INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
·
IF 7.7
Jinxian Shan,Feiyun Li,Hongming Lou,Yanjun Tang
The cost of enzymolysis is a major bottleneck for the industrialisation of lignocellulosic enzymatic hydrolysis technology, and recycling cellulase can reduce this cost. Herein, a sulfobetaine prepolymer (CPS) with terminal chlorine was grafted onto enzymatic hydrolysis residual lignin (EHL) from corncob to construct thermosensitive lignin-based “molecular glues” (lignin-based sulfobetaine polymers, L-CPS) that were used to recover and recycle cellulase. L-CPS 2 (1.0 g/L) was added to the corncob residue (CCR) enzymolysis system (50 °C, pH 4.5). After hydrolysis, L-CPS 2 co-precipitated with cellulase through hydrophobic binding when cooling to 25 °C. This co-precipitation decreased the amount of cellulase by 40 %. In summary, a thermally responsive lignin-based molecular glue was constructed for green recycling of cellulase, providing a new approach to decreasing the cost of lignocellulosic enzymolysis and high value utilisation of industrial lignin.
研究领域:
生物化学
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可再生资源工程
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产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Hong Guo,Shaolan Zou,Boshi Liu,Rongxin Su,Renliang Huang,Wei Qi,Minhua Zhang,Zhimin He
Enzyme recycling by re-adsorption is one of the primary methods for reducing enzyme usage in lignocellulose conversion. This work proposes the combination of an engineered yeast strain that expresses β-glucosidase with enzyme recycling to reduce the amount of supplemented β-glucosidase in enzyme recycling experiments. Using the engineered strain, a slight increase in ethanol concentration was obtained after a 96-h fermentation of pretreated corncobs. Ethanol concentrations increased by 34.7% and 62.7% in the following two recycle rounds using the engineered strain compared with those using its parental strain without β-glucosidase addition. Furthermore, with the addition of β-glucosidase at 30 CBU/g cellulose, the ethanol concentration after two recycle rounds exceeded 90% of that observed in the first SSF round with the engineered strain at a high initial cellulase loading of 45 FPU/g cellulose.
研究领域:
生物技术
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酶工程
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发酵工程
✓ 已验证
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 5
·1141-1151
·
IF 9.405
Cheng Cai,Yu Bao,Xuejuan Zhan,Xuliang Lin,Hongming Lou,Yuxia Pang,Yong Qian,Xueqing Qiu
The conversion of lignocelluloses into fermentable sugars by enzymatic hydrolysis is a key step in biorefining. However, there are still some bottleneck problems such as low hydrolysis efficiency, high cost of cellulase and low utilization of lignin. In this work, the nonionic surfactant monomethoxy polyethylene glycol (MPEG) was grafted on enzymatic hydrolysis lignin (EHL) to obtain a pH-responsive polymer (EHL-MPEG). EHL-MPEG could achieve rapid dissolution–precipitation conversion by the ionization and protonation of carboxyl groups. By adjusting the grafting amount of MPEG, EHL-MPEG could not only enhance the enzymatic hydrolysis of lignocelluloses, but also efficiently recover cellulase after hydrolysis. Adding 3 g L−1 EHL-MPEG40 (the mass ratio of MPEG to EHL was 40%) could increase the glucose yield of corncob residue (CCR) and pretreated eucalyptus from 79.4% and 48.3% to 92.5% and 89.5%, respectively, which was comparable to the effect of the nonionic surfactant PEG4600. By simply adjusting the pH of solutions, more than 85% of cellulase proteins could be recovered by EHL-MPEG40 with almost complete recovery of β-glycosidase, exoglucanase V and xylanase. Compared with a pH-responsive lignin amphoteric surfactant (pH-LAS) obtained by grafting ionic groups on lignin, EHL-MPEG40 had a more sensitive pH response and a stronger cellulase recovery ability. In the enzymatic hydrolysis of CCR, a pH-LAS could save about 50% of cellulase, while EHL-MPEG40 could save more than 60% of cellulase. Furthermore, approximately 96% of EHL-MPEG40 could be reused. This new method can not only evade the process of immobilization, but also avoid the activity loss and component change of cellulase through immobilization. Using recyclable EHL-MPEG to improve glucose yield and recover cellulase during lignocellulosic hydrolysis is of great significance for improving the enzymatic saccharification process, reducing the cost of cellulase and realizing comprehensive utilization of lignocelluloses.
