Chitosan: Properties and Its Application in Agriculture in Context of Molecular Weight

Abstract

Chitosan is a naturally occurring compound that can be obtained from deacetylated chitin, which is obtained from various sources such as fungi, crustaceans, and insects. Commercially, chitosan is produced from crustaceans. Based on the range of its molecular weight, chitosan can be classified into three different types, namely, high molecular weight chitosan (HMWC, >700 kDa), medium molecular weight chitosan (MMWC, 150–700 kDa), and low molecular weight chitosan (LMWC, less than 150 kDa). Chitosan shows several properties that can be applied in horticultural crops, such as plant root growth enhancer, antimicrobial, antifungal, and antiviral activities. Nevertheless, these properties depend on its molecular weight (MW) and acetylation degree (DD). Therefore, this article seeks to extensively review the properties of chitosan applied in the agricultural sector, classifying them in relation to chitosan’s MW, and its use as a material for sustainable agriculture.

Urea Coated with Polyaspartic Acid-Chitosan Increases Foxtail Millet (Setaria italica L. Beauv.) Grain Yield by Improving Nitrogen Metabolism

“…Recent research has indicated that PASP combined with urea could increase nitrogen accumulation in the upper part of sorghum, and improve nitrogen use efficiency and grain yield [8]; increase NR activity and promote nitrogen assimilation in maize seedlings [35]; and increase the activities of enzymes of nitrogen metabolism and the content of soluble protein in functional leaves of rice [21]. CTS, the other component of PAC, also has good adsorption and sustained-release effects, which can accelerate life activities of microorganisms in soil, promote soil respiration, improve nutrient availability [9], and the fertilizer absorption efficiency of plants [16]. Also, CTS can increase grain nitrogen accumulation and improve grain quality [36].…”

“…Because of the advantages above, PASP has been widely applied in agriculture as the absorption promoter of fertilizers, a controlled-release agent, and so on [7,8]. CTS is a derivative of chitin and is considered the second most common polymer in the world after cellulose [9]. CTS has generated great attention in a range of fields due to its exceptional biological activities, such as biodegradability [10], biocompatibility [11], non-toxicity [12], and antimicrobial activity [13].…”

Simultaneous Optimization of Deacetylation Degree and Molar Mass of Chitosan from Shrimp Waste

“…In the literature, there are a lot of studies related to the relationship between MM and DD of chitosan and its applications. Thus, the study by Román-Doval et al [ 11 ] showed the connection between different types of chitosan of different molar mass and its antifungal, antiviral, and antibacterial properties with applications in agriculture. The corresponding mechanism of different types of chitosan depends on both MM and DD.…”

“…The corresponding mechanism of different types of chitosan depends on both MM and DD. Low-molar-mass chitosan, via amino groups, can react much more easily with negatively charged bacterial cell membranes than high-molar-mass chitosan [ 11 ]. Joseph et al [ 6 ] reviewed, among other things, the properties and applications of chitosan depending on its molar mass and its degree of deacetylation.…”

Impact of Molar Composition on the Functional Properties of Glutinous Rice Starch–Chitosan Blend: Natural-Based Active Coating for Extending Mango Shelf Life

“…Yan et al [16] elucidated that the -NH 3 + group of deacetylated chitosan interacts electrostatically with the phosphoryl groups of microbial cell membranes, resulting in cell leakage. Chitosan also exhibits anti-fungal properties by directly impeding fungal growth and activating specific biological processes in plant tissue [17]. Its ability to inhibit gas exchange between fruits and their surroundings, thereby reducing respiration rates, positions chitosan as a compelling option for extending the post-harvest longevity of diverse produce, such as berry fruit [18], fresh fig [19], and mango [20].…”