Picture of How to isolate plastic degrading bacteria from soil!
With all of the publicity about how plastics are piling up in landfills and the ocean there has been an assumption that the plastics are incapable of breaking down. During my undergrad as a Microbiology major at Cal Poly SLO I was interested in environmental microbiology. During this time I was given a link to an article about a Canadian teenager, Daniel Burd, who found an aerobic (grows in presence of oxygen) bacteria that can degrade plastic. Well this got me thinking, maybe the whole idea that plastics could be degraded actually made sense, I mean there are some really complex molecules in nature that can be broken down, why not the simple design of plastics. So I started planning an experiment, looking for anaerobic (grows without oxygen) bacteria that degrade plastic using a Winogradsky Column which consists of soil at the bottom of the column and liquid at the surface of the column, limiting the amount of air that can diffuse into the soil. I did this with the hope that if I could find plastic degrading bacteria I could make a microbial fuel cell which would essentially breakdown plastic and produce electricity at the same time. Yes, a little ambitious but worth a try. If you are interested in how I went through developing the procedure and results please feel free to read the following paragraphs. If you just want to get straight to business skip to the the next page! 

With a vague idea of what Daniel Burd had done with his aerobic experiment I decided to design a similar experiment. In just a small sample of soil there are literally millions of bacteria, most are unable to be cultured in a lab. These bacteria and their relationships are so complicated that we may never be capable of understanding the exact ecology of a population of microbes in a spoonful of soil. With this general idea in mind it made sense to me that if put into an extreme environment, the microbes would adapt in order to survive. The nice thing with microbes is their ability to adapt quickly, turning on and off a variety of metabolic pathways to best utilize the resources available to them. That is exactly why microbes can be found almost everywhere on the planet. So my idea was to put soil microbes in an environment full of all the tasty elements they use to grow. I used Bushnell Hass Broth which is composed of Magnesium Sulfate, Calcium Chloride, Monopotassium Phosphate, Dipotassium Phosphate, Ammonium Nitrate, and Ferric Chloride. Or if you can see it better in terms of elements (Mg, S, O, Ca, Cl, K, N, H, Fe). You will notice that there is one KEY element missing from this solution, Carbon. Well lucky for us plastic is made up of Carbon (and Hydrogen) in long chains. Since Carbon is absolutely essential for microbes to grow (and all known life really) I was hoping that with all the other necessary ingredients available to them the microbes would use the Carbon found on the plastic to grow and luckily I was correct. So I will show you in just a few really simple steps how you can find plastic degrading bacteria from soil (I used landfill soil but I believe any soil would work).

Currently I am working on becoming a teacher and it is my personal belief that publishing this research for profit would really defeat the purpose.This would take away access to most people (who would have to fork over some serious cash just to look at it), especially when this could make a real, noticeable difference for a real environmental problem we face today. So I invite you to perform this experiment on your own, see what kind of results you get and collaborate our results. Please leave feedback for me in the comments, because this is my first instructable and I would like to make it the best it could possibly be. Thanks :)

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willf38 months ago

this is helpful for my research and experiment. thank you

willf38 months ago

this is helpful for my research and experiment. thank you

willf38 months ago

this is helpful for my research and experiment. thank you

willf38 months ago

this is helpful for my research and experiment. thank you

willf38 months ago

this is helpful for my research and experiment. thank you

willf38 months ago

this is helpful for my research and experiment. thank you

Greetings! This is an excellent article and ties well with my project in Uganda.

I just have two quick questions, the first might answer the second.
Firstly, I am not a scientist of any sorts, so if these questions seem like the answers are obvious, please excuse my ignorance. What I AM good at is asking questions until I overstand. I'm just a simple grassroots organizer, searching for possibilities to the scourge of plastic on our environment.

Question One: When the plastics have been broken down, does the remnant lose its toxicity? As in, will this byproduct be safe for the environment? How should one go about putting it to use? Can we dump it close to areas we are farming in and not have to worry about any toxic compounds entering into our food source?

