Extraction, characterization, and nematicidal activity of chitin and chitosan derived from shrimp shell wastes

Abstract

Chitin has been chemically extracted from the Egyptian shrimp shell waste. The obtained chitin was transformed into the more soluble chitosan. Chitin and chitosan were characterized using Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectrometry. These products were also characterized by their nematicidal potential against the root-knot nematode, Meloidogyne incognita, infecting tomato in a glasshouse. Chitin or chitosan was incorporated into the soil at the rate of 1, 3, 5, and 10 g/kg, and their nematicidal activity was compared with that of the synthetic nematicide oxamyl at the rate of 0.01 g a.i./kg. The effects of the treatments on the growth of tomato were also examined. The obtained results show that chitin and chitosan reduced tomato root galls and J 2 of M. incognita in the soil in a dose-dependent manner. Chitosan was more effective in the reduction of galls and J 2 in the soil than chitin. However, the efficacy of chitin and chitosan in reducing the number of J 2 in the soil was less than that of oxamyl. As compared to the untreated inoculated plants, the length of shoots and roots was significantly (p≤0.05) increased in soil amended with either chitin or chitosan, whereas both treatments did not significantly (p>0.05) differ with respect to the inoculated control on the effect on the dry weight of shoot and root systems. Furthermore, neither chitin nor chitosan treatments at the tested rates were phytotoxic to tomato plants.

Chitin Amendment Increases Soil Suppressiveness toward Plant Pathogens and Modulates the Actinobacterial and Oxalobacteraceal Communities in an Experimental Agricultural Field

“…There is still unexplored potential to raise the suppressiveness of soils toward plant pathogens by adding biopolymers such as chitin (4,39,40). Previous work already indicated that amendments of soil with chitin modify the soil's chemistry and structure and, importantly, the structures of the microbial communities that occur in association with plants (2, 3).…”

“…In this context, it has long been suspected that suppressiveness can be enhanced by adding biopolymers such as chitin and derivatives. For instance, soil treatment with chitin and/or chitosan from shrimp waste has been shown to temporarily increase root growth (e.g., of tomato) and decrease the rate of infection of plant roots by nematodes (2)(3)(4). Although not definitely proven in all cases, the mechanisms behind this suppressiveness enhancement most often relate to a change in the structure and/or activity of the microbiota in soil, which thus confers suppression of plant pathogens (1,5).…”

Development of shrimp shells-based compost and plant-based pesticide using bio-activators from Golden Apple Snails and their effects on the kenaf plant growth and pest population

“…The low N level could also be due to the chitin and CaCO 3 content of the shrimp shells. Shrimp shells consisted of protein (25%-40%), chitin ( (C 8 H 13 NO 5 ) n ) (15%-20%), and calcium carbonate (CaCO 3 ) (45%-50%) (Kandra et al 2012 ;Radwan et al 2012;Paul et al 2015). Chitin can be further processed into chitosan ( (C 6 H 11 NO 4 )n) and glucosamine (C 6 H 13 NO 5 ).…”

Potential of chitosan alone and in combination with agricultural wastes against the root-knot nematode, Meloidogyne incognita infesting eggplant

“…It is made from the outer shell of crustaceans and cell walls of certain fungi. It has been reported that chitosan displayed elicitor activity by inducing local and systemic resistance mechanisms of tomato plants against the root-knot nematode, M. in cognita (Radwan et al 2012). Several studies have shown that chitosan can induce plant resistance to several pathogens by restricting pathogen growth and/or by eliciting several defense mechanisms (Rabea et al 2003).…”