1
|
Feng S, Pan L, Li Q, Zhang Y, Mou F, Liu Z, Zhang Y, Duan L, Qin B, Hu Z. The Isolation, Identification and Immobilization Method of Three Novel Enzymes with Diosgenin-Producing Activity Derived from an Aspergillus flavus. Int J Mol Sci 2023; 24:17611. [PMID: 38139441 PMCID: PMC10743735 DOI: 10.3390/ijms242417611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 12/15/2023] [Accepted: 12/16/2023] [Indexed: 12/24/2023] Open
Abstract
Diosgenin is an important raw material used in the synthesis of steroid drugs, and it is widely used in the pharmaceutical industry. The traditional method of producing diosgenin is through using raw materials provided via the plant Dioscorea zingiberensis C. H. Wright (DZW), which is subsequently industrially hydrolyzed using a high quantity of hydrochloric and sulfuric acids at temperatures ranging from 70 °C to 175 °C. This process results in a significant amount of unmanageable wastewater, creates issues of severe environmental pollution and consumes high quantities of energy. As an alternative, the enzymolysis of DZW to produce diosgenin is an environmentally and friendly method with wide-ranging prospects for its application. However, there are still only a few enzymes that are suitable for production on an industrial scale. In this study, three new key enzymes, E1, E2, and E3, with a high conversion stability of diosgenin, were isolated and identified using an enzyme-linked-substrate autography strategy. HPLC-MS/MS identification showed that E1, a 134.45 kDa protein with 1019 amino acids (AAs), is a zinc-dependent protein similar to the M16 family. E2, a 97.89 kDa protein with 910 AAs, is a type of endo-β-1,3-glucanase. E3, a 51.6 kDa protein with 476 AAs, is a type of Xaa-Pro aminopeptidase. In addition, the method to immobilize these proteins was optimized, and stability was achieved. The results show that the optimal immobilization parameters are 3.5% sodium alginate, 3.45% calcium chloride concentration, 1.4 h fixed time, and pH 8.8; and the recovery rate of enzyme activity can reach 43.98%. A level of 70.3% relative enzyme activity can be obtained after employing six cycles of the optimized technology. Compared with free enzymes, immobilized enzymes have improved stability, acid and alkaline resistance and reusability, which are conducive to large-scale industrial production.
Collapse
Affiliation(s)
- Shirong Feng
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Lintao Pan
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Quanshun Li
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Yi Zhang
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Fangyuan Mou
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Zhao Liu
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Yuanyuan Zhang
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Longfei Duan
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Baofu Qin
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China; (S.F.); (L.P.); (Q.L.); (Y.Z.); (F.M.); (Z.L.); (Y.Z.); (L.D.)
| | - Zhongqiu Hu
- College of Food Science and Engineering, Northwest A&F University, Xianyang 712100, China
| |
Collapse
|
2
|
Nano-biocatalytic Systems for Cellulose de-polymerization: A Drive from Design to Applications. Top Catal 2023. [DOI: 10.1007/s11244-023-01785-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
|
3
|
Guo H, Zhao Y, Chang JS, Lee DJ. Enzymes and enzymatic mechanisms in enzymatic degradation of lignocellulosic biomass: A mini-review. BIORESOURCE TECHNOLOGY 2023; 367:128252. [PMID: 36334864 DOI: 10.1016/j.biortech.2022.128252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Enzymatic hydrolysis is the key step limiting the efficiency of the biorefinery of lignocellulosic biomass. Enzymes involved in enzymatic hydrolysis and their interactions with biomass should be comprehended to form the basis for looking for strategies to improve process efficiency. This article updates the contemporary research on the properties of key enzymes in the lignocellulose biorefinery and their interactions with biomass, adsorption, and hydrolysis. The advanced analytical techniques to track the interactions for exploiting mechanisms are discussed. The challenges and prospects for future research are outlined.
Collapse
Affiliation(s)
- Hongliang Guo
- College of Forestry, Northeast Forestry University, Harbin 150040, China
| | - Ying Zhao
- College of Forestry, Northeast Forestry University, Harbin 150040, China
| | - Jo-Shu Chang
- Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan; Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong; Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-li 32003, Taiwan.