Question Two: We are looking at TONS of plastic in Uganda. How easy would it be to upscale this system? Would a simple ratio increase work or is it more complex than that?

I can be emailed with details at dreadymayer@hotmail.com

You can find our project on facebook at "zuukuka!", which is the umbrella organization, and the actual project is called "Projekt Cavella". (Cavella is the local name for plastic bags here.)

Much appreciation for the free spreading of knowledge. If everyone had such a mentality, the world would be much different.


gravityisweak8 months ago

Great work, this is really cool! Do you have any updates of your own or from people who have contacted you about their own research?

rch121 (author)  gravityisweak8 months ago

Thank you so much! Unfortunately I never got a chance to continue this research in any capacity but quite a few people have talked to me about trying it themselves. However, most haven't gotten back to me after their initial contact. Hopefully that changes at some point but I am just glad so many people have read about this experiment, over 26k now...so crazy!

hello sir. I am a student of msc microbiolgy. And i am very interested in this plastic degradable microbes. If i get chance i will do this expwriment. Thanks for your update. If i have getting prblem i will contact you. And salute for your nice job ...

rch121 (author)  pmahatta.bokakhat8 months ago

Hey. thanks a lot! It's great to hear that you will be giving this experiment a try. I wish you the best of luck and let me know if there is any way I can help!

produ1 year ago

Did this in college as well; got some cool SEM images of it, too!

rch121 (author)  produ8 months ago

Hey thanks for the comment. Sorry for the ridiculous response time, but any chance you still have those images? I would be interested to see what they look like!

lanerenner produ10 months ago


lanerenner10 months ago


lanerenner10 months ago

block bacteria!

huymai1 year ago
hey ryan, Nice experiment. I am going to try this experiment and was wondering when you put in the plastic. Did you put in inside the soil or just on the soil so it can be exposed to the layer of broth?
rch121 (author)  huymai1 year ago

Thank you! Sorry for such a late reply....hopefully my answer isn't too late! To answer your question I first added the broth to the column and then completely put the plastic bags into the soil. Some of the bags just happened to be part way in the soil and part way in the broth. However, all of the bags had access to the broth because the soil was completely saturated with the broth. Hope that helps!

Cryb3by1 year ago
I was wondering if the % of degradation for the plastic strips may have been affected by the fact that it was being tested in plastic containers. I'm no microbiologist but I was just wondering

rch121 (author)  Cryb3by1 year ago

Hello! Thanks for the comment. Sorry about such a late response! I think the % degradation of the plastic bags was independent of the plastic container. Any bacteria growing on the plastic bags probably wouldn't have been affected by the container (plastic or glass or whatever). I think at least :)

