BIORESOURCE TECHNOLOGY
·
2023
·
IF 11.4
Na Li,Huan Xia,Yanbin Jiang,Jun Xiong,Wenyong Lou
Improving the activity of β-xylosidase at high temperature and organic solvents is important for the conversion of xylan, phytochemicals and some hydroxyl-containing substances to produce xylose and bioactive substances. In this study, a β-xylosidase R333H and an endoxylanase were simultaneously co-immobilized on the metal–organic framework UiO-66-NH 2 . Compared with the single R333H immobilization system, the co-immobilization enhanced the activity of R333H at high temperature and high concentration of acetone, and the relative activities at 95 °C and 50% acetone solution were >95%. The K m value of co-immobilized R333H towards p-Nitrophenyl-β-D-xylopyranoside (pNPX) shifted from 2.04 to 0.94 mM, which indicated the enhanced affinity towards pNPX. After 5 cycles, the relative activities of the co-immobilized enzymes towards pNPX and corncob xylan were 52% and 70% respectively, and the accumulated amount of reducing sugars obtained by co-immobilized enzymes degrading corncob xylan in 30% (v/v) acetone solution was 1.7 times than that with no acetone.
研究领域:
生物技术
·
酶学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2013
·
IF 2.906
Xiuling Zhu,Xin Zhang,Yongkang Sun,Di Su,Yi Sun,Bing Hu,Xiaoxiong Zeng
Sesaminol triglucoside (STG), the most abundant lignan glycoside existing in sesame cake/meal, has exhibited various biological activities. However, little information about its in vitro fermentation with intestinal microbiota is available. Therefore, the effect of STG from sesame cake on the fermentation of human fecal microbiota was evaluated. First, high-purity STG was successfully prepared from defatted sesame cake by extraction with 80% ethanol and simple purification procedures of polyamide column chromatography and Toyopearl HW-40S column chromatography. Then the influence of STG on intestinal microbiota was conducted by monitoring bacterial populations and analyzing the concentrations of short-chain fatty acids (SCFA). We found that STG could significantly induce an increase in numbers of Lactobacillus–Enterococcus group and Bifidobacterium in fermentation in vitro with human fecal microbiota, while it did not stimulate the bacterial growth of Eubacterium rectale–Clostridium coccoides group, Clostridium histolyticum group, and Bacteroides–Prevotella group. Furthermore, it was found that concentrations of formic, acetic, propionic, and butyric acids in STG culture increased significantly during the fermentation, and its total SCFA concentration was relatively higher than those of the control and glucose cultures at 6 and 12 h fermentation. Our findings provided further evidence for the importance of human intestinal bacteria in the bioactivity of STG and its metabolites in the maintenance of human health.
研究领域:
食品科学
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微生物学
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营养学
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产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Hao Cao,Lichao Sun,Ying Huang,Xin Liu,Dong Yang,Tengfei Liu,Xiaojing Jia,Boting Wen,Tianyi Gu,Fengzhong Wang,Fengjiao Xin
Enzymes are usually characterized by their evolutionarily conserved catalytic domains; however, this work presents the incidental gain-of-function of an enzyme in a loop region by natural evolution of its amino acids. A bifunctional acetyl ester–xyloside hydrolase (CLH10) was heterologously expressed, purified, and characterized. The primary sequence of CLH10 contains the fragments of the conserved sequence of esterase and glycosidase, which distribute in a mixed type. The crystal structure revealed that the primary sequence folded into two independent structural regions to undertake both acetyl esterase and β-1,4-xylanase hydrolase functions. CLH10 is capable of cleaving both the β-1,4-xylosidic bond-linked main chain and the ester bond-linked acetylated side chain of xylan, which renders it valuable because it can degrade acetylated xylan within one enzyme. Significantly, the β-1,4-xylanase activity of CLH10 appears to have been fortuitously obtained because of the variable Asp10 and Glu139 located in its loop region, which suggested that the exposed loop region might act as a potential hot-spot for the design and generation of promising enzyme function in both directed evolution and rational protein design.
