BIOTECHNOLOGY AND BIOENGINEERING
·
2014
·Vol. 111
·期 12
·2580-2586
·
IF 4.164
Jia-Le Yu,Xiao-Xia Xia,Jian-Jiang Zhong,Zhi-Gang Qian
The C6 dicarboxylic acid, adipic acid, is an important platform chemical in industry. Biobased production of adipic acid is a promising alternative to the current petrochemical route. Here, we report biosynthesis of adipic acid using an artificial pathway inspired by the reversal of beta-oxidation of dicarboxylic acids. The biosynthetic pathway comprises condensation of acetyl-CoA and succinyl-CoA to form the C6 backbone and subsequent reduction, dehydration, hydrogenation, and release of adipic acid from its thioester. The pathway was first tested in vitro with reconstituted pathway enzymes and then functionally introduced into Escherichia coli for the biosynthesis and excretion of adipic acid into the culture medium. The production titer was increased by approximately 20-fold through the combination of recruiting enzymes that were more suitable to catalyze the synthetic reactions and increasing availability of the condensation substrates. This work demonstrates direct biosynthesis of adipic acid via non-natural synthetic pathway, which may enable its renewable production. Biotechnol. Bioeng. 2014;111: 2580–2586. © 2014 Wiley Periodicals, Inc.
研究领域:
生物技术
·
代谢工程
·
合成生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DAIRY SCIENCE
·
2013
·
IF 2.566
Liang Li,Ying Ma
The influence of fatty acids on the β-oxidation system and thioesterase of Lactococcus lactis was investigated in this study. The results showed that fatty acids (C8:0–C16:0) significantly inhibited the growth of Lactococcus lactis , and laurate (C12:0) had the highest bactericidal effects. We detected the maximum activity of β-oxidation at different incubation times (8, 12, and 18 h) to be 6.460, 7.751, and 8.203, respectively, and the maximum activity of thioesterase at different incubation times (8, 12, and 18 h) to be 19.498, 27.180, and 12.800, respectively. Fatty acids were seen to induce the β-oxidation system and activity of thioesterase; decanoic acid (C10:0) and palmitic acid (C16:0) were also seen to induce the β-oxidation system of Lactococcus lactis , but the induced ability was significantly different. Octanoic acid (C8:0) and palmitic acid (C16:0) were seen to induce thioesterase activity in Lactococcus lactis . When 1 m M palmitic acid (C16:0) was added to M17 broth, the activity of thioesterase increased 5-fold after 2 min; however, adding octanoic acid (C8:0) changed the activity little. Evidence showed that the ability to induce the β-oxidation system and thioesterase activity was related to the fatty acids’ chain lengths.
研究领域:
微生物学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACTA PHARMACOLOGICA SINICA
·
2019
·Vol. 40
·期 8
·1106-1118
·
IF 4.01
Zhao Kai-jing,Chen Yang,Hong Shi-jin,Yang Yi-ting,Xu Jiong,Yang Han-yu,Zhu Liang,Liu Ming,Xie Qiu-shi,Tang Xian-ge,Yang Ting-ting,Zhou Ya-qian,Liu Li,Liu Xiao-dong
Cinnamic acid and its analogues (pyragrel and ozagrel) undergo chain-shortened (β-oxidative) and reductive metabolism on acyl side chain. In this study, we characterized the β-oxidative and reductive metabolism on acyl side chain of cinnamic acid and its analogues using primary rat hepatocytes, hepatic mitochondrial, and microsomal systems. A compartmental model including parent compounds and metabolites was developed to characterize in vivo β-oxidative and reductive metabolism following an intravenous dose of parent compounds to rats. The fitted total in vivo clearance values were further compared with the in vitro values predicted by the well-stirred model. We showed that hepatic microsomal CYP450s did not catalyze β-oxidative or reductive metabolism of the three compounds. Similar to β-oxidation of fatty acids, β-oxidative metabolism on their acyl side chain occurred mainly in mitochondria, which was highly dependent on ATP, CoA and NAD + . Fatty acids and NADH inhibited the β-oxidative metabolism. Reductive metabolism occurred in both mitochondria and microsomes. Reduction in mitochondria was ATP-, CoA-, and NAD(P)H-dependent and reversible, which was suppressed by enoyl reductase inhibitor triclosan. Reduction in microsomes was ATP-, CoA-, and NADPH-dependent but little affected by triclosan. Both plasma concentrations of β-oxidative metabolites and reductive metabolites were successfully fitted using the compartmental model. The estimated total in vivo clearance values were consistent with those predicted from hepatocytes and organelles, implicating significance of in vitro kinetics. These findings demonstrate the roles of hepatic mitochondria and microsomes in β-oxidative and reductive metabolism on acyl side chain of cinnamic acid and its analogues along with their metabolic characteristics.
