Molecular Catalysis
·
2022
·
IF 5.089
Hengtao Tang,Zheng Zhou,Zhi Chen,Xin Ju,Liangzhi Li
Monosaccharides from biomass can be used as cost-effective raw materials to produce rare sugars which are valuable sweeteners. Enzymes play a pivotal role in such biomass biorefinery processes to develop novel synthetic routes, and improve the environmental friendliness of current routes. Here we propose a proof of concept biorefinery process to prepare useful rare sugars of D-xylulose and D-ribulose from D-xylose which was abundant in biomass. Ribose-5-phosphate isomerase B from Ochrobactrum sp. (OsRpiB) with a unique substrate scope was engineered to intensify the activity of transforming D-xylose to D-xylulose. A double mutant R94N/N137Q with 80% higher catalytic efficiency was identified, and kinetic and molecular dynamic studies were conducted to explore the mechanism underneath. The results revealed a correlation between enhancing stability and activity simultaneously. Then a one-pot enzyme cascade was constructed with OsRpiB and D-tagatose-3-epimerase from Pseudomonas cichorii and transformed D-xylulose further to D-ribulose. The conversions of D-xylose and D-xylulose in cascade reaction were 1.80-fold and 1.83-fold of that in separate reactions with the aid of process parameter adjustment. The presented work is the first reported enzyme cascade converting D-xylose to D-ribulose, and proves the promising role of monosaccharide isomerase platforms in the refinery of biomass.
研究领域:
生物化学
·
酶工程
·
生物质精炼
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产品关联
DOI
高影响因子
Plant Methods
·
2019
·Vol. 15
·期 1
·1-13
·
IF 3.17
Song Yadi,Chen Shang,Wang Xiujuan,Zhang Rui,Tu Lichan,Hu Tianyuan,Liu Xihong,Zhang Yifeng,Huang Luqi,Gao Wei
Background Tripterygium wilfordii Hook. f. ( T. wilfordii ) is an important medicinal plant with anti-inflammatory, immunosuppressive and anti-tumor activities. The main bioactive ingredients are diterpenoids and triterpenoids, such as triptolide, triptophenolide and celastrol. However, the production of terpenoids from original plants, hairy roots and dedifferentiated cells (DDCs) are not satisfactory for clinical applications. To find a new way to further improve the production of terpenoids, we established a new culture system of cambial meristematic cells (CMCs) with stem cell-like properties, which had strong vigor and high efficiency to produce large amounts of terpenoids of T. wilfordii . Results CMCs of T. wilfordii were isolated and cultured for the first time. CMCs were characterized consistent with stem cell identities based on their physiological and molecular analysis, including morphology of CMCs, hypersensitivity to zeocin, thin cell wall and orthogonal partial least square-discriminant analysis, combination of transcriptional data analysis. After induction with methyl jasmonate (MJ), the maximal production of triptolide, celastrol and triptophenolide in CMCs was 312%, 400% and 327% higher than that of control group, respectively. As for medium, MJ-induced CMCs secreted 231% triptolide and 130% triptophenolide at the maximum level into medium higher than that of control group. Maximal celastrol production of induced CMCs medium was 48% lower than that of control group. Long-term induction significantly enhanced the production of terpenoids both in cells and medium. The reason for increasing the yield of terpenoids was that expression levels of 1 - deoxy - d - xylulose - 5 - phosphate synthase ( DXS ), 1 - deoxy - d - xylulose - 5 - phosphate reductoisomerase ( DXR ) and hydroxymethylglutaryl - CoA synthase ( HMGS ) were upregulated in CMCs after induction. Conclusions For the first time, CMCs of T. wilfordii were isolated, cultured, characterized and applied. Considering the significant enrichment of terpenoids in CMCs of T. wilfordii , CMCs could provide an efficient and controllable platform for sustainable production of terpenoids, which can be a better choice than DDCs.
