5 ms·

Any one know what the by-products of the fungus' metabolism are?

ars 15y ago
Polyurethane, like virtually all plastics is made of nitrogen, carbon, hydrogen and oxygen. So the byproducts are things like water, carbon dioxide, ammonia, alcohol. Plastics burn really well, they are not actually that hard to destroy safely - their decomposition products are very clean if the fire is hot enough.
- kragen 15y ago
  It's possible to burn polyurethane safely, but it's not trivial. If you burn it at low temperatures, you get hydrogen cyanide, and if you burn it (or, in air, anything) at high temperatures, you get deadly nitrogen dioxide instead. You can get rid of the nitrogen dioxide with sufficient effort; http://www.aat.cc/store.asp?pid=26808 http://www.aat.cc/store.asp?pid=26808, for example, sells a six-stage air scrubber system using a sequence of strong oxidizing and reducing agents. In short, "not actually that hard to destroy safely" is wildly off the mark. Your other statement is wildly off the mark, too. Metabolic byproducts are incredibly diverse, including all of the chemical compounds produced in the course of an organism's life cycle. One of the organisms studied in this paper was Aspergillus niger, whose metabolism produces, among other things, aflatoxin. EDIT: Oops, WRONG. It's other Aspergillus species that produce aflatoxin, sorry. A. niger is mostly notable for producing 99% of the citric acid in your food.
  - kragen 15y ago
    I should also point out that there are plastics that are even harder than polyurethane to burn safely, namely, anything containing chlorine or fluorine. The common ones are polytetrafluoroethylene (Teflon) and poly(vinyl chloride) ("vinyl"). These, regardless of how you burn them, are going to produce compounds of fluorine and chlorine, typically gaseous hydrofluoric and hydrochloric acids, which will EAT YOUR FUCKING LUNGS. HF will also poison the fuck out of you. On the plus side, these gases are light and will disperse rapidly if they're not confined.
    - ars 15y ago
      Those acids are very easy to deal with, just bubble them through baking soda. The chlorine makes salt, and the fluoride can be sold to be added to city drinking water.
      - o2sd 15y ago
        >> The chlorine makes salt, and the fluoride can be sold to be added to city drinking water. Yes, because what our drinking water REALLY needs is more rat poison. On the up side,in clinical trials, fluoride stops rats from breeding, so if the same effect is observed in humans, at least we will have an answer to the world's population problem.
      - kragen 15y ago
        Hey, good point. Are there other chlorine and fluorine compounds in the exhaust that are harder to deal with?
  - ars 15y ago
    Nitrogen dioxide is a problem, but at an industrial scale it's not a huge problem. Among other things it can easily be captured with fractional distillation (water, CO2 and NO2 have very different boiling points), converted to nitric acid and sold. And aflatoxin (and others) are not byproducts, they are deliberately made by the organism, regardless of what it eats. A byproduct is waste that depends on the food source.
ajkessler 15y ago
This seems like the most important question... Since the paper is paywalled, and science reporting is terrible, can someone with access inform us just what the hell the fungus turns the plastic into?
- bcn 15y ago
  http://aem.asm.org/cgi/reprint/AEM.00521-11v1.pdf http://aem.asm.org/cgi/reprint/AEM.00521-11v1.pdf
  - the_tubes 15y ago
    lol In reality, just like any scientific articles you see like this one that could change everything, you will never hear of this magic fungus again. Nor will it save the world and the world continues as its normal self.
- gerggerg 15y ago
  I'm hoping it's gold. That way we can all get rich.

ars 15y ago

Polyurethane, like virtually all plastics is made of nitrogen, carbon, hydrogen and oxygen. So the byproducts are things like water, carbon dioxide, ammonia, alcohol. Plastics burn really well, they are not actually that hard to destroy safely - their decomposition products are very clean if the fire is hot enough.

kragen 15y ago
It's possible to burn polyurethane safely, but it's not trivial. If you burn it at low temperatures, you get hydrogen cyanide, and if you burn it (or, in air, anything) at high temperatures, you get deadly nitrogen dioxide instead. You can get rid of the nitrogen dioxide with sufficient effort; http://www.aat.cc/store.asp?pid=26808 http://www.aat.cc/store.asp?pid=26808, for example, sells a six-stage air scrubber system using a sequence of strong oxidizing and reducing agents. In short, "not actually that hard to destroy safely" is wildly off the mark. Your other statement is wildly off the mark, too. Metabolic byproducts are incredibly diverse, including all of the chemical compounds produced in the course of an organism's life cycle. One of the organisms studied in this paper was Aspergillus niger, whose metabolism produces, among other things, aflatoxin. EDIT: Oops, WRONG. It's other Aspergillus species that produce aflatoxin, sorry. A. niger is mostly notable for producing 99% of the citric acid in your food.
- kragen 15y ago
  I should also point out that there are plastics that are even harder than polyurethane to burn safely, namely, anything containing chlorine or fluorine. The common ones are polytetrafluoroethylene (Teflon) and poly(vinyl chloride) ("vinyl"). These, regardless of how you burn them, are going to produce compounds of fluorine and chlorine, typically gaseous hydrofluoric and hydrochloric acids, which will EAT YOUR FUCKING LUNGS. HF will also poison the fuck out of you. On the plus side, these gases are light and will disperse rapidly if they're not confined.
  - ars 15y ago
    Those acids are very easy to deal with, just bubble them through baking soda. The chlorine makes salt, and the fluoride can be sold to be added to city drinking water.
    - o2sd 15y ago
      >> The chlorine makes salt, and the fluoride can be sold to be added to city drinking water. Yes, because what our drinking water REALLY needs is more rat poison. On the up side,in clinical trials, fluoride stops rats from breeding, so if the same effect is observed in humans, at least we will have an answer to the world's population problem.
    - kragen 15y ago
      Hey, good point. Are there other chlorine and fluorine compounds in the exhaust that are harder to deal with?
- ars 15y ago
  Nitrogen dioxide is a problem, but at an industrial scale it's not a huge problem. Among other things it can easily be captured with fractional distillation (water, CO2 and NO2 have very different boiling points), converted to nitric acid and sold. And aflatoxin (and others) are not byproducts, they are deliberately made by the organism, regardless of what it eats. A byproduct is waste that depends on the food source.

ajkessler 15y ago

This seems like the most important question... Since the paper is paywalled, and science reporting is terrible, can someone with access inform us just what the hell the fungus turns the plastic into?

bcn 15y ago
http://aem.asm.org/cgi/reprint/AEM.00521-11v1.pdf http://aem.asm.org/cgi/reprint/AEM.00521-11v1.pdf
- the_tubes 15y ago
  lol In reality, just like any scientific articles you see like this one that could change everything, you will never hear of this magic fungus again. Nor will it save the world and the world continues as its normal self.
gerggerg 15y ago
I'm hoping it's gold. That way we can all get rich.