EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2014
·Vol. 239
·期 5
·827-835
·
IF 1.387
Wang Panxue,Li Aixia,Dong Mei,Fan Mingtao
The aim of this study was to purify a malolactic enzyme (MLE) from Oenococcus oeni ( O. oeni ) strain and determine its properties in detail. O. oeni SD-2a was cultivated in the ATB broth supplemented with 7 g/L l -malic acid for harvesting the cells. After harvest, the cells were washed and disrupted for purification of MLE. MLE was purified from the supernatant of the disrupted cells through protamine sulfate precipitation, anion exchange chromatography and gel filtration chromatography. The purified MLE was identified using mass spectrometry. The MLE was purified by 43-fold with a yield of 0.42 % and possessed a specific activity of 419.2 U/mg. The purified enzyme with a nominal molecular mass of 59 kDa and a theoretical p I of 4.76 exhibited a maximum enzyme activity at 35 °C and pH 6.0, which retained over 50 % of its initial activity in the presence of 14 % (v/v) ethanol. Mn 2+ was proven to be the most effective divalent cation to promote enzyme activity. Under the conditions of temperature 30 °C and pH 6.0, the K
m and V
max of MLE on l -malic acid were 12.5 × 10 −3 M and 43.86 μmol/(min × mg), respectively. Moreover, the purified enzyme exhibited a higher stability with 0.1 M NaCl in addition and had a half-life of 30 days at 4 °C.
研究领域:
微生物学
·
酶学
✓ 已验证
产品关联
DOI
高影响因子
BMC MICROBIOLOGY
·
2024
·Vol. 24
·期 1
·1-12
·
IF 4
Sun Zongping,Fang Yuting,Zhu Yaohuan,Tian Wen,Yu Junjie,Tang Jun
Background The mycotoxin zearalenone (ZEA) produced by toxigenic fungi is widely present in cereals and its downstream products. The danger of ZEA linked to various human health issues has attracted increasing attention. Thus, powerful ZEA-degrading or detoxifying strategies are urgently needed. Biology-based detoxification methods are specific, efficient, and environmentally friendly and do not lead to negative effects during cereal decontamination. Among these, ZEA detoxification using degrading enzymes was documented to be a promising strategy in broad research. Here, two efficient ZEA-degrading lactonases from the genus Gliocladium, ZHDR52 and ZHDP83, were identified for the first time. This work studied the degradation capacity and properties of ZEA using purified recombinant ZHDR52 and ZHDP83.Results According to the ZEA degradation study, transformed Escherichia coli BL21(DE3) PLySs cells harboring the zhdr52 or zhdp83 gene could transform 20 µg/mL ZEA within 2 h and degrade > 90% of ZEA toxic derivatives, α/β-zearalanol and α/β-zearalenol, within 6 h. Biochemical analysis demonstrated that the optimal pH was 9.0 for ZHDR52 and ZHDP83, and the optimum temperature was 45 °C. The purified recombinant ZHDR52 and ZHDP83 retained > 90% activity over a wide range of pH values and temperatures (pH 7.0–10.0 and 35–50 °C). In addition, the specific activities of purified ZHDR52 and ZHDP83 against ZEA were 196.11 and 229.64 U/mg, respectively. The results of these two novel lactonases suggested that, compared with ZHD101, these two novel lactonases transformed ZEA into different products. The slight position variations in E126 and H242 in ZDHR52/ZEA and ZHDP83/ZEA obtained via structural modelling may explain the difference in degradation products. Moreover, the MCF-7 cell proliferation assay indicated that the products of ZEA degradation using ZHDR52 and ZHDP83 did not exhibit estrogenic activity.Conclusion sZHDR52 and ZHDP83 are alkali ZEA-degrading enzymes that can efficiently and irreversibly degrade ZEA into non-estrogenic products, indicating that they are potential candidates for commercial application. This study identified two excellent lactonases for industrial ZEA detoxification.