研究领域:
药理学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DAIRY SCIENCE
·
2014
·
IF 2.55
Liang Li,Ying Ma
The effects of divalent metal ions (Ca 2+ , Mg 2+ , Fe 2+ , and Cu 2+ ) on the growth, β-oxidation system, and thioesterase activity of Lactococcus lactis were investigated. Different metal ions significantly influenced the growth of L. lactis : Ca 2+ and Fe 2+ accelerated growth, whereas Cu 2+ inhibited growth. Furthermore, Mg 2+ inhibited growth of L. lactis at a low concentration but stimulated growth of L. lactis at a high concentration. The divalent metal ions had significant effects on activity of the 4 key enzymes of the β-oxidation system (acyl-CoA dehydrogenase, enoyl-CoA hydratase, L-3-hydroxyacyl-CoA dehydrogenase, and thiolase) and thioesterase of L. lactis. The activity of acyl-CoA dehydrogenases increased markedly in the presence of Ca 2+ and Mg 2+ , whereas it decreased with 1 mmol/L Fe 2+ or 12 mmol/L Mg 2+ . All the metal ions could induce activity of enoyl-CoA hydratase. In addition, 12 mmol/L Mg 2+ significantly stimulated activity of L-3-hydroxyacyl-CoA dehydrogenase, and all metal ions could induce activity of thiolase, although thiolase activity decreased significantly when 0.05 mmol/L Cu 2+ was added into M17 broth. Inhibition of thioesterase activity by all 4 metal ions could be reversed by 2 mmol/L Ca 2+ . These results help us understand the effect of metal ions on the β-oxidation system and thioesterase activity of Lactococcus lactis .
研究领域:
微生物学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
BIOLOGICAL TRACE ELEMENT RESEARCH
·
2024
·
IF 3.4
Zhu Jiamei,Nie Gaohui,Dai Xueyan,Wang Dianyun,Li ShanXin,Zhang Caiying
Cadmium (Cd) and high molybdenum (Mo) pose deleterious effects on health. Prior studies have indicated that exposure to Mo and Cd leads to damage in duck kidneys, but limited studies have explored this damage from the perspective of fatty acid metabolism. In this study, 40 healthy 8-day-old ducks were randomly assigned to four groups and fed a basic diet containing Cd (4 mg/kg Cd) or Mo (100 mg/kg Mo) or both. Kidney tissues were harvested on the 16th week. Results demonstrated that Cd and/or Mo inhibited mitochondrial fatty acid β-oxidation and disrupted mitochondrial dynamics, along with significant suppression of peroxisome proliferator-activated receptor β/δ (PPARβ/δ) protein in duck kidneys. In vitro study, duck renal tubular epithelial cells were exposed for 12 h to either Mo (480 μM Mo), Cd (2.5 μM Cd), and GW0742 (0.3 μM, a potent agonist of PPARβ/δ) alone or in combination. The results demonstrated that Cd and/or Mo led to marked fatty acid oxidation deficiency and mitochondrial dysfunction and that PPARβ/δ protein was involved in the process. Altogether, this study found that activating PPARβ/δ-mediated fatty acid β-oxidation mitigates mitochondrial dysfunction co-induced by Mo and Cd in duck kidneys.
研究领域:
毒理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CyTA-Journal of Food
·
2018
·
IF 1.371
Liang Li,Ying Ma
Methyl ketones can be formed by the metabolism of intermediate products of β-oxidation by enzymes. In this article, the effect of soluble saccharides on the activity of key enzymes involved in methyl ketone synthesis in L. lactis was studied by detecting the relationship between soluble saccharides and enzyme activity. The results showed that glucose, fructose, sucrose, lactose and galactose could promote the growth of L. lactis. Glucose induced the activity of enoyl-coenzyme A (CoA) hydratase but inhibited the activity of β-hydroxyacyl-CoA dehydrogenase. Fructose induced the activities of acyl-CoA dehydrogenase and enoyl-CoA hydratase while maintaining the activity of β-hydroxyacyl-CoA dehydrogenase. Sucrose induced the activities of enoyl-CoA hydratase and β-hydroxyacyl-CoA dehydrogenase and maintained the activity of thiolase. Lactose also induced enoyl-CoA hydratase activity. Galactose induced enoyl-CoA hydratase activity and maintained thiolase activity. Glucose, lactose, fructose and galactose induced thioesterase activity. The data showed fructose and lactose could inhibit thiolase activity and induce thioesterase activity, which would be beneficial to methyl ketone synthesis, so fructose and lactose were the best soluble saccharides, followed by galactose, glucose and sucrose. A positive and significant correlation was found between thioesterase activity and enoyl-CoA hydratase activity (p < 0.01). In summary, the β-oxidation system of L. lactis is related to sugar metabolism.
