Production of a Thermostable Chitosanase from Shrimp Heads via Paenibacillus mucilaginosus TKU032 Conversion and its Application in the Preparation of Bioactive Chitosan Oligosaccharides.

Chien Thang Doan,Anh Dzung Nguyen,Thi Ngoc Tran,Van Bon Nguyen,San-Lang Wang

doi:10.3390/md17040217

Chien Thang Doan, Anh Dzung Nguyen + Show 3 more

Open Access

https://doi.org/10.3390/md17040217

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Journal: Marine Drugs	Publication Date: Apr 10, 2019
Citations: 32	License type: CC BY 4.0

Affiliation: Tamkang University, Thai Nguyen University

Abstract

Chitosanase has attracted great attention due to its potential applications in medicine, agriculture, and nutraceuticals. In this study, P. mucilaginosus TKU032, a bacterial strain isolated from Taiwanese soil, exhibited the highest chitosanase activity (0.53 U/mL) on medium containing shrimp heads as the sole carbon and nitrogen (C/N) source. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, a chitosanase isolated from P. mucilaginosus TKU032 cultured on shrimp head medium was determined at approximately 59 kDa. The characterized chitosanase showed interesting properties with optimal temperature and thermal stability up to 70 °C. Three chitosan oligosaccharide (COS) fractions were isolated from hydrolyzed colloidal chitosan that was catalyzed by TKU032 chitosanase. Of these, fraction I showed the highest α-glucosidase inhibitor (aGI) activity (65.86% at 20 mg/mL); its inhibitory mechanism followed the mixed noncompetitive inhibition model. Fractions II and III exhibited strong 2,2-diphenyl1-picrylhydrazyl (DPPH) radical scavenging activity (79.00% at 12 mg/mL and 73.29% at 16 mg/mL, respectively). In summary, the COS fractions obtained by hydrolyzing colloidal chitosan with TKU032 chitosanase may have potential use in medical or nutraceutical fields due to their aGI and antioxidant activities.

Highlights

Chitosan is a polymer composed of β-1,4 linked D-glucosamine with varying amounts of N-acetyl-D-glucosamine [1]
The reason might be related to the difference in protein/chitin/mineral salts ratio of each chitinous material, in which shrimp heads powder (SHP) contents had higher amounts of protein and mineral salts but lower amount of chitin than those of the other materials [36,39]
In the search to find a suitable and cost effective source for producing bioactive compounds via microorganism conversion, shrimp heads, a by-product from shrimp processing, were suggested as potential material as they have been reported as the best sole carbon and nitrogen (C/N) source for producing chitosanase (B. cereus TKU027) [14], aGI

Summary

Introduction

Chitosan is a polymer composed of β-1,4 linked D-glucosamine with varying amounts 50%) of N-acetyl-D-glucosamine [1]. Chitosan is of interest to many researchers as it exhibits various biological activities and has many biotechnological uses [2,3,4]. Chitosan has poor solubility at neutral pH, potentially limiting its application. COS demonstrate antidiabetic [6,7], prebiotic [8,9], antioxidant [5,8], anti-inflammatory [5,10], anticancer [10], antitumor [11], and antibacterial biological activities [12,13].

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