研究领域:
生物化学
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酶学
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结构生物学
·
分子进化
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DOI
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2019
·Vol. 43
·期 11
·e13027
·
IF 1.358
Mengnan Hong,Jing Li,Yuwen Chen
This work aim to study the tolerance and aroma-related enzymes activities of the non- Saccharomyces yeasts in Vidal blanc icewine from the Huanren region of China. The strains were identified by sequencing internal transcribed spacer (ITS) region and the 26S rDNA D1/D2 domain genes and all representative non- Saccharomyces yeasts were belonged to genera Metschnikowia , Hanseniaspora , Torulaspora, Candida , and Debaryomyces . A total of 28 strains were carried out for tolerance experiments and results suggested that most of them could tolerate 500 g/L glucose, 4% ethanol, 20 g/L tartaric acid, and 350 mg/L SO 2 . Finally, a total of 17 strains with better tolerance were carried out for the β-glucosidase, β-xylosidase, and pectinase activities experiments. The results showed that Candida railenensis HC08 and the strains of Hanseniaspora genus have satisfactory multi-enzyme activities, which can be used to design mixed fermentation to produce characteristic icewine. Practical applications Non- Saccharomyces yeasts produces a series of hydrolytic enzymes that are thought to have a significant contribution to the aroma complexity of wines, however, are poorly explored in icewine. In this work, most of the non- Saccharomyces yeasts screened from Chinese icewine can adapt well to the high-sugar and high-acid environment of icewine, and can secrete hydrolase. The application of these strains in mixed fermentation could provide a prospect for the production of characteristic icewine.
研究领域:
酿酒学
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微生物学
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食品科学
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Na Li,Huan Xia,Shiyuan Liu,Junjiang Teng,Yanbin Jiang
In order to improve the activity and reusability of β-xylosidase, the β-xylosidase mutant S160N-R333H (R333H) which could convert notoginsenoside R1 to ginsenoside Rg1 and xylose was immobilized on the metal-organic framework (MOF) UiO-66-NH 2 . The physical and biochemical properties of immobilized β-xylosidase ( [email protected] 2 ) were studied in detail. The results showed improved performances, i.e. the high immobilization yield of 93% and recovery activity of 192.8%, better stability under acidic or trypsin-containing conditions, the higher activity in the reaction containing ions , and the improved catalytic efficiency (was 1.37-fold than that of free R333H). Importantly, the ginsenoside Rg1 yields remained more than 80% after six recycles in McIlvaine buffer and pure water. The UiO-66-NH 2 could catalyze xylose dehydration to produce furfural and the yield reached 69%. Thus this study provides a promising method for production of bioactive or platform chemicals via continuous conversion of xyloylated substrates using nanocatalyst synthesized by β-xylosidase and MOF.
研究领域:
生物技术
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酶工程
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化学工程
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药学
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产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 34
·21028-21035
·
IF 3.108
Yuyu Liu,Xiaohui Wang,Ting Mo,Yaru Yan,Yuelin Song,Yunfang Zhao,Jun Li,Shepo Shi,Xiao Liu,Pengfei Tu
Recently, owing to the important pharmaceutical properties of malonylated glycosides, their chemoenzymatic synthesis using malonyltransferase has received significant attention. In the present study, a new malonyltransferase, NbMaT1, was identified from Nicotiana benthamiana. Extensive enzymatic assays revealed its significant substrate tolerance based on HPLC-UV and HR-MS analyses. Moreover, 16 of the tested glycosides including flavone glycosides, flavonol glycosides, dihydroflavone glycosides, isoflavone glycosides, coumarin glycosides, and phenylethyl chromone glycosides with various sugar moieties (such as glucose, xylose, and galactose) substituted at different positions of their skeleton could be accepted by NbMaT1 to conduct the corresponding malonylation. Among these, enzymatic malonylation of phenylethyl chromone glycosides as well as xylosides and galactosides has rarely been reported earlier. Furthermore, one-pot synthesis using the known malonyl-CoA synthetase MatB and NbMaT1 as well as an unnatural fusion protein MatB–NbMaT1 was designed, which allowed malonic acid to be directly used in the malonylation reaction without the addition of expensive malonyl-CoA. Moreover, a remarkably improved conversion rate was observed for all the tested substrates, with both commercial and industrial application values. The malonylated product of the bioactive flavonoid diglycoside icariin was prepared and NMR spectroscopy revealed that the malonyl group was specifically transferred onto the 6-OH group of the glucose moiety. NbMaT1 was expected to be a universal and effective tool for chemoenzymatic synthesis of diverse bioactive-malonylated glycoside derivatives for drug discovery.
