Frontiers in Bioengineering and Biotechnology
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2021
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IF 5.89
Miao Ting,Basit Abdul,Liu Junquan,Zheng Fengzhen,Rahim Kashif,Lou Huiqiang,Jiang Wei
Xylanases with high specific activity has been focused with great interest as a useful enzyme in biomass utilization. The production of recombinant GH11 xylanase (MYCTH_56237) from Myceliophthora thermophila has been improved through N-terminal signal peptide engineering in P. pastoris. The production of newly recombinant xylanase (termed Mtxyn11C) was improved from 442.53 to 490.7 U/mL, through a replacement of α-factor signal peptide with the native xylanase signal peptide segment (MVSVKAVLLLGAAGTTLA) in P. pastoris. Scaling up of Mtxyn11C production in a 7.5 L fermentor was improved to the maximal production rate of 2503 U/mL. In this study, the degradation efficiency of Mtxyn11C was further examined. Analysis of the hydrolytic mode of action towards the birchwood xylan (BWX) revealed that Mtxyn11C was clearly more effective than commercial xylanase and degrades xylan into xylooligosaccharides (xylobiose, xylotriose, xylotetraose). More importantly, Mtxyn11C in combination with a single multifunctional xylanolytic enzyme, improved the hydrolysis of BWX into single xylose by 40%. Altogether, this study provided strategies for improved production of xylanase together with rapid conversion of xylose from BWX, which provides sustainable, cost-effective and environmental friendly approaches to produce xylose/XOSs for biomass energy or biofuels production.
研究领域:
生物技术
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酶学
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生物化学工程
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Abdul Basit,Ting Miao,Junquan Liu,Jiaqi Wen,Lina Song,Fengzhen Zheng,Huiqiang Lou,Wei Jiang
Here, we report highly efficient degradation of xylan into xylose by a single multifunctional xylanolytic enzyme from the filamentous fungus Thermothelomyces thermophila (termed Ttxy43). Ttxy43 shows three different enzyme activities toward carbohydrates, β-xylosidase (80.8 U/mg), endoxylanase (105.42 U/mg), and α-l-arabinofuranosidase enzyme activities (15.81 U/mg). Analysis of the catalytic mode of action of Ttxy43 for birchwood-xylan (BWX) reveals that endoxylanase initially degrades xylan to unbranched xylooligosaccharides (XOSs) (xylobiose, xylotriose, xylotetraose) as intermediates, which are then quickly hydrolyzed into single xylose by β-xylosidase. Site-directed mutagenesis studies indicate that Ttxy43 residues Asp134 and Glu228 are essential catalytic sites, while Glu176, Asp38, and Asp85 play an accessory role. More importantly, Ttxy43 displays higher degradation efficiency in comparison with a commercial β-xylosidase and endoxylanase “cocktail”. These findings elucidate an efficient integrated degradation mechanism of xylan under industrial reaction conditions, which provides a novel strategy to design techniques for biomass energy production.
研究领域:
生物化学
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生物技术
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酶学
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可再生能源
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DOI
高影响因子
Frontiers in Microbiology
·
2022
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IF 6.064
Zheng Fengzhen,Basit Abdul,Zhuang Huan,Chen Jun,Zhang Jianfen,Chen Weiqing
Acidophilic β-xylanases have attracted considerable attention due to their excellent activity under extreme acidic environments and potential industrial utilizations. In this study, a novel β-xylanase gene (Xyl11) of glycoside hydrolase family 11, was cloned from Trichoderma asperellum ND-1 and efficiently expressed in Pichia pastoris (a 2.0-fold increase). Xyl11 displayed a maximum activity of 121.99 U/ml at pH 3.0 and 50°C, and exhibited strict substrate specificity toward beechwood xylan (Km = 9.06 mg/ml, Vmax = 608.65 μmol/min/mg). The Xyl11 retained over 80% activity at pH 2.0–5.0 after pretreatment at 4°C for 1 h. Analysis of the hydrolytic pattern revealed that Xyl11 could rapidly convert xylan to xylobiose via hydrolysis activity as well as transglycosylation. Moreover, the results of site-directed mutagenesis suggested that the Xyl11 residues, Glu127, Glu164, and Glu216, are essential catalytic sites, with Asp138 having an auxiliary function. Additionally, a high degree of synergy (15.02) was observed when Xyl11 was used in association with commercial β-xylosidase. This study provided a novel acidophilic β-xylanase that exhibits excellent characteristics and can, therefore, be considered a suitable candidate for extensive applications, especially in food and animal feed industries.
