JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Bin Li,Wenjing Gao,Ling Ling,Shaoning Yu,Liangqiang Chen,Fan Yang
Lactose is an important nutrient but its content in milk products poses concerns for people with lactose intolerance . Thus, a simple, rapid, and high-throughput assay for lactose determination is needed to maintain specified lactose levels during production and in final milk products. Here, we report a reactive matrix-assisted laser desorption/ionization mass spectrometry ( Re MALDI MS) method for the determination of lactose in milk products. The selective reactivity and the excellent laser absorption properties of 4-hydrazinoquinazoline (4-HQ) matrix increase the sensitivity of traditional MALDI MS analysis of lactose by 100 folds. After optimization of the method, lactose was detected distinctly in milk without pretreatment . Using xylobiose as an internal standard, the assay accurately quantified lactose in the concentration range of 1.00−700 μg/mL (R 2 = 0.994). Due to the high sensitivity and specificity, the lactose content in different types of milk samples was determined successfully, as well as the residual lactose in low-lactose and lactose-free milk.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2019
·
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
·
生物质能
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Baojun Feng,Hong Liao,Wenjun Ying,Junhua Zhang,Zhangjing Chen
Short-chain xylo-oligosaccharides (XOS) such as xylobiose (X2) and xylotriose (X3) have higher biological activities. Therefore, it is interesting to produce highly active XOS enriched with X2 and X3. In this work, pH-controlled lactic acid (LA) hydrolysis was used to produce XOS from xylan in moso bamboo and xylanase was used to convert high DP XOS into low DP XOS to increase the percentage of X2 + X3 in XOS. A 33.1 % XOS yield was obtained from 2 % LA hydrolysis (pH = 3.2). After xylanase hydrolysis of the LA hydrolysate, the total XOS yield reached 64.1 %, with X2 + X3 yield reaching 58.4 %. The percentage of X2 + X3 increased from 52.3 % to a high level of 91.0 %. The deep eutectic solvent pretreatment removed 87.2 % lignin from the residue and the glucose yield of the delignified residue hydrolyzed by cellulase was 96.9 %. The results suggested that the integrated process of LA and xylanase hydrolysis could effectively produce X2 + X3 from xylan in moso bamboo.
研究领域:
生物化学
·
可再生资源与环境科学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2025
·
IF 6.2
Fulong Zhang,Xu Zeng,Wu Lan,Xuejin Zhang,Chuanfu Liu
The enzymatic hydrolysis of pretreated lignocellulose to produce value-added oligosaccharides presents the advantages of a simplified procedural approach with reduced environmental impact. The subsequent purification is necessary to improve the purity of oligosaccharides for further application. In this work, a high-yield xylooligosaccharides-rich hydrolysate was obtained by ball-mill-assisted alkaline peroxide (BAP) pretreatment and enzymatic hydrolysis, and the sequential separation of xylobiose and cellobiose was performed by activated carbon adsorption. Adsorption kinetics and isotherm models of saccharides on activated carbon were systematically investigated to understand the adsorption behavior. Results indicate that separation achieves a purity exceeding 70 %, with 38.21 % of xylobiose and 84.22 % of cellobiose being adsorbed. Density functional theory (DFT) calculations reveal the involvement of oxygen-containing groups on the activated carbon surface in sugar adsorption from the molecular level. The findings of this study establish a theoretical foundation for separating xylobiose and cellobiose from oligosaccharides hydrolysate through activated carbon adsorption.
