moment that technological innovation and necessity converged to make it fit for use. Now, new super-moisture-absorbent gels developed by Yu and a team of researchers can pull that moisture from the air and bring it into soil, potentially expanding the map of farmable land around the globe to dry and remote regions that suffer from water shortages.
"This opens up opportunities to turn those previously poor-quality or inhospitable lands to become useable and without need of centralized water and power supplies," Yu said.
A renewable source of freshwater
The hydrogels are a gelatin-like substance made from synthetic materials. The gels activate in cooler, humid overnight periods and draw water from the air. During a four-week experiment, Yu's team observed that soil with these gels provided enough water to support seed germination and plant growth without an additional liquid water supply. And the soil was able to maintain the moist environment for more than a month, according to Yu.
The super absorbent gels developed at the University of Texas at Austin.
Xingyi Zhou, UT Austin
"It is promising to liberate underdeveloped and drought areas from the long-distance water and power supplies for agricultural production," Yu said.
Crops also rely on fertilizer to maintain soil fertility and increase the production yield, but it is easily lost through leaching. Runoff increases agricultural costs and contributes to environmental pollution. The interaction between the gels and agrochemicals offer slow and controlled fertilizer release to maintain the balance between the root of the plant and the soil.
The possibilities are endless
Harvesting atmospheric water is exciting on multiple fronts. The super-moisture-absorbent gel can also be used for passively cooling solar panels. Solar radiation is the magic behind the process. Overnight, as temperatures cool, the gels absorb water hanging in the atmosphere. The moisture is stored inside the gels until the thermometer rises. Heat from the sun serves as the faucet that turns the gels on so they can release the stored water and cool down the panels. Effective cooling of the solar panels is important for sustainable long-term power generation.
In addition to agricultural uses and cooling for energy devices, atmospheric water harvesting technologies could even reach people's homes.
"They could be developed to enable easy access to drinking water through individual systems for household usage," Yu said.
Next steps
Yu and the team are now focused on affordability and developing practical applications for use. The goal is to optimize the gel materials to achieve higher levels of water uptake from the atmosphere.
"We are exploring different kinds of polymers and solar absorbers while exploring low-cost raw materials for production," Yu said.
The ability to transform atmospheric water vapor into a cheap and plentiful water source would be a game-changer. One day in the not-too-distant future, if climate change intensifies and droughts worsen, this innovation may become vital to our very survival.
Based on recent research, new therapies could promote a mix of viruses in the intestines to help prevent diseases of aging.
The microbiota and aging
In the early 1970s, scientists discovered that the composition of our gut microbiota changes as we age. Recent studies have found that the changes are remarkably predictable and follow a pattern: The microbiota undergoes rapid, dramatic changes as toddlers transition to solid foods; further changes become less dramatic during childhood as the microbiota strikes a balance between the host and the environment; and as that balance is achieved, the microbiota remains mostly stable during our adult years (ages 18-60). However, that stability is lost as we enter our elderly years, and the microbiome undergoes dramatic reorganization. This discovery led scientists to question what causes this change and what effect it has on health.
Centenarians have a distinct gut community enriched in microorganisms that synthesize potent antimicrobial molecules that can kill multidrug-resistant pathogens.
“We are always eager to find out why some people live extremely long lives. Previous research has shown that the intestinal bacteria of old Japanese citizens produce brand-new molecules that make them resistant to pathogenic — that is, disease-promoting — microorganisms. And if their intestines are better protected against infection, well, then that is probably one of the things that cause them to live longer than others,” said Joachim Johansen, a researcher at the University of Copenhagen.
In 2021, a team of Japanese scientists set out to characterize the effect of this change on older people’s health. They specifically wanted to determine if people who lived to be over 100 years old — that is, centenarians — underwent changes that provided them with unique benefits. They discovered centenarians have a distinct gut community enriched in microorganisms that synthesize potent antimicrobial molecules that can kill multidrug-resistant pathogens, including Clostridioides difficile and Enterococcus faecium. In other words, the late-life shift in microbiota reduces an older person’s susceptibility to common gut pathogens.
Viruses can change alter the genes of bacteria
Although the late-in-life microbiota change could be beneficial to health, it remained unclear what facilitated this shift. To solve this mystery, Johansen and his colleagues turned their attention to an often overlooked member of the microbiome: viruses. “Our intestines contain billions of viruses living inside bacteria, and they could not care less about human cells; instead, they infect the bacterial cells. And seeing as there are hundreds of different types of bacteria in our intestines, there are also lots of bacterial viruses,” said Simon Rasmussen, Johansen’s research advisor.
Centenarians had a more diverse virome, including previously undescribed viral genera.
For decades, scientists have explored the possibility of phage therapy — that is, using viruses that infect bacteria (called bacteriophages or simply phages) to kill pathogens. However, bacteriophages can also enhance the bacteria they infect. For example, they can provide genes that help their bacterial host attack other bacteria or provide new metabolic capabilities. Both of these can change which bacteria colonize the gut and, in turn, protect against certain disease states.
Intestinal viruses give bacteria new abilities
Johansen and his colleagues were interested in what types of viruses centenarians had in their gut and whether those viruses carried genes that altered metabolism. They compared fecal samples of healthy centenarians (100+ year-olds) with samples from younger patients (18-100 year-olds). They found that the centenarians had a more diverse virome, including previously undescribed viral genera.
They also revealed an enrichment of genes supporting key steps in the sulfate metabolic pathway. The authors speculate that this translates to increased levels of microbially derived sulfide, which may lead to health-promoting outcomes, such as supporting mucosal integrity and resistance to potential pathogens.
“We have learned that if a virus pays a bacterium a visit, it may actually strengthen the bacterium. The viruses we found in the healthy Japanese centenarians contained extra genes that could boost the bacteria,” said Johansen.
Simon Rasmussen added, “If you discover bacteria and viruses that have a positive effect on the human intestinal flora, the obvious next step is to find out whether only some or all of us have them. If we are able to get these bacteria and their viruses to move in with the people who do not have them, more people could benefit from them.”
This article originally appeared on Big Think, home of the brightest minds and biggest ideas of all time.
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