研究领域:
酶学
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生物技术
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微生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
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IF 8.025
Huifang Wang,Tianren Xue,Shuo Wang,Xiaoli Jia,Shenghui Cao,Baolong Niu,Ruijie Guo,Hong Yan
Xylan could be considered as a good potential candidate for food packaging film because of the vast source and biodegradability , however, its application was restricted by the drawbacks of poor film-forming property, humidity sensitivity, weak mechanical strength and poor antibacterial property . In this paper, xylan was firstly modified by quaternization to improve the film-forming property, then ZnO nanoparticles encapsulated by xylan (nano ZnO@Xylan) was prepared by nanoprecipitation method, finally a series of biodegradable composite films were prepared using quaternized xylan and polyvinyl alcohol with incorporation of nano ZnO@Xylan. The surface morphology, molecular structure and crystallography structure of the films were characterized. The addition of nano ZnO@Xylan decreased water vapor permeability and solubility, meanwhile obviously increased the ultraviolet shielding performance as well as the antibacterial properties of the films. The bacteriostasis rate of the films against E. coli and S. aureus reached up to 99 %. Furthermore, the preservation time of cherry tomatoes covered with ZnO@Xylan/QX/PVA films was extended to at least 21 days. In conclusion, all the results ensure that the fabricated composite films have considerable promising application in the food packaging industry.
研究领域:
食品科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Sustainable Energy & Fuels
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2025
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IF 4.1
Guozhang Chang,Shanshan Dai,Xingyu Ye,Jie Li,Yunxiu Ren,Weiwei Cui,Cuiping Wang,Jian Zhang
Individual organic components namely cellulose, xylan and lignin are fundamental and essential factors for generation of bio-based monocyclic aromatic hydrocarbons (MAHs) from pyrolysis of lignocellulosic biomass. In this study, the influence of individual components on the characteristics of thermal decomposition and MAHs generation in pyrolysis of cellulose/xylan/lignin mixtures were investigated by a TG-MS analyzer and a Py-GC/MS analyzer. Results show that both increase in contents of cellulose and xylan were conductive to the thermal decomposition of cellulose/xylan/lignin mixtures, while the increase in content of lignin presented the opposite effect. The orders of effect on the thermal decomposition were cellulose > xylan > lignin. Benzene was released in pyrolysis from 281 to 766°C, and its release amount increased with the increased cellulose, xylan, or lignin with various mechanisms. Toluene was released from 281 to 692°C and its release amount was only increased with the increased lignin. Compared to linear heating technique (15°C/min), fast pyrolysis technique (20°C/ms) was conductive to the formation of xylene. MAHs was rarely directly produced both in pyrolysis of cellulose and xylan, but both the presence of the two components were beneficial to promoting MAHs yield. The promotion ratio of the increased cellulose (86.13%) was higher than that of the increased xylan (30.73%).
研究领域:
能源与燃料
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生物质化学
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产品关联
DOI
高影响因子
Microbial Cell Factories
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2022
·Vol. 21
·期 1
·1-14
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IF 6.352
Xia Yanwei,Wang Jingfan,Guo Chuanxu,Xu Huanhuan,Wang Wei,Yang Mingzhu,Shen Qirong,Zhang Ruifu,Miao Youzhi
Background Filamentous fungi are highly efficient at deconstructing plant biomass by secreting a variety of enzymes, but the complex enzymatic regulation underlying this process is not conserved and remains unclear.Results In this study, cellulases and xylanases could specifically respond to Avicel- and xylan-induction, respectively, in lignocellulose-degrading strain Trichoderma guizhouense NJAU4742, however, the differentially regulated cellulases and xylanases were both under the absolute control of the same TgXyr1-mediated pathway. Further analysis showed that Avicel could specifically induce cellulase expression, which supported the existence of an unknown specific regulator of cellulases in strain NJAU4742. The xylanase secretion is very complex, GH10 endoxylanases could only be induced by Avicel, while, other major xylanases were significantly induced by both Avicel and xylan. For GH10 xylanases, an unknown specific regulator was also deduced to exist. Meanwhile, the post-transcriptional inhibition was subsequently suggested to stop the Avicel-induced xylanases secretion, which explained the specifically high xylanase activities when induced by xylan in strain NJAU4742. Additionally, an economical strategy used by strain NJAU4742 was proposed to sense the environmental lignocellulose under the carbon starvation condition, that only slightly activating 4 lignocellulose-degrading genes before largely secreting all 33 TgXyr1-controlled lignocellulases if confirming the existence of lignocellulose components.Conclusion sThis study, aiming to explore the unknown mechanisms of plant biomass-degrading enzymes regulation through the combined omics analysis, will open directions for in-depth understanding the complex carbon utilization in filamentous fungi.
