Nanoengineered Azotobacter <i>Pseudomonas stutzeri</i> A1501 for Soil Ecology Restoration and Biological Nitrogen Fixation

Biological nitrogen fixation (BNF) facilitated by nitrogen-fixing bacteria (NFBac) offers a sustainable alternative to conventional nitrogen fertilizers. However, acidic soil conditions, characterized by reduced pH levels, nutrient deficiencies, and disrupted microbiomes, present a significant challenge to the effectiveness of NFBac. This study proposes a nanoengineering approach to bolster the resilience and functionality of NFBac in acidic soils. Azotobacter <i>Pseudomonas stutzeri</i> A1501 cells are sequentially coated with a pH-responsive copolymer L100-55 and calcium phosphate nanoparticles (CaP NPs), resulting in the development of a robust biofertilizer (A1501@L@CaP). This biofertilizer can effectively buffer acidic pH levels, release nutrients, promote nutrient cycling, enhance soil enzymatic activity, and modulate soil microbiomes, rendering substantial enhancements in soil ecology and plant growth. The engineered NFBac offer a viable strategy for integrating BNF into acidic soils in a sustainable manner.