Biotechnology Journal
·
2024
·Vol. 19
·期 11
·e202400518
·
IF 3.2
Fangzhi Deng,Zhenru Zhou,Zhen Du,Mohamed Mohany,Qunyue Wu,Weiyang Liang,Lei Zhang,Shan Li
Murideoxycholic acid (MDCA), as a significant secondary bile acid derived from the metabolism of α/β-muricholic acid in rodents, is an important component in maintaining the bile acid homeostasis. However, the biosynthesis of MDCA remains a challenging task. Here, we present the development of cytochrome P450 monooxygenase CYP102A1 (P450 BM3) from Bacillus megaterium , employing semi-rational protein engineering technique. Following three rounds of mutagenesis, a triple variant (T260G/G328A/L82V) has been discovered that proficiently catalyzes the 6β-hydroxylation of lithocholic acid (LCA), thereby generating MDCA with an impressive 8.5-fold increase in yield compared to the template P450 BM3 mutant. The MDCA selectivity has been also promoted from 62.0% to 96.3%. This biocatalyst introduces a novel approach for the biosynthesis of MDCA from LCA. Furthermore, molecular docking and dynamics simulations have been employed to unravel the molecular mechanisms underlying the enhanced LCA conversion and MDCA selectivity.
研究领域:
生物化学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
METABOLIC ENGINEERING
·
2013
·
IF 6.859
Wei Du,Feiyan Liang,Yangkai Duan,Xiaoming Tan,Xuefeng Lu
Because cyanobacteria are photosynthetic, fast-growing microorganisms that can accumulate sucrose under salt stress, they have a potential application as a sugar source for the biomass-derived production of renewable fuels and chemicals. In the present study, the production of sucrose by the cyanobacteria Synechocystis sp. PCC6803, Synechococcus elongatus PCC7942, and Anabaena sp. PCC7120 was examined. The three species displayed different growth curves and intracellular sucrose accumulation rates in response to NaCl. Synechocystis sp. PCC6803 was used to examine the impact of modifying the metabolic pathway on the levels of sucrose production. The co-overexpression of sps ( slr0045 ) , spp ( slr0953 ), and ugp ( slr0207 ) lead to a 2-fold increase in intracellular sucrose accumulation, whereas knockout of ggpS ( sll1566 ) resulted in a 1.5-fold increase in the production of this sugar. When combined, these genetic modifications resulted in a fourfold increase in intracellular sucrose accumulation. To explore methods for optimizing the transport of the intracellular sucrose to the growth medium, the acid-wash technique and the CscB (sucrose permease)-dependent export method were evaluated using Synechocystis sp. PCC6803. Whereas the acid-wash technique proved to be effective, the CscB-dependent export method was not effective. Taken together, these results suggest that using genetic engineering, photosynthetic cyanobacteria can be optimized for efficient sucrose production.
研究领域:
微生物学
·
遗传学
·
生物工程
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Wei Lin,Kangchao Lu,Shijian Zhou,Jian Wang,Feihu Mu,Yun Wang,Yong Wu,Yan Kong
Excessive or deficient defects in graphitic carbon nitride (g-C 3 N 4 ) nanosheets are detrimental to their photocatalytic activities . In this work, the approach of fluorine-containing solvothermal treatment has been applied to remodel the defects in g-C 3 N 4 nanosheets (CNS). The fabrication process has been comprehensively investigated and the samples are characterized by various techniques. The results manifest that the solvothermal treatment declines the amount of defects, while the addition of fluorine stimulates the emergence of nitrogen vacancies for producing new active sites which makes the obtained fluorine modified CNS present excellent photocatalytic activities. The average rate of photocatalytic hydrogen evolution under visible light irradiation is 2607.4 μmol·h −1 ·g −1 , which is almost 13 and 1.3 times of bulk g-C 3 N 4 (BCN) and CNS, respectively, and the degradation rate of rhodamine B is about 3.4 and 1.9 times, respectively.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 3.8
Min Zhang,Yongfu Ruan,Yi Hu,Yiying Huo,Meng Wang,Zhiwei Zhu,Yunming Fang
