Poly-γ-glutamic acid (γ-PGA) is a multifunctional biopolymer with significant potential in agriculture owing to its high water solubility, biodegradability, and environmental compatibility. Studies have shown that γ-PGA fermentation broth can increase the abundance of soil bacteria and fungi, thereby promoting crop growth. Additionally, γ-PGA has been found to enhance drought resistance in plants. Field and laboratory evidence indicates that the application of γ-PGA can improve crop yield and quality, while also enhancing the soil microenvironment. For instance, field experiments conducted in arid regions demonstrated that γ-PGA application significantly increased soil moisture retention, aggregate stability, and nutrient uptake efficiency in crops. These findings underscore the potential of γ-PGA to improve soil structure, boost water and nutrient use efficiency, and support sustainable agricultural practices.
Experimental results indicate that γ-PGA application contributes to increased soil pH, organic matter, and nitrogen content, while reducing soil bulk density. Comprehensive evaluation of soil quality—including parameters such as pH, bulk density, organic matter, and enzyme activity—has been emphasized in assessing the efficacy of soil conditioners. Moreover, recent research suggests that γ-PGA significantly lowers soil bulk density, promotes the formation of macroaggregates, and improves soil aeration and water retention. These enhancements contribute to a healthier soil environment, support robust plant growth, and align with sustainable agricultural development goals.
Drought resistance studies have demonstrated that γ-PGA application can significantly alter the soil microbial community structure and diversity. Key bacterial groups such as Proteobacteria, Actinobacteriota, Acidobacteria, and Chloroflexi are notably enriched following γ-PGA treatment. Among these, Actinobacteriota—including filamentous bacteria like Streptomyces—are known for producing antibiotics and degrading complex organic polymers such as plant biomass. Streptomyces also contributes to environmental benefits by enhancing drought tolerance in plants, assisting in humus decomposition and formation, and even participating in plastic degradation. Other genera within this phylum, including Nocardioides and Lamia, play important roles in nutrient cycling, pathogen suppression, and the production of enzymes and hormones. Although less commonly reported, Lechevalieria has shown potential for synthesizing growth-promoting secondary metabolites.
Proteobacteria, another major group enhanced by γ-PGA, are integral to processes such as nitrogen fixation and the breakdown of polycyclic aromatic hydrocarbons. Within this phylum, Lysobacter is recognized for its biocontrol capabilities through the production of bioactive compounds, while Sphingomonas supports pollutant degradation and nitrogen cycling, thereby improving soil fertility and plant health. Devosia offers additional benefits for bioremediation, leveraging its efficient peptide uptake systems to metabolize diverse organic compounds. Furthermore, Streptomyces and Lechevalieria contribute to
Poly-γ-glutamic acid (γ-PGA) is a multifunctional biopolymer with significant potential in agriculture owing to its high water solubility, biodegradability, and environmental compatibility. Studies have shown that γ-PGA fermentation broth can increase the abundance of soil bacteria and fungi, thereby promoting crop growth. Additionally, γ-PGA has been found to enhance drought resistance in plants. Field and laboratory evidence indicates that the application of γ-PGA can improve crop yield and quality, while also enhancing the soil microenvironment. For instance, field experiments conducted in arid regions demonstrated that γ-PGA application significantly increased soil moisture retention, aggregate stability, and nutrient uptake efficiency in crops. These findings underscore the potential of γ-PGA to improve soil structure, boost water and nutrient use efficiency, and support sustainable agricultural practices.
Experimental results indicate that γ-PGA application contributes to increased soil pH, organic matter, and nitrogen content, while reducing soil bulk density. Comprehensive evaluation of soil quality—including parameters such as pH, bulk density, organic matter, and enzyme activity—has been emphasized in assessing the efficacy of soil conditioners. Moreover, recent research suggests that γ-PGA significantly lowers soil bulk density, promotes the formation of macroaggregates, and improves soil aeration and water retention. These enhancements contribute to a healthier soil environment, support robust plant growth, and align with sustainable agricultural development goals.
Drought resistance studies have demonstrated that γ-PGA application can significantly alter the soil microbial community structure and diversity. Key bacterial groups such as Proteobacteria, Actinobacteriota, Acidobacteria, and Chloroflexi are notably enriched following γ-PGA treatment. Among these, Actinobacteriota—including filamentous bacteria like Streptomyces—are known for producing antibiotics and degrading complex organic polymers such as plant biomass. Streptomyces also contributes to environmental benefits by enhancing drought tolerance in plants, assisting in humus decomposition and formation, and even participating in plastic degradation. Other genera within this phylum, including Nocardioides and Lamia, play important roles in nutrient cycling, pathogen suppression, and the production of enzymes and hormones. Although less commonly reported, Lechevalieria has shown potential for synthesizing growth-promoting secondary metabolites.
Proteobacteria, another major group enhanced by γ-PGA, are integral to processes such as nitrogen fixation and the breakdown of polycyclic aromatic hydrocarbons. Within this phylum, Lysobacter is recognized for its biocontrol capabilities through the production of bioactive compounds, while Sphingomonas supports pollutant degradation and nitrogen cycling, thereby improving soil fertility and plant health. Devosia offers additional benefits for bioremediation, leveraging its efficient peptide uptake systems to metabolize diverse organic compounds. Furthermore, Streptomyces and Lechevalieria contribute to soil aggregation and structural stability through the secretion of viscous organic substances and acids, facilitating improved gas exchange and overall soil quality.
In conclusion, γ-PGA application significantly altered the soil’s metabolic landscape by modulating the types and concentrations of various chemical metabolites. This not only improved the soil’s physical and chemical properties, creating a more favorable environment for plant growth, but also provided essential nutrients for microbial activity. By promoting microbial growth and reproduction, γ-PGA treatment enhances the diversity and functionality of soil microbial communities, further increasing soil fertility and plant resilience to stress.
| Action Level | Specific Effects, Mechanisms of Action | Benefits |
| Soil Physical Properties | Reduce soil bulk density | Improve soil structure, and make it more porous |
| Promote the formation of large aggregates | Enhance soil stability, and improve aeration and water permeability | |
| Improve water retention capacity | Significantly enhance soil moisture retention, especially in arid areas | |
| Improve soil aeration | Promote root respiration and microbial activity | |
| Soil Chemical Properties | Increase soil pH | Improve acidic soils |
| Increase organic matter content | Enhance basic soil fertility | |
| Increase nitrogen content | Increase key soil nutrients | |
| Improve nutrient absorption efficiency | Reduce fertilizer loss and improving fertilizer utilization | |
| Soil Biological Properties | Increase enzyme activity | Enhance soil biochemical reactions and serve as a sensitive indicator of soil health |
| Plant Effects | Promote crop growth | Improve the rhizosphere environment, directly promote root development and nutrient uptake |
| Enhance plant drought resistance | Improve soil moisture conditions and microbial communities | |
| Macro-Benefits | Improve the soil microenvironment | Omprehensively improve soil physical, chemical, and biological properties |
| Improve water and fertilizer use efficiency | Reduce resource inputs and increase outputs | |
| Support sustainable agricultural practices | Environmentally compatible and biodegradable, in line with green development goals. |
PolyGlutamic Acid (γ-PGA)
Dora PolyGlutamic Acid (γ-PGA) is a great fertilizer synergist and a natural, organic, and environment-friendly plant nutritions enhancer.