16907-86-1Relevant articles and documents
Characterization of Two New Endo-β-1,4-xylanases from Eupenicillium parvum 4–14 and Their Applications for Production of Feruloylated Oligosaccharides
Long, Liangkun,Xu, Meijuan,Shi, Yuexin,Lin, Qunying,Wang, Jing,Ding, Shaojun
, p. 816 - 833 (2018/05/15)
Two new endo-1,4-beta-xylanases encoding genes EpXyn1 and EpXyn3 were isolated from mesophilic fungus Eupenicillium parvum 4–14. Based on analysis of catalytic domain and phylogenetic trees, the xylanases EpXYN1 (404 aa) and EpXYN3 (220 aa) belong to glycoside hydrolase (GH) family 10 and 11, respectively. Both EpXYN1 and EpXYN3 were successfully expressed in Pichia pastoris and the recombinant enzymes were characterized using beechwood xylan, birchwood xylan, or oat spelt xylan as substrates, respectively. The optimum temperatures and pH values were 75?°C and 5.5 for EpXYN1, and 55?°C and 5.0 for EpXYN3. EpXYN1 exhibited a high stability at high temperature (65?°C) or at pH values from 8 to 10. EpXYN3 kept over 80% enzymatic activity after treatment at pH values from 3 to 10. The specific activities of EpXYN1 and EpXYN3 were 384.42 and 214.20?U/mg?using beechwood xylan as substrate, respectively. EpXYN1 showed lower Km values and higher specific activities toward different xylans compared to EpXYN3. Thin-layer chromatography analysis indicated that the hydrolysis profiles of xylans or xylo-oligosacharides were different by EpXYN1and EpXYN3. EpXYN3 had a higher efficiency than EpXYN1 in production of feruloylated oligosaccharides (FOs) from de-starched wheat bran. The maximum levels of FOs released by EpXYN1 and EpXYN3 were 11.1 and 14.4?μmol/g, respectively. In conclusion, the two xylanases are potential candidates for various industrial applications.
Characterization of a thermostable, specific GH10 xylanase from Caldicellulosiruptor bescii with high catalytic activity
An, Jiao,Xie, Yuan,Zhang, Yong,Tian, Dongsheng,Wang, Shuhao,Yang, Guangyu,Feng, Yan
, p. 13 - 20 (2015/05/13)
Xylanase (EC 3.2.1.8) is one of the most important enzymes for the biodegradation of xylan. Since many industrial processes utilizing xylanase are operated at elevated temperatures, thermostable xylanases are highly desirable. In the present study, xyn10B gene from thermophilic bacterium Caldicellulosiruptor bescii that encodes a glycoside hydrolase (GH) family 10 xylanase was overexpressed in Escherichia coli and systematically characterized. CbXyn10B exhibited optimal activity at pH 7.2 and 70 °C. It had a half-life of about 7.7 h at 60 °C, and retained over 85% of maximal activity after incubation at pH 4.0-12.0. The activity of this xylanase was not affected by most divalent cations, but inhibited by Fe3+ and Zn2+. CbXyn10B exhibited high activity on beech wood xylan, oat spelt xylan, and birch wood xylan, with specific activities of about 450 U mg-1. Compared with other GH10 xylanases, CbXyn10B was highly specific for xylan and showed low catalytic efficiency toward sodium carboxymethyl cellulose and p-nitrophenyl-β-d-xylopyranoside. HPLC analysis of the products released from xylo-oligosaccharides and xylan revealed that xylobiose was the predominant hydrolytic product. The action mode of the enzyme was studied by product analysis, homology modeling and molecular docking to gain an insight into the structural basis for its substrate recognition mechanism.
Two family 11 xylanases from Achaetomium sp. Xz-8 with high catalytic efficiency and application potentials in the brewing industry
Zhao, Liang,Meng, Kun,Bai, Yingguo,Shi, Pengjun,Huang, Huoqing,Luo, Huiying,Wang, Yaru,Yang, Peilong,Song, Wei,Yao, Bin
, p. 6880 - 6889 (2013/08/23)
This study identified two family-11 xylanase genes (xynC81 and xynC83) in Achaetomium sp. Xz-8, a thermophilic strain from a desert area with substantial xylanase activity, and successfully expressed them in Pichia pastoris. Their deduced amino acid sequences showed the highest identity of ≤90% to known fungal xylanases and of ≤62% with each other. The purified recombinant xylanases showed optimal activities at pH 5.5 and 60-65 C and exhibited stability over pH 5.0-10.0 and temperatures at 55 C and below. XynC81 had high catalytic efficiency (6082 mL/s/mg), and XynC83 was favorable for xylooligosaccharide production. Under simulated mashing conditions, combination of XynC83 and a commercial β-glucanase improved the filtration rate by 34.76%, which is much better than that of Novozymes Ultraflo (20.71%). XynC81 and XynC83 had a synergistic effect on viscosity reduction (7.08%), which is comparable with that of Ultraflo (8.47%). Thus, XynC81 and XynC83 represent good candidates for application in the brewing industry.
