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Jia L, Zhao L, Qin B, Lu F, Liu D, Liu F. Enhancement of rice husks saccharification through hydrolase preparation assisted by lytic polysaccharide monooxygenase. Enzyme Microb Technol 2023; 171:110319. [PMID: 37672961 DOI: 10.1016/j.enzmictec.2023.110319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/08/2023]
Abstract
Rice husk is an abundant agricultural waste generated from rice production, but its application is limited. Considering its complex components, the rice husk was hydrolyzed by different enzymes to enhance its saccharification. In this study, saccharification of the rice husk by cellulase, xylosidase, and xylanase was first investigated. The synergistic effect of LPMO on the above hydrolases and different enzyme combinations in the saccharification process was then explored. Thereafter, the formulation of the enzyme cocktail and the degradation conditions were optimized to obtain the highest saccharification efficiency. The results showed that the optimum enzyme cocktail consists of Celluclast 1.5 L (83.3 mg/g substrate), the key enzymes in the saccharification process, worked with BpXyl (20 mg/g substrate), BpXyn11 (24 mg/g substrate), and R17L/N25G (4 mg/g substrate). The highest reducing sugar concentration (1.19 mg/mL) was obtained at pH 6.0 and 60 ℃ for 24 h. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to characterize the structural changes in the rice husk after degradation. The results showed that the key chemical bonds in cellulose and hemicellulose were broken. This study illuminated the concept of saccharifying lignocellulose from rice husk using LPMO synergistically assisted combined-hydrolase including cellulase, xylosidase, and xylanase, and provided a theoretical basis for lignocellulose biodegradation.
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Affiliation(s)
- Li Jia
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, PR China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, PR China; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, PR China
| | - Lei Zhao
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, PR China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, PR China; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, PR China
| | - Bo Qin
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, PR China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, PR China; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, PR China
| | - Fuping Lu
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, PR China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, PR China; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, PR China
| | - Dingkuo Liu
- Tianjin Enterprise Key Laboratory of Biological Feed Additives, Tianjin 300111, PR China
| | - Fufeng Liu
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, PR China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, PR China; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, PR China.
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Lee Q, Han X, Zheng M, Lv F, Liu B, Zeng F. Preparation of low molecular weight polysaccharides from Tremella fuciformis by ultrasonic-assisted H 2O 2-Vc method: Structural characteristics, in vivo antioxidant activity and stress resistance. ULTRASONICS SONOCHEMISTRY 2023; 99:106555. [PMID: 37582309 PMCID: PMC10448212 DOI: 10.1016/j.ultsonch.2023.106555] [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: 06/11/2023] [Revised: 07/27/2023] [Accepted: 08/05/2023] [Indexed: 08/17/2023]
Abstract
Different methods were used to degrade Tremella fuciformis polysaccharides (TFP) and prepare low molecular weight polysaccharides of Tremella fuciformis (TFLP) to improve their bioavailability. It was found that the TFLP prepared by ultrasonic-assisted H2O2-Vc method showed the highest level of antioxidant activity and stress resistance in C. elegans. The structural characteristics, in vivo antioxidant and stress resistance of TFLP-1 were evaluated after isolation and purification of TFLP, it was found that TFLP-1 was an acid polysaccharide with a molecular weight of 75770 Da, which mainly composed of mannose. Meanwhile, it could regulate the antioxidant activity and stress resistance in C. elegans by upregulating the transcription of fat-5, fat-7, acs-2, glp-1, hsf-1, hsp-1, mtl-1, nhr-49, skn-1 and sod-3 mRNA. The improvement effects were closely related to the significant regulation of galactose metabolism, alpha linolenic acid metabolism, and pantothenate and CoA biosynthesis metabolic pathways. These results provided insights into the high value application of Tremella fuciformis in the food industry and the development of antioxidant related functional foods.
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Affiliation(s)
- Quancen Lee
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xianjing Han
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Mingfeng Zheng
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Engineering Research Center of Fujian Subtropical Fruit and Vegetable Processing, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Feng Lv
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Engineering Research Center of Fujian Subtropical Fruit and Vegetable Processing, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Bin Liu
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Engineering Research Center of Fujian Subtropical Fruit and Vegetable Processing, Fujian Agriculture and Forestry University, Fuzhou 350002, China; National Engineering Research Center of JUNCAO Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Feng Zeng
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Engineering Research Center of Fujian Subtropical Fruit and Vegetable Processing, Fujian Agriculture and Forestry University, Fuzhou 350002, China; National Engineering Research Center of JUNCAO Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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3
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Zhang Z, Ge M, Guo Q, Jiang Y, Jia W, Gao L, Hu J. Ultrahigh-Throughput Screening of High-β-Xylosidase-Producing Penicillium piceum and Investigation of the Novel β-Xylosidase Characteristics. J Fungi (Basel) 2022; 8:jof8040325. [PMID: 35448556 PMCID: PMC9024563 DOI: 10.3390/jof8040325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/07/2022] [Accepted: 03/16/2022] [Indexed: 02/04/2023] Open
Abstract
A droplet-based microfluidic ultrahigh-throughput screening technology has been developed for the selection of high-β-xylosidase-producing Penicillium piceum W6 from the atmospheric and room-temperature plasma-mutated library of P. piceum. β-xylosidase hyperproducers filamentous fungi, P. piceum W6, exhibited an increase in β-xylosidase activity by 7.1-fold. A novel β-D-xylosidase was purified from the extracellular proteins of P. piceum W6 and designated as PpBXL. The optimal pH and temperature of PpBXL were 4.0 and 70 °C, respectively. PpBXL had high stability an acidic pH range of 3.0-5.0 and exhibited good thermostability with a thermal denaturation half-life of 10 days at 70 °C. Moreover, PpBXL showed the bifunctional activities of α-L-arabinofuranosidase and β-xylosidase. Supplementation with low-dose PpBXL (100 μg/g substrate) improved the yields of glucose and xylose generated from delignified biomass by 36-45%. The synergism between PpBXL and lignocellulolytic enzymes enhanced delignified biomass saccharification, increased the Xyl/Ara ratio, and decreased the strength of hydrogen bonds.