| |
Collapse
|
4
|
Bioethanol Production from Lignocellulosic Biomass-Challenges and Solutions. Molecules 2022; 27:molecules27248717. [PMID: 36557852 PMCID: PMC9785513 DOI: 10.3390/molecules27248717] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Regarding the limited resources for fossil fuels and increasing global energy demands, greenhouse gas emissions, and climate change, there is a need to find alternative energy sources that are sustainable, environmentally friendly, renewable, and economically viable. In the last several decades, interest in second-generation bioethanol production from non-food lignocellulosic biomass in the form of organic residues rapidly increased because of its abundance, renewability, and low cost. Bioethanol production fits into the strategy of a circular economy and zero waste plans, and using ethanol as an alternative fuel gives the world economy a chance to become independent of the petrochemical industry, providing energy security and environmental safety. However, the conversion of biomass into ethanol is a challenging and multi-stage process because of the variation in the biochemical composition of biomass and the recalcitrance of lignin, the aromatic component of lignocellulose. Therefore, the commercial production of cellulosic ethanol has not yet become well-received commercially, being hampered by high research and production costs, and substantial effort is needed to make it more widespread and profitable. This review summarises the state of the art in bioethanol production from lignocellulosic biomass, highlights the most challenging steps of the process, including pretreatment stages required to fragment biomass components and further enzymatic hydrolysis and fermentation, presents the most recent technological advances to overcome the challenges and high costs, and discusses future perspectives of second-generation biorefineries.
Collapse
|
5
|
Cellulose-degrading enzymes: key players in biorefinery development. Biologia (Bratisl) 2022. [DOI: 10.1007/s11756-022-01274-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
6
|
Zhang H, Zhang T, Zang J, Lv C, Zhao G. Construction of alginate beads for efficient conversion of CO2 into vaterite CaCO3 particles. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
7
|
Enhancement of anaerobic digestion performance of corn straw via combined sodium hydroxide-cellulase pretreatment. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
8
|
Di Fabio E, Iazzetti A, Incocciati A, Caseli V, Fabrizi G, Boffi A, Bonamore A, Macone A. Immobilization of Lathyrus cicera Amine Oxidase on Magnetic Microparticles for Biocatalytic Applications. Int J Mol Sci 2022; 23:6529. [PMID: 35742969 PMCID: PMC9223840 DOI: 10.3390/ijms23126529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 12/19/2022] Open
Abstract
Amine oxidases are enzymes belonging to the class of oxidoreductases that are widespread, from bacteria to humans. The amine oxidase from Lathyrus cicera has recently appeared in the landscape of biocatalysis, showing good potential in the green synthesis of aldehydes. This enzyme catalyzes the oxidative deamination of a wide range of primary amines into the corresponding aldehydes but its use as a biocatalyst is challenging due to the possible inactivation that might occur at high product concentrations. Here, we show that the enzyme's performance can be greatly improved by immobilization on solid supports. The best results are achieved using amino-functionalized magnetic microparticles: the immobilized enzyme retains its activity, greatly improves its thermostability (4 h at 75 °C), and can be recycled up to 8 times with a set of aromatic ethylamines. After the last reaction cycle, the overall conversion is about 90% for all tested substrates, with an aldehyde production ranging between 100 and 270 mg depending on the substrate used. As a proof concept, one of the aldehydes thus produced was successfully used for the biomimetic synthesis of a non-natural benzylisoquinoline alkaloid.
Collapse
Affiliation(s)
- Elisa Di Fabio
- Department of Biochemical Sciences “Alessandro Rossi Fanelli”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (E.D.F.); (A.I.); (A.B.)
| | - Antonia Iazzetti
- Department of Chemistry and Technology of Drugs, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (A.I.); (G.F.)
- Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, L.go Francesco Vito 1, 00168 Rome, Italy
| | - Alessio Incocciati
- Department of Biochemical Sciences “Alessandro Rossi Fanelli”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (E.D.F.); (A.I.); (A.B.)
| | - Valentina Caseli
- Center for Life Nano Science@Sapienza, Istituto Italiano Di Tecnologia, V.le Regina Elena 291, 00161 Rome, Italy;
| | - Giancarlo Fabrizi
- Department of Chemistry and Technology of Drugs, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (A.I.); (G.F.)
| | - Alberto Boffi
- Department of Biochemical Sciences “Alessandro Rossi Fanelli”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (E.D.F.); (A.I.); (A.B.)