hey ryan i like ur idea very much
so i m going to try ur idea for making fuel
if u have any suggesstion let me know
rch121 (author)  vartika singh2 years ago
Thank you very much. If you can isolate some bacteria then you might be able to mess with their DNA. It might be beneficial to look into some information about bacteria being used to create fuel, and then applying that to the bacteria you isolate from this experiment.
hi im a master microbiology student.im totally interested in your research..whats about your new projects regarding this research? have any new more advanced ideas regarding plastic degradation.
rch121 (author)  arunpalakkad2 years ago
Thank you very much! Unfortunately I have not been able to repeat this experiment or start any new ones :( I still think that you could construct an anaerobic fuel cell with plastic, but you would first need to do this experiment first to get the isolates. What do you plan on doing?
raj19962 years ago
Hey, I'm doing this project for my school project and is there a contact ID where I can contact you about the results?
rch121 (author)  raj19962 years ago
Sure no problem, what level of school are you in currently? You can contact me through a message on here or my email, rch121@gmail.com
sauravmann2 years ago
hey rch121
I am a biotech master student n wana try tis experiment thankz 4 postin it will contact u if i will need ur help n will surely tell u the results
rch121 (author)  sauravmann2 years ago
Awesome, good luck and I look forward to hearing from you.
haleyrose892 years ago
Thank you so much. I loved reading this and following your thought process. I am a microbiologist too! I am more focused on the clinical side though. I just finished my undergrad and other than the job searching I caught up on reading books I never got to read during college. Basically I am just recollecting myself. I am impressed with your ambition and thoughts. Good luck and keep nurturing your brilliant mind. :)
rch121 (author)  haleyrose892 years ago
Thank you very much, and Im glad you enjoyed it! Good luck on the job search!
nkozlowski3 years ago
This is awesome! How do you think using plastic bottles as your container medium affect the plastic degrading microbes in the experiment? Is the soda bottle plastic more stable (longer carbon chains) than the plastic bags used? Do you think if you kept it long enough the soda bottle would thin out over time?
rch121 (author)  nkozlowski3 years ago
Thank you! I think using the plastic bottles would work. I don't know for a fact if the carbon chain is longer but I assume since the material is stronger and more rigid that is the case. In fact I could do the exact same experiment but weigh the plastic bottles before and after a given amount of time. I would hypothesize that the plastic would indeed lose weight and if thats the case I would expect the bottle to thin over time.
Low Density Polyethylene or LDPE (plastic bags) and PET (bottles) are distinct polymers, arranged quite different, so even that most of the monomers of plastics are made of Carbon and Hydrogen, they behave in distinct forms. PETE would be quite hard to break into smaller chains from my experience. Of course, I understand plastics on a industrial basis, and have a shallow knowledge regarding molecular behavior of polymers, specially if there is bacterias involved.

My 2 cents are that probably you need to test on different materials. It's a shame you lost your specimens. This is something quite important for the future.
rch121 (author)  Lunatic0br3 years ago
Im not an expert by any means but I do think it would be possible for bacteria to degrade the varying kinds of plastic. Even if the monomer are arranged differently I think some bacteria would find a way to gain access to the carbon. But I definitely agree that I need to test multiple kinds of plastic, luckily this experiment should work for all the different kinds. Ya I was kind of bummed about losing the specimens but it will give me a chance to repeat the experiment with small improvements and hopefully get the same results. I will be starting new experiments once I put up the experiment on a crowd funding site. I tried kickstarter and they declined my project, so I am looking into using indiegogo. Thanks for you comment!
If you suceed to go on a crowd funding site, please let us (or at least me) know :)
I love reading your stuff, makes me excited, though I know I have no time to try it out myself. Would love to read more!
Maybe one day...
How far is your new experiment?
Do you think it would be possible to internationally ship bacteria? Maybe I could do the first step of your experiment and ship you my bacteria, so you have a higher variety of bacteria from diferent places... Or just some soil...
rch121 (author)  FetterChiller2 years ago
Thank you very much, I really appreciate it. For the time being I am way to busy to redo the experiment (between school, work, and teaching Im pretty spread out this semester). Hopefully summer will give me enough time to throw more time and energy into this project. But ya, none of the bacteria were stored from my initial experiment so I would have to do the whole thing over again, its not hard or anything, just takes some time. So again, I will see how my summer looks.

Im not sure on the rules of shipping soil and bacteria but I have a feeling you might get in trouble for doing it. Maybe its worth looking into but in the meantime your more then welcome to try it out for yourself and we can see where your at in a few months. Are you located in the US?
I'm actually located in germany - and it's winter here right now. Guess it's not the best time to start a culture (guess there are less bacteria around).
So maybe I'll try it in summer (if you remember, remember me :P).
rch121 (author)  FetterChiller2 years ago
Dang it must be cold over there. The winter over means that it may get down in the 30s but its usually in the 50s and 60s. haha. Anyways ya just shoot me a comment or message when you get to a chance to give it a try. best of luck!
Samtomate2 years ago
Thanks I hope so.Actually I have planned to work on a study of plastic degrading bacteria in soil for my undergraduate dissertation next semester but we have only about 4-6 months of actual lab work so I was wondering if it would yield good results in that short time span.
Samtomate2 years ago
Thanks a lot for this wonderful instructable! Do you think that I would get decent results if I leave the Winogradsky columns for 2 months only?
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