研究领域:
生物化学
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药理学
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植物生物技术
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酶学
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DOI
高影响因子
BMC BIOTECHNOLOGY
·
2018
·Vol. 18
·期 1
·1-11
·
IF 2.605
Li Qi,Wu Tao,Qi Zhipeng,Zhao Linguo,Pei Jianjun,Tang Feng
Background β-D-xylosidase is a vital exoglycosidase with the ability to hydrolyze xylooligosaccharides to xylose and to biotransform some saponins by cleaving outer β-xylose. β-D-xylosidase is widely used as one of the xylanolytic enzymes in a diverse range of applications, such as fuel, food and the pharmaceutical industry; therefore, more and more studies have focused on the thermostable and xylose-tolerant β-D-xylosidases.Results A thermostable β-xylosidase gene (xln-DT) of 1509 bp was cloned from Dictyoglomus thermophilum and expressed in E.coli BL21. According to the amino acid and phylogeny analyses, the β-xylosidase Xln-DT is a novel β-xylosidase of the GH family 39. The recombinant β-xylosidase was purified, showing unique bands on SDS-PAGE, and had a protein molecular weight of 58.7 kDa. The β-xylosidase Xln-DT showed an optimal activity at pH 6.0 and 75 °C, with p-nitrophenyl-β-D-xylopyranoside (pNPX) as a substrate. Xln-DT displayed stability over a pH range of 4.0-7.5 for 24 h and displayed thermotolerance below 85 °C. The values of the kinetic parameters K
m
and V
max
for pNPX were 1.66 mM and 78.46 U/mg, respectively. In particular, Xln-DT displayed high tolerance to xylose, with 60% activity in the presence of 3 M xylose. Xln-DT showed significant effects on the hydrolyzation of xylobiose. After 3 h, all the xylobiose tested was degraded into xylose. Moreover, β-xylosidase Xln-DT had a high selectivity for cleaving the outer xylose moieties of natural saponins, such as notoginsenoside R1 and astragaloside IV, which produced the ginsenoside Rg1 with stronger anti-fatigue activity and produced cycloastragenol with stronger anti-aging activity, respectively.Conclusion This study provides a novel GH 39 β-xylosidase displaying extraordinary properties of highly catalytic activity at temperatures above 75 °C, remarkable hydrolyzing activity of xylooligosaccharides and rare saponins producing ability in the pharmaceutical and commercial industries.