研究领域:
生物化学
·
可再生资源技术
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产品关联
DOI
高影响因子
BIOTECHNOLOGY AND BIOENGINEERING
·
2016
·Vol. 114
·期 3
·543-551
·
IF 4.243
Renliang Huang,Hong Guo,Rongxin Su,Wei Qi,Zhimin He
Recycling cellulases by substrate adsorption is a promising strategy for reducing the enzyme cost of cellulosic ethanol production. However, β-glucosidase has no carbohydrate-binding module (CBM). Thus, additional enzymes are required in each cycle to achieve a high ethanol yield. In this study, we report a new method of recycling cellulases without β-glucosidase supplementation using lignocellulosic substrate, an engineered strain expressing β-glucosidase and Tween 80. The cellulases and Tween 80 were added to an aqueous suspension of diluted sulfuric acid/ammonia-treated corncobs in a simultaneous saccharification and fermentation (SSF) process for ethanol production. Subsequently, the addition of fresh pretreated corncobs to the fermentation liquor and remaining solid residue provided substrates with absorbed cellulases for the next SSF cycle. This method provided excellent ethanol production in three successive SSF cycles without requiring the addition of new cellulases. For a 10% (w/v) solid loading, a cellulase dosage of 30 filter paper units (FPU)/g cellulose, 0.5% Tween 80, and 2 g/L of the engineered strain, approximately 90% of the initial ethanol concentration from the first SSF process was obtained in the next two SSF processes, with a total ethanol production of 306.27 g/kg corncobs and an enzyme productivity of 0.044 g/FPU. Tween 80 played an important role in enhancing cellulase recovery. This new enzyme recycling method is more efficient and practical than other reported methods. Biotechnol. Bioeng. 2017;114: 543–551. © 2016 Wiley Periodicals, Inc.
研究领域:
生物技术
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酶工程
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发酵工程
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产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2024
·
IF 5.5
Xiwen Jia,Dong Liu,Hao Lin,Hui Zhang,Xueyan Liang,Kaili Ding,Guanya Ji,Lujia Han,Weihua Xiao
Background The simultaneous saccharification and co-fermentation (SSCF) at high solid loading is an effective approach to improve the economic feasibility of bioethanol. Methods In this study, the high-solid SSCF of superfine grinding corn stover was treated with cheap and readily available deionized water (DW) instead of sodium citrate buffer solution (SCBS). Additionally, the evaluation of temperature, enzyme loading, solid loading, and cellulose recovery were carried out to determine their impact on ethanol production. Significant Findings The results of the analysis indicated that replacing SCBS with DW had negligible effects on the SSCF of ethanol and byproducts (acetic acid and glycerol). The ethanol yield increased by 18 % at 35 °C compared to the yield at 30 °C. As enzyme loading increased, more cellulose active sites in corn stover were bound by cellulase , which increased the ethanol yield by improving the efficiency of enzymatic hydrolysis. The SSCF process didn't incorporate any buffer, resulting in an even higher ethanol titer (55.42 g/L). Furthermore, the cellulase productivity increased by 71 % after recovery, compared to the non-recovery. The results indicated that the optimized SSCF process is a potential technique for producing bioethanol on a commercial level because it improves the production efficiency while keeping costs low.
研究领域:
生物技术
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Feiyun Li,Yuxia Pang,Hongming Lou,Xueqing Qiu
Recycling cellulase can reduce the cost of lignocellulosic enzymatic hydrolysis. Here, a lignin-grafted sulfobetaine (LSB) was first synthesized by grafting sulfobetaine (SB) on enzymatic hydrolysis lignin (EHL). LSB had a sensitive response of pH and temperature. LSB dissolved under the conditions of lignocellulosic enzymatic hydrolysis (pH 5.0, 50 °C). After hydrolysis, LSB co-precipitated with cellulase when lowering pH of the hydrolysate to 4.0 and cooling to 25 °C. When 3.0 g/L LSB-100 was added to the hydrolysis system of corncob residue (CCR), 70 % of amount of cellulase was saved. LSB had a remarkable response and stronger cellulase recovery capacity. This was attributed that carboxylate radical in LSB was protonated, and positive and negative ions of SB associated to form salt at 25 °C. This work provides a new idea for reducing the cost for preparing fermentable sugars from lignocellulose, and increasing the added value of EHL.