研究领域:
植物生物技术
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植物化学
·
药用植物
✓ 已验证
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Yan-Fei Liang,Shuai Feng,Dan Wu,Meng Ma,Jin-Tao Ren,Qian Zhao,Wen-Yun Gao,Heng Li
1-Deoxy- D- xylulose-5-phosphate synthase (DXS) is the first rate-limiting enzyme in the 2-methyl- D- erythritol-4-phosphate (MEP) terpenoid biosynthetic pathway. To explore the active sites of the protein, we made a series of mutations to the key amino acid residues of Escherichia coli DXS including H49, R420, D427, and R478. The results show that several mutants including H49Q lose almost all their catalytic activity in DXP synthesis, but the double-point mutants H49QD427H and H49QD427 N recover 100 % activity of the wild type enzyme. The kinetic characterization displays that the affinity of the double-point mutants for pyruvate and D- glyceraldehyde-3-phosphate only slightly decreases. We also assessed impact of the mutation on the oxidative decarboxylation activity of all the mutants. Despite the fact that H49QD427H and H49QD427 N get back the full activity with regard to DXP synthesis, their oxidase activity remains unrestored. Furthermore, we assayed the acceptor substrate spectrum of the mutants and the results show that a large portion of them catalyzes ligation between pyruvate and nitrosobenzene to form N-phenyl-N-hydroxyacetamide, whereas R420D, R420F, and D427H exhibit activity in connection of pyruvate and benzaldehyde to afford phenylacetocarbinol (PAC), with the first two mutants yielding ( S )-PAC (yields 21 %-25 %, ee values 71–75 %) while D427H furnishing ( R )-PAC (yield 41 %, ee value 91 %), implying the key role of D427 for the acceptor substrate recognition and the stereoselectivity of the enzyme. It is worth noting that this is the first report of DXS mutants that can recognize benzaldehyde as an acceptor substrate and generate both enantiomers of PAC.
研究领域:
生物化学
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分子生物学
✓ 已验证
产品关联
DOI
高影响因子
AMB Express
·
2019
·Vol. 9
·期 1
·1-11
·
IF 2.226
Guo Zongren,Long Liangkun,Ding Shaojun
d -Mannose and l -ribose are two important monosaccharides, which have attracted public attention recently because of their great application potentials in food, cosmetic and pharmaceutical industries. Sugar isomerases catalyze the sugar isomerization and therefore can be used as the biocatalysts for production of the high-value sugars from inexpensive sugars. l -arabinose isomerase catalyzes the conversion of l -arabinose to l -ribulose, while d -lyxose isomerase catalyzes l -ribulose and d -fructose to l -ribose and d -mannose, respectively. In this paper, a putative d -LI from Bacillus velezensis (BvLI) was identified, characterized and used to produce d -mannose and l -ribose from d -fructose and l -arabinose, respectively. The recombinant BvLI exhibited a maximum activity at 55 °C and pH 6.5, in the presence of 0.1 mM Co 2+ . Approximately 110.75 g/L d -mannose was obtained from 500 g/L d -fructose in 6 h by the recombinant BvLI, and approximately 105 g/L l -ribose was obtained from 500 g/L l -arabinose in 8 h by the successive biocatalysis of l -arabinose isomerase from Bacillus licheniformis (BlAI) and BvLI.
研究领域:
生物化学
·
生物技术
·
食品科学
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制药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biotechnology Journal
·
2024
·Vol. 19
·期 9
·2400360
·
IF 3.2
Yue Yan,Haodong Zhao,Dingyu Liu,Jie Zhang,Yuwan Liu,Huifeng Jiang
Global climate deterioration intensifies the demand for exploiting efficient CO 2 utilization approaches. Converting CO 2 to biorefinery feedstock affords an alternative strategy for third-generation biorefineries. However, upcycling CO 2 into complex chiral carbohydrates remains a major challenge. Previous attempts at sugar synthesis from CO 2 either produce mixtures with poor stereoselectivity or require ATP as a cofactor. Here, by redesigning glycolaldehyde synthase, the authors constructed a synthetic pathway for biorefinery feedstock D-xylulose from CO 2 that does not require ATP as a cofactor. The artificial D-xylulose pathway only requires a three-step enzyme cascade reaction to achieve the stereoselective synthesis of D-xylulose at a concentration of 1.2 g L −1 . Our research opens up an alternative route toward future production of chemicals and fuels from CO 2 .
研究领域:
生物技术
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生物化学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2022
·Vol. 103
·期 4
·1974-1980
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IF 4.125
Hengtao Tang,Zhi Chen,Yu Shao,Xin Ju,Liangzhi Li
BACKGROUND The fermentation valorization of two main lignocellulosic monosaccharides, glucose and xylose, is extensively developed; however, it is restricted by limited yield and process complexity. An in vitro enzymatic cascade reaction can be an alternative approach. RESULTS In this study, a three-stage, five-enzyme cascade was developed to convert pretreated biomass to valuable chemicals. First, a ribose-5-phosphate isomerase B mutant isomerized xylose to d -xylulose with high substrate specificity, and a d -arabinose dehydrogenase continued to reduce d -xylulose to d -arabitol. Simultaneously, glucose was utilized for the coenzyme regeneration catalyzed by a glucose dehydrogenase, generating useful gluconic acid and achieving 73% of total conversion rate after 36 h. Then, six kinds of pretreated biomass lignocellulose were hydrolyzed by cellulase and hemicellulase, and corn cob was identified as the initial substrate for providing the highest monosaccharide content. A 65% conversion rate of the lignocellulosic xylose was obtained after 24 h. CONCLUSIONS This study presents a proof of concept to convert main lignocellulosic monosaccharides systematically by an enzymatic cascade at stoichiometric ratio. © 2022 Society of Chemical Industry.