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Affiliation(s)
- Zhaokun Zhang
- School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot 010051, China;
| | - Mingyue Ge
- Tianjin Key Laboratory for Industrial BioSystems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, No. 32, Xiqi Road, Tianjin Airport Economic Park, Tianjin 300308, China; (M.G.); (Q.G.); (Y.J.); (W.J.)
| | - Qi Guo
- Tianjin Key Laboratory for Industrial BioSystems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, No. 32, Xiqi Road, Tianjin Airport Economic Park, Tianjin 300308, China; (M.G.); (Q.G.); (Y.J.); (W.J.)
| | - Yi Jiang
- Tianjin Key Laboratory for Industrial BioSystems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, No. 32, Xiqi Road, Tianjin Airport Economic Park, Tianjin 300308, China; (M.G.); (Q.G.); (Y.J.); (W.J.)
| | - Wendi Jia
- Tianjin Key Laboratory for Industrial BioSystems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, No. 32, Xiqi Road, Tianjin Airport Economic Park, Tianjin 300308, China; (M.G.); (Q.G.); (Y.J.); (W.J.)
| | - Le Gao
- Tianjin Key Laboratory for Industrial BioSystems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, No. 32, Xiqi Road, Tianjin Airport Economic Park, Tianjin 300308, China; (M.G.); (Q.G.); (Y.J.); (W.J.)
- Correspondence: (L.G.); (J.H.)
| | - Jianhua Hu
- School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot 010051, China;
- Correspondence: (L.G.); (J.H.)
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Understanding the structure and composition of recalcitrant oligosaccharides in hydrolysate using high-throughput biotin-based glycome profiling and mass spectrometry. Sci Rep 2022; 12:2521. [PMID: 35169269 PMCID: PMC8847591 DOI: 10.1038/s41598-022-06530-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 01/24/2022] [Indexed: 11/18/2022] Open
Abstract
Novel Immunological and Mass Spectrometry Methods for Comprehensive Analysis of Recalcitrant Oligosaccharides in AFEX Pretreated Corn Stover. Lignocellulosic biomass is a sustainable alternative to fossil fuel and is extensively used for developing bio-based technologies to produce products such as food, feed, fuel, and chemicals. The key to these technologies is to develop cost competitive processes to convert complex carbohydrates present in plant cell wall to simple sugars such as glucose, xylose, and arabinose. Since lignocellulosic biomass is highly recalcitrant, it must undergo a combination of thermochemical treatment such as Ammonia Fiber Expansion (AFEX), dilute acid (DA), Ionic Liquid (IL) and biological treatment such as enzyme hydrolysis and microbial fermentation to produce desired products. However, when using commercial fungal enzymes during hydrolysis, only 75–85% of the soluble sugars generated are monomeric sugars, while the remaining 15–25% are soluble recalcitrant oligosaccharides that cannot be easily utilized by microorganisms. Previously, we successfully separated and purified the soluble recalcitrant oligosaccharides using a combination of charcoal and celite-based separation followed by size exclusion chromatography and studies their inhibitory properties on enzymes. We discovered that the oligosaccharides with higher degree of polymerization (DP) containing methylated uronic acid substitutions were more recalcitrant towards commercial enzyme mixtures than lower DP and neutral oligosaccharides. Here, we report the use of several complementary techniques that include glycome profiling using plant biomass glycan specific monoclonal antibodies (mAbs) to characterize sugar linkages in plant cell walls and enzymatic hydrolysate, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) using structurally-informative diagnostic peaks offered by negative ion post-secondary decay spectra, gas chromatography followed by mass spectrometry (GC–MS) to characterize oligosaccharide sugar linkages with and without derivatization. Since oligosaccharides (DP 4–20) are small, it is challenging to mobilize these molecules for mAbs binding and characterization. To overcome this problem, we have applied a new biotin-coupling based oligosaccharide immobilization method that successfully tagged most of the low DP soluble oligosaccharides on to a micro-plate surface followed by specific linkage analysis using mAbs in a high-throughput system. This new approach will help develop more advanced versions of future high throughput glycome profiling methods that can be used to separate and characterize oligosaccharides present in biomarkers for diagnostic applications.
