Enzymatic preparation and potential applications of agar oligosaccharides: a review

AbstractOligosaccharides derived from agar, that is, agarooligosaccharides and neoagarooligosaccharides, have demonstrated various kinds of bioactivities which have been utilized in a variety of fields. Enzymatic hydrolysis is a feasible approach that principally allows for obtaining specific agar oligosaccharides in a sustainable way at an industrial scale. This review summarizes recent technologies employed to improve the properties of agarase. Additionally, the relationship between the degree of polymerization, bioactivities, and potential applications of agar-derived oligosaccharides for pharmaceutical, food, cosmetic, and agricultural industries are discussed. Engineered agarase exhibited general improvement of enzymatic performance, which is mostly achieved by truncation. Rational and semi-rational design assisted by computational methods present the latest strategy for agarase improvement with greatest potential to satisfy future industrial needs. Agarase immobilized on magnetic Fe3O4 nanoparticles via covalent bond formation showed characteristics well suited for industry. Additionally, albeit with the relationship between the degree of polymerization and versatile bioactivities like anti-oxidants, anti-inflammatory, anti-microbial agents, prebiotics and in skin care of agar-derived oligosaccharides are discussed here, further researches are still needed to unravel the complicated relationship between bioactivity and structure of the different oligosaccharides.Keywords: Agaroligosaccharidesengineered agaroseapplications Author contributionsJie Long: Conceptualization, Investigation, Writing - original draft, Writing - review & editing, Revision. Ziying Ye: Conceptualization, Investigation, Writing - original draft. Xingfei Li: Information curation, Investigation. Yaoqi Tian and Yuxiang Bai: Information curation, Formal analysis. Long Chen and Chao Qiu: Validation, review & editing. Zhengjun Xie: Methodology, review & editing. Zhengyu Jin: Supervision, Resources, Project administration. Birte Svensson: Writing - review & editing.Disclosure statementNo conflicts of interest are declared for any of the authors.Additional informationFundingThis study was supported by the National Natural Science Foundation of China (No. 32072164), National Key Research and Development Program of China (No. 2020YFC1606804), Natural Science Foundation of Jiangsu Province (No. BK20210458), the National key R&D Program of China (2017YFC1601002) and International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China.