Mashed up purple marine bacteria makes an excellent eco-friendly fertilizer

New research published in npj Sustainable Agriculture reports that biomass made from the purple photosynthetic marine bacterium Rhodovulum sulfidophilum is an excellent nitrogen fertilizer.

Led by Keiji Numata from the RIKEN Center for Sustainable Resource Science (CSRS) and Kyoto University, the study shows that this biomass is as effective as common inorganic synthetic fertilizers but avoids several side effects that harm the environment.

The Biomacromolecules Research Team at RIKEN CSRS has been searching for a natural source of nitrogen that can replace ammonia-based synthetic fertilizers and help prevent a future crisis.

Purple non-sulfur bacteria (PNSBs) are known to have enzymes that help them take nitrogen from the atmosphere and incorporate it into proteins, but until now, no one has tested their effectiveness as fertilizers.

To create a PNSB fertilizer for the new study, the team mashed up the PNSB R. sulfidophilum and generated dried biomass from the released cellular material. Analysis showed that the nitrogen content of the PNSB fertilizer was 11% by weight, which is much higher than what is found in other organic fertilizers, including biomass made from other microbes or microalgae.

Image source: Morey-Yagu et al. (2024), npj Sustainable Agriculture.