- Center for Life Nano Science@Sapienza, Istituto Italiano Di Tecnologia, V.le Regina Elena 291, 00161 Rome, Italy;
| | - Alessandra Bonamore
- Department of Biochemical Sciences “Alessandro Rossi Fanelli”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (E.D.F.); (A.I.); (A.B.)
| | - Alberto Macone
- Department of Biochemical Sciences “Alessandro Rossi Fanelli”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (E.D.F.); (A.I.); (A.B.)
| |
Collapse
|
9
|
Gülmez C. Glucose Tolerance, Antiprotease Activity and Total Oxidant/Antioxidant Capacity Studies of β-Glucosidase Hybrid Nanoflower for Industrial Applications. Chem Biodivers 2022; 19:e202200170. [PMID: 35675565 DOI: 10.1002/cbdv.202200170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/27/2022] [Indexed: 11/09/2022]
Abstract
β-Glycosidases, which catalyse the hydrolysis of glycoside bonds, have a wide spectrum of industrial applications. However, the reaction product glucose inhibits the activities of many β-glucosidases. Consequently, the reduced catalytic activities of the enzyme limit the industrial applications of the enzymes. For that reason, the studies dealing with maintaining the activities of the relevant enzymes at high glucose concentrations are a great interest among the researchers. In this context, herein, protein-inorganic hybrid nanoflowers were synthesized using β-glucosidase and copper ion by fast sonication method for 10 min. After characterization of synthesized nanoflowers, pH/temperature studies, glucose tolerance, anti-protease activity, recyclability and total antioxidant and total oxidative capacity levels were estimated. Accordingly, the optimum pHs of free β-glucosidase and hybrid nanoflower (β-GNF) were found to be 6 and 5, respectively, and the optimum temperature values for both hybrid nanoflowers and free enzyme were 40 °C. β-GNF exhibited better activity than free enzyme in low acidic and alkaline environment and at high temperature. The nanoflower retained nearly all (99 %) of its initial activity at all glucose concentrations (0.01, 0.05 and 0.1 mg/mL), especially at pH 5 and 6. Also, β-GNF maintained more than 90 % of initial activity at 0.01 and 0.05 mg/mL glucose at pH 4 and 7. It also displayed about 96 % high residual activity after proteinase K treatment for 3 h at 37 °C, while that of the free β-glucosidase was about 87 %. The reusability studies showed that β-GNF only lost ∼28 % of its initial activities at the end of five cycles. The hybrid nanoflowers at 5 mg/mL concentration exhibited the high total antioxidant capacity. In addition, low total oxidant capacity and oxidative stress index levels were recorded at the same concentration of the hybrid nanoflower. The findings of the present study revealed that β-GNFs may be evaluated as a candidate for various industrial applications due to its high glucose tolerance, anti-protease activity, reusability and resistance to low acidic/alkaline environment and high temperature.
Collapse
Affiliation(s)
- Canan Gülmez
- Department of Pharmacy Services, Tuzluca Vocational High School, Igdir University, 76000, Igdir, Türkiye
| |
Collapse
|
10
|
Cellulase immobilized by sodium alginate-polyethylene glycol-chitosan for hydrolysis enhancement of microcrystalline cellulose. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.02.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
11
|
Ozturk E, Oztop MH, Alpas H. Use of high hydrostatic pressure (HHP) for increasing the product yield of lignocellulosic biomass hydrolysis: A study for peanut hull and microcrystalline cellulose. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
12
|
Guo R, Zheng X, Wang Y, Yang Y, Ma Y, Zou D, Liu Y. Optimization of Cellulase Immobilization with Sodium Alginate-Polyethylene for Enhancement of Enzymatic Hydrolysis of Microcrystalline Cellulose Using Response Surface Methodology. Appl Biochem Biotechnol 2021; 193:2043-2060. [PMID: 33544365 DOI: 10.1007/s12010-021-03517-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/27/2021] [Indexed: 10/22/2022]
Abstract
A novel method of immobilizing cellulase on sodium alginate (SA)-polyethylene glycol (PEG) enabled the cellulase to be used repeatedly. The matrix of the immobilized cellulase was detected and characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. In comparison with SA-immobilized cellulase, the relative enzyme activity and immobilization rate increased by 25% and 18%, respectively. The application range of the immobilized enzyme in terms of temperature and pH was larger than that of the free enzyme, and its thermal stability increased. The immobilized enzyme was used in enzymatic hydrolysis, in which MCC was used as the substrate. The optimal conditions for enzymatic hydrolysis were as follows: the dosage of SA-PEG-immobilized cellulase was 3.55 g/g total solids of the substrate, the concentration of the substrate was 13.16%, and the pH was 5.11. In comparison with the yield of reducing sugars in the first round of hydrolysis of MCC by SA-immobilized cellulase, the yield in the hydrolysis of MCC by SA-PEG-immobilized cellulase increased by 133%. After five cycles of repeated use, the total yield of reducing sugars when MCC was hydrolyzed by SA-PEG-immobilized cellulase was similar to that achieved with free cellulase. In comparison with the free enzyme, the highest yield when the immobilized enzyme was used was 22.68%. Therefore, the immobilized cellulase exhibited high performance in enzymatic hydrolysis.
