A Quest for Solutions

My name is Agustina Cartagena and I am starting an experimental proof of concept mealworm plastic composting.  I’ve read a few articles, research papers and seen one other person on the internet set up an experiment, but they are always short term. My ambition is to set up some sort of recycling program that uses a variety of organisms to consume plastics – there are also some species of mushrooms that consume polyeurathane but they only do this process in anaerobic conditions based off of initial research – but there is so little information out there on how to set it up or the feasibility of some sort of program. So, my first step is to just learn and observe mealworms.

Where will I be sourcing my worms from? What kind of containers will I be using?

Honestly, I was just going to call fishing shops until I found one (preferably both) of the species of meal worms (yellow mealworm/Tenebrio molitor and dark mealworms/Tenebrio obscurus) and then plop them into prepared containers.  I’m going to use a self sorting set up, and this video best illustrates what my finished set up is going to be like. I have found other set ups that people have for mealworm farms, but I’m going to start with this due to space constraints. My plan so far is to have 4 of these bins, 2 for each of the mealworm species

I want to include the mixture of the two just to find out if the worms would have a preference for one over the other. I don’t know if it’s “important” to know this, but I want to know. I didn’t think it was important to state where I sourced the worms from, is there some sort of preference? I will obviously be making sure I track where I get the worms from now, and thank you so much for asking that.

 Efficiency of Scale?

I have no idea how efficient something like this is, it’s actually one of my most important questions. I don’t know how long it would take for me to find this out, but based off of rates of consumption online, it would take 100 worms little less than a year to consume a standard Styrofoam cup.

      100 mealworms eat 34-39mg of Styrofoam/day

       Standard Styrofoam cup weighs around 11 grams=11000mg

       11000/34=323 days

 So right now, the scale is not very efficient. But maybe a worm going through a full life cycle would be a bit faster? How much space does 100 mealworms really take? If I add 100 more mealworms, would it take 6 months to break down that cup? Or would it take them less time? Does efficiency of consumption change at all when there are more worms around? How would I introduce moisture to the process to that they don’t dehydrate? Can I breed more efficient worms? (though initial findings from a new study published in Environmental Science and Technology suggest that dark mealworms are more efficient at consuming polystyrene). These are just a few of the questions I hope to answer in the next year in terms of efficiency.

 What other kinds of byproducts are produced?

Everything that I’m reading states that the polystyrene is depolymerized and broken down to carbon dioxide, carbon biomass, and fecula. It’s sort of amazing and why I’m so incredibly excited to explore this as a solution to plastics in our environment.

 USDA or FDA comments on this?

As far as I could find, neither the USDA or the FDA have looked into this as a form of vermiculture.

 Do the worms pupate into something else?

I don’t think so, I think they just turn into beetles and then breed to start a new cycle. My plan is to really breed them, and keep the lifecycle going as long as I can. It might become hard to manage fairly quickly, but I’ll sort of deal with it then? I’m estimating that I’ll have about 3 months to figure that out from once I start the project.

 I’m in contact with the sustainability committee here at NWRO and next Monday I’m going to be collecting Styrofoam from my coworkers here. I’m even playing with the idea of having “clean” Styrofoam vs “dirty Styrofoam” to see if there are any better outcomes, and it would be more practical to not have a restriction on just using “clean” Styrofoam for composting. I don’t think americans would be on board with washing Styrofoam that they are just going to throw away. (which would mean six bins, instead of 4, so I might just wash soiled Styrofoam for now and then expand later)

BY ROB JORDAN

Mealworms munch on Styrofoam, a hopeful sign that solutions to plastics pollution exist. Wei-Min Wu, a senior research engineer in the Department of Civil and Environmental Engineering, discovered the larvae can live on polystyrene. (Photo: Yu Yang)

Consider the plastic foam cup. Every year, Americans throw away 2.5 billion of them. And yet, that waste is just a fraction of the 33 million tons of plastic Americans discard every year. Less than 10 percent of that total gets recycled, and the remainder presents challenges ranging from water contamination to animal poisoning.

