A chitinase with antifungal activity from naked oat (Avena chinensis) seeds

Abstract

A chitinase was purified from naked oat (Avena chinensis) seeds using simple chromatographic techniques. Its molecular weight and isoelectric point were determined as 35 kDa and 8.9, respectively. The purified chitinase exhibited specific activity of 3.6 U/mg and 15.6% yield using colloidal chitin as substrate. Partial amino acid sequence analysis and homology search indicated that it probably belonged to Class I plant chitinase, glycosyl hydrolase family 19. With chitin as substrate, the optimum pH and temperature of the chitinase were pH 7.0 and 40°C, respectively. The chitinase was remarkably stable from 30°C up to 50°C, but was inactivated at high temperatures above 85°C. Antifungal activity in vitro tests demonstrated this purified chitinase had potent, dose‐dependent inhibitory activity against the fungi Panus conchatus and Trichoderma reesei. Practical applications Chitinase has broad applications in many fields including the food industry and is recognized as one of the antifungal substances with potential use in plant disease resistance or biological control in agriculture. This study developed cost‐effective purification methods for producing chitinase from naked oat (Avena chinensis) seeds, which may favor large‐scale production of the enzyme. The remarkable stability of the chitinase at moderate temperatures (30°C–50°C), makes it a potentially useful enzyme in bioprocessing to produce chitooligosaccharides for various applications in the food, health, and agriculture sectors.

Agro-Food Byproducts as a New Source of Natural Food Additives

“…Taking this into account, preservatives are widely used in the food industry in order to prevent microbial contaminations, demonstrating a significant impact upon a product’s shelf-life as well as food safety [58,66,67,68]. There are different antimicrobial compounds that can potentially be used as preservatives ranging from enzymes, bacteriocins, fungicides, and salts to essential oils and other components, some of which may be found agro-food byproducts [7,69,70,71,72,73,74,75,76]. The use of natural compounds to replace traditional additives is an emerging trend that has been driven by the consumer’s preferences for “clean labels”, with the scientific community striving to provide natural alternatives, some of which may be attained from agro-food byproducts (e.g., phenolic compounds) [7,44,77].…”

Comprehensive Analysis of the Chitinase Gene Family in Cucumber (Cucumis sativus L.): From Gene Identification and Evolution to Expression in Response to Fusarium oxysporum

“…Plants are devoid of chitin and it has been proposed that plant chitinases may play a role in defense response by degrading the chitin in the cell walls of invading pathogens [4,5,6]. Chitinases isolated from plants were reported to inhibit the growth of chitin-containing fungi, both in vitro [6,7] and in vivo [8,9], and over-expressed chitinases in plants confer resistance against several fungal pathogens [10,11,12,13,14]. Chitinases contains catalytic domains defining the two major GH families (GH18 and GH19) and are classified into seven classes (Class I–VII) [15,16].…”

Transcriptome Analysis Identified Core Genes Involved in Maize Resistance to Rhizoctonia Solani

“…PR8 genes encode chitinases that have well-understood antifungal activity due to their hydrolytic action [73,74]. Plant chitinases are widely distributed and structurally heterogeneous enzymes, and they mainly function in plant-fungus interaction.…”