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Zadeike D, Vaitkeviciene R, Degutyte R, Bendoraitiene J, Rukuiziene Z, Cernauskas D, Svazas M, Juodeikiene G. A comparative study on the structural and functional properties of water‐soluble and alkali‐soluble dietary fibres from rice bran after hot‐water, ultrasound, hydrolysis by cellulase, and combined pre‐treatments. Int J Food Sci Technol 2021. [DOI: 10.1111/ijfs.15480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Daiva Zadeike
- Department of Food Science and Technology Kaunas University of Technology Radvilenu rd. 19 Kaunas LT‐50254 Lithuania
| | - Ruta Vaitkeviciene
- Department of Food Science and Technology Kaunas University of Technology Radvilenu rd. 19 Kaunas LT‐50254 Lithuania
| | - Rimgaile Degutyte
- Department of Food Science and Technology Kaunas University of Technology Radvilenu rd. 19 Kaunas LT‐50254 Lithuania
| | - Joana Bendoraitiene
- Department of Polymer Chemistry and Technology Kaunas University of Technology Radvilenu rd. 19 Kaunas LT‐50254 Lithuania
| | - Zaneta Rukuiziene
- Centre of Laboratories Faculty of Mechanical Engineering and Design Kaunas University of Technology Studentu str. 56 Kaunas LT‐51424 Lithuania
| | - Darius Cernauskas
- Food Institute of Kaunas University of Technology Radvilenu rd. 19 Kaunas LT‐50254 Lithuania
| | - Mantas Svazas
- Department of Food Science and Technology Kaunas University of Technology Radvilenu rd. 19 Kaunas LT‐50254 Lithuania
| | - Grazina Juodeikiene
- Department of Food Science and Technology Kaunas University of Technology Radvilenu rd. 19 Kaunas LT‐50254 Lithuania
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Méndez-Líter JA, de Eugenio LI, Nieto-Domínguez M, Prieto A, Martínez MJ. Hemicellulases from Penicillium and Talaromyces for lignocellulosic biomass valorization: A review. BIORESOURCE TECHNOLOGY 2021; 324:124623. [PMID: 33434871 DOI: 10.1016/j.biortech.2020.124623] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 05/26/2023]
Abstract
The term hemicellulose groups different polysaccharides with heterogeneous structures, mannans, xyloglucans, mixed-linkage β-glucans and xylans, which differ in their backbone and branches, and in the type and distribution of glycosidic linkages. The enzymatic degradation of these complex polymers requires the concerted action of multiple hemicellulases and auxiliary enzymes. Most commercial enzymes are produced by Trichoderma and Aspergillus species, but recent studies have disclosed Penicillium and Talaromyces as promising sources of hemicellulases. In this review, we summarize the current knowledge on the hemicellulolytic system of these genera, and the role of hemicellulases in the disruption and synthesis of glycosidic bonds. In both cases, the enzymes from Penicillium and Talaromyces represent an interesting alternative for valorization of lignocellulosic biomass in the current framework of circular economy.
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Affiliation(s)
- Juan A Méndez-Líter
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Laura I de Eugenio
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Manuel Nieto-Domínguez
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Alicia Prieto
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - María Jesús Martínez
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain.
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Cunha JT, Romaní A, Inokuma K, Johansson B, Hasunuma T, Kondo A, Domingues L. Consolidated bioprocessing of corn cob-derived hemicellulose: engineered industrial Saccharomyces cerevisiae as efficient whole cell biocatalysts. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:138. [PMID: 32782474 PMCID: PMC7414751 DOI: 10.1186/s13068-020-01780-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 07/29/2020] [Indexed: 05/24/2023]
Abstract
BACKGROUND Consolidated bioprocessing, which combines saccharolytic and fermentative abilities in a single microorganism, is receiving increased attention to decrease environmental and economic costs in lignocellulosic biorefineries. Nevertheless, the economic viability of lignocellulosic ethanol is also dependent of an efficient utilization of the hemicellulosic fraction, which contains xylose as a major component in concentrations that can reach up to 40% of the total biomass in hardwoods and agricultural residues. This major bottleneck is mainly due to the necessity of chemical/enzymatic treatments to hydrolyze hemicellulose into fermentable sugars and to the fact that xylose is not readily consumed by Saccharomyces cerevisiae-the most used organism for large-scale ethanol production. In this work, industrial S. cerevisiae strains, presenting robust traits such as thermotolerance and improved resistance to inhibitors, were evaluated as hosts for the cell-surface display of hemicellulolytic enzymes and optimized xylose assimilation, aiming at the development of whole-cell biocatalysts for consolidated bioprocessing of corn cob-derived hemicellulose. RESULTS These modifications allowed the direct production of ethanol from non-detoxified hemicellulosic liquor obtained by hydrothermal pretreatment of corn cob, reaching an ethanol titer of 11.1 g/L corresponding to a yield of 0.328 g/g of potential xylose and glucose, without the need for external hydrolytic catalysts. Also, consolidated bioprocessing of pretreated corn cob was found to be more efficient for hemicellulosic ethanol production than simultaneous saccharification and fermentation with addition of commercial hemicellulases. CONCLUSIONS These results show the potential of industrial S. cerevisiae strains for the design of whole-cell biocatalysts and paves the way for the development of more efficient consolidated bioprocesses for lignocellulosic biomass valorization, further decreasing environmental and economic costs.
