BIORESOURCE TECHNOLOGY
·
2023
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IF 11.4
Yufei Zhang,Junhua Yun,Guoyan Zhang,Amreesh Parvez,Lei Zhou,Hossain M. Zabed,Jia Li,Xianghui Qi
3-Hydroxypropionic acid (3-HP) is a top value-added chemical with multifaceted application in chemical, material, and food field. However, limited availability of robust strains and elevated fermentation costs currently impose constraints on sustainable biosynthesis of 3-HP. Herein, transporter engineering, metabolic dynamic modulation, and enzyme engineering were combined to address above limitations. First, a glucose-utilizing 3-HP biosynthetic pathway was constructed in Escherichia coli , followed by recruiting alternative glucose transport system to overcome center metabolism overflow. Next, the Cra (a transcription factor)-dependent switch was applied to autonomously fine-tune carbon flux, which alleviated growth retardation and improved the 3-HP production. Subsequently, inactivation of glycerol facilitator (GlpF) increased intracellular glycerol levels and boosted 3-HP biosynthesis, but caused toxic intermediate 3-hydroxypropionaldehyde (3-HPA) accumulation. Furthermore, semi-rational design of aldehyde dehydrogenase (YdcW) increased its activity and eliminated 3-HPA accumulation. Finally, fed-batch fermentation of the final strain resulted in 52.73 g/L 3-HP, with a yield of 0.59 mol/mol glucose.
研究领域:
生物化学
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合成生物学
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微生物学
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产品关联
DOI
PubMed
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2017
·Vol. 40
·期 6
·901-910
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IF 1.87
Zhang Qiang,Gong Jin-Song,Dong Ting-Ting,Liu Ting-Ting,Li Heng,Dou Wen-Fang,Lu Zhen-Ming,Shi Jin-Song,Xu Zheng-Hong
3-Hydroxypropionic acid (3-HP) is an important platform chemical in organic synthesis. Traditionally, 3-HP was produced by chemical methods and fermentation process. In this work, a novel enzymatic method was developed for green synthesis of 3-HP. A yeast strain harboring nitrile-hydrolyzing enzyme was newly isolated from environmental samples using 3-hydroxypropionitrile (3-HPN) as the sole nitrogen source. It was identified to be Meyerozyma guilliermondii CGMCC12935 by sequencing of the 18S ribosomal DNA and internal transcribed spacer, together with analysis of the morphology characteristics. The catalytic properties of M. guilliermondii CGMCC12935 resting cells were determined, and the optimum activity was achieved at 55 °C and pH 7.5. The enzyme showed broad substrate specificity towards nitriles, especially 3-HPN, aminoacetonitrile and 3-cyanopyridine. The presence of Ag + , Pb 2+ and excess substrate inhibited the enzyme activity, whereas 5% (v/v) ethyl acetate had a positive effect on the enzyme activity. M. guilliermondii CGMCC12935 resting cells by addition of 3% glucose could thoroughly hydrolyze 500 mM 3-HPN into 3-HP within 100 h and the maximal accumulative production of 3-HP reached 216.33 mM, which was over twofolds than the control group with no additional glucose. And this work would lay the foundation for biological production of 3-HP in industry.
研究领域:
生物化学
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工业微生物学
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DOI
PubMed
高影响因子
CELLULOSE
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2017
·Vol. 24
·期 12
·5327-5339
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IF 3.417
Gan Linhuo,Zhu Jundong,Lv Li
Acidic carbonaceous solids were synthesized from mass pine alkali lignin via hydrothermal carbonization followed by sulfonation. Hydrothermal carbonization of lignin in the presence of acrylic acid (LAHC-SO 3 H) provided many more carboxylic groups than that in the absence of acrylic acid, allowing subsequent sulfonation to produce a highly active and stable catalyst for cellulose hydrolysis in the [BMIM]Cl-H 2 O solvent system. The hydrochar and catalyst were characterized using field emission scanning electron microscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, thermal gravimetric analysis, Fourier transform infrared spectrometer, Brunauer–Emmett–Teller and acid–base titration. Results showed that a high acid content of 5.48 mmol/g, including carboxylic group (2.85 mmol/g), phenolic hydroxyl group (1.05 mmol/g) and sulfonic acid group (1.58 mmol/g), contributed significantly to the highly efficient hydrolysis of cellulose. Further, it was found that addition of trace water in [BMIM]Cl was favorable to cellulose hydrolysis. The highest yield (75.4%) of total reducing sugar (TRS) obtained in [BMIM]Cl-H 2 O at a mass ratio of 100:1 was more than twice that (36.1%) achieved in [BMIM]Cl without water; the corresponding reaction conditions were 50 mg of microcrystalline cellulose, 30 mg of catalyst, 1.0 g of [BMIM]Cl, 10 mg of H 2 O, reaction temperature of 130 °C and reaction time of 2 h. Furthermore, the TRS yield with 5 cycles for LAHC-SO 3 H was higher than 68.1%, and the catalytic activity of catalyst could be fully recovered (74.0% of TRS yield) easily by regeneration.