Collapse
Affiliation(s)
- Rongxin Guo
- Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Xusheng Zheng
- Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yang Wang
- Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yiwen Yang
- Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yifang Ma
- Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Dexun Zou
- Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yanping Liu
- Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
| |
Collapse
|
13
|
Current Developments in Lignocellulosic Biomass Conversion into Biofuels Using Nanobiotechology Approach. ENERGIES 2020. [DOI: 10.3390/en13205300] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The conversion of lignocellulosic biomass (LB) to sugar is an intricate process which is the costliest part of the biomass conversion process. Even though acid/enzyme catalysts are usually being used for LB hydrolysis, enzyme immobilization has been recognized as a potential strategy nowadays. The use of nanobiocatalysts increases hydrolytic efficiency and enzyme stability. Furthermore, biocatalyst/enzyme immobilization on magnetic nanoparticles enables easy recovery and reuse of enzymes. Hence, the exploitation of nanobiocatalysts for LB to biofuel conversion will aid in developing a lucrative and sustainable approach. With this perspective, the effects of nanobiocatalysts on LB to biofuel production were reviewed here. Several traits, such as switching the chemical processes using nanomaterials, enzyme immobilization on nanoparticles for higher reaction rates, recycling ability and toxicity effects on microbial cells, were highlighted in this review. Current developments and viability of nanobiocatalysts as a promising option for enhanced LB conversion into the biofuel process were also emphasized. Mostly, this would help in emerging eco-friendly, proficient, and cost-effective biofuel technology.
Collapse
|
14
|
Kamdem Tamo A, Doench I, Morales Helguera A, Hoenders D, Walther A, Madrazo AO. Biodegradation of Crystalline Cellulose Nanofibers by Means of Enzyme Immobilized-Alginate Beads and Microparticles. Polymers (Basel) 2020; 12:E1522. [PMID: 32660071 PMCID: PMC7407417 DOI: 10.3390/polym12071522] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/29/2020] [Accepted: 07/03/2020] [Indexed: 12/20/2022] Open
Abstract
Recent advances in nanocellulose technology have revealed the potential of crystalline cellulose nanofibers to reinforce materials which are useful for tissue engineering, among other functions. However, the low biodegradability of nanocellulose can possess some problems in biomedical applications. In this work, alginate particles with encapsulated enzyme cellulase extracted from Trichoderma reesei were prepared for the biodegradation of crystalline cellulose nanofibers, which carrier system could be incorporated in tissue engineering biomaterials to degrade the crystalline cellulose nanoreinforcement in situ and on-demand during tissue regeneration. Both alginate beads and microparticles were processed by extrusion-dropping and inkjet-based methods, respectively. Processing parameters like the alginate concentration, concentration of ionic crosslinker Ca2+, hardening time, and ionic strength of the medium were varied. The hydrolytic activity of the free and encapsulated enzyme was evaluated for unmodified (CNFs) and TEMPO-oxidized cellulose nanofibers (TOCNFs) in suspension (heterogeneous conditions); in comparison to solubilized cellulose derivatives (homogeneous conditions). The enzymatic activity was evaluated for temperatures between 25-75 °C, pH range from 3.5 to 8.0 and incubation times until 21 d. Encapsulated cellulase in general displayed higher activity compared to the free enzyme over wider temperature and pH ranges and for longer incubation times. A statistical design allowed optimizing the processing parameters for the preparation of enzyme-encapsulated alginate particles presenting the highest enzymatic activity and sphericity. The statistical analysis yielded the optimum particles characteristics and properties by using a formulation of 2% (w/v) alginate, a coagulation bath of 0.2 M CaCl2 and a hardening time of 1 h. In homogeneous conditions the highest catalytic activity was obtained at 55 °C and pH 4.8. These temperature and pH values were considered to study the biodegradation of the crystalline cellulose nanofibers in suspension. The encapsulated cellulase preserved its activity for several weeks over that of the free enzyme, which latter considerably decreased and practically showed deactivation after just 10 d. The alginate microparticles with their high surface area-to-volume ratio effectively allowed the controlled release of the encapsulated enzyme and thereby the sustained hydrolysis of the cellulose nanofibers. The relative activity of cellulase encapsulated in the microparticles leveled-off at around 60% after one day and practically remained at that value for three weeks.
Collapse
Affiliation(s)
- Arnaud Kamdem Tamo
- Institute of Microsystems Engineering IMTEK, Laboratory for Sensors, University of Freiburg, 79110 Freiburg, Germany; (A.K.T.); (I.D.)
- Freiburg Materials Research Center FMF, University of Freiburg, 79104 Freiburg, Germany; (D.H.); (A.W.)