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Affiliation(s)
- Joana T. Cunha
- CEB–Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal
| | - Aloia Romaní
- CEB–Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
| | - Björn Johansson
- Center of Molecular and Environmental Biology (CBMA), University of Minho, Braga, Portugal
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
| | - Lucília Domingues
- CEB–Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal
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Chen X, Zhai R, Li Y, Yuan X, Liu ZH, Jin M. Understanding the structural characteristics of water-soluble phenolic compounds from four pretreatments of corn stover and their inhibitory effects on enzymatic hydrolysis and fermentation. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:44. [PMID: 32175010 PMCID: PMC7065323 DOI: 10.1186/s13068-020-01686-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 02/22/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND For bioethanol production from lignocellulosic biomass, phenolics derived from pretreatment have been generally considered as highly inhibitory towards enzymatic hydrolysis and fermentation. As phenolics are produced from lignin degradation during pretreatment, it is likely that the pretreatment will exert a strong impact on the structure of phenolics, resulting in varied levels of inhibition of the bioconversion process. Despite the extensive studies on pretreatment, it remains unclear how pretreatment process affects the properties of generated phenolics and how the inhibitory effect of phenolics from different pretreatment varies on enzymatic hydrolysis and fermentation. RESULTS In this study, the structural properties of phenolic compounds derived from four typical pretreatment [dilute acid (DA), liquid hot water pretreatment (LHW), ammonia fiber expansion (AFEX) and alkaline pretreatment (AL)] were characterized, and their effect on both enzymatic hydrolysis and fermentation were evaluated. The inhibitory effect of phenolics on enzymatic hydrolysis followed the order: AFEX > LHW > DA > AL, while the inhibitory effect of phenolics on Zymomonas mobilis 8b strain fermentation followed the order: AL > LHW > DA > AFEX. Interestingly, this study revealed that phenolics derived from AFEX showed more severe inhibitory effect on enzymatic hydrolysis than those from the other pretreatments at the same phenolics concentrations (note: AFEX produced much less amount of phenolics compared to AL and DA), while they exhibited the lowest inhibitory effect on fermentation. The composition of phenolics from different pretreatments was analyzed and model phenolics were applied to explore the reason for this difference. The results suggested that the amide group in phenolics might account for this difference. CONCLUSIONS Pretreatment process greatly affects the properties of generated phenolics and the inhibitory effects of phenolics on enzymatic hydrolysis and fermentation. This study provides new insight for further pretreatment modification and hydrolysate detoxification to minimize phenolics-caused inhibition and enhance the efficiency of enzymatic hydrolysis and fermentation.
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Affiliation(s)
- Xiangxue Chen
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Xuanwu District, Nanjing, 210094 China
| | - Rui Zhai
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Xuanwu District, Nanjing, 210094 China
| | - Ying Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Xuanwu District, Nanjing, 210094 China
| | - Xinchuan Yuan
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Xuanwu District, Nanjing, 210094 China
| | - Zhi-Hua Liu
- Department of Plant Pathology and Microbiology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Xuanwu District, Nanjing, 210094 China
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9
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Montoya-Rosales JDJ, Olmos-Hernández DK, Palomo-Briones R, Montiel-Corona V, Mari AG, Razo-Flores E. Improvement of continuous hydrogen production using individual and binary enzymatic hydrolysates of agave bagasse in suspended-culture and biofilm reactors. BIORESOURCE TECHNOLOGY 2019; 283:251-260. [PMID: 30913433 DOI: 10.1016/j.biortech.2019.03.072] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
Continuous hydrogen (H2) production from individual (Stonezyme, IH) and binary (Celluclast-Viscozyme, BH) enzymatic hydrolysates of agave bagasse was evaluated in continuous stirred-tank reactors (CSTR) and trickling bed reactors (TBR). The volumetric H2 production rates (VHPR) in CSTR were 13 and 2.25 L H2/L-d with BH and IH, respectively. Meanwhile, VHPR of 5.76 and 2.0 L H2/L-d were obtained in the TBR configuration using BH and IH, respectively. Differences on VHPR between reactors could be explained by substrate availability, which is intrinsic to the growth mode of each reactor configuration; while differences of VHPR between hydrolysates were possibly related to the composition of enzymatic hydrolysates. Furthermore, homoacetogenesis was strongly influenced by H2 and substrate transfer conditions. Considering VHPR, H2 yields, and costs of hydrolysis, hydrogen production from binary hydrolysates of agave bagasse was identified as the most promising alternative evaluated with scale-up potential for the production of energy biofuels.