研究领域:
生物化学
·
可再生资源工程
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2025
·
IF 9
Haiyan Yu,Bolin Liu,Xue Han,Jingru Yang,Yulong Li,Xiaoxuan Bai,Yanli Jia,Shang Li,Liansheng Zhao,Yulu Wang,Fengjiao Xin
Xylan represents a promising resource for generating high-value bioproducts in lignocellulosic biorefineries. Nevertheless, the intricate structure of xylan poses challenges for its degradation, requiring the synergistic action of specialized side-chain cleaving enzymes to enhance the efficiency of endo -xylanases. In this study, we identified and characterized a novel acetylxylan esterase ( Bt AcXE) from Bacteroides thetaiotaomicron VPI-5482, featuring a unique dual-catalytic domain architecture comprising an N -terminal CE1 domain (NTD) and a C-terminal CE3 domain (CTD). Bt AcXE exhibited remarkable activity of 6864.1 ± 745.6 U/mg against p -nitrophenylacetate, exceeding that of the individual NTD and CTD enzymes, as well as an equimolar mixture of both domains. Furthermore, supplementing xylanase with Bt AcXE enhanced the hydrolysis of birchwood xylan by 1.9-fold, yielding up to 0.182 ± 0.003 g/g acetic acid and 0.304 ± 0.029 g/g reducing sugars, respectively. Acetic acid yields of 0.019–0.058 g/g were further achieved from more complex pretreated lignocellulosic feedstocks. Notably, the native dual-domain structure of Bt AcXE conferred inter-domain synergy, resulting in an overall increase in the release of both acetic acid and reducing sugars. This study establishes Bt AcXE as a highly efficient Axe with substantial potential for enhancing the high-value utilization of lignocellulosic biomass and provides valuable insights for designing and applying multicatalytic-domain xylanolytic enzymes.
研究领域:
生物化学
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生物技术
·
可再生能源
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酶工程
·
木质纤维素生物炼制
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Shuangqi Tian,Ziyi Yang,Feng Yan,Xing'ao Xue,Jing Lu
Rice husks are rich in xylan , which can be hydrolyzed by xylanase to form xylooligosaccharides (XOS). XOS are a functional oligosaccharide such as improving gut microbiota and antioxidant properties. In this study, the structure and functional characteristics of XOS were studied. The optimal xylanase hydrolysis conditions through response surface methodology (RSM) were: xylanase dosage of 3000 U/g, hydrolysis time of 3 h, hydrolysis temperature of 50 °C. Under this condition, the yield of XOS was 150.9 mg/g. The TG-DTG curve showed that XOS began to decompose at around 200 °C. When the concentration of XOS reached 1.0 g/L, the clearance rate of DPPH reached 65.76 %, and the scavenging rate of OH reached 62.10 %, while the clearance rate of ABTS free radicals reached 97.70 %, which was equivalent to the clearance rate of V C . XOS had a proliferative effect on four probiotics : Lactobacillus plantarum , Lactobacillus brucelli , Lactobacillus acidophilus , and Lactobacillus rhamnosus . However, the further experiments are needed to explore the improvement effect of XOS on human gut microbiota, laying a foundation for the effective utilization of XOS. XOS have a wide range of sources, low price, and broad development prospects. The reasonable utilization of XOS can bring greater economic benefits.
研究领域:
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Biomolecules
·
2024
·Vol. 14
·期 9
·1188
·
IF 4.8
Jiao Ma,Zhongke Sun,Zifu Ni,Yanli Qi,Qianhui Sun,Yuansen Hu,Chengwei Li
This study identified a salt-tolerant GH11 xylanase, Xyn st , which was isolated from a soil bacterium Bacillus sp. SC1 and can resist as high as 4 M NaCl. After rational design and high-throughput screening of site-directed mutant libraries, a double mutant W6F/Q7H with a 244% increase in catalytic activity and a 10 °C increment in optimal temperature was obtained. Both Xyn st and W6F/Q7H xylanases were stimulated by high concentrations of salts. In particular, the activity of W6F/Q7H was more than eight times that of Xyn st in the presence of 2 M NaCl at 65 °C. Kinetic parameters indicated they have the highest affinity for beechwood xylan ( K m = 0.30 mg mL −1 for Xyn st and 0.18 mg mL −1 for W6F/Q7H), and W6F/Q7H has very high catalytic efficiency ( K cat / K m = 15483.33 mL mg −1 s −1 ). Molecular dynamic simulation suggested that W6F/Q7H has a more compact overall structure, improved rigidity of the active pocket edge, and a flexible upper-end alpha helix. Hydrolysis of different xylans by W6F/Q7H released more xylooligosaccharides and yielded higher proportions of xylobiose and xylotriose than Xyn st did. The conversion efficiencies of Xyn st and W6F/Q7H on all tested xylans exceeded 20%, suggesting potential applications in the agricultural and food industries.