研究领域:
生物化学
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生物质工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Cheng Cai,Yuxia Pang,Xuejuan Zhan,Meijun Zeng,Hongming Lou,Yong Qian,Dongjie Yang,Xueqing Qiu
Some zwitterionic surfactants exhibit upper critical solution temperature (UCST) in aqueous solutions. For the zwitterionic surfactant solution mixed with cellulase, when its temperature is below UCST, the cellulase can be recovered by coprecipitation with zwitterionic surfactant. In this work, 3-(Hexadecyldimethylammonio) propanesulfonate (SB3-16) was selected to enhance the enzymatic hydrolysis of lignocelluloses and recover the cellulase. After adding 2 mmol/L of SB3-16, the enzymatic digestibility of eucalyptus pretreated by dilute acid (Eu-DA) and by sulfite (Eu-SPORL) increased from 27.9% and 35.1% to 72.6% and 89.7%, respectively. The results showed that SB3-16 could reduce the non-productive adsorption of cellulase on hydrophobic interface, while it did not significantly inhibit the activity of cellulase. For the solution contained 1 wt% SB3-16 and 200 mg protein/L CTec2 cellulase, 55.2% of protein could be recovered by cooling. The filter paper activity of the recovered cellulase was 1.93 FPU/mg protein, which was 95.8% of its initial activity.
研究领域:
生物化学
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可再生资源与环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 6
·587
·
IF 4.501
Guosi Li,Fucheng Zhu,Fangli Gu,Xinjian Yin,Qilin Xu,Menghua Ma,Li Zhu,Baowei Lu,Naidong Chen
Reaction coupling separation systems using calcium fumarate as a substrate can break the reaction equilibrium and promote the production ofl-malate. However, the low reusability and stability of fumarase limit its further application. In this study, partially purified fumarase ofThermus thermophilus(87.0 U mg−1) was immobilized within konjac-κ-carrageenan beads. An amalgamation of konjac and carrageenan gum (2%) was used to form the beads, and polyethylene polyamine (0.2%) and glutaraldehyde (0.1%) were used as the cross-linking agents. The pH and temperature profiles of free and immobilized fumarases were remarkably similar. The diffusion limit of immobilized fumarase caused a decline in the maximal velocity (Vmax), whereas the kinetic constant (Km) value increased. Optimization of the parameters for biotransformation by immobilized fumarase showed that 88.3% conversion of 200 mM calcium fumarate could be achieved at 55 °C within 8 h. The beads were stored for 30 days at 4 °C with minimal loss in activity and were reusable for up to 20 cycles with 78.1% relative activity. By recycling the reaction supernatant, a total amount of 3.98 M calcium fumarate was obtained with a conversion of 99.5%, which is the highest value ever reported.Keywords:l-malate;fumarase;immobilization;konjac-κ-carrageenan beads
研究领域:
生物化学
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酶学
·
生物技术
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Xinyue Pan,Feiyun Li,Peng Yuan,Yanjun Tang
Enzymatic strengthening and cellulase recovery are effective ways for improving the economy of lignocellulosic hydrolysis. A series of temperature-responsive quaternary ammonium salt type enzymatic hydrolysis promoters (PSDM) were obtained by aqueous-solution free radical polymerization. PSDM dissolved under lignocellulosic enzymatic hydrolysis conditions (50°C). After hydrolysis, it co-precipitated with cellulase when cooling. PSDM had significantly improved hydrolysis and recycling enzyme properties. The efficiency of high-solid substrate enzymatic hydrolysis of corncob residues improved to 1.2 times, and 50% of the cellulase amount was saved when adding 1.5 g/L of PSDM 1 to the system. Hydrophobic binding may be the main driving force for co-precipitation between PSDM and cellulase. In this work, regulation of glucose yield and cellulase consumption were realized by adjusting the ratio of positive and negative charges in PSDM. This work provides a new idea for reducing the cost of technology for this lignocellulosic sugar platform.
