Biotechnology for Biofuels
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2018
·Vol. 11
·期 1
·1-13
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IF 5.497
Liu Ya-Jun,Liu Shiyue,Dong Sheng,Li Renmin,Feng Yingang,Cui Qiu
Background Clostridium thermocellum is considered one of the most efficient natural cellulose degraders because of its cellulosomal system. As the major exoglucanase of cellulosome in C. thermocellum, Cel48S plays key roles and influences the activity and features of cellulosome to a great extent. Thus, it is of great importance to reveal the enzymatic features of Cel48S. However, Cel48S has not been well performed due to difficulties in purifying either recombinant or native Cel48S proteins.Results We observed that the soluble fraction of the catalytic domain of Cel48S (Cel48S_CD) obtained by heterologous expression in Escherichia coli and denaturation-refolding treatment contained a large portion of incorrectly folded proteins with low activity. Using a previously developed seamless genome-editing system for C. thermocellum, we achieved direct purification of Cel48S_CD from the culture supernatant of C. thermocellum DSM1313 by inserting a sequence encoding 12 successive histidine residues and a TAA stop codon immediately behind the GH domain of Cel48S. Based on the fully active protein, biochemical and structural analyses were performed to reveal its innate characteristics. The native Cel48S_CD showed high activity of 117.61 ± 2.98 U/mg and apparent substrate preference for crystalline cellulose under the assay conditions. The crystal structure of the native GH48 protein revealed substrate-coupled changes in the residue conformation, indicating induced-fit effects between Cel48S_CD and substrates. Mass spectrum and crystal structural analyses suggested no significant posttranslational modification in the native Cel48S_CD protein.Conclusion Our results confirmed that the high activity and substrate specificity of Cel48S_CD from C. thermocellum were consistent with its importance in the cellulosome. The structure of the native Cel48S_CD protein revealed evidence of conformational changes during substrate binding. In addition, our study provided a reliable method for in situ purification of cellulosomal and other secretive proteins from C. thermocellum.
研究领域:
生物化学
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微生物学
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结构生物学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2017
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IF 3.582
Bin-Bin Hu,Ming-Jun Zhu
Clostridium thermocellum 27405 is a potential consolidated bioprocessing (CBP) strain due to the efficient lignocellulose degradation ability. Here, the spent mushroom substrate (SMS), a lignocellulosic byproduct of agriculture, was used as a substrate for hydrogen production by C. thermocellum . SMS showed a good performance for hydrogen production and the hydrogen production was significantly enhanced by C. thermocellum supplemented with β-glucosidases, with the highest production reaching 56.0 mM, an increase of 37%. Additionally, β-glucosidase and Triton X-100 had a synergistic effect on biological saccharification , resulted in an accumulation of 5.06 g/L reducing sugars, an increase of 28%. However, fusion β-glucosidase showed no improvement on hydrogen production and biological saccharification. The present study demonstrates the different influences of β-glucosidase and fusion β-glucosidase on hydrogen production and biological saccharification in CBP system and provides valuable information on the biodegradation of SMS using C. thermocellum .
研究领域:
微生物学
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生物工程
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产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
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2013
·
IF 4.387
Yun Fa,Haiyan Yang,Chengshuai Ji,He Cui,Xinshu Zhu,Juan Du,Jun Gao
An improved method for the simultaneous determination of 20 amino acids and 7 carbohydrates using one-valve switching after injection, ion chromatography, and integrated pulsed amperometric detection is proposed. The resolution of the amino acids and carbohydrates in the cation trap column was investigated. In addition, parameters including flow liquid type, flow rate, concentration, and valve-switch timing were optimized. The method is time-saving, effective, and accurate for the simultaneous separation of amino acids and carbohydrates, with a mean correlation coefficient of >0.99 and repeatability of 0.5–4.6% for eight replicates. The method was successfully applied in the analysis of amino acids and carbohydrates in aseptic media and in extracellular culture media of three phenotypes of Clostridium thermocellum .
