Integrating Microbial Ecology and Sustainability: Linking Agricultural Waste Gas Streams to Microbial Community Shifts in a Photobioreactor

Photobioreactors (PBRs) connected to farms can help reduce harmful gases like CO2 and NH3 while creating useful biomass. In this study, researchers observed how microbial communities in a PBR changed over time, with a focus on their ability to handle carbon and nitrogen. The PBR used Spirulina, a type of algae, and was fed with air from a chicken house.

As air passed through the PBR, the microbial makeup and genes linked to carbon and nitrogen processing varied. Tests of dissolved inorganic nitrogen showed that the amount in the water didn't fully return to normal levels in the harvested Spirulina. Microorganisms that convert ammonia to other compounds were found near dark areas with little light.

These findings suggest the potential for ammonia-oxidizing activity, but not enough to support significant nitrification. Special structures called carriers helped create places where microbes could live, especially those that were less common in the main water flow. Reusing these carriers made it easier to grow Spirulina again.

Overall, using PBRs with farm exhaust gases can help grow biomass while keeping different types of microbes in specific areas. This could be useful for reducing emissions and creating a cycle of biomass production.