Artemisinin, a vital antimalarial agent, is traditionally extracted from Artemisia annua L. by plant-based extraction. The microbial biosynthesis of the artemisinin precursor, amorpha-4,11-diene (AD), followed by its chemical conversion into artemisinin provides a sustainable solution to meet the demand for artemisinin while overcoming the limitations of plant-based extraction. Kluyveromyces marxianus is a promising host for microbial cell factories owing to its robust thermotolerance, rapid growth kinetics, and ability to utilize a wide range of carbon sources. Herein, genetic modification tools for K. marxianus , including transformation methods and expression vectors, were identified and optimized, while the sesquiterpene biosynthetic capacity of K. marxianus was preliminarily evaluated. To enhance the precursor metabolite supply, eight key genes from the endogenous mevalonate pathway were overexpressed within the K. marxianus genome. A dual co-expression strategy, involving both extrachromosomal and chromosomally integrated expression of amorpha-4,11-diene synthase ( ADS ) was employed, followed by high-temperature fermentation to optimize production. Finally, an engineered K. marxianus strain was developed for the first time, capable of stable, efficient, and cost-effective production of AD, with a titer of 66.78 mg/L, a 113-fold increase compared with the wild-type strain. This engineered strain serves as a robust chassis and a valuable reference for the production and study of other terpenoids, laying the groundwork for further exploration of K. marxianus characteristics and the biosynthesis of AD.
研究领域:
微生物学
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生物技术
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药理学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Jing Feng,Yiting Liu,Xia Pan,Fa Jin,Liangquan Wu,Jianquan Chen,Bing Wan,Xiuwei Zhang,Lígia R. Rodrigues,Yunlei Zhang
Despite recent preclinical progress with oncolytic bacteria in cancer therapy, dose-limiting toxicity has been a long-standing challenge for clinical application. Genetic and chemical modifications for enhancing the bacterial tumor-targeting ability have been unable to establish a balance between increasing its specificity and effectiveness while decreasing side effects. Herein, we report a simple, highly efficient method for rapidly self-assembling a clinically used lipid on bacterium and for reducing its minimum effective dose and toxicity to normal organs. The resultant bacteria present the ability to reverse-charge between neutral and acidic solutions, thus enabling weak interactions with the negatively charged normal cells, hence increasing their biocompatibility with blood cells and with the immune system. Additionally, the lipid-coated bacteria exhibit a longer blood circulation lifetime and low tissue trapping compared with the wild-type strains. Thereby, the engineered bacteria show enhanced tumor specificity and effectiveness even at low doses. Multiple visualization techniques are used for vividly demonstrating the time course of bacterial circulation in the blood and normal organs after intravenous administration. We believe that these methods for biointerfacial lipid self-assembly and evaluation of bacterial systemic circulation possess vast potential in exquisitely fabricating engineered bacteria for cancer therapy in the future.
研究领域:
医学
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生物工程
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癌症治疗
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产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Shuyang Dong,Long He,Liang Li,Yajun Wu,Xuefeng Wang
Polymer gels are widely used in the oil and gas industry, and high-molecular-weight polymer gels have significant effects on reservoir water plugging operations. Based on nontoxic polyvinyl alcohol (PVA), its stability in solvents containing formation saltwater (Tahe oilfield, NW China) was studied, and the composite gel solution was prepared using saltwater. The polymerization mechanism of PVA with phenolic resin (PF) and polyacrylamide (PAM) was analyzed, using hexamethylenetetramine (HMTA) instead of formaldehyde for cross-linking, and the rheological properties of the prepared gel were tested; the results showed excellent elastic properties. The application value of the gel was evaluated by gelation performance, thermal stability, and indoor simulated core displacement. The gelation time of the PVA/PAM/PF gel at 130 °C was 4 h; after aging at 130 °C for 40 days, the gel strength of the polymer gel remained at the G level, and no dehydration occurred. The simulated core plugging results showed that the breakthrough pressure was 11.79 MPa and the plugging rate was 99.83%. Compared with the PAM/PF gel, the PVA/PAM/PF gel has a higher breakthrough pressure, which is beneficial to reduce the permeability of the porous medium.
