Encapsulation of Plant Biocontrol Bacteria with Alginate as a Main Polymer Material

Abstract

One of the most favored trends in modern agriculture is biological control. However, many reports show that survival of biocontrol bacteria is poor in host plants. Providing biocontrol agents with protection by encapsulation within external coatings has therefore become a popular idea. Various techniques, including extrusion, spray drying, and emulsion, have been introduced for encapsulation of biocontrol bacteria. One commonly used biopolymer for this type of microencapsulation is alginate, a biopolymer extracted from seaweed. Recent progress has resulted in the production of alginate-based microcapsules that meet key bacterial encapsulation requirements, including biocompatibility, biodegradability, and support of long-term survival and function. However, more studies are needed regarding the effect of encapsulation on protective bacteria and their targeted release in organic crop production systems. Most importantly, the efficacy of alginate use for the encapsulation of biocontrol bacteria in pest and disease management requires further verification. Achieving a new formulation based on biodegradable polymers can have significant effects on increasing the quantity and quality of agricultural products.

Salinity Stress: Toward Sustainable Plant Strategies and Using Plant Growth-Promoting Rhizobacteria Encapsulation for Reducing It

“…In addition, the activity of photosystem II is inhibited during salinity stress, which leads to a reduction in photosynthetic efficiency [21]. Plants under salt stress show some morphological changes, including leaf thickening and succulence, decreased internode lengths, necrosis of organs or entire plants, wilting, and drying [22].…”

Reducing Drought Stress in Plants by Encapsulating Plant Growth-Promoting Bacteria with Polysaccharides

“…Drought is a concern that adversely affects crop yield, but it also affects the survival of beneficial microbes. Agriculturally beneficial soil microorganisms have, therefore, been encapsulated inside polymer coatings for protection against adverse environmental conditions [ 16 , 17 ] to improve their effectiveness in promoting plant growth under drought stress. Achieving a suitable formulation by encapsulation is a novel technology for bacterial agents, resulting in the gradual release of encapsulated bacteria into the soil, increasing the survival of bacterial agents, and thus improving their activity to reduce drought stress in plants.…”

Novel Approaches for Encapsulation of Plant Probiotic Bacteria with Sustainable Polymer Gums: Application in the Management of Pests and Diseases

“…Another ingredient used in the coating of capsules is starch from potatoes, wheat, rice, corn, and its derivatives. Alginate is another available and 3 Advances in Polymer Technology inexpensive compound used in tablets that are extracted from brown algae and can produce stable gels by reacting with calcium ions [25][26][27]. Protein-containing compounds and substances such as soy protein, polypeptide, gelatin derivatives, and milk derivatives can form stable emulsions with volatile flavors and high water solubility [28].…”