研究领域:
生物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 103
·期 19
·7983-7995
·
IF 3.67
Guo Jingui,Xie Yixiao,Yu Zhu,Meng Geng,Wu Zhe
For the first time, Lactobacillus plantarum strains carrying heterologous genes encoding multifunctional glycoside hydrolases were constructed and used as additives for alfalfa silage. The chemical characteristics, nonstructural carbohydrate composition, and fermentation quality of alfalfa silage were examined. The supernatant of L. plantarum expressing CbXyn10C and Bgxg1 (LP11AG) showed activities on xylan, Avicel, and carboxymethylcellulose (CMC), while the supernatant of the wild-type L. plantarum showed no activity. When LP11AG was used as silage additive, the water-soluble carbohydrate content of alfalfa silage increased by 72%, 55%, and 155% compared with control when the silage was stored at 20 °C, 30 °C, and 40 °C, respectively. With LP11AG being used as an additive for the alfalfa silage stored at 20 °C, the hemicellulose, cellulose, and acid detergent ligninin (ADL) contents decreased by 17%, 6%, and 14% compared with the control ( p < 0.05), respectively. Compared with the corresponding original contents, the contents of glucose, arabinose, galactose, and fructose detected in silage treated with LP11AG after 45 days of ensiling increased by 55%, 1494%, 68%, and 5% , respectively, when stored at 40 °C. Raffinose and stachyose, originally present in alfalfa, disappeared after ensiling. In conclusion, our results suggest that LP11AG provides a substantial benefit as a silage additive.
研究领域:
微生物学
·
动物营养学
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产品关联
DOI
PubMed
高影响因子
Biotechnology for Biofuels and Bioproducts
·
2023
·Vol. 16
·期 1
·1-13
·
IF 0
Zhang Xiaoling,Miao Qin,Tang Bingling,Mijakovic Ivan,Ji Xiao-Jun,Qu Lingbo,Wei Yongjun
Xylo-oligosaccharides (XOS) are considered as a promising type of prebiotics that can be used in foods, feeds, and healthcare products. Xylanases play a key role in the production of XOS from xylan. In this study, we conducted a metagenomic analysis of the fecal microbiota from dairy cows fed with different types of fodders. Despite the diversity in their diets, the main phyla observed in all fecal microbiota were Firmicutes and Bacteroidetes. At the genus level, one group of dairy cows that were fed probiotic fermented herbal mixture-containing fodders displayed decreased abundance of Methanobrevibacter and increased growth of beneficial Akkermansia bacteria. Additionally, this group exhibited a high microbial richness and diversity. Through our analysis, we obtained a comprehensive dataset comprising over 280,000 carbohydrate-active enzyme genes. Among these, we identified a total of 163 potential xylanase genes and subsequently expressed 34 of them in Escherichia coli . Out of the 34 expressed genes, two alkaline xylanases with excellent temperature stability and pH tolerance were obtained. Notably, CDW-xyl-8 exhibited xylanase activity of 96.1 ± 7.5 U/mg protein, with an optimal working temperature of 55 ℃ and optimal pH of 8.0. CDW-xyl-16 displayed an activity of 427.3 ± 9.1 U/mg protein with an optimal pH of 8.5 and an optimal temperature at 40 ℃. Bioinformatic analyses and structural modeling suggest that CDW-xyl-8 belongs to GH10 family xylanase, and CDW-xyl-16 is a GH11 family xylanase. Both enzymes have the ability to hydrolyze beechwood xylan and produce XOS. In conclusion, this metagenomic study provides valuable insights into the fecal microbiota composition of dairy cows fed different fodder types, revealing main microbial groups and demonstrating the abundance of xylanases. Furthermore, the characterization of two novel xylanases highlights their potential application in XOS production.
