JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2022
·Vol. 102
·期 11
·4522-4531
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IF 4.125
Fen Yan,Junying Chen,Ting Cai,Jinfu Zhong,Shaolong Zhang
BACKGROUND Alginate oligosaccharides (AOS), with various physiological effects, have been widely used in the food, agricultural, and pharmaceutical industries. The biological enzymatic method of preparing AOS, using alginate lyase, has more advantages compared with physical and chemical methods. Cloning and heterologously expressing alginate lyase are therefore very important. RESULTS A novel alginate lyase, BY17PV7, from Microbulbifer sp. BY17, isolated from Gracilaria , was cloned and expressed in Escherichia coli BL21(DE3). BY17PV7 was about 27 KDa. BY17PV7 showed the greatest activity (150.42 ± 3.32 U/mg) at 43 °C and pH 8.9. It could be activated by Ca 2+ , Mn 2+ , Co 2+ , Fe 3+ , Na + , and inhibited by Mg 2+ , Zn 2+ , Ba 2+ , Cu 2+ , sodium dodecyl sulfate (SDS), ethylene diamine tetraacetic acid (EDTA). BY17PV7 had a wide range of substrate specificity and good degradation effects for poly β-D-mannuronate (polyM) and poly α-L-guluronate (polyG), demonstrating that it is a bifunctional alginate lyase. The kinetic parameters showed that BY17PV7 had a greater affinity for polyG. BY17PV7 released AOS with a degree of polymerization (DP) of 3–4 in an endolytic manner from sodium alginate. Alginate oligosaccharides showed strong antioxidant ability of reducing Fe 3+ and scavenging radicals such as hydroxyl, 2,2-azion-bia (3-ethylbenzo-thiazoline-6-sulfonic acid diammonium salt) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). CONCLUSION A novel bifunctional alginate lyase, BY17PV7, was expressed and characterized in Escherichia coli BL21(DE3). The results were helpful for the analysis of the molecular mechanisms of degrading patterns in the polysaccharide lyase (PL) family. © 2022 Society of Chemical Industry.
研究领域:
生物化学
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酶学
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食品科学
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药剂学
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DOI
PubMed
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 21
·3915
·
IF 3.06
Yue Yang,Zhou Zheng,Yifei Xiao,Jiaojiao Zhang,Yu Zhou,Xiao Li,Shangyong Li,Huiqing Yu
Chitosanase plays an important role in the production of chitooligosaccharides (CHOS), which possess various biological activities. Herein, a glycoside hydrolase (GH) family 46 chitosanase-encoding gene,csnB, was cloned from marine bacteriumBacillussp. BY01 and heterologously expressed inEscherichia coli. The recombinant chitosanase, CsnB, was optimally active at 35 °C and pH 5.0. It was also revealed to be a cold-adapted enzyme, maintaining 39.5% and 40.4% of its maximum activity at 0 and 10 °C, respectively. Meanwhile, CsnB showed wide pH-stability within the range of pH 3.0 to 7.0. Then, an improved reaction condition was built to enhance its thermostability with a final glycerol volume concentration of 20%. Moreover, CsnB was determined to be an endo-type chitosanase, yielding chitosan disaccharides and trisaccharides as the main products. Overall, CsnB provides a new choice for enzymatic CHOS production.Keywords:chitosanase;Bacillussp. BY01;cold-adaption
研究领域:
酶学
·
海洋生物学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2022
·
IF 10.723
Fangfang Zhao,Yang Li,Caiming Li,Xiaofeng Ban,Zhengbiao Gu,Zhaofeng Li
Starch is crucial to gluten-free bread (GFB) quality. Amylolytic enzymes modified starch in situ during breadmaking , impacting the quality of both fresh and stored bread. Here, the breadmaking and storage properties of GFB with added endo-amylases, exo-amylases and debranching enzymes were compared. The results demonstrated that the addition of amylolytic enzymes, especially exo-amylases and debranching enzymes, facilitated interactions between the enzymatically modified starch segments and structural agents to improve the structure and texture of fresh GFB. Exo-type β-amylase produced lower crumb firming rate than endo-type α-amylase, although they produced similar retrogradation enthalpies and relative crystallinities . Maltooligosaccharide-forming enzymes with a non-strict endo-/exo-mode of cleavage and debranching enzymes markedly reduced the crumb firming rate and retrogradation enthalpy. Yet, maltooligosaccharide-forming enzymes produced a similar relative crystallinity as α-amylase, indicating that enzymes with endo-/exo-modes depended less on the reduction of starch recrystallization to retard crumb firming compared with debranching enzymes.
研究领域:
食品科学
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烘焙技术
·
酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）