Imagine owning a beautiful farm, with 50 black and white cows with an adorable pink nose. You have a big barn of course, to host your dear cows and you have a large field, where they can happily graze. You are aware that your business has consequences on the environment, and for this reason many regulations are in place to reduce the impact of your activity. The emission of many different pollutants has to be controlled, among which there are the two gasses ammonia and methane. As a farmer, you have to make a choice on which device to choose for complying with regulations that preserve the environment. Why would you, as a farmer, choose Cattlelyst? To help you develop your own answer to this question we must describe the existing technologies. Some of them even use microorganisms, as Cattlelyst does. So, then what is special about Cattlelyst, the biofilter that WUR iGEM team 2021 is designing? We aim to give 3 original features to our biofilter:
We want to tackle the emissions of both methane (CH4) and ammonia (NH3).
We want to do it using genetically engineered bacteria, optimized for the job
We have designed three levelsof safety to ensure that the GMOs stay confined.
You will see from the following introduction to the existing methods that all these features are quite unique to our design. And this is mainly due to the fact that none of the existing systems for reducing the emissions from animal sheds tackle both gasses. This is because methane and ammonia have different properties. This is why we decided to use optimized microorganisms! In this way we want to achieve something that would be otherwise unfeasible.
Cattlelyst and current control of ammonia emissions
Ammonia is produced when the cow’s pee and poop come into contact. All together they are called manure (see our previous blog). On one hand, using bacteria (let’s call them ammoniatrophs) for the reduction of ammonia emissions offers an advantage over chemical air treatment methods. Chemical filtration produces environmentally harmful waste streams that have to be specially treated, while this is not the case in biofilters. On the other hand, the current methods for reducing ammonia using ammoniatrophs found in nature produce nitrogen-rich waste streams. They also run the risk of producing the toxic nitrite or nitrous oxide, very potent greenhouse gas, which has a global warming potential 280 times higher than CO2 over 100 years. This is why we want to engineer an ammoniatroph to reduce ammonia emissions, without producing any unwanted compounds.
Cattlelyst and current control of methane emission
As we’ve described in our previous blogpost, the emission of methane from cattle can derive from cow’s breath after digestion or from the manure. You can imagine that collecting methane from breath is quite challenging, thus efficient animal friendly solutions are still at research stage. Biofilters using bacteria (these are called methanotrophs) able to consume methane could be an environmentally friendly solution. You can guess that in addition to the ammoniatroph, we also want to improve the methanotroph! A better methanotroph could be able to consume the available methane more efficiently. However, the challenge in the design of the biofilters lies in concentrating the methane coming from the breath over the whole air flow. Low methane concentrations require otherwise filters of very large sizes. Therefore, we must acknowledge that increasing the concentration of methane to the biofilter is even more important in order to reduce the filter size. This is why we plan to use a device to collect not only the methane coming from the manure, but also a concentrated methane-rich airflow from cow’s breath.
Cattlelyst got inspired by existing systems and existing microorganisms. Based on the urgency for the reduction of both emissions and the bottlenecks current solutions faced, our team decided to put effort into a combined solution designed with the help of synthetic biology. We are aware that complex problems such as the skyrocketing emissions of pollutants and their consequences on environment and the society cannot be solved by only one approach. Being a farmer is a lifestyle, a beautiful one, connected with animals and nature. However, ironically these farms, especially in the dairy sector, have a negative impact on nature too. Our vision is to offer a relatively short term technical solution that relieves a bit of the large environmental impact that dairy farms have, thus helping the environment.
Do you want to stay updated on our project? Register to this blog to get notified by email when a new post is published! Coming-soon topics of the blog are: interviews to our team members working on their theses, lab routines and insights of our practical lecture with primary school children. In case of questions, feel free to send an email at igem@wur.nl
Credits for header image to @Jenny Bakker
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