研究领域:
微生物学
·
生物化学
✓ 已验证
DOI
高影响因子
Cell Discovery
·
2024
·Vol. 10
·期 1
·1-7
·
IF 13
Li Yang,Chen Zhi-Peng,Xu Da,Wang Liang,Cheng Meng-Ting,Zhou Cong-Zhao,Chen Yuxing,Hou Wen-Tao
Human ABC transporters ABCD1–3 are all localized on the peroxisomal membrane and participate in the β-oxidation of fatty acyl-CoAs, but they differ from each other in substrate specificity. The transport of branched-chain fatty acids from cytosol to peroxisome is specifically driven by ABCD3, dysfunction of which causes severe liver diseases such as hepatosplenomegaly. Here we report two cryogenic electron microscopy (cryo-EM) structures of ABCD3 bound to phytanoyl-CoA and ATP at resolutions of 2.9 Å and 3.2 Å, respectively. A pair of phytanoyl-CoA molecules were observed in ABCD3, each binding to one transmembrane domain (TMD), which is distinct from our previously reported structure of ABCD1, where each fatty acyl-CoA molecule strongly crosslinks two TMDs. Upon ATP binding, ABCD3 exhibits a conformation that is open towards the peroxisomal matrix, leaving two extra densities corresponding to two CoA molecules deeply embedded in the translocation cavity. Structural analysis combined with substrate-stimulated ATPase activity assays indicated that the present structures might represent two states of ABCD3 in the transport cycle. These findings advance our understanding of fatty acid oxidation and the molecular pathology of related diseases.
研究领域:
生物化学
·
分子生物学
·
医学遗传学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2012
·
IF 4.951
Yingying Hu,Zhaoyin Wen,Xiangwei Wu,Jun Jin
Porous carbon films with tunable pore structure to modify the β″-alumina electrolyte surface are fabricated through a low-cost and direct wet chemistry method with glucose and poly(methyl-methacrylate) (PMMA) as precursors. FTIR analysis confirms the effective connection between the carbohydrate and the pore-forming agent PMMA through hydrogen bonds . The experimental results indicate that the structural parameters of the porous carbon films, including mean pore size and film thickness, can be tuned simply by adjusting the amount of PMMA in the glucose/PMMA composite. This soft-template-assisted method could be readily extended to modify any other ceramic surfaces. The porous carbon films are demonstrated to greatly improve the wettability of the β″-alumina ceramics by molten sodium . Na/β″-alumina/Na cells are used to investigate the interfacial properties between sodium and the β″-alumina electrolyte. The results obtained at 350 °C reveal that the polarization behavior of the cell is alleviated by the porous coating . This work represents a successful method to coat ceramics with porous carbon and offers a promising solution to overcome the polarization problems of the sodium/β″-alumina interface in Na-based batteries .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2013
·
IF 4.675
Yingying Hu,Zhaoyin Wen,Xiangwei Wu,Yan Lu
Polarization problem caused by the incomplete wetting of sodium on β″-alumina has been considered as one of the most difficult issues in Na-beta batteries . Here, nickel nanowire network coatings have been designed and fabricated directly on the β″-alumina electrolyte surface to effectively alleviate this problem. The coating consists of interconnecting nickel nanowires with diameter of about ∼100 nm, forming a highly porous morphology. The structural parameters of the nickel network coatings can be tuned mainly by the amount of the poly(methyl-methacrylate) soft template in the precursors. The nickel nanowire network coatings are demonstrated to greatly improve the wettability of the β″-alumina ceramics by molten sodium. Moreover, the nickel coating displays low sheet resistance of ca. 1 Ω sq −1 . The results of Na/β″-alumina/Na symmetric cells at 350 °C reveal that the polarization and the interfacial resistance of the cell is alleviated intensively by the nickel coating, mainly due to the greatly improved wetting performance of the β″-alumina ceramics. This modification design and the soft-template-assisted synthetic method could be readily extended to any other substrate surfaces with arbitrary shape.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2012
