Efficient Preparation of Chitooligosaccharide With a Potential Chitosanase Csn-SH and Its Application for Fungi Disease Protection

• Published in: Frontiers in microbiology Vol. 12; p. 682829
• Main Authors: Cui, Dandan, Yang, Jin, Lu, Bosi, Shen, Hong
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 17.06.2021
• Subjects: antifungal activity; Bacillus atrophaeus; chitooligosaccharide; chitosanase; hydrolysis rate; Microbiology
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2021.682829

Chitosanase plays a vital role in bioactive chitooligosaccharide preparation. Here, we characterized and prepared a potential GH46 family chitosanase from Bacillus atrophaeus BSS. The purified recombinant enzyme Csn-SH showed a molecular weight of 27.0 kDa. Csn-SH displayed maximal activity toward chitosan at pH 5.0 and 45°C. Thin-layer chromatography and electrospray ionization–mass spectrometry indicated that Csn-SH mainly hydrolyzed chitosan into (GlcN) 2 , (GlcN) 3 , and (GlcN) 4 with an endo-type cleavage pattern. Molecular docking analysis demonstrated that Csn-SH cleaved the glycoside bonds between subsites −2 and + 1 of (GlcN) 6 . Importantly, the chitosan hydrolysis rate of Csn-SH reached 80.57% within 40 min, which could reduce time and water consumption. The hydrolysates prepared with Csn-SH exhibited a good antifungal activity against Magnaporthe oryzae and Colletotrichum higginsianum . The above results suggested that Csn-SH could be used to produce active chitooligosaccharides efficiently that are biocontrol agents applicable for safe and sustainable agricultural production.