研究领域:
石油工程
·
高分子化学
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产品关联
DOI
高影响因子
ORGANIC GEOCHEMISTRY
·
2024
·
IF 2.6
Can Xie,Gangtian Zhu,Yuguang Hou,Zhiliang He
Steroid acids are unique molecular fossils composed of a steroid carbon skeleton linked to a carboxyl group. These biomarkers contain special geological and biological clues in their structures. However, the origin of steroid acids remains a subject of debate, and there is a lack of direct evidence in previous studies. Here, we present experimental evidence for the origin of steroid acids. The origin of steroid acids during biodegradation in crude oil was observed for the first time. Molecular structures of these steroid acids reveal that they arose from steranes via bacterial oxidation of sidechain terminal methyl groups. Our results suggest that microbial activities indeed contribute to the formation of carboxyl groups on the eukaryotic steroid skeletons, and we believe steroid acids are a promising biomarker for both geomicrobial processes and ancient eukaryotic life in the rock record.
研究领域:
地质生物学
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微生物学
·
古生物学
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DOI
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Ping Wei,Ze-Wang Guo,Xiao-Ling Wu,Shan Liang,Xiao-Yang Ou,Pei Xu,Min-Hua Zong,Ji-Guo Yang,Wen-Yong Lou
Chiral alcohols and their derivatives are vital building blocks to synthesize pharmaceutical drugs and high-valued chemicals. Wild-type carbonyl reductase Ac CR from Acetobacter sp. has ideal enantioselectivity toward 11 prochiral substrates ( e.e. >99%) but poor activity. In this work, a semi-rational engineering was performed to enhance the activity of Ac CR. Fortunately, three positive double-mutants (mut-E144A/G152 L, mut-G152 L/Y189 N, and mut-I147 V/G152 L) with specific activity 17–61 folds higher than that of enzyme without modified were achieved. Kinetic studies suggested that the catalytic efficiencies ( k cat / K m ) of these mutants were also well enhanced. Finally, these modified mut- Ac CRs were successfully applied in asymmetric reductions of 11 structurally diverse prochiral substrates (200 mM) with excellent product yields (76.8%–99.1%) and enantiomeric excess ( e.e. >99%), which provides an alternative strategy for efficient synthesis of chiral alcohols for pharmaceuticals industry with ideal yield and enantioselectivity.
研究领域:
生物化学
·
酶工程
·
制药工业
✓ 已验证
产品关联
DOI
高影响因子
BIOMATERIALS
·
2021
·
IF 12.479
Liying Wang,Zimo Liu,Quan Zhou,Sufang Gu,Xiangsheng Liu,Jianxiang Huang,Haiping Jiang,Huifang Wang,Liping Cao,Jihong Sun,Youqing Shen,Huan Meng,Xiangrui Liu
Accumulating evidence suggests that stromal modifications improve chemotherapeutic outcomes in pancreatic ductal adenocarcinoma (PDAC). However, combination regimens of stroma-modifying agents and small-molecule cytotoxic drugs have achieved only limited improvements in the clinic, probably due to unsatisfactory pharmacokinetic profiles and restricted drug distribution in tumors. Here, we developed self-assembled prodrug nanoparticles integrating a stromal reprogramming inducer, calcipotriol (CAL), and a potent chemotherapeutic agent, 7-Ethyl-10-hydroxycamptothecin (SN38), to treat PDAC. While SN38 is conjugated to the block polymer backbone , CAL is loaded into the inner hydrophobic space during polymer self-assembly into nanoparticles. To achieve an efficient drug co-package, a planar and hydrophobic cholesterol domain was introduced to stabilize the hydrophobic CAL. Notably, the blood circulation time of CAL significantly improved as CAL|SN38 nanoparticle (CAL|SN38 NP). In addition, CAL|SN38 NP treatment significantly decreased the expression of N-cadherin, collagen , and fibronectin in tumors, which play critical roles in PDAC metastasis. Potent inhibition of primary tumor growth and vigorous anti-metastasis effects were observed after systemic administration of CAL|SN38 NP to stroma-rich PDAC orthotopic tumor-bearing mice. These findings provide a promising paradigm for developing tailor-made nanoparticles with potent stroma-modification capability to combat metastatic cancer.