研究领域:
生物技术
·
生物化工
·
酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Yuqiu Wu,Fanjin Meng,Jiaolong Fu,Yuyang Zhou,Huan Fan,Xin Ju,Liangzhi Li
D-xylose, a biomass derivative, is used as a substrate to generate D-xylulose and D-ribulose with high-added value through a cascade reaction. During this process, the thermal stability and catalytic efficiency of rate-limiting enzymes during cascade reactions are important issues that must be addressed in industrial applications. In this study, we prepared and validated PDA/SiO 2 microspheres as highly loaded immobilization carriers by oxidative self-polymerization of polydopamine (PDA) on silica (SiO 2 ) microspheres. D-xylose was successfully catalyzed by the co-immobilized D-5-phosphate ribose isomerase B (RpiB) and D-tagatose-3-epimerase (DTE), denoted PDA/SiO 2 -RpiB-DTE, to produce D-ribulose and D-xylulose. After immobilization, the K m of co-immobilized RpiB and DTE decreased, which suggested increased substrate affinity. The half-life of the co-immobilized enzymes was 3.5–8 fold higher than that of the free enzymes at 50–70 °C, and the inactivation rate constant was reduced, demonstrating that immobilization improved significantly the thermal stability. The conversion of D-xylose at 10 mM was 29.98% under optimal conditions, which contained 9.85% D-ribulose and 20.13% D-xylulose. PDA/SiO 2 -RpiB-DTE showed up to 89.10% initial enzyme activity after 3 recycle runs. The thermal stability and recovery aspects were improved by immobilization, which facilitates the use of biomass to produce high-value-added products and further exploitation.
研究领域:
生物技术
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酶工程
·
生化工程
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产品关联
DOI
高影响因子
GENE
·
2022
·
IF 3.913
Xiaohong Chen,Yueya Zhang,Haifeng Yan,Meiyun Niu,Yuping Xiong,Xinhua Zhang,Yuan Li,Jaime A. Teixeira da Silva,Guohua Ma
The commercial value of Santalum album L. lies in its aromatic heartwood and essential oil. Sesquiterpenes are the main components of sandal essential oil, and these are synthesized through the plant’s mevalonate (MVA) and methylerythritol phosphate (MEP) pathways. In this study, the first key rate-limiting enzyme, 1-deoxy- d -xylulose-5-phosphate synthase (SaDXS), was investigated to provide a theoretical molecular basis for the sandalwood MEP sesquiterpene biosynthetic pathway. The biofunctions of SaDXS were also analyzed. SaDXS promoters were successfully cloned from a seven-year-old S. album tree. SaDXS1A/1B promoter activity was verified by a β-glucuronidase (GUS) assay and by analyzing cis -acting elements of the promoters, which carried light- and methyl jasmonate (MeJA)-responsive signals. In an experiment involving yellow S. album seedlings, exposure to light upregulated SaDXS1A/1B expression and increased chlorophyll and carotenoid contents when overexpressed in Arabidopsis thaliana . Analysis of the expression of SaDXS1A/1B and SaSSy , key genes of santalol biosynthesis, revealed SaDXS1A expression in all tissues whereas SaDXS1B was expressed in tissues that contained photosynthetic pigments, such as stems, leaves and flowers. Sandal seedlings exogenously treated with two hormones, MeJA and ethylene, revealed similar expression patterns for SaDXS1A/1B and SaSSy . Sandal seedlings were treated with an inhibitor of DXS, clomazone, but showed no significant changes in the contents of α-santalene, β-santalene and α-santalol between treatment and control groups. These results suggest that SaDXS1A/1B play a role in the synthesis of sandalwood sesquiterpenes, providing carbon for downstream secondary metabolites. SaDXS1A/1B also play a role in the biosynthesis of chlorophyll, carotenoids, and primary metabolites.
