A team of researchers demonstrated that they could 3D-print delicious edible cookies out of plastic waste that was digested by yeast.

Are we eating enough plastic already?

  • rhythmisaprancer@quokk.auEnglish
    9·
    15 hours ago

    While this could be good, I think about this much older article that talks about somewhat similar things, specifically

    turkey offal, tires, plastic bottles, harbor-dredged muck, old computers, municipal garbage, cornstalks, paper-pulp effluent, infectious medical waste, oil-refinery residues, even biological weapons such as anthrax spores

    but they ended up only doing (what I remember being) the turkey offal. The article mentioned here says

    plastic compounds and agricultural byproducts like discarded plant stalks into proteins, fats, acids, and flavorings

    and while it has been 20+ years, my concern is that it will end up doing much less than promised. But I can hope for more.

  • NaibofTabr@infosec.pubEnglish
    831·
    22 hours ago

    Before the yeast can start feasting, the PET plastics are subjected to a process called oxidative hydrothermal dissolution to break them down into smaller bits that the microbes can digest.

    Sensationalism aside, this could actually be a big deal. We use a lot of PET (polyethylene). Plastic drink bottles, plastic bags, plastic wrap, tape, fabrics, even some car parts. PET is a huge market segment of consumer products that are difficult to replace with environmentally friendly alternatives.

    If we can boil it and then feed it to a vat of yeast to break down, that would be fantastic. Even better, it could remove some of the difficulty of plastic sorting which is a major part of the recycling problem. Basically, if you dump some plastic into the vat that the yeast can’t eat, well it just won’t eat it, so just sift it out of the vat later for a different disposal process, no big deal.

    Even if humans can’t directly consume the byproduct, I’m sure we can use it for something else.

    My biggest question is how long this takes, which they don’t address in the article. How long do you have to boil the material (how much energy, how much water, how much oxygen, how big a facility to process X volume of waste), and how long does it take the yeast to break it down? If it can be done in hours or days that’s well worth spending some resources to build a processing center. If it takes months or years it will require more planning and analysis.

    • huppakee@lemmy.worldEnglish
      27·
      22 hours ago

      My biggest question is how long this takes, which they don’t address in the article. How long do you have to boil the material (how much energy, how much water, how much oxygen, how big a facility to process X volume of waste), and how long does it take the yeast to break it down? If it can be done in hours or days that’s well worth spending some resources to build a processing center. If it takes months or years it will require more planning and analysis.

      They don’t put in a direct answer, but there is an indirect one: $60 per kilo. That needs to come down A LOT before there is a real future for this. I heard of projects that try and turn plastics into fuels. Sooner or later somebody will figure it out.

      • NaibofTabr@infosec.pubEnglish
        13·
        22 hours ago

        Yes, I’m assuming that this is being done in a lab environment without purpose-built equipment, and also that developing the specialized yeast strain was part of the cost.

        Assuming that the genetic change is stable and that the yeast is self-propagating like normal yeast, then engineering the rest of it into an assembly line shouldn’t be too difficult and should bring the cost down by orders of magnitude.

        Plus, if we can turn the output hydrocarbons into a viable market product then the recycler can offset the operating cost, which would make this even more interesting. Right now plastic recycling is just losses.

        • nilloc@discuss.tchncs.deEnglish
          2·
          17 hours ago

          Assuming that the genetic change is stable and that the yeast is self-propagating like normal yeast, then…

          …we will have to stop using so much plastic, because it won’t be reliable shelf stable packaging one the yeast that eats it is loose.

          • NaibofTabr@infosec.pubEnglish
            4·
            14 hours ago

            Possibly, but:

            Before the yeast can start feasting, the PET plastics are subjected to a process called oxidative hydrothermal dissolution to break them down into smaller bits that the microbes can digest.

            “Oxidative hydrothermal dissolution” - basically they boil the plastic and oxidize it, I think at the same time. Maybe hydrogen peroxide + water? Essentially this is kind of an accelerated aging.

            Anyway, the yeast can’t eat the plastic without some processing first, which is probably good because it means existing plastic packages won’t just start falling apart. On the other hand if this does get loose, it might be able to eat any PET litter that has started breaking down in the environment due to exposure to sun, rain, ocean water, etc. The absolute easiest waste for this to eat would be any PET that has broken down into microplastic particles and ended up in soil or water, which would be kind of an ideal situation.

            • nilloc@discuss.tchncs.deEnglish
              3·
              3 hours ago

              Evolution finds a way.

              But seriously I thought the article implied the oxidation process just made the particle smaller so they’d have more surface area and get consumed quicker. Even if it’s slow, won’t the yeast that have a taste for PET still want to grow on it, like they do with bread.

  • antianarchist@sopuli.xyzEnglish
    3·
    15 hours ago

    The yeast breaks down the components of plastic compounds and agricultural byproducts like discarded plant stalks into proteins, fats, acids, and flavorings that we can eat.

  • kibblebits@quokk.auEnglish
    23·
    23 hours ago

    Wait they haven’t even tasted it? If I was a scientist turning plastic into food I would be at least licking it.

    • Zahille7@lemmy.worldEnglish
      7·
      23 hours ago

      I thought that was about a subset of people who had mutated to digest plastic, not that they modified themselves to do so.

      The whole opening scene has a small child too young for surgery, just going ham on his trash can.

      • YaksPT@sh.itjust.worksEnglish
        5·
        23 hours ago

        I didn’t want to give away everything but yes, the other plastic eaters had modified themselves and somehow a surgical modification changed a live birth to be able to be the first human to be able to eat plastic. Hence the kid.

  • azimir@lemmy.mlEnglish
    9·
    22 hours ago

    Has anyone read Diamond Age? I’d suggest you give it a try, even with the weird Stephenson jumps near the end, it explores molecular level production of products, including food.

    I feel this work is a huge deal for NASA and other space flight tech dev. Instead of trying to pack a ship with cookies, pack it with plastic and convert as needed.

    • dhork@lemmy.worldEnglish
      3·
      22 hours ago

      I do remember it is an awesome book, but it’s been probably 20 years since I read it

  • azimir@lemmy.mlEnglish
    8·
    22 hours ago

    “We produce 400 million tons a year of plastic waste. You’re not going to turn it all into cookies.”

    That’s quitter talk. Have you seen the shit Americans eat? We could do 400 million tons of cookies and a large diet coke without flinching.