In this part, we want to show you how to build a simulated rumen system. We have obtained some inspiration from a paper by Roque et al. (2019), for which you can find the full source down below.
What do you need to simulate a rumen for? In our case, it is a viable alternative to animal testing, as it allows us to control most variables, and comes with reduced ethical grey areas. You may need to understand molecular interactions within an intestinal organ, or you may want to understand alterations within such a system over time. In our case, we wanted to understand how much methane is produced, and how much our product can reduce it.
Some important points for such a simulation are:
Control of temperature: Intestines are often at a very specific temperature, so that microbes express their optimal functions to which they are adapted.
Control of Oxygen: Intestines are anaerobic, meaning that the oxygen content of any gaseous phases needs to be as low as possible.
Control of any input: To take continuous measurements, one would want to introduce and remove specific compounds (e.g. chemicals, feed).
3-Necked Round Bottom Flask
Hopefully you were able to find all of the components or were able to improvise a little. Beneath is a series of videos of Tim setting up the simulated rumen.
If your experiment is going to measure things such as DNA content (e.g. sequencing of the microbiome) or other intricate measuring techniques, you are going to have to sterilize all of your glassware and wear gloves from here on out. Make sure to protect your glassware optimally by wearing other protective equipment that could reduce contamination, such as mouth masks, glasses and others.
Anaerobic conditions are oftentimes needed when simulating any type of intestinal system. For this reason you may want to check that you are able to achieve such conditions using an oxygen measurement device, which can be seen in the next video.
Thank you very much for watching our instructional videos. Remember that, if you are taking different measurements, or have other requirements for in- and output, that you may need to change some things. In our case, we wanted to run both one simulation with our product added, and a control simulation. This setup can be seen underneath.
Roque, B. M., Brooke, C. G., Ladau, J., Polley, T., Marsh, L. J., Najafi, N., ... & Hess, M. (2019). Effect of the macroalgae Asparagopsis taxiformis on methane production and rumen microbiome assemblage. Animal Microbiome, 1(1), 1-14.