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Affiliation(s)
- José de Jesús Montoya-Rosales
- Instituto Potosino de Investigación Científica y Tecnológica A.C., División de Ciencias Ambientales, Camino a la Presa San José 2055, Lomas 4a Sección, C.P. 78216 San Luis Potosí, SLP, Mexico
| | - Diana Karime Olmos-Hernández
- Instituto Potosino de Investigación Científica y Tecnológica A.C., División de Ciencias Ambientales, Camino a la Presa San José 2055, Lomas 4a Sección, C.P. 78216 San Luis Potosí, SLP, Mexico
| | - Rodolfo Palomo-Briones
- Instituto Potosino de Investigación Científica y Tecnológica A.C., División de Ciencias Ambientales, Camino a la Presa San José 2055, Lomas 4a Sección, C.P. 78216 San Luis Potosí, SLP, Mexico
| | - Virginia Montiel-Corona
- Instituto Potosino de Investigación Científica y Tecnológica A.C., División de Ciencias Ambientales, Camino a la Presa San José 2055, Lomas 4a Sección, C.P. 78216 San Luis Potosí, SLP, Mexico
| | - Angelo Gabriel Mari
- Universidade Estadual do Oeste do Paraná (UNIOESTE), Rua Universitária 2069, 85819-110 Cascavel, PR, Brazil
| | - Elías Razo-Flores
- Instituto Potosino de Investigación Científica y Tecnológica A.C., División de Ciencias Ambientales, Camino a la Presa San José 2055, Lomas 4a Sección, C.P. 78216 San Luis Potosí, SLP, Mexico.
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Mohapatra S, Mishra C, Merritt BB, Pattathil S, Thatoi H. Evaluating the Role of Ultrasonication-Assisted Alkali Pretreatment and Enzymatic Hydrolysis on Cellwall Polysaccharides of Pennisetum
Grass Varieties as Potential Biofuel Feedstock. ChemistrySelect 2019. [DOI: 10.1002/slct.201802187] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sonali Mohapatra
- Department of Biotechnology; College of Engineering and Technology; Biju Pattnaik University of Technology; Bhubaneswar- 751003 India
| | - Chinmaya Mishra
- Department of Biotechnology; College of Engineering and Technology; Biju Pattnaik University of Technology; Bhubaneswar- 751003 India
| | - Brian B Merritt
- Complex Carbohydrate Research Center; University of Georgia, GA 30602 USA and BioEnergy Science Center (BESC); Oak Ridge National Laboratory; Oak Ridge, TN 37831 USA
| | - Sivakumar Pattathil
- Complex Carbohydrate Research Center; University of Georgia, GA 30602 USA and BioEnergy Science Center (BESC); Oak Ridge National Laboratory; Oak Ridge, TN 37831 USA
| | - Hrudayanath Thatoi
- Department of Biotechnology; North Orissa University; Sriram Chandra vihar, Takatpur Baripada- 757003, Odisha India
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Kinetic Parameters of Saccharomyces cerevisiae Alcohols Production Using Nepenthes mirabilis Pod Digestive Fluids-Mixed Agro-Waste Hydrolysates. FERMENTATION-BASEL 2019. [DOI: 10.3390/fermentation5010010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, microbial growth kinetics and modeling of alcohols production using Saccharomyces cerevisiae were evaluated using different hydrolysates in a single pot (batch) system. Mixed agro-waste hydrolysates from different pre-treatment methods, i.e., N. mirabilis/CP and HWP/DAP/CP, were used as the sole nutrient source in the fermentations used to produce the alcohols of interest. The maximum Saccharomyces cerevisiae concentration of 1.47 CFU/mL (×1010) was observed with HWP/DAP/CP hydrolysates, with a relative difference of 21.1% when compared to the N. mirabilis/CP cultures; the product yield based on biomass generation was relatively (20.2%) higher for the N. mirabilis/CP cultures. For the total residual phenolic compounds (TRPCs) generation, a relative difference (24.6%) between N. mirabilis/CP and HWP/DAP/CP pre-treatment systems was observed, suggesting that N. mirabilis/CP generates lower inhibition by-products. This was further evidenced by the lowest substrate utilization rate (3.3 × 10−4 g/(L·h)) for the N. mirabilis/CP cultures while achieving relatively similar product formation rates to those observed for the HWP/DAP/CP. A better correlation (R2 = 0.94) was obtained when predicting substrate utilization for the N. mirabilis/CP cultures. Generally, the pre-treatment of mixed agro-waste using N. mirabilis/CP seemed appropriate for producing hydrolysates which Saccharomyces cerevisiae can effectively use for alcohol production in the biorefinery industry.
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Li W, Li Q, Wang Y, Zheng L, Zhang Y, Yu Z, Chen H, Zhang J. Efficient bioconversion of organic wastes to value-added chemicals by soaking, black soldier fly (Hermetia illucens L.) and anaerobic fermentation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 227:267-276. [PMID: 30199722 DOI: 10.1016/j.jenvman.2018.08.084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 08/04/2018] [Accepted: 08/23/2018] [Indexed: 06/08/2023]
Abstract
Corncob degradation is an issue that needs to be address for it to be further utilized as bioenergy. We explored a new comprehensive degradation strategy for corncob. First, restaurant wastewater was used to improve the corncob biochemical characteristics and partly degrade the lignocelluloses. After the restaurant wastewater treatment, the residue was converted using black soldier fly larvae (BSFL), and the supernatant was utilized for biogas production by anaerobic fermentation. The highest product rates of glucose, xylose, and arabinose were obtained at the optimal corncob soaking condition at 75 °C, 5 h, and 60 g/L from lignocellulose. The soaking residue was converted using BSFL for 10 days, and 24.34% grease yield was extracted. The soaking residue can be utilized by BSFL and produce grease, which is similar to other wastes such as rice straw and pig manure. The corncob soaking supernatant was utilized for biogas production by anaerobic fermentation. The degradation of cellulose, hemicellulose, and lignin reached about 27.34%, 45.14%, and 29.33%, respectively. A total of 500 mL supernatant mixed with 30% anaerobic sludge under 35 ± 2 °C produced about 7.52 L of biogas with about 3.22 L methane. In conclusion, the above comprehensive process can effectively degrade lignocellulose in corncob and obtain two bioenergy products, namely insect grease and biogas.