·
IF 1.66
Baoxiu Zhao,Mou Lv,Li Zhou
Perfluorooctanoic acid (PFOA) is a new-found hazardous persistent organic pollutant, and it is resistant to decomposition by hydroxyl radical (HO) due to its stable chemical structure and the high electronegativity of fluorine. Photocatalytic reduction of PFOA with β-Ga 2 O 3 in anoxic aqueous solution was investigated for the first time, and the results showed that the photoinduced electron (e − cb ) coming from the β-Ga 2 O 3 conduction band was the major degradation substance for PFOA, and shorter-chain perfluorinated carboxylic acids (PFCAs, C n F 2n+1 COOH, 1 ≤ n ≤ 6) were the dominant products. Furthermore, the concentration of F − was measured by the IC technique and defluorination efficiency was calculated. After 3 hr, the photocatalytic degradation efficiency was 98.8% and defluorination efficiency was 31.6% in the presence of thiosulfate and bubbling N 2 . The degradation reaction followed first-order kinetics ( k = 0.0239 min −1 , t 1/2 = 0.48 hr). PFCAs (C n F 2n+1 COOH, 1 ≤ n ≤ 7) were detected and measured by LC-MS and LC-MS/MS methods. It was deduced that the probable photocatalytic degradation mechanism involves e − cb attacking the carboxyl of C n F 2n + 1 COOH, resulting in decarboxylation and the generation of C n F 2n + 1 . The produced C n F 2n + 1 reacted with H 2 O, forming C n F 2n + 1 OH, then C n F 2n + 1 OH underwent HF loss and hydrolysis to form C n F 2n+1 COOH.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Jin Liu,Wei Lu,Qian Zhong,Hongzhang Wu,Yunlin Li,Lili Li,Zhenling Wang
Semiconductor photocatalysis has become the focus of recent research on antibiotic treatment because it is a green and efficient technology. In this study, α-GaOOH with several novel microstructures has been synthesized at a low temperature and its subsequent thermal transformation. The influence of pH on the synthesis of α-GaOOH is studied, and the results indicate that pH played an important role in the microstructures of α-GaOOH and β-Ga 2 O 3 . All Ga 2 O 3 samples possess macro-mesoporous network structures and exhibits a remarkable photocatalytic activity for antibiotic degradation. The photoelectron chemical tests show that the separation efficiency of photogenerated charge carriers of Ga 2 O 3 -7.0 is higher than that of other Ga 2 O 3 . The enhanced photocatalytic activity of Ga 2 O 3 -7.0 is mainly ascribed to its morphology and oxygen vacancy . The active species trapping and photoluminescence measurement experiments indicate that OH and O 2 − are the major active species contributing to the photocatalytic process. This study will bring about the potential application in treatment of the antibiotic pollutants.
研究领域:
材料科学
·
环境科学
·
半导体光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POWDER TECHNOLOGY
·
2020
·
IF 4.142
Yu Zhang,Qian Shao,Chunyu Chen,Heyun Jiang,Fengmei Su,Qian Hu,Zhanhu Guo
Facile microwave-hydrothermal method was successfully used to synthesize Beta-bismuth (III) oxide (β-Bi 2 O 3 ) nanopowders under the low calcination temperature (350 °C) with a demonstrated diameter of about 40–200 nm. UV–vis diffuse reflection spectroscopy revealed that the resulting β-Bi 2 O 3 nanopowders exhibited a broad absorption with a low band gap of about 2.64–2.85 eV. When the reaction temperature of microwave-hydrothermal process was 180 °C (the sample is named as 180 MH), an optimal methyl orange (MO) degradation efficiency of 95.0% was achieved after visible light irradiation of 120 min. β-Bi 2 O 3 nanopowders also had a strong degradation effect on the tetracycline (TC). Kinetic studies indicated that the photocatalytic degradation process of MO and TC could be well fitted to the pseudo-first-order kinetics. The mechanisms for the enhanced photocatalytic degradation were disclosed as well, and the h + and O 2 •- were dominating radicals for MO degradation. This paper provides a way to synthesize nanostructural materials for wide applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）