Enter the mighty mealworm. The tiny worm, which is the larvae form of the darkling beetle, can subsist on a diet of Styrofoam and other forms of polystyrene, according to two companion studies co-authored by Wei-Min Wu, a senior research engineer in the Department of Civil and Environmental Engineering at Stanford. Microorganisms in the worms' guts biodegrade the plastic in the process – a surprising and hopeful finding.

"Our findings have opened a new door to solve the global plastic pollution problem," Wu said.

The papers, published in Environmental Science and Technology, are the first to provide detailed evidence of bacterial degradation of plastic in an animal's gut. Understanding how bacteria within mealworms carry out this feat could potentially enable new options for safe management of plastic waste.

"There's a possibility of really important research coming out of bizarre places," said Craig Criddle, a professor of civil and environmental engineering who supervises plastics research by Wu and others at Stanford. "Sometimes, science surprises us. This is a shock."

Plastic for dinner

In the lab, 100 mealworms ate between 34 and 39 milligrams of Styrofoam – about the weight of a small pill  – per day. The worms converted about half of the Styrofoam into carbon dioxide, as they would with any food source.

Within 24 hours, they excreted the bulk of the remaining plastic as biodegraded fragments that look similar to tiny rabbit droppings. Mealworms fed a steady diet of Styrofoam were as healthy as those eating a normal diet, Wu said, and their waste appeared to be safe to use as soil for crops.

Researchers, including Wu, have shown in earlier research that waxworms, the larvae of Indian mealmoths, have microorganisms in their guts that can biodegrade polyethylene, a plastic used in filmy products such as trash bags. The new research on mealworms is significant, however, because Styrofoam was thought to have been non-biodegradable and more problematic for the environment.

Researchers led by Criddle, a senior fellow at the Stanford Woods Institute for the Environment, are collaborating on ongoing studies with the project leader and papers' lead author, Jun Yang of Beihang University in China, and other Chinese researchers. Together, they plan to study whether microorganisms within mealworms and other insects can biodegrade plastics such as polypropylene (used in products ranging from textiles to automotive components), microbeads (tiny bits used as exfoliants) and bioplastics (derived from renewable biomass sources such as corn or biogas methane).

As part of a "cradle-to-cradle" approach, the researchers will explore the fate of these materials when consumed by small animals, which are, in turn, consumed by other animals.

Marine diners sought

Another area of research could involve searching for a marine equivalent of the mealworm to digest plastics, Criddle said. Plastic waste is a particular concern in the ocean, where it fouls habitat and kills countless seabirds, fish, turtles and other marine life.

More research is needed, however, to understand conditions favorable to plastic degradation and the enzymes that break down polymers. This, in turn, could help scientists engineer more powerful enzymes for plastic degradation, and guide manufacturers in the design of polymers that do not accumulate in the environment or in food chains.

Criddle's plastics research was originally inspired by a 2004 project to evaluate the feasibility of biodegradable building materials. That investigation was funded by the Stanford Woods Institute's Environmental Venture Projects seed grant program. It led to the launch of a company that is developing economically competitive, nontoxic bioplastics.

With this post, I wanna focus on mushrooms. They are of particular fascination to me because they have some fantastic soil clean up properties.

WTF is Mycoremediation?

Mycoremediation is simply the use of mushrooms to remediatiate a contaminated environment. Remediation is the process of fixing a fucked up environment because us humans like to mess with things, and forget that we sometimes break things while we are messing around.

Oyster Mushrooms will clean up soil contaminated with diesel range oils (and they are supposedly safe to eat, according to one test done, but I still wouldn't),  ​in the last few years we have found a few species of mushrooms that will accelerate decomposition of plastics, and there are a wide range of mushrooms that will consume heavy metals, pesticides, dyes, and organic pollutants in the soil they reside in. ​

Recently, the state of California has deployed the use of various kinds of mushrooms to clear up contaminants released during last years fires.

You can read more of that here.

The saddest thing about mycoremediation (or bioremediation, which is the use of microbes to remediate local ecosystems) is that there’s no way to really profit from it. which is why there’s almost no new research or wide scale application of this possibly amazing solution to environmental degredation.

But if you find this, and are interested, leave me a comment. I love talking about this stuff, and i don’t nearly enough about it.