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Affiliation(s)
- Wu Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, PR China
| | - Qing Li
- College of Science, Huazhong Agricultural University, Wuhan, 430070 PR China
| | - YuanYuan Wang
- College of Engineering, Huazhong Agricultural University, 430070 Wuhan, PR China
| | - Longyu Zheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, PR China
| | - Yanlin Zhang
- College of Engineering, Huazhong Agricultural University, 430070 Wuhan, PR China
| | - Ziniu Yu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, PR China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, PR China
| | - Jibin Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, PR China.
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Ding C, Li M, Hu Y. High-activity production of xylanase by Pichia stipitis: Purification, characterization, kinetic evaluation and xylooligosaccharides production. Int J Biol Macromol 2018; 117:72-77. [DOI: 10.1016/j.ijbiomac.2018.05.128] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 05/18/2018] [Accepted: 05/18/2018] [Indexed: 10/16/2022]
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14
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Carvalho AFA, Marcondes WF, de Oliva Neto P, Pastore GM, Saddler JN, Arantes V. The potential of tailoring the conditions of steam explosion to produce xylo-oligosaccharides from sugarcane bagasse. BIORESOURCE TECHNOLOGY 2018; 250:221-229. [PMID: 29174899 DOI: 10.1016/j.biortech.2017.11.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/09/2017] [Accepted: 11/13/2017] [Indexed: 06/07/2023]
Abstract
In this study, the potential of the steam explosion (SE) method to produce high levels XOS from sugarcane bagasse, a xylan-rich hemicellulosic feedstock, was assessed. The effect of different operating conditions on XOS production yield and selectivity were investigated using a mini-pilot scale SE unit. The results show that even under a non-optimized condition (190 °C, 5 min and 0.5% H2SO4 as catalyst), SE led to about 40% xylan recovery as XOS, which was comparable to the well-known, multi-step, enzymatic production of XOS from alkaline-extracted xylan, and other commonly employed chemical methods. In addition, the XOS-rich hydrolysate from SE constituted of greater diversity in the degree of polymerization, which has been shown to be desirable for prebiotic application.
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Affiliation(s)
- Ana Flavia Azevedo Carvalho
- Department of Wood Science, Forest Sciences Centre, University of British Columbia, 2424 Main Mall, V6TIZ4 Vancouver, BC, Canada; Associated Laboratory of Bioenergy Research Institute (IPBEN), Bioprocess Unit, São Paulo State University (UNESP), Av. Dom Antonio, 2100, 19806-380 Assis, SP, Brazil; Department of Food Science, School of Food Engineering, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 80, 13083-862 Campinas, SP, Brazil
| | - Wilian Fioreli Marcondes
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo (USP), Lorena, SP, Brazil
| | - Pedro de Oliva Neto
- Associated Laboratory of Bioenergy Research Institute (IPBEN), Bioprocess Unit, São Paulo State University (UNESP), Av. Dom Antonio, 2100, 19806-380 Assis, SP, Brazil
| | - Glaucia Maria Pastore
- Department of Food Science, School of Food Engineering, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 80, 13083-862 Campinas, SP, Brazil
| | - Jack N Saddler
- Department of Wood Science, Forest Sciences Centre, University of British Columbia, 2424 Main Mall, V6TIZ4 Vancouver, BC, Canada
| | - Valdeir Arantes
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo (USP), Lorena, SP, Brazil.
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15
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Sporck D, Reinoso FAM, Rencoret J, Gutiérrez A, del Rio JC, Ferraz A, Milagres AMF. Xylan extraction from pretreated sugarcane bagasse using alkaline and enzymatic approaches. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:296. [PMID: 29234463 PMCID: PMC5719793 DOI: 10.1186/s13068-017-0981-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 11/26/2017] [Indexed: 05/10/2023]
Abstract
BACKGROUND New biorefinery concepts are necessary to drive industrial use of lignocellulose biomass components. Xylan recovery before enzymatic hydrolysis of the glucan component is a way to add value to the hemicellulose fraction, which can be used in papermaking, pharmaceutical, and food industries. Hemicellulose removal can also facilitate subsequent cellulolytic glucan hydrolysis. RESULTS Sugarcane bagasse was pretreated with an alkaline-sulfite chemithermomechanical process to facilitate subsequent extraction of xylan by enzymatic or alkaline procedures. Alkaline extraction methods yielded 53% (w/w) xylan recovery. The enzymatic approach provided a limited yield of 22% (w/w) but produced the xylan with the lowest contamination with lignin and glucan components. All extracted xylans presented arabinosyl side groups and absence of acetylation. 2D-NMR data suggested the presence of O-methyl-glucuronic acid and p-coumarates only in enzymatically extracted xylan. Xylans isolated using the enzymatic approach resulted in products with molecular weights (Mw) lower than 6 kDa. Higher Mw values were detected in the alkali-isolated xylans. Alkaline extraction of xylan provided a glucan-enriched solid readily hydrolysable with low cellulase loads, generating hydrolysates with a high glucose/xylose ratio. CONCLUSIONS Hemicellulose removal before enzymatic hydrolysis of the cellulosic fraction proved to be an efficient manner to add value to sugarcane bagasse biorefining. Xylans with varied yield, purity, and structure can be obtained according to the extraction method. Enzymatic extraction procedures produce high-purity xylans at low yield, whereas alkaline extraction methods provided higher xylan yields with more lignin and glucan contamination. When xylan extraction is performed with alkaline methods, the residual glucan-enriched solid seems suitable for glucose production employing low cellulase loadings.