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT, University of Freiburg, 79110 Freiburg, Germany
| | - Ingo Doench
- Institute of Microsystems Engineering IMTEK, Laboratory for Sensors, University of Freiburg, 79110 Freiburg, Germany; (A.K.T.); (I.D.)
- Freiburg Materials Research Center FMF, University of Freiburg, 79104 Freiburg, Germany; (D.H.); (A.W.)
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT, University of Freiburg, 79110 Freiburg, Germany
| | - Aliuska Morales Helguera
- Chemical Bioactive Center CBQ, Molecular Simulation and Drug Design Group, Central University of Las Villas, Santa Clara 54830, Cuba;
| | - Daniel Hoenders
- Freiburg Materials Research Center FMF, University of Freiburg, 79104 Freiburg, Germany; (D.H.); (A.W.)
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT, University of Freiburg, 79110 Freiburg, Germany
- Institute for Macromolecular Chemistry, University of Freiburg, 79104 Freiburg, Germany
| | - Andreas Walther
- Freiburg Materials Research Center FMF, University of Freiburg, 79104 Freiburg, Germany; (D.H.); (A.W.)
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT, University of Freiburg, 79110 Freiburg, Germany
- Institute for Macromolecular Chemistry, University of Freiburg, 79104 Freiburg, Germany
| | - Anayancy Osorio Madrazo
- Institute of Microsystems Engineering IMTEK, Laboratory for Sensors, University of Freiburg, 79110 Freiburg, Germany; (A.K.T.); (I.D.)
- Freiburg Materials Research Center FMF, University of Freiburg, 79104 Freiburg, Germany; (D.H.); (A.W.)
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT, University of Freiburg, 79110 Freiburg, Germany
| |
Collapse
|
15
|
Catalytic Performance of Sulfonated Carbon Catalysts for Hydrolysis of Palm Oil Empty Fruit Bunch. JURNAL KIMIA SAINS DAN APLIKASI 2020. [DOI: 10.14710/jksa.23.6.209-215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Utilizing lignocellulosic biomass into valuable products, such as chemicals and fuels, has attracted global interest. One of lignocellulosic biomass, palm oil empty fruit bunch (EFB), has major content of cellulose (30-40%), which is highly potential to be a raw material for fermentable sugar production. In this research, a series of sulfonated carbon catalysts with various concentrations of sulfuric acid (H2SO4, 10-30 v/v%) solutions have been successfully prepared and applied for a single stage of heterogeneous acid-catalyzed hydrolysis over microcrystalline cellulose and EFB under moderate temperature condition and ambient pressure. The catalysts’ physical and chemical properties were characterized by using a Thermogravimetric Analyzer (TGA), X-ray diffractometer, surface area analyzer, and Fourier-transform infrared spectrophotometer. The characterization results showed that sulfonated carbon had relatively similar physical properties with the parent of active carbon. The hydrolysis activity of sulfonated carbon catalysts gave various Total Reducing Sugar (TRS). The effects of sulfate loading amount in catalyst samples and various ionic liquids were investigated. The hydrolysis of pure microcrystalline cellulose powder (Avicel) using 30%-sulfonated carbon (30-SC) catalyst in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid at 150°C yielded the highest TRS of 16.11%. Subsequently, the catalyst of 30-SC was also tested for hydrolysis of EFB and produced the highest TRS of 40.76% in [BMIM]Cl ionic liquid at 150°C for 4 h. The obtained results highlight the potential of sulfonated carbon catalysts for hydrolysis of EFB into fermentable sugar as an intermediate product for ethanol production.
Collapse
|
16
|
Papadopoulou A, Zarafeta D, Galanopoulou AP, Stamatis H. Enhanced Catalytic Performance of Trichoderma reesei Cellulase Immobilized on Magnetic Hierarchical Porous Carbon Nanoparticles. Protein J 2020; 38:640-648. [PMID: 31549278 DOI: 10.1007/s10930-019-09869-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cellulase from Trichoderma reesei was immobilized by covalent or non-covalent binding onto magnetic hierarchical porous carbon (MHPC) nanomaterials. The immobilization yield and the enzyme activity were higher when covalent immobilization approach was followed. The covalent immobilization approach leads to higher immobilization yield (up to 96%) and enzyme activity (up to 1.35 U mg-1) compared to the non-covalent cellulase binding. The overall results showed that the thermal, storage and operational stability of the immobilized cellulase was considerably improved compared to the free enzyme. The immobilized cellulose catalyzed the hydrolysis of microcrystalline cellulose up to 6 consecutive successive reaction cycles, with a total operation time of 144 h at 50 °C. The half-life time of the immobilized enzyme in deep eutectic solvents-based media was up to threefold higher compared to the soluble enzyme. The increased pH and temperature tolerance of the immobilized cellulase, as well as the increased operational stability in aqueous and deep eutectic solvents-based media indicate that the use of MHPCs as immobilization nanosupport could expand the catalytic performance of cellulolytic enzymes in various reaction conditions.