研究领域:
植物生物技术
·
分子生物学
·
生物化学
·
植物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Si Long,Zhi Chen,Xin Ju,Liangzhi Li
Isomerization cascade is a promising strategy to prepare valuable rare sugars from biomass xylose. However current conversions are not satisfactory due to factors of enzyme efficiency and reaction equilibrium. An isomerase/isomerase cascade has been newly developed employing an isomerase of xylose and a tagatose-3-epimerase (DTE) to prepare xylulose and ribulose from xylose, with a total xylose conversion of 43.2 %. In this study, two microbial glucose isomerases (GI) were tested as alternatives to isomerize xylose for their high activity towards xylose and thermal stability, aiming to explore the adaption effect of enzyme in the isomerization type of cascade. GIs from Streptomyces rubiginosus (SrGI) and Piromyces sp. (PsGI) both showed higher xylose conversions than the previously used isomerase of xylose, ribose-5-phosphate isomerase. The optimal reaction conditions of GIs for xylose conversion were compared in the single transformation of xylose and the cascade reactions catalyzed by GI/DTE, and it revealed the importance of high reaction temperature to substrate conversion and enzyme deactivation. The activity profile and thermal stability of SrGI were better than PsGI, making it a potential biocatalyst in biomass sugar isomerization which was favorable at high temperatures. The conversion of xylose by the PsGI/DTE cascade was improved to 71.3 % by efforts of enzyme adaption and reaction condition adjusting. Additionally, the standstill of isomerization reaction of monosaccharide can be attributed to thermal dynamic equilibrium at low temperatures and enzyme deactivation at high temperatures based on the results of this study.
研究领域:
生物化学
·
酶工程
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Zou Zhufan,Yu Zhenjie,Guan Weixiang,Liu Yanfang,Yao Yumin,Han Yang,Li Guangyi,Wang Aiqin,Cong Yu,Liang Xinmiao,Zhang Tao,Li Ning
Indan and tetralin are widely used as fuel additives and the intermediates in the manufacture of thermal-stable jet fuel, many chemicals, medicines, and shockproof agents for rubber industry. Herein, we disclose a two-step route to selectively produce 5-methyl-2,3-dihydro-1 H -indene (abbreviated as methylindan) and tetralin with xylose or the hemicelluloses from agricultural or forestry waste. Firstly, cyclopentanone (CPO) was selectively formed with ~60% carbon yield by the direct hydrogenolysis of xylose or hemicelluloses on a non-noble bimetallic Cu-La/SBA-15 catalyst. Subsequently, methylindan and tetralin were selectively produced with CPO via a cascade self-aldol condensation/rearrangement/aromatization reaction catalyzed by a commercial H-ZSM-5 zeolite. When we used cyclohexanone (another lignocellulosic cycloketone) in the second step, the main product switched to dimethyltetralin. This work gives insights into the selective production of bicyclic aromatics with lignocellulose.
研究领域:
化学工程
·
可再生资源利用
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2025
·
IF 6.1
Zhanjun Li,Yunwei Liu,Mingru Kong,Yibin Xu,Kunlun Wang,Ke Ma,Qingfen Zhang
This study focused on the valorization of Pinus koraiensis seed scale residues for furfural production from regenerated hemicellulose via solid acid catalysis. The optimized process included solid acid catalysis, ultrasonic pretreatment, and microwave-assisted processing, and the optimal conditions were 50% ethanol (30:1 mL/g), 80 W of ultrasonic power (10 min, 40°C), 3% solid acid, and 385 W of microwave power (20 min), resulting in a theoretical furfural yield of 10.50 mg/g and an actual yield of 10.36 mg/g (conversion rate of 31.49%). The recovered solid acid exhibited similar catalytic performance to the fresh solid acid (yield of 10.23 mg/g and conversion rate of 31.11%). Kinetic analysis revealed that reaction equilibrium was reached within 10 min, with activation energies of 11.96 kJ/mol at 30–40°C and 25.24 kJ/mol at 40–50°C, indicating inhibition at higher temperatures. Characterization confirmed the acidity, high thermal stability and excellent reusability of the acid despite slight deactivation after recovery. Future research will focus on optimizing the efficiency and reusability of solid acid catalysts and exploring the use of regenerated hemicellulose derivatives in biobased chemical and sustainable material applications. As renewable and biodegradable resources with tunable structures, hemicellulose derivatives offer great potential for producing biobased chemicals, ecofriendly materials, and catalysts, advancing the biobased economy while reducing fossil fuel dependence and environmental impacts.
研究领域:
生物化学
·
可再生资源工程
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE RESEARCH
·
2017
·
IF 2.096
Louis Patrick Conway,Fang Fang Liu,Qian Li,Josef Voglmeir
Galactokinases are a class of enzymes which belong to the GHMP (galactokinase, homoserine kinase, mevalonate kinase , and phosphomevalonate kinase) superfamily and catalyse the phosphorylation of galactose in the first step of the Leloir pathway . Here we report the discovery of three enzymes from Shewanella woodyi which have been classified as galactokinases based on sequence similarity. However, each of these enzymes show little to no significant activity towards galactose and instead exhibit a strong preference for glucose. Furthermore, in contrast to the usual galactose-1-phosphate product of the galactokinase-catalysed reaction, these enzymes produce glucose-6-phosphate. This radical change in enzyme functionality is postulated to be linked to the mutation of a glycine residue which is conserved in all other sequenced galactokinases.
研究领域:
生物化学
·
微生物学
✓ 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）