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Affiliation(s)
- Daniele Sporck
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Felipe A. M. Reinoso
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Jorge Rencoret
- Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Av. Reina Mercedes, 10, 41012 Seville, Spain
| | - Ana Gutiérrez
- Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Av. Reina Mercedes, 10, 41012 Seville, Spain
| | - José C. del Rio
- Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Av. Reina Mercedes, 10, 41012 Seville, Spain
| | - André Ferraz
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Adriane M. F. Milagres
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
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Malgas S, Chandra R, Van Dyk JS, Saddler JN, Pletschke BI. Formulation of an optimized synergistic enzyme cocktail, HoloMix, for effective degradation of various pre-treated hardwoods. BIORESOURCE TECHNOLOGY 2017; 245:52-65. [PMID: 28892706 DOI: 10.1016/j.biortech.2017.08.186] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/25/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
In this study, two selected hardwoods were subjected to sodium chlorite delignification and steam explosion, and the impact of pre-treatments on synergistic enzymatic saccharification evaluated. A cellulolytic core-set, CelMix, and a xylanolytic core-set, XynMix, optimised for glucose and xylose release, respectively, were used to formulate HoloMix cocktail for optimal saccharification of various pre-treated hardwoods. For delignified biomass, the optimized HoloMix consisted of 75%:25% protein dosage, CelMix: XynMix, while for untreated and steam exploded biomass the HoloMix consisted of 93.75%:6.25% protein dosage. Saccharification by HoloMix (27.5mgprotein/gbiomass) for 24h achieved 70-100% sugar yields. Pre-treatment of the hardwoods (especially those with a higher proportion of lignin) with a laccase, improved saccharification by HoloMix. This study provided insights into enzymatic hydrolysis of various pre-treated hardwood substrates and showed the same lignocellulolytic cocktail comparable to/if not better than commercial enzyme preparations can be used to efficiently hydrolyse different hardwood species.
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Affiliation(s)
- S Malgas
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, Eastern Cape, South Africa
| | - R Chandra
- Forest Products Biotechnology Group, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T1Z4, Canada
| | - J S Van Dyk
- Forest Products Biotechnology Group, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T1Z4, Canada
| | - J N Saddler
- Forest Products Biotechnology Group, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T1Z4, Canada
| | - B I Pletschke
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, Eastern Cape, South Africa.
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17
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Ye Y, Li X, Cao Y, Du J, Chen S, Zhao J. A β-xylosidase hyper-production Penicillium oxalicum mutant enhanced ethanol production from alkali-pretreated corn stover. BIORESOURCE TECHNOLOGY 2017; 245:734-742. [PMID: 28917109 DOI: 10.1016/j.biortech.2017.08.155] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/23/2017] [Accepted: 08/24/2017] [Indexed: 05/09/2023]
Abstract
β-Xylosidase activity is deficient in most cellulase enzymes secreted by filamentous fungi, which limits effective enzymatic hydrolysis of hemicellulose in lignocellulose materials and resulted in accumulation of xylo-oligosaccharides that inhibit the cellulase and xylanase activitives. An endogenous β-xylosidase gene, xyl3A, was overexpressed using two types of promoters in cellulolytic P. oxalicum RE-10. The mutants RXyl, RGXyl-1 and RGXyl-2 displayed higher β-xylosidase production than native strain RE-10 besides higher cellulase and xylanase activities, especially RGXyl-1, showing the highest β-xylosidase activity of 15.05±1.79IU/mL, about 29 folds higher than native strain, more than the highest level reported by literature. Enzymatic hydrolysis results indicated the cellulase RGXyl-1 not only increased glucose and xylose yields and thus resulted in high ethanol yield during the simultaneous saccharification and fermentation, but decreased the total enzyme loading compared to starting RE-10, which indicated a good prospect of industrial application in bioconversion of lignocellulose.
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Affiliation(s)
- Yanxin Ye
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China
| | - Xuezhi Li
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China
| | - Yuan Cao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China
| | - Jian Du
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China
| | - Shicheng Chen
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China.
