نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد گروه علوم خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان ایران
2 دانشیار ، گروه علوم خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان ایران
3 استاد، گروه علوم و مهندسی صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives:
The rapid growth of the global population and increasing demand for agricultural production, coupled with the degradation of soil quality and water resources, have created significant challenges in sustainable agriculture. Therefore, the application of plant growth-promoting bacteria (PGPB) has been considered as a supplement to chemical fertilizers and to reduce their consumption. These bacteria play crucial roles in enhancing plant growth, improving soil fertility, and mitigating environmental stresses. However, their survival under field conditions is often compromised by unfavorable environmental factors such as drought, salinity. This study aimed to evaluate the effectiveness of a bioformulation composed of sodium alginate, bentonite, starch, and nanosilica on capsule stability, viability of encapsulated PGPB and the controlled release of bacterium into the environment.
Materials and Methods:
To conduct this study, a bacterial suspension was first prepared using a nutrient broth medium. Capsules were then produced using the droplet method in a 2% calcium chloride solution using formulations containing sodium alginate, bentonite, starch, and nanosilica. Various physical and biological parameters were assessed, including capsule diameter, expansion rate, loading efficiency, bacterial viability, biodegradability, bacterial release rate, and survival rate of the bacterial cells.
Findings:
The results indicated that incorporating bentonite into the formulation enhanced the mechanical strength of the capsules and reduced their biodegradation rate. Capsules containing both bentonite and starch exhibited less diameter reduction after the drying process than those without these components, indicating greater structural stability. The expansion rate was higher in capsules containing bentonite, suggesting improved water absorption and the formation of a more stable gel matrix. The bacterial cell counts within the capsules were influenced by the formulation type. While higher initial viability was observed in formulations without bentonite (CK and A), a significant decline in the bacterial population was recorded over 90 days. In contrast, formulations containing bentonite and starch demonstrated a slower and more controlled bacterial release and maintained higher viable bacterial populations after 90 days than formulations without these additives and the non-encapsulated control (free cells).
Conclusion:
This study demonstrated that the use of a sodium alginate–bentonite–starch–nanosilica formulation is an effective strategy for enhancing the viability and persistence of plant growth-promoting bacteria under laboratory conditions. Bentonite contributed to improved mechanical strength, reduced biodegradability, and better-controlled bacterial release, while starch served as a protective agent enhancing bacterial survival. Therefore, this technology holds promise in the future as a suitable supplement to chemical fertilizers in agriculture, and play an important role in improving soil fertility and promoting plant growth.
کلیدواژهها [English]
Shabaan, M., Asghar, H. N., Zahir, Z. A., Zhang, X., Sardar, M. F., & Li, H. (2022). Salt-tolerant PGPR confer salt tolerance to maize through enhanced soil biological health, enzymatic activities, nutrient uptake and antioxidant defense.
9.Simó, G., Fernández‐Fernández, E., Vila‐Crespo, J., Ruipérez, V., & Rodríguez‐Nogales, J. M. (2017). Research progress in coating techniques of alginate gel polymer for cell encapsulation. Carbohydrate Polymers, 170, 1–14. doi.org/10.1016/j.carbpol.2017.04.013
23.Wu, Z., Guo, L., Qin, S., & Li, C. (2012). Encapsulation of R. planticola Rs-2 from alginate-starch-bentonite and its controlled release and swelling behavior under simulated soil conditions. Journal of Industrial Microbiology and Biotechnology, 39(2), 317–327. doi.org/10.1007/s10295-011-1028-2