研究领域:
生物化学
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催化化学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2012
·
IF 2.237
Weina Liu,Yucui Hou,Weize Wu,Zhenyu Liu,Qingya Liu,Shidong Tian,Kenneth N. Marsh
Cellulose is the most widely distributed source of biomass, and its efficient conversion to a variety of chemicals is important for a sustainable future. In this work, sulfur dioxide (SO2) dissolved in hot water has been demonstrated to be an efficient catalyst for the selective conversion of cellulose to chemicals such as glucose and levulinic acid. The selectivity of products can be tuned by the SO2 concentration, temperature, and reaction time. SO2 acts both as a supply of H+ ions through ionization of H2SO3 when dissolved in water and as a Lewis acid catalyst that breaks the hydrogen bonds in cellulose. Importantly, SO2 in the reaction mixture can be recovered completely by stream stripping, thus avoiding the formation of acidic wastewater. This work provides a new, efficient, and environmentally benign way to convert cellulose to chemicals.
研究领域:
化学工程
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可持续化学
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生物质转化
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xuezhi Wang,Yuan Sun,Ming Liu,Guyu You,Ting Fan,Hongmiao Wu,Liwei Xu,Xiaoli Zhao,Dongjie Ma
Polylactic acid (PLA) plastic is increasingly recognized as a sustainable alternative to petroleum-based plastics. However, its biodegradability remains a challenge, requiring substantial improvements to its biodegradation efficiency. This study explored the use of combined hydrothermal treatment (HTT) (160°C–240°C) and anaerobic digestion (AD) to improve methane yield from PLA. HTT enhanced significant structural changes in PLA, yielding 2-hydroxypropanoic acid, 1-decanol, 1-tetradecanol, pentan-2-one, and butyl 2-hydroxypropanoate, which facilitated PLA degradation. The methane yield from AD of hydrothermal-treated PLA (HTT-PLA) products at 180°C was 493 NmL/g-volatile solid, a 21.4-fold increased compared to untreated PLA. Genomic and proteomic analyses identified key genes and proteins involved in HTT-PLA products biodegradation, elucidating pathway for HTT-PLA products transformation in biodegradation process. The residues from AD of HTT-PLA products at 180°C exhibited rapeseeds germination index of approximately 90% and maintain stability locomotion and vitality in Caenorhabditis elegans , indicating their suitability for land application. Enhanced methane production offers a renewable energy source, and reduces PLA’s environmental footprint, providing significant practical implications for bioplastic waste management and sustainability.
研究领域:
环境科学
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生物技术
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可再生能源
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微生物学
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毒理学
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DOI
高影响因子
ACS Synthetic Biology
·
2024
·
IF 3.7
Xiao Ning,Fei Li,Xinlei Wei,Zhiguang Zhu,Chun You
3-Hydroxypropionic acid (3-HP) is a highly sought-after platform chemical serving as a precursor to a variety of high value-added chemical products. In this study, we designed and constructed a novel light-powered in vitro synthetic enzymatic biosystem comprising acetyl-CoA ligase, acetyl-CoA carboxylase, malonyl-CoA reductase, and phosphotransferase to efficiently produce 3-HP through CO2 fixation from acetate, a cost-effective and readily available substrate. The system employed natural thylakoid membranes (TMs) for the regeneration of adenosine triphosphate and nicotinamide adenine dinucleotide phosphate. Comprehensive investigations were conducted on the effects of buffer solutions, substrate concentrations, enzyme loading levels, and TMs loading levels to optimize the yield of 3-HP. Following optimization, a production of 0.46 mM 3-HP was achieved within 6 h from an initial 0.5 mM acetate, with a yield nearing 92%. This work underscores the simplicity of 3-HP production via an in vitro biomanufacturing platform and highlights the potential for incorporating TMs as a sustainable and environmentally friendly approach in biomanufacturing processes.