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18
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Production and Characteristics of a Novel Xylose- and Alkali-tolerant GH 43 β-xylosidase from Penicillium oxalicum for Promoting Hemicellulose Degradation. Sci Rep 2017; 7:11600. [PMID: 28912429 PMCID: PMC5599605 DOI: 10.1038/s41598-017-11573-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/23/2017] [Indexed: 11/09/2022] Open
Abstract
β-xylosidase is a pivotal enzyme for complete degradation of xylan in hemicelluloses of lignocelluloses, and the xylose- and alkali-tolerant β-xylosidase with high catalytic activity is very attractive for promoting enzymatic hydrolysis of alkaline-pretreated lignocellulose. In this study, a novel intracellular glycoside hydrolase family 43 β-xylosidase gene (xyl43) from Penicillium oxalicum 114-2 was successfully high-level overexpressed in Pichia pastoris, and the secreted enzyme was characterized. The β-xylosidase Xyl43 exhibited great pH stability and high catalytic activity in the range of pH 6.0 to 8.0, and high tolerance to xylose with the Ki value of 28.09 mM. The Xyl43 could effectively promote enzymatic degradation of different source of xylan and hemicellulose contained in alkaline-pretreated corn stover, and high conversion of xylan to xylose could be obtained.
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Camarillo MK, Domen JK, Stringfellow WT. Physical-chemical evaluation of hydraulic fracturing chemicals in the context of produced water treatment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 183:164-174. [PMID: 27591844 DOI: 10.1016/j.jenvman.2016.08.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 08/03/2016] [Accepted: 08/24/2016] [Indexed: 06/06/2023]
Abstract
Produced water is a significant waste stream that can be treated and reused; however, the removal of production chemicals-such as those added in hydraulic fracturing-must be addressed. One motivation for treating and reusing produced water is that current disposal methods-typically consisting of deep well injection and percolation in infiltration pits-are being limited. Furthermore, oil and gas production often occurs in arid regions where there is demand for new water sources. In this paper, hydraulic fracturing chemical additive data from California are used as a case study where physical-chemical and biodegradation data are summarized and used to screen for appropriate produced water treatment technologies. The data indicate that hydraulic fracturing chemicals are largely treatable; however, data are missing for 24 of the 193 chemical additives identified. More than one-third of organic chemicals have data indicating biodegradability, suggesting biological treatment would be effective. Adsorption-based methods and partitioning of chemicals into oil for subsequent separation is expected to be effective for approximately one-third of chemicals. Volatilization-based treatment methods (e.g. air stripping) will only be effective for approximately 10% of chemicals. Reverse osmosis is a good catch-all with over 70% of organic chemicals expected to be removed efficiently. Other technologies such as electrocoagulation and advanced oxidation are promising but lack demonstration. Chemicals of most concern due to prevalence, toxicity, and lack of data include propargyl alcohol, 2-mercaptoethyl alcohol, tetrakis hydroxymethyl-phosphonium sulfate, thioglycolic acid, 2-bromo-3-nitrilopropionamide, formaldehyde polymers, polymers of acrylic acid, quaternary ammonium compounds, and surfactants (e.g. ethoxylated alcohols). Future studies should examine the fate of hydraulic fracturing chemicals in produced water treatment trains to demonstrate removal and clarify interactions between upstream and downstream processes.
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Affiliation(s)
- Mary Kay Camarillo
- Ecological Engineering Research Program, School of Engineering & Computer Science, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA.
| | - Jeremy K Domen
- Ecological Engineering Research Program, School of Engineering & Computer Science, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA
| | - William T Stringfellow
- Ecological Engineering Research Program, School of Engineering & Computer Science, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA; Earth & Environmental Sciences Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
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Jain A, Bediako SH, Henson JM. Correlation analysis of enzyme activities and deconstruction of ammonia-pretreated switchgrass by bacterial-fungal communities. BIORESOURCE TECHNOLOGY 2016; 218:1082-1089. [PMID: 27469088 DOI: 10.1016/j.biortech.2016.07.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/07/2016] [Accepted: 07/08/2016] [Indexed: 06/06/2023]
Abstract
The mixed microbial communities that occur naturally on lignocellulosic feedstocks can provide feedstock-specific enzyme mixtures to saccharify lignocelluloses. Bacterial-fungal communities were enriched from switchgrass bales to deconstruct ammonia-pretreated switchgrass (DSG). Correlation analysis was carried out to elucidate the relationship between microbial decomposition of DSG by these communities, enzymatic activities produced and enzymatic saccharification of DSG using these enzyme mixtures. Results of the analysis showed that β-glucosidase and xylosidase activities limited the extent of microbial deconstruction and enzymatic saccharification of DSG. The results also underlined the importance of ligninase activity for the enzymatic saccharification of pretreated lignocellulosic feedstock. The bacterial-fungal communities developed in this research can be used to produce enzyme mixtures to deconstruct DSG, and the results from the correlation analysis can be used to optimize these enzyme mixtures for efficient saccharification of DSG to produce second-generation biofuels.
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Affiliation(s)
- Abhiney Jain
- Biotechnology Institute, University of Minnesota, Twin Cities, 1479 Gortner Avenue, Falcon Heights, MN 55108, United States
| | - Sandra H Bediako
- Sacred Heart University, Department of Biology, 5151 Park Avenue, Fairfield, CT 06825, United States
| | - J Michael Henson
- Department of Biological Sciences, 157A Life Sciences