Collapse
Affiliation(s)
- Athena Papadopoulou
- Laboratory of Biotechnology, Department of Biological Applications and Technologies, University of Ioannina, 45110, Ioannina, Greece
| | - Dimitra Zarafeta
- Institute of Chemical Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, 11635, Athens, Greece
| | | | - Haralambos Stamatis
- Laboratory of Biotechnology, Department of Biological Applications and Technologies, University of Ioannina, 45110, Ioannina, Greece.
| |
Collapse
|
17
|
Biochemical Characteristics of Microbial Enzymes and Their Significance from Industrial Perspectives. Mol Biotechnol 2019; 61:579-601. [DOI: 10.1007/s12033-019-00187-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
18
|
Transforming food waste: how immobilized enzymes can valorize waste streams into revenue streams. NPJ Sci Food 2018; 2:19. [PMID: 31304269 PMCID: PMC6550151 DOI: 10.1038/s41538-018-0028-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 10/11/2018] [Indexed: 11/08/2022] Open
Abstract
Food processing generates byproduct and waste streams rich in lipids, carbohydrates, and proteins, which contribute to its negative environmental impact. However, these compounds hold significant economic potential if transformed into revenue streams such as biofuels and ingredients. Indeed, the high protein, sugar, and fat content of many food waste streams makes them ideal feedstocks for enzymatic valorization. Compared to synthetic catalysts, enzymes have higher specificity, lower energy requirement, and improved environmental sustainability in performing chemical transformations, yet their poor stability and recovery limits their performance in their native state. This review article surveys the current state-of-the-art in enzyme stabilization & immobilization technologies, summarizes opportunities in enzyme-catalyzed valorization of waste streams with emphasis on streams rich in mono- and disaccharides, polysaccharides, lipids, and proteins, and highlights challenges and opportunities in designing commercially translatable immobilized enzyme systems towards the ultimate goals of sustainable food production and reduced food waste.
Collapse
|
19
|
Das A, Basak P, Pattanayak R, Kar T, Majumder R, Pal D, Bhattacharya A, Bhattacharyya M, Banik SP. Trehalose induced structural modulation of Bovine Serum Albumin at ambient temperature. Int J Biol Macromol 2017; 105:645-655. [DOI: 10.1016/j.ijbiomac.2017.07.074] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 10/19/2022]
|
20
|
Kuo HP, Wang R, Lin YS, Lai JT, Lo YC, Huang ST. Pilot scale repeated fed-batch fermentation processes of the wine yeast Dekkera bruxellensis for mass production of resveratrol from Polygonum cuspidatum. BIORESOURCE TECHNOLOGY 2017; 243:986-993. [PMID: 28747009 DOI: 10.1016/j.biortech.2017.07.053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/07/2017] [Accepted: 07/08/2017] [Indexed: 06/07/2023]
Abstract
Resveratrol has long been used as an ingredient in functional foods. Currently, Polygonum cuspidatum extract is the greatest natural source for resveratrol because of high concentrations of glycosidic-linked resveratrol. Thus, developing a cost-effective procedure to hydrolyze glucoside could substantially enhance resveratrol production from P. cuspidatum. This study selected Dekkera bruxellensis from several microorganisms based on its bioconversion and enzyme-specific activities. We demonstrated that the cells could be reused at least nine times while maintaining an average of 180.67U/L β-glucosidase activity. The average resveratrol bioconversion efficiency within five rounds of repeated usage was 108.77±0.88%. This process worked effectively when the volume was increased to 1200L, a volume at which approximately 35mgL-1h-1 resveratrol per round was produced. This repeated fed-batch bioconversion process for resveratrol production is comparable to enzyme or cell immobilization strategies in terms of reusing cycles, but without incurring additional costs for immobilization.