研究领域:
分子生物学
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微生物学
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生物技术
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酶学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Jingqiao Zhu,Hanping Xu,Qiangli Hu,Yujia Yang,Siyang Ni,Feng Peng,Xiaojuan Jin
Stretchable and tough hydrogels have been extensively used in tissue engineering scaffolds and flexible electronics. However, it is still a significant challenge to prepare hydrogels with both tensile strength and toughness by utilizing xylan , which is abundant in nature. Herein, we present a novel hydrogel of carboxymethyl xylan(CMX) graft gelatin (G) and doped with conductive hydroxyl carbon nanotubes (OCNT). CMX and G are combined through amide bonding as well as intermolecular hydrogen bonding to form a semi-interpenetrating hydrogel network. The hydrogel was further subjected to salting-out treatment, which induced the aggregation of the CMX-g-G molecular chain and the formation of chain bundles to toughen the hydrogel, the tensile strain, tensile stress, and toughness of CMX-g-G hydrogels were 1.547 MPa, 324 %, and 2.31 MJ m −3 , respectively. In addition, OCNT was used as a conductive filler to impart electrical conductivity and further improve the mechanical properties of CMX-g-G/OCNT hydrogel, and a tensile strength of 1.62 MPa was obtained. Thus, the synthesized CMX-g-G/OCNT hydrogel can be used as a reliable and sensitive strain sensor for monitoring human activity. This study opens up new horizons for the preparation of xylan-based high-performance hydrogels.
研究领域:
材料科学
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生物医学工程
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高分子化学
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产品关联
DOI
PubMed
高影响因子
Scientific Reports
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2015
·Vol. 5
·期 1
·1-14
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IF 5.578
Liao Hanpeng,Zheng Haiping,Li Shuixian,Wei Zhong,Mei Xinlan,Ma Hongyu,Shen Qirong,Xu Yangchun
A multiple xylanase system with high levels of xylanase activity produced from Penicillium oxalicum GZ-2 using agricultural waste as a substrate has been previously reported. However, the eco-physiological properties and origin of the multiplicity of xylanases remain unclear. In the present study, eight active bands were detected using zymography and all bands were identified as putative xylanases using MALDI-TOF-MS/MS. These putative xylanases are encoded by six different xylanase genes. To evaluate the functions and eco-physiological properties of xylanase genes, xyn10A , xyn11A , xyn10B and xyn11B were expressed in Pichia pastoris . The recombinant enzymes xyn10A and xyn10B belong to the glycoside hydrolase (GH) family 10 xylanases, while xyn11A and xyn11B belong to GH11 xylanases. Biochemical analysis of the recombinant proteins revealed that all enzymes exhibited xylanase activity against xylans but with different substrate specificities, properties and kinetic parameters. These results demonstrated that the production of multiple xylanases in P. oxalicum GZ-2 was attributed to the genetic redundancy of xylanases and the post-translational modifications, providing insight into a more diverse xylanase system for the efficient degradation of complex hemicelluloses.
