The different operations of bioreactors: chemostat, turbidostat, stressostat, and more

Jan 31, 2022 Posted by: Cameron Davidson-Pilon

Bioreactors have an advantage of being able to closely control an environment for microbes. Often, we wish for a bioreactor to precisely control a single, important variable, and we observe how the microbes respond. We can even push this variable to an extreme value - to an environment that the microbes are not familiar with, with interesting results.

Pioreactor Dev log #14 - Our hardware, version 2

Dec 27, 2021 Posted by: Cameron Davidson-Pilon

We've been working on the version 2 of our HAT for over 6 months now, putting together all the improvements, learnings, and ideas since testing our version 1 board. In this post, we'll go through some of the changes that we are most excited about. 

Pioreactor dev log #13 - Heating improvements

Dec 13, 2021 Posted by: Cameron Davidson-Pilon

Each Pioreactor has built-in heating and temperature sensors. I emphasize temperature sensors, since I've used enough hot plates to not trust a graduated knob to have any reliability. With a combination of heating and temperature sensors, the Pioreactor is able to keep a set temperature for the culture, regardless of the Pioreactor variations in the construction, ambient temperature, etc.

Pioreactor dev blog #11 - creating custom Raspberry Pi images

Nov 12, 2021 Posted by: Cameron Davidson-Pilon

We care a lot about onboarding. I've seen enough Raspberry Pi projects that seem to require deep experience in software compilers and package management (don't worry if you don't know what those are...) before you can get started. This is an immediate barrier to your project! From a "funnel" perspective, you may end up losing up a large fraction of your users just at this stage. Can we do better?

Pioreactor dev blog #10 - happy little algae

Nov 04, 2021 Posted by: Cameron Davidson-Pilon

Algae have a very different set of living conditions compared to other organisms that we have tested in the Pioreactor. Algae require both light and CO₂ to grow. We had the foresight to think of algae's unique growing requirements during development, hence the Pioreactor has additional pockets for LEDs in the main body. When these pockets are occupied by white-light LEDs, the Pioreactor turns from a bioreactor into a photo-bioreactor. 

Our new plugin lets you push logs to your Slack workplace

Oct 11, 2021 Posted by: Cameron Davidson-Pilon

We just released a new plugin that may be useful for teams that use Slack. The plugin, Logs2Slack, will publish logs from the Pioreactor to a chosen Slack channel, so you and your team can discuss important events in Slack. Installation is quite easy, too!

Pioreactor development blog #9

Oct 06, 2021 Posted by: Cameron Davidson-Pilon

A few months ago, we introduced temperature control via internal heating to the Pioreactor. This has been a success, and something that differentiates us from other bioreactors, but it was creating artifacts in our optical density measurements. Why is that? Well, an LED's brightness varies as the temperature changes: a higher temperature reduces brightness, and lower temperatures increase brightness. 

Pioreactor development log #8

Sep 23, 2021 Posted by: Cameron Davidson-Pilon

The role of stirring in the Pioreactor is important for a few reasons: i) it allows for modest gas exchange between the media and the air, ii) more importantly: it creates a homogenous environment for microbes and nutrients alike. This last point also means that our optical signals won't vary spatially - something that would make the whole system much more complicated. 

Pioreactor development log #7

Sep 13, 2021 Posted by: Cameron Davidson-Pilon

The past few weeks I've been thinking a lot about optics. Too much. It's given me a headache. But we've characterized some really important details about how the Pioreactor works. Let's first talk about how microbial cells interact with light.