研究领域:
生物技术
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生物化学
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环境科学
·
合成生物学
✓ 已验证
DOI
PubMed
高影响因子
mBio
·
2024
·
IF 5.1
Jiejie Shen,Wenping Wu,Kangle Wang,Jingyi Wu,Bing Liu,Chunyang Li,Zijun Gong,Xin Hong,Han Fang,Xingwei Zhang,Xiaoling Xu
Acetyl-CoA carboxylases (ACCs) convert acetyl-CoA to malonyl-CoA, a key step in fatty acid biosynthesis and autotrophic carbon fixation pathways. Three functionally distinct components, biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and carboxyltransferase (CT), are either separated or partially fused in different combinations, forming heteromeric ACCs. However, an ACC with fused BC-BCCP and separate CT has not been identified, leaving its catalytic mechanism unclear. Here, we identify two BC isoforms (BC1 and BC2) from Chloroflexus aurantiacus, a filamentous anoxygenic phototroph that employs 3-hydroxypropionate (3-HP) bi-cycle rather than Calvin cycle for autotrophic carbon fixation. We reveal that BC1 possesses fused BC and BCCP domains, where BCCP could be biotinylated by E. coli or C. aurantiacus BirA on Lys553 residue. Crystal structures of BC1 and BC2 at 3.2 Å and 3.0 Å resolutions, respectively, further reveal a tetramer of two BC1-BC homodimers, and a BC2 homodimer, all exhibiting similar BC architectures. The two BC1-BC homodimers are connected by an eight-stranded β-barrel of the partially resolved BCCP domain. Disruption of β-barrel results in dissociation of the tetramer into dimers in solution and decreased biotin carboxylase activity. Biotinylation of the BCCP domain further promotes BC1 and CTβ-CTα interactions to form an enzymatically active ACC, which converts acetyl-CoA to malonyl-CoA in vitro and produces 3-HP via co-expression with a recombinant malonyl-CoA reductase in E. coli cells. This study revealed a heteromeric ACC that evolves fused BC-BCCP but separate CTα and CTβ to complete ACC activity.
研究领域:
生物化学
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分子生物学
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结构生物学
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微生物学
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产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Yufei Zhang,Junhua Yun,Hossain M. Zabed,Yuan Dou,Guoyan Zhang,Mei Zhao,Mohammad J. Taherzadeh,Arthur Ragauskas,Xianghui Qi
3-Hydroxypropionic acid (3-HP) and 1,3-propanediol (1,3-PDO) are value-added chemicals with versatile applications in the chemical, pharmaceutical, and food industries. Nevertheless, sustainable production of 3-HP and 1,3-PDO is often limited by the lack of efficient strains and suitable fermentation configurations. Herein, attempts have been made to improve the co-production of both metabolites through metabolic engineering of Escherichia coli and process optimization. First, the 3-HP and 1,3-PDO co-biosynthetic pathways were recruited and optimized in E. coli , followed by coupling the pathways to the transhydrogenase-mediated cofactor regeneration systems that increased cofactor availability and product synthesis. Next, pathway rebalancing and block of by-product formation significantly improved 3-HP and 1,3-PDO net titer. Subsequently, glycerol flux toward 3-HP and 1,3-PDO synthesis was maximized by removing metabolic repression and fine-tuning the glycerol oxidation pathway. Lastly, the combined fermentation process optimization and two-stage pH-controlled fed-batch fermentation co-produced 140.50 g/L 3-HP and 1,3-PDO, with 0.85 mol/mol net yield.
研究领域:
生物技术
·
代谢工程
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化学工程
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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）