The Optimization of High-Protein Duckweed Cultivation in Eutrophicated Water with Mutualistic Bacteria

Abstract

SUMMARYThe exponential increase in the human population is the leading cause of a global food crisis and the rise of humanity’s carbon footprint level. One such approach to resolve these issues is the cultivation of duckweed (Wolffia globosa) for consumption in the Northern and Northeastern provinces of Thailand. In particular, duckweed has drawn increasing attention due to its rapid growth rate, adaptability to extreme conditions, and potential as a protein alternative; however, their properties can be greatly enhanced. Our research investigates two optimizations for the cultivation of duckweeds: in the medium’s nitrogen-phosphorus concentration and the use of plant growth-promoting bacteria (PGPB). We hypothesized that using phosphorus-rich water and PGPB would significantly increase duckweed biomass production, while nitrogen-rich water would increase protein content. This was based on evidence from past research showing that aquatic plants have high nitrogen and phosphorus uptake and that PGPB can support the growth of plants by nitrogen fixation. We found that the phosphorus-rich group boosted biomass greatly, while the nitrogen-rich group significantly enhanced their protein value. Furthermore, PGPB yielded the highest increase in biomass, but had an insignificant impact on protein. Based on our results, we recommend the use of nitrogen and phosphorus-rich water and PGPB to optimize duckweed cultivation, addressing the global food crisis and environmental impact.