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
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DOI
PubMed
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
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可再生能源
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酶工程
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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
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分子生物学
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产品关联
DOI
PubMed
高影响因子
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