Collapse
Affiliation(s)
- Hsiao-Ping Kuo
- Bioresources Collection and Research Center, Food Industry Research and Development Institute, Hsinchu 30062, Taiwan
| | - Reuben Wang
- Department of Food Science, Tunghai University, Taiwan No. 1727, Sec. 4 Taiwan Boulevard, Xitun District, Taichung 40704, Taiwan
| | - Yi-Sheng Lin
- Bioresources Collection and Research Center, Food Industry Research and Development Institute, Hsinchu 30062, Taiwan
| | - Jinn-Tsyy Lai
- Bioresources Collection and Research Center, Food Industry Research and Development Institute, Hsinchu 30062, Taiwan
| | - Yi-Chen Lo
- Institute of Food Science and Technology, National Taiwan University, No. 1, Sec. 4 Roosevelt Rd., Taipei 10617, Taiwan
| | - Shyue-Tsong Huang
- Bioresources Collection and Research Center, Food Industry Research and Development Institute, Hsinchu 30062, Taiwan.
| |
Collapse
|
21
|
Malgas S, Thoresen M, van Dyk JS, Pletschke BI. Time dependence of enzyme synergism during the degradation of model and natural lignocellulosic substrates. Enzyme Microb Technol 2017; 103:1-11. [DOI: 10.1016/j.enzmictec.2017.04.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 04/18/2017] [Accepted: 04/21/2017] [Indexed: 10/19/2022]
|
22
|
Fernandez-Lafuente R. Special Issue: Enzyme Immobilization 2016. Molecules 2017; 22:E601. [PMID: 28397749 PMCID: PMC6153742 DOI: 10.3390/molecules22040601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 04/06/2017] [Accepted: 04/06/2017] [Indexed: 12/29/2022] Open
Affiliation(s)
- Roberto Fernandez-Lafuente
- Departamento de Biocatálisis, Instituto de Catálisis-CSIC, C/Marie Curie 2, Campus UAM-CSIC, Cantoblanco, 28049 Madrid, Spain.
| |
Collapse
|
23
|
Li H, Li S, Tian P, Wu Z, Li Z. Prevention of Bacterial Contamination of a Silica Matrix Containing Entrapped β-Galactosidase through the Action of Covalently Bound Lysozymes. Molecules 2017; 22:molecules22030377. [PMID: 28264511 PMCID: PMC6155228 DOI: 10.3390/molecules22030377] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 01/24/2023] Open
Abstract
β-galactosidase was successfully encapsulated within an amino-functionalised silica matrix using a “fish-in-net” approach and molecular imprinting technique followed by covalent binding of lysozyme via a glutaraldehyde-based method. Transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy were used to characterise the silica matrix hosting the two enzymes. Both encapsulated β-galactosidase and bound lysozyme exhibited high enzymatic activities and outstanding operational stability in model reactions. Moreover, enzyme activities of the co-immobilised enzymes did not obviously change relative to enzymes immobilised separately. In antibacterial tests, bound lysozyme exhibited 95.5% and 89.6% growth inhibition of Staphylococcus aureus ATCC (American type culture collection) 653 and Escherichia coli ATCC 1122, respectively. In milk treated with co-immobilised enzymes, favourable results were obtained regarding reduction of cell viability and high lactose hydrolysis rate. In addition, when both co-immobilised enzymes were employed to treat milk, high operational and storage stabilities were observed. The results demonstrate that the use of co-immobilised enzymes holds promise as an industrial strategy for producing low lactose milk to benefit people with lactose intolerance.
Collapse
Affiliation(s)
- Heng Li
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China.
- Informalization Center for Education and Management, Jilin Agricultural University, Changchun 130118, China.
| | - Shuai Li
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China.
| | - Pu Tian
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China.
| | - Zhuofu Wu
- College of Life Science, Jilin Agricultural University, Changchun 130118, China.
| | - Zhengqiang Li
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China.
| |
Collapse
|
24
|
Jia J, Zhang W, Yang Z, Yang X, Wang N, Yu X. Novel Magnetic Cross-Linked Cellulase Aggregates with a Potential Application in Lignocellulosic Biomass Bioconversion. Molecules 2017; 22:molecules22020269. [PMID: 28208644 PMCID: PMC6155674 DOI: 10.3390/molecules22020269] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/02/2017] [Indexed: 01/14/2023] Open
Abstract
The utilization of renewable biomass resources to produce high-value chemicals by enzymatic processes is beneficial for alternative energy production, due to the accelerating depletion of fossil fuels. As immobilization techniques can improve enzyme stability and reusability, a novel magnetic cross-linked cellulase aggregate has been developed and applied for biomass bioconversion. The crosslinked aggregates could purify and immobilize enzymes in a single operation, and could then be combined with magnetic nanoparticles (MNPs), which provides easy separation of the materials. The immobilized cellulase showed a better activity at a wider temperature range and pH values than that of the free cellulase. After six cycles of consecutive reuse, the immobilized cellulase performed successful magnetic separation and retained 74% of its initial activity when carboxylmethyl cellulose (CMC) was used as the model substrate. Furthermore, the structure and morphology of the immobilized cellulase were studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Moreover, the immobilized cellulase was shown to hydrolyze bamboo biomass with a yield of 21%, and was re-used in biomass conversion up to four cycles with 38% activity retention, which indicated that the immobilized enzyme has good potential for biomass applications.