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DOI
PubMed
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2023
·
IF 5
Si Zhenyuan,Cai Yang,Zhao Lang,Han Lu,Wang Feng,Yang Xiaobing,Gao Xiangdong,Lu Meiling,Liu Wei
Abstract α-L-Arabinofuranosidases (Abfs) play a crucial role in the degradation of hemicelluloses, especially arabinoxylans (AX). Most of the available characterized Abfs are from bacteria, while fungi, as natural decomposers, contain Abfs with little attention given. An arabinofuranosidase ( Th Abf1), belonging to the glycoside hydrolase 51 (GH51) family, from the genome of the white-rot fungus Trametes hirsuta , was recombinantly expressed, characterized, and functionally determined. The general biochemical properties showed that the optimal conditions for Th Abf1 were pH 6.0 and 50°C. In substrate kinetics assays, Th Abf1 preferred small fragment arabinoxylo-oligosaccharides (AXOS) and could surprisingly hydrolyze di-substituted 2 3 ,3 3 -di-L-arabinofuranosyl-xylotriose (A 2,3 XX). It also synergized with commercial xylanase (XYL) and increased the saccharification efficiency of arabinoxylan. The crystal structure of Th Abf1 indicated the presence of an adjacent cavity next to the catalytic pocket which led to the ability of Th Abf1 to degrade di-substituted AXOS. The narrow binding pocket prevents Th Abf1 from binding larger substrates. These findings have strengthened our understanding of the catalytic mechanism of GH51 family Abfs and provided a theoretical foundation for the development of more efficient and versatile Abfs to accelerate the degradation and biotransformation of hemicellulose in biomass. Key points ThAbf1 from Trametes hirsuta degraded di-substituted arabinoxylo-oligosaccharide. ThAbf1 performed detailed biochemical characterization and kinetics. ThAbf1 structure has been obtained to illustrate the substrate specificity. Graphical abstract
研究领域:
生物化学
·
酶学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2023
·Vol. 46
·期 20
·2300384
·
IF 3.1
Zheng Jiang,Hong Wang,Miao Yu,Cheng Qu,Wei Yue,Qinan Wu
In this study, a low-cost efficient online derivatization system was developed which allows for the detection of various types of mono- and oligo-saccharides only utilizing high-performance liquid chromatography (HPLC)-ultraviolet detector (UV) system. In the proposed method, phenylhydrazine was used as the derivatization reagent and directly spiked in the mobile phase, allowing for the separation and detection of mono- and oligosaccharides in an accessible instrument system (HPLC-UV). And the online derivatization design of the proposed method has significantly reduced the potential harm of derivatization reagents to the analysts. Furthermore, critical chromatographic parameters were optimized via the Box-Behnken design strategy, culminating in the ideal response for saccharides. Finally, the methodology validation of the proposed method was conducted. The proposed method showed satisfactory linear ranges with acceptable correlation coefficients (R 2 > 0.99), outstanding accuracy (Recovery: 95.3%–105.6%), high intra-day precision (relative standard deviation [RSD]: 1.4%–7.1%) and inter-day precision (RSD: 2.0%–7.4%). The robustness and ruggedness of the proposed method were proved as the recovery values in the range of 95.0%–104.6% and 95.1%–104.8% for robustness and ruggedness, respectively. These satisfactory validation results confirm the applicability and reliability of the proposed method for the analysis of saccharides in various complex real-world samples.
研究领域:
分析化学
·
食品科学
✓ 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）