In the search for solutions to man-caused pollution, researchers keep stumbling on organisms that already know how to do it. Here are some examples.
Wax Worms and Plastic Pollution
The wax worm is the larva of a moth. Researchers at Spain’s Center for Scientific Investigations report that this little caterpillar has an amazing talent. It breaks down plastic.
A few years ago, a new field of research opened up with the discovery that some insect species of the Lepidoptera and Coleoptera orders are able to degrade polyethylene and polystyrene. “In our lab, we discovered the insect that seems to be the fastest of all: the larvae of the lepidopteran Galleria mellonella, commonly known as the wax worm,” says Bertocchini. “These larvae are able to oxidise and break down the polymers in the plastic really quickly,” (after just one hour’s exposure). [Emphasis added.]
The enzymes were found in the larva’s saliva. This discovery is promising, because 70 percent of plastic pollution is made up of three polymers, and polyethylene is one of the toughest to degrade. Now they find these lowly worms that like to eat the stuff — and they are not the only ones.
One of the most promising research areas with the greatest potential is the biological degradation of plastics. This process is known as biodegradation and is associated with microorganisms such as bacteria and fungi. However, to date, only a handful of microorganisms are known to break down the tough plastic polymers forming polyethylene. What is more, in most cases, aggressive pre-treatment is needed to guarantee oxidation and thus enable the micro-organisms to exert some effect (albeit slow) on the plastic.
Why bother inventing chemical processes when you can find the biological enzymes that already know how to do the job?
Superworms and Styrofoam
Polystyrene is another pollutant found in Styrofoam cups, packing material and plastic forks. It often ends up in landfills or the ocean. Scientists at the University of Queensland have found that “superworms — the larvae of Zophobas moriodarkling beetles — are eager to dine on the substance, and their gut enzymes could hold the key to higher recycling rates.” Read about these larvae on Phys.org.
The two-inch edible worms eventually hatch into beetles, of course. Scientists could learn how to mimic the enzymatic breakdown of polystyrene and take the worms out of the equation, leading to a sustainable process for reducing plastic waste.
Soil Recovery after Oil Spills
Oil in soil — what a mess that is to clean up. Soil health depends on microbes. A story in Phys.org discusses what the American Society for Agronomy is learning about soil bacteria after “thermal desorption” (heating contaminated soil) and “landfarming” (spreading out the polluted soil over large areas till it degrades naturally). After both treatments, the healthy microbes bounced back just fine, and crops could be planted safely again.
Fungi Forest Service
Wildfires have been in the news a lot. Every summer and fall we witness tragic megafires burning out of control, especially in California and the Western states. But there are microbes and fungi that work as forest recovery agents, scientists at UC Riverside have found. News from UCR talks about “the forest microbes that can survive megafires.” Author Jules Bernstein reports that “Burns allow fungi, bacteria to transform redwood forests.”
UCR researchers expected losses of many microbes after fires, but they were “surprised that some yeast and bacteria not only survived the fire but increased in abundance.” These included microbes and fungi able to break down plant material such as the lignin in wood, control pathogens, remediate heavy metals in soil, and promote plant growth.
In general, little is known about fungi and the full extent of their effects on the environment. It is imperative that studies like these continue to reveal the ways they can help the environment recover from fires.
That would be a grand opportunity for design scientists. They could build on the work of Michael Denton who has written extensively about the prior fitness of oxygen in the atmosphere for land animals and plants. See, most recently, his book The Miracle of Man.
The proper ratio of inert nitrogen and highly reactive oxygen is balanced, Denton explains, so that beings like us could use fire and technology for good, but not spontaneously combust or watch the whole world burn up. Megafires do occur, but oxygen, remarkably, tends to be less reactive at ambient temperatures. The fuel in wood allows for a slow burn in a campfire for enjoyment while releasing elements like potassium back to the soil. Speaking of potassium, watch a fascinating video about potash by Derek Muller on his popular YouTube channel.
More to Come
There is so much more to learn about beneficial organisms. Some of the above organisms were discovered serendipitously, but scientists at ETH Zurich are thinking ahead. In a recent story titled “Tapping the ocean as a potential source of natural products,” reporter Peter Rüegg writes, “Using DNA data, ETH researchers have examined seawater to find not only new species of bacteria, but also previously unknown natural products that may one day prove beneficial.”
Our knowledge of beneficial marine organisms is “rudimentary,” the article points out. Delving into coded information in eDNA (environmental DNA) from a thousand sites in the oceans of the world, the Swiss teams have already found some useful “biosynthetic gene clusters” or BCGs — groups of genes that provide the synthetic pathway for a natural product. How many more helpful enzymes or products will turn up in the 40,000 BCGs they have collected so far?
None of these findings, it must be pointed out, should be taken as an excuse to pollute or imply that concerns are unwarranted. They are, however, indications of foresight in the design of the biosphere for many contingencies.