Purification, Characterization, and Hydrolysate Analysis of Dextranase From Arthrobacter oxydans G6-4B

Abstract

Dextran has aroused increasingly more attention as the primary pollutant in sucrose production and storage. Although enzymatic hydrolysis is more efficient and environmentally friendly than physical methods, the utilization of dextranase in the sugar industry is restricted by the mismatch of reaction conditions and heterogeneity of hydrolysis products. In this research, a dextranase from Arthrobacter oxydans G6-4B was purified and characterized. Through anion exchange chromatography, dextranase was successfully purified up to 32.25-fold with a specific activity of 288.62 U/mg protein and a Mw of 71.12 kDa. The optimum reaction conditions were 55°C and pH 7.5, and it remained relatively stable in the range of pH 7.0–9.0 and below 60°C, while significantly inhibited by metal ions, such as Ni+, Cu2+, Zn2+, Fe3+, and Co2+. Noteworthily, a distinction of previous studies was that the hydrolysates of dextran were basically isomalto-triose (more than 73%) without glucose, and the type of hydrolysates tended to be relatively stable in 30 min; dextranase activity showed a great influence on hydrolysate. In conclusion, given the superior thermal stability and simplicity of hydrolysates, the dextranase in this study presented great potential in the sugar industry to remove dextran and obtain isomalto-triose.

Marine Bacterial Dextranases: Fundamentals and Applications

“…The optimal reaction conditions were 55 °C and pH 7.5, and it remained relatively stable in the pH range of 7.0–9.0 and below 60 °C, while being significantly inhibited by metal ions such as Ni + , Cu 2+ , Zn 2+ , Fe 3+ , and Co 2+ . Notably, unlike in previous studies, the dextran hydrolysates were mostly isomaltoiose (more than 73%), with no glucose, and the hydrolysates were relatively stable after 30 min; dextranase activity had a large effect on the hydrolyzate [ 86 ].…”

“…Ethanol precipitation and ammonium sulfate precipitation were used to remove polysaccharides and proteins [ 34 ]. A study [ 86 ] purified and characterized dextranase from Arthrobacter oxydans G6-4B. In addition, using anion exchange chromatography, dextranase was successfully purified by 32.25 times with a specific activity of 288.62 U/mg of protein and a molecular weight of 71.12 kDa.…”

Purification and characterization of cold-adapted and salt-tolerant dextranase from Cellulosimicrobium sp. THN1 and its potential application for treatment of dental plaque

“…Then the dextranase was purified by HiTrap Q Sepharose FastFlow on AKTA Pure Chromatography system (GE Healthcare, Uppsala, Sweden). The detailed operation referred to Liu et al (2022). The fractions possessing high dextranase activity were gathered and analyzed by SDS-PAGE (8%).…”

“…Numerous isomaltooligosaccharides were produced by endodextranases and possessed broad applications in the food industry as dietary fibers and prebiotics (Sorndech, 2018). Intriguingly, the effective oligosaccharides with DPs 2-10 foreboded more applications and enormous business benefits in the food and health products (Seo et al, 2007;Liu et al, 2022).…”

Study of key amino acid residues of GH66 dextranase for producing high-degree polymerized isomaltooligosaccharides and improving of thermostability

“…Compared with chemical catalysts, biocatalysts are more efficient and stable, can perform the catalytic task better, and reduce plant costs, and are also greener, so dextranase with higher enzyme activity and better stability has an invaluable role in industry, food and pharmaceutical industries ( Espina et al, 2021 ). Also, having good thermal stability is the basis for the enzyme to be stable in the sugar industry and other industries ( Liu et al, 2021 ). In general, dextranases with higher enzyme activity and stability are invaluable for different industries, including food and pharmaceutical industries.…”