研究领域:
肿瘤学
·
药理学
·
纳米技术
·
癌症研究
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产品关联
DOI
PubMed
高影响因子
ACS Food Science & Technology
·
2024
·
IF 2.6
Qian Hou,Zongxiao Huang,Huicong Chen,Weining Huang,Ning Li,Xiaoqing Mu
Due to the low pH and high temperature in dough rising and baking processes of starchy foods, high thermostability and acidic resistance have become the most important characteristics for commercial maltogenic amylase as a baking antiaging additive. Therefore, a novel maltogenic amylase from Lactobacillus paralimentarius, exhibiting an activity of 274.79 U·mg–1 under optimal conditions at 50 °C and pH 5.0, was screened through EnzymeMiner-assisted preliminary screening, microbial sources-assisted reselection, and structure analysis-assisted final selection, which was based on the bioinformatics. Data-driven rational design was carried out to construct a mutation library for the improvement of thermostability; the optimal reaction temperature and activity of mutant A375P/S257P were increased to 65 °C and 430.15 U·mg–1, respectively, while the half-life at 60 °C increased by 7.09-fold. The structural analysis indicated that the formation of new hydrogen bonds and the increase in rigidity reduce the free energy of mutant A375P/S257P, thereby further enhancing its thermostability.
研究领域:
食品科学
·
生物信息学
·
酶工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Juwei Ao,Xuewei Pan,Qiang Wang,Hengwei Zhang,Kexin Ren,An Jiang,Xian Zhang,Zhiming Rao
α-Arbutin is extensively used in cosmetic industries. The lack of highly active enzymes and the cytotoxicity of hydroquinone limit the biosynthesis of α-arbutin. In this study, a whole-cell biocatalytic approach based on enzyme engineering and engineered cell modification was identified as effective in enhancing α-arbutin production. First, a sucrose phosphorylase (SPase) mutant with higher enzyme activity was obtained by experimental screening. Next, to avoid the oxidation of hydroquinone, we established an anaerobic process to improve the robustness of the cells by knocking out lytC, sdpC, and skfA in Bacillus subtilis and overcoming the inhibitory effect of a high concentration of hydroquinone. Finally, the engineered strain was used for biotransformation in a 5 L fermenter with batch feeding for 24 h. The final yield of α-arbutin achieved was 129.6 g/L, which may provide a basis for the large-scale industrial production of α-arbutin.
研究领域:
生物化学
·
酶工程
·
工业微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 11
·1727
·
IF 4.7
Chengyu Lu,Ziwei Chen,Yuvaraj Ravikumar,Guoyan Zhang,Xinrui Tang,Yufei Zhang,Mei Zhao,Wenjing Sun,Xianghui Qi
L-Arabinose isomerase (L-AI) has been commonly used as an efficient biocatalyst to produce D-tagatose via the isomerization of D-galactose. However, it remains a significant challenge to efficiently synthesize D-tagatose using the native (wild type) L-AI at an industrial scale. Hence, it is extremely urgent to redesign L-AI to improve its catalytic efficiency towards D-galactose, and herein a structure-based molecular modification ofLactobacillus plantarumCY6 L-AI (LpAI) was performed. Among the engineered LpAI, both F118M and F279I mutants showed an increased D-galactose isomerization activity. Particularly, the specific activity of double mutant F118M/F279I towards D-galactose was increased by 210.1% compared to that of the wild type LpAI (WT). Besides the catalytic activity, the substrate preference of F118M/F279I was also largely changed from L-arabinose to D-galactose. In the enzymatic production of D-tagatose, the yield and conversion ratio of F118M/F279I were increased by 81.2% and 79.6%, respectively, compared to that of WT. Furthermore, the D-tagatose production of whole cells expressing F118M/F279I displayed about 2-fold higher than that of WT cell. These results revealed that the designed site-directed mutagenesis is useful for improving the catalytic efficiency of LpAI towards D-galactose.
研究领域:
生物化学
·
食品科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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