研究领域:
生物化学
·
材料科学
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可再生资源技术
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产品关联
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 11
·6725-6738
·
IF 3.917
Liang You,Zeng Meijun,Cai Cheng,Zhan Xuejuan,Pang Yuxia,Lou Hongming,Qiu Xueqing
Abstract A linear pH-responsive zwitterionic copolymer P(MDB) was synthesized from functional monomers methacrylic acid, 2-(dimethylamino) ethyl methacrylate (DMA) and benzyl methacrylate (BMA) through free radical polymerization to recover cellulases and enhance the enzymatic hydrolysis. The hydrophobicity and molecular weight of the copolymer was controlled by the feed ratio of monomers and the mass ratio of initiator to monomers, respectively. UV-turbidity showed P(MDB) exhibited sensitive pH-responsiveness with dissolution–precipitation ΔpH about 1 pH unit. The precipitation pH φ of P(MDB) was 5.0–5.5 and over 90% of P(MDB) could precipitate in the vicinity of its isoelectric point. Increasing the hydrophobicity or molecular weight of P(MDB) could improve its pH sensitivity and precipitation rate. P(MDB) could enhance the enzymatic hydrolysis of dilute acid pretreated Eucalyptus by 10–25%. P(MDB) could recover the free cellulases in enzymatic hydrolysate by co-precipitation. SDS-PAGE analysis showed that P(MDB) could recover 100% β-glucosidase (β-GL) and the recovery rates of cellobiohydrolase (CBH) and endoglucanase (EG) increased as the hydrophobicity and molecular weight of P(MDB) increased. The mechanism was proposed that hydrophobic affiliation was the main binding force of P(MDB) to cellulases. Increasing the hydrophobicity and molecular weight of copolymer could increase its binding force and the number of binding sites to cellulases thus the overall cellulase recovery performance was improved. Graphic abstract
研究领域:
生物化学
·
材料科学
·
可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2021
·Vol. 23
·期 7
·2738-2746
·
IF 10.182
Feiyun Li,Feiyang Qin,Yuxia Pang,Hongming Lou,Cheng Cai,Weifeng Liu,Yong Qian,Xueqing Qiu
In order to reduce the enzyme cost of lignocellulosic enzymatic hydrolysis, upper critical solution temperature (UCST) additives are used to recover and reuse cellulase by regulating the temperature. A sulfobetaine polymer, PSPE, showed a sensitive UCST response in buffer, and its UCST-performance was optimised by adjusting the molecular weight of the polymer. PSPE-3 (Mw = 355.1 kDa) was added to the cellulase buffer at 50 °C, and PSPE-3 and cellulase were co-precipitated by cooling to the room temperature of 25 °C. PSPE-3 and cellulase co-precipitated mainly through hydrophobic interactions via cooling. Compared with octadecyl sulfobetaine (SB3–18), PSPE-3 had a more sensitive UCST response and stronger cellulase recovery ability. Adding only 40% PSPE-3 (accounting for the mass fraction of cellulase) can save more than 50% cellulase in the enzymatic hydrolysis system of eucalyptus chips pre-treated with dilute acid (Eu-DA). However, for the Eu-DA system, adding 100% SB3–18 can only save about 30% of cellulase. In this work, efficient recycling of cellulase was achieved at room temperature by adding UCST-type PSPE. The process is green without consuming acid and alkali, and this work provides a new idea for reducing the production cost of cellulosic ethanol.
研究领域:
生物化学
·
可再生资源与环境工程
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Xueying Chen,Yuxiao Hu,Zhijian Tan
Traditional three-phase partitioning (TPP) systems used for extracting and purifying bioactive substances typically consist of t -butanol and ammonium sulfate. However, the use of volatile and flammable organic solvents and high-concentration inorganic salts results in environmental pollution. Therefore, an innovative TPP based on deep eutectic solvents (DESs) and sugars (sugaring-out effect) was used to extract and preliminarily purify cucumber peroxidase (POD). Various factors affecting the extraction were optimized using response surface methodology (RSM). DES-8 (menthol: octanoic acid = 1:1) and sucrose were selected as the optimal constituents of TPP. Under these conditions, the sucrose concentration was 36% (w/v), DES: crude extract (v/v) was 1.4:1, system pH was not adjusted, extraction time was 6 min, and extraction temperature was 31 °C; the enzyme recovery and purification fold reached 84.53% and 5.28, respectively. Recycling experiments demonstrated that the DESs can be well recycled and reused after five recycles. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze cucumber POD, which showed that the TPP system achieved primary purification of cucumber POD. This TPP is much greener and more efficient than traditional TPP systems and shows great application potential in the enzymes and proteins separation field.
研究领域:
生物化学
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生物技术
·
环境科学
·
酶学
✓ 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）