研究领域:
微生物学
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酶学
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生物技术
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
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IF 2.931
Pei Yang,Ziqi Zhu,Minzhi Chen,Xiaoyan Zhou,Weimin Chen
A facile and straightforward microwave-assisted method was used to prepare polyamine-functionalized carbon dots (CDs) from a precursor comprising renewable xylan and branched polyethyleneimine (BPEI). The as-prepared BPEI-CDs were monodispersed sphere particles with an average diameter of about 8.62 nm, and exhibited excellent fluorescent property and high stability, as well as excitation-independent emission behavior. Furthermore, it is attractive that the BPEI-CDs can be used as novel fluorescent probes for detecting tannic acid (TA) sensitively and selectively. At the optimum condition, the TA detection system was established in water solution and ethanol solution with a dynamic range from 0.1 to 5 μM, and their detection limit of 36.8 nM and 44.9 nM were also determined, respectively. Most importantly, the BPEI-CDs-based sensors can be successfully applied to detect TA in real lake water and white wine samples, suggesting the low-cost and excellent BPEI-CDs are potential suitable for TA detection in practical application.
研究领域:
材料科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Jun Rao,Ziwen Lv,Gegu Chen,Xiang Hao,Ying Guan,Feng Peng
To realize the application of xylan based film in food and drug packaging, the poor mechanical property and film-forming property of xylan based film must be overcome. Herein, a good oxygen barrier composite film with desired mechanical properties was prepared based on carboxymethly xylan (CMX), chitosan (CS), and graphene oxide (GO). The results of scanning electron microscope revealed the composite film had a dense and continuous structure, which will endow the composite film with excellent mechanical property. As expected, the composite film with the 0.5% mass fraction of GO exhibited best mechanical property, among which the tensile stress, tensile strain, and Young's modulus of the composite film reached 50.81 MPa, 47.61%, and 1.39 GPa, respectively. The oxygen barrier properties of the composite films significantly increased with the addition of graphene oxide due to the dense, stacked multilayer structure. In addition, these composite films exhibited good antibacterial properties . Therefore, these films show great promise in the field of food packaging and wound dressing due to their excellent mechanical, oxygen barrier and antibacterial properties .
研究领域:
材料科学
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食品科学
·
生物医学
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Siquan Xu,Donghui Pan,Yuanfeng Wu,Jingdeng Fan,Ningxin Wu,Lijing Gao,Wenqi Li,Guomin Xiao
The mesoporous SBA-15 has long been used as an adsorbent for the removal of toxic metal ions. Achieving secondary utilize of spent adsorbent is undoubtedly an advisible option for environmental protection and recycling economy. In the present study, phosphoric acid-modified SBA-15 (P-SBA-15) was found to be an available adsorbent, and the composites (Cr3+/P-SBA-15) formed after adsorption of Cr3+ ions have the ability to efficiently catalyze the conversion of xylose and xylan into furfural. The physicochemical properties of the Cr3+/P-SBA-15 composites were characterized, and the effects of various reaction parameters on their catalytic performance were also investigated. Among the Cr3+/P-SBA-15 composites with different Cr3+ contents, the (0.25)Cr3+/P-SBA-15 composite not only achieved excellent 91% and 58% furfural yields from xylose and xylan, but also had almost constant catalytic performance after five cycles. The findings herein provided a reference for achieving high yields of furfural and reuse of spent adsorbents.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2019
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IF 4.12
Bin Hu,Qiang Lu,Zhen-Xi Zhang,Yu-Ting Wu,Kai Li,Chang-Qing Dong,Yong-Ping Yang
The fast pyrolysis mechanism of xylose , xylobiose and xylan was investigated with combined fast pyrolysis experiments and quantum chemistry calculations. The results indicate that acyclic d -xylose is an important intermediate for the formation of the major pyrolytic products in xylose pyrolysis, i.e., 1,4-anhydro- d -xylopyranose (ADX), furfural (FF) and hydroxyacetaldehyde (HAA). ADX derives from the successive cyclization of d -xylose which is the only source for ADX formation. 3-Deoxy-xylose is the most important intermediate for FF formation. HAA results from the C C bond scission by retro-aldol and cyclic Grob fragment. In addition, the five-membered intermediate derived from the ring-contraction reaction can transform into FF with high selectivity. The dehydrated xylose is also another source for HAA formation. The fast pyrolysis mechanism of xylobiose is similar to that of xylose, and thus similar pyrolytic product distribution can be obtained from them. However, the pyrolytic products of xylan differ significantly from those of xylose and xylobiose, which is ascribed to its high degree of polymerization and the branches in it.
研究领域:
化学工程
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生物质能
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）