Collapse
Affiliation(s)
- Junqi Jia
- Key Laboratory of Green Chemistry Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Weiwei Zhang
- School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
| | - Zengjie Yang
- Key Laboratory of Green Chemistry Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Xianling Yang
- Key Laboratory of Green Chemistry Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Na Wang
- Key Laboratory of Green Chemistry Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Xiaoqi Yu
- Key Laboratory of Green Chemistry Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| |
Collapse
|
25
|
Nanosilicalites as Support for β-Glucosidases Covalent Immobilization. Appl Biochem Biotechnol 2017; 182:1619-1629. [DOI: 10.1007/s12010-017-2422-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/20/2017] [Indexed: 10/20/2022]
|
26
|
Rai M, Ingle AP, Gaikwad S, Dussán KJ, da Silva SS. Role of Nanoparticles in Enzymatic Hydrolysis of Lignocellulose in Ethanol. NANOTECHNOLOGY FOR BIOENERGY AND BIOFUEL PRODUCTION 2017. [DOI: 10.1007/978-3-319-45459-7_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
27
|
An overview of holocellulose-degrading enzyme immobilization for use in bioethanol production. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcatb.2016.08.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
28
|
Immobilization of Glycoside Hydrolase Families GH1, GH13, and GH70: State of the Art and Perspectives. Molecules 2016; 21:molecules21081074. [PMID: 27548117 PMCID: PMC6274110 DOI: 10.3390/molecules21081074] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 12/20/2022] Open
Abstract
Glycoside hydrolases (GH) are enzymes capable to hydrolyze the glycosidic bond between two carbohydrates or even between a carbohydrate and a non-carbohydrate moiety. Because of the increasing interest for industrial applications of these enzymes, the immobilization of GH has become an important development in order to improve its activity, stability, as well as the possibility of its reuse in batch reactions and in continuous processes. In this review, we focus on the broad aspects of immobilization of enzymes from the specific GH families. A brief introduction on methods of enzyme immobilization is presented, discussing some advantages and drawbacks of this technology. We then review the state of the art of enzyme immobilization of families GH1, GH13, and GH70, with special attention on the enzymes β-glucosidase, α-amylase, cyclodextrin glycosyltransferase, and dextransucrase. In each case, the immobilization protocols are evaluated considering their positive and negative aspects. Finally, the perspectives on new immobilization methods are briefly presented.
Collapse
|
29
|
Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus. Appl Environ Microbiol 2016; 82:2021-2030. [PMID: 26801571 DOI: 10.1128/aem.03158-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/14/2016] [Indexed: 02/02/2023] Open
Abstract
Psychrophilic enzymes play crucial roles in cold adaptation of microbes and provide useful models for studies of protein evolution, folding, and dynamic properties. We examined the crystal structure (2.2-Å resolution) of the psychrophilic β-glucosidase BglU, a member of the glycosyl hydrolase 1 (GH1) enzyme family found in the cold-adapted bacterium Micrococcus antarcticus. Structural comparison and sequence alignment between BglU and its mesophilic and thermophilic counterpart enzymes (BglB and GlyTn, respectively) revealed two notable features distinct to BglU: (i) a unique long-loop L3 (35 versus 7 amino acids in others) involved in substrate binding and (ii) a unique amino acid, His299 (Tyr in others), involved in the stabilization of an ordered water molecule chain. Shortening of loop L3 to 25 amino acids reduced low-temperature catalytic activity, substrate-binding ability, the optimal temperature, and the melting temperature (Tm). Mutation of His299 to Tyr increased the optimal temperature, the Tm, and the catalytic activity. Conversely, mutation of Tyr301 to His in BglB caused a reduction in catalytic activity, thermostability, and the optimal temperature (45 to 35°C). Loop L3 shortening and H299Y substitution jointly restored enzyme activity to the level of BglU, but at moderate temperatures. Our findings indicate that loop L3 controls the level of catalytic activity at low temperatures, residue His299 is responsible for thermolability (particularly heat lability of the active center), and long-loop L3 and His299 are jointly responsible for the psychrophilic properties. The described structural basis for the cold adaptedness of BglU will be helpful for structure-based engineering of new cold-adapted enzymes and for the production of mutants useful in a variety of industrial processes at different temperatures.
Collapse
|
30
|
Editorial: Special issue--Enzyme immobilization. Molecules 2014; 19:20671-4. [PMID: 25514057 PMCID: PMC6271884 DOI: 10.3390/molecules191220671] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 12/08/2014] [Indexed: 12/20/2022] Open
|