研究领域:
生物化学
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微生物学
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产品关联
DOI
PubMed
高影响因子
FUEL
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2022
·
IF 8.035
Huilei Wang,Yilin Le,Jianzhong Sun
Bioconversion of biomass to bioenergy and recycle of cadmium wastewater are widespread and of significant economic importance. The development of an efficient and cost effective bioconversion process remains challenging. Here, recycling cadmium and un-pretreated biomass conversion were combined into a single operation. A modified consolidated bioprocessing (CBP) strategy of biomass and synthetic cadmium wastewater as mixed substrates for hydrogen generation through a couple of whole-cell catalysis with photocatalysis was established by Clostridium thermocellum . The process was accomplished by biotransformation of cadmium ions to cadmium sulfide (CdS) by C. thermocellum . The formed hybrid C. thermocellum -CdS complex converted biomass into hydrogen production through the integration of two reactions together, biocatalysis and photocatalysis. After optimization, the hydrogen production produced by C. thermocellum- CdS was remarkably increased by 36.1% if compared with that by C. thermocellum only . This exploration is expected to provide a novel strategy of collaborative disposal of cadmium wastewater and waste biomass, which would not only bring a great potential in the recycling and reusing of cadmium wastewater and waste biomass, but also provide new approach both for bioenergy recovery and environmental improvement.
研究领域:
生物能
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环境科学
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微生物学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2015
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IF 3.313
Huan-Na Lin,Bin-Bin Hu,Ming-Jun Zhu
Clostridium thermocellum can degrade lignocellulosic materials to produce hydrogen , acetate, lactate and ethanol, and surfactants have been proven to have the ability of increasing the enzymatic hydrolysis of cellulosic substrates. Here, the effects of surfactants on the fermentation of spent mushroom compost by C. thermocellum were investigated and their underlying mechanisms were preliminarily studied. PEG8000 and JFC-E had different effects on the fermentation performance of spent mushroom compost. Under optimum conditions, PEG8000 increased the hydrogen production by 59.78%, compared to the control without surfactant, while JFC-E improved the accumulation of glucose and xylose rather than hydrogen yield. PEG8000 also had different impacts on the bioconversion of non-lignin substrates (Avicel, carboxyl methyl cellulose and filter paper). With added PEG8000, the hydrogen production was improved when using Avicel as the substrate, and with PEG8000, the yields of products and sugar accumulation were different from those without PEG8000, indicating that PEG8000 may increase the hydrogen yield by shifting the microbial metabolism.
研究领域:
微生物学
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生物能
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2022
·
IF 14.224
Huilei Wang,Yilin Le,Jianzhong Sun
Widespread application of synthetic dyes could generate colored wastewaters causing a range of serious environmental problems. Due to the complex nature of effluents from textile industries , it is difficult to obtain satisfactory treatment of dyes-contaminated wastewater using one single method. Biohybrids coupling of photocatalysts and biocatalysts have great potential in environmental purification. However, how to select suitable organisms and enhance the hybrid’s catalytic activities remain challenging. Here, a novel biohybrid system ( Clostridium thermocellum -CdS), created for light-driven biodecolorization under thermophilic treatment by using non-photosynthetic microorganism C. thermocellum self-photosensitized with CdS nanoparticles was established. The biohybrids exhibited remarkable decolorization effects on triphenylmethane dyes. The highest decolorization rate was 0.206 min −1 . More importantly, enhanced catalytic activities of cadmium sulfide (CdS)-based biohybrids by controlling the particle sizes of semiconductors were demonstrated. Biohybrids systems ( Clostridium thermocellum -CdS) through the self-precipitation of CdS with different particle sizes not only showed dramatic changes in the optical properties but also exhibited a very different decolorization rate. This work can not only further broaden targeted applications of CdS-based biohybrids but also demonstrate a promising route for improving biohybrids corresponding photocatalytic capabilities through in situ precipitation CdS with different particle sizes.
研究领域:
环境科学
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微生物学
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光催化
✓ 已验证
DOI
PubMed
高影响因子
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