研究领域:
生物化学
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酶学
·
生物技术
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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
·
生物技术
·
酶学
·
可再生能源
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产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2024
·
IF 3.5
Yang Shuanghao,Feng Ruirui,Sun Bo,Lu Meizi,Zhao Xingchu,Shen Qirong,Wan Qun
Corncob, as an agricultural waste rich in hemicellulose, plays a crucial role in the effective utilization for biomass conversion and biorefinery. Here, we report a thermophilic GH11 xylanase (Xyn11B) and a β-xylosidase (Xyl43B) in the compost metatranscriptome database, with optimal temperature of 75 ℃ and 70 ℃, respectively, utilized for the synergistic degradation of corncob. Xyn11B consists of a catalytic domain (CD) and a carbohydrate-binding module 60 (CBM60). After deleting CBM60, the T m of the remaining CD Xyn increased by 2.4 ℃ and the half-life at 80 ℃ increased threefold. After 10-h hydrolysis on the NaOH-treated corncob using Xyn11B and CD Xyn , the conversion yield reached 78 and 94 mg sugar/g raw corncob, respectively. Interestingly, in the absence of alkali pretreatment, the conversion yield can reach 107 mg sugar/g raw corncob using 0.1% (mg enzyme/mg corncob) Xyn11B, which is two times higher than that of CD Xyn . Our analysis shows that CBM60 can reduce the non-catalytic adsorption to lignin, which increases the capability of the full-length enzyme to hydrolyze hemicellulose without alkali pretreatment. Furthermore, synergistic hydrolysis with both 0.1% Xyn11B and 0.1% Xyl43B considerably elevates the conversion yield to 296 mg sugar/g raw corncob, which is 2.8-fold higher than that achieved using Xyn11B alone, and comparable to the enzymatic effect observed with the combination of CD Xyn and Xyl43B in alkali pretreatment. Our strategy demonstrates a good example of green hydrolysis of lignocellulosic biomass using enzymes without chemical pretreatment.
研究领域:
生物技术
·
生物化学
·
酶学
·
农业废弃物管理
·
可持续化学
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产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2017
·Vol. 183
·期 4
·1488-1502
·
IF 1.751
Wang Liming,Chen Yan
Cycloastragenol (CA), an exclusive telomerase activator, was derived from the Astragali Radix which is widely distributed in Turkey. Until now, there is no report to produce CA with effective and environment-friendly methods. Biotransformation is considered to be a promising technology. Thus, the present study was aimed to establish a biotransformation technology that could efficiently produce CA. In this paper, a microorganism, LG-502, was used to successfully transform astragaloside IV (ASI) to CA by analysis of thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The phylogenetic analysis of the 16S rRNA indicated that this strain belongs to Bacillus sp. Three metabolites were separated during the fermentation and characterized to be cyclogaleginoside B, CA, and 20 R , 24 S -epoxy-6 α , 16 β , 25-trihydroxy-9, 19-cycloartan-3-one based on NMR and MS spectroscopic analyses. The conversion rate of ASI and yield rate of CA were achieved as high as 89 and 84%, respectively, under optimized conditions. Enzymatic analysis showed that the glycosidases were mainly located inside the bacterial body, and the activities of glucosidases were much higher than the xylosidases under the experimental conditions. This study provides a feasible, effective, and eco-friendly way to prepare CA from ASI, which might greatly contribute to the applications of ASI.
研究领域:
药学
·
生物技术
·
微生物学
·
有机化学
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DOI
PubMed
高影响因子
Journal of Functional Foods
·
2021
·
IF 4.451
Zhenfeng Huang,You Luo,Xuesen Xia,Anping Wu,Zhenqiang Wu
Fermentation results in the release and biotransformation of phenolic compounds in guava leaves. This study aimed to evaluate the bioaccessibility, safety and antidiabetic effect of phenolic-rich extract from fermented guava leaves (PE-fgl) using Monascus anka and Bacillus sp. BS2. The total phenolics and flavonoids were 51.18% and 16.60% bioaccessible after gastrointestinal digestion, respectively. High bioaccessibility was observed, particularly for ellagic acid, isoquercitrin, quercetin-3-O-β-D-xylopyranoside, quercetin-3-O-α-L-arabinofuranoside and avicularin, resulted in high recovery of α-glucosidase inhibition activity and antioxidant capacity. Moreover, PE-fgl was practically nontoxic with a median lethal dose (LD 50 ) greater than 5000 mg/kg and was without evidence of toxicity following subchronic administration up to the dose limit of 2000 mg/kg. Furthermore, PE-fgl significantly improved serum glucose and lipid levels as well as antioxidant capacity in diabetic mice. Liver, kidney and pancreas damage was also significantly alleviated. These results suggested that PE-fgl could be a nontoxic candidate for diabetes treatment.
研究领域:
药理学
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营养学
·
糖尿病研究
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食品科学
·
毒理学
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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）