研究领域:
微生物学
·
食品科学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Jian Peng,Enhui Wu,Xiaoxuan Lou,Qian Deng,Xiaohong Hou,Chongning Lv,Qi Hu
Anthraquinones (AQs) are hard-degraded substances that can cause significant harm to the environment. Many treatment methods are under consideration, among which biodegradation by laccase is competitive. AQs can be degraded by laccase, but the mechanism is indistinct, and the free laccase lacks stability and reusability. In this study, an eco-friendly metal–organic framework (MOF) composite, a MOF/polyvinyl alcohol (PVA) cryogel, is synthesized to construct a MOF/PVA immobilized laccase, i.e., MOF/PVA/Lac. Among all the MOF/PVA/Lac, the MIL-68(Al)/PVA/Lac (MIL-68(Al) is one of MOFs) showed excellent enzymatic properties where the pH stability, thermal stability, and operational stability were enhanced. The MIL-68(Al)/PVA/Lac achieved a high removal efficiency (95.86%) of alizarin green within 12 h and maintained more than 60% of its activity after six reaction cycles. Using molecular docking, mass spectrometry (MS), and two-dimensional nuclear magnetic resonance (2D-NMR), the final product of the degradation process, p-toluidine, was identified. The affinity sites of laccase for alizarin green were determined, and the reaction mechanism, C-α oxidation, was confirmed.
研究领域:
环境科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2017
·
IF 1.815
W.S. Huo,H. Zeng,Y. Yang,Y.H. Zhang
Enzymatic electrodes over-coated by thin film of nano-composite made up of polymer and functionalized nano-gold particle was prepared. Glucose/O 2 membrane-free enzymatic fuel cell based on nano-composite based electrodes with incorporated glucose oxidase and laccase was assembled. This enzymatic fuel cell exhibited high energy out-put density even when applied in human serum. Catalytic cycle involved in enzymatic fuel cell was limited by oxidation of glucose occurred on bioanode resulting from impact of sophisticated interaction between active site in glucose oxidase and nano-gold particle on configuration of redox center of enzyme molecule which crippled catalytic efficiency of redox protein.
研究领域:
生物化学
·
纳米生物学
·
能源科学
✓ 已验证
DOI
高影响因子
SENSORS
·
2023
·Vol. 23
·期 10
·4818
·
IF 3.9
Jiuqing Feng,Yizhou Jiang,Kai Wang,Jianzheng Li,Jialong Zhang,Mi Tian,Guoping Chen,Laigui Hu,Yiqiang Zhan,Yajie Qin
Real-time sweat monitoring is vital for athletes in order to reflect their physical conditions, quantify their exercise loads, and evaluate their training results. Therefore, a multi-modal sweat sensing system with a patch-relay-host topology was developed, which consisted of a wireless sensor patch, a wireless data relay, and a host controller. The wireless sensor patch can monitor the lactate, glucose, K+, and Na+concentrations in real-time. The data is forwarded via a wireless data relay through Near Field Communication (NFC) and Bluetooth Low Energy (BLE) technology and it is finally available on the host controller. Meanwhile, existing enzyme sensors in sweat-based wearable sports monitoring systems have limited sensitivities. To improve their sensitivities, this paper proposes a dual enzyme sensing optimization strategy and demonstrates Laser-Induced Graphene (LIG)-based sweat sensors decorated with Single-Walled Carbon Nanotubes (SWCNT). Manufacturing an entire LIG array takes less than one minute and costs about 0.11 yuan in materials, making it suitable for mass production. The in vitro test result showed sensitivities of 0.53 μA/mM and 3.9 μA/mM for lactate and glucose sensing, and 32.5 mV/decade and 33.2 mV/decade for K+and Na+sensing, respectively. To demonstrate the ability to characterize personal physical fitness, an ex vivo sweat analysis test was also performed. Overall, the high-sensitivity lactate enzyme sensor based on SWCNT/LIG can meet the requirements of sweat-based wearable sports monitoring systems.Keywords:laser-induced graphene;lactate enzyme electrode;wearable sensor;sweat sensing system;human motion monitoring;single-walled carbon nanotubes;health monitoring
研究领域:
生物医学工程
·
材料科学
·
传感器与执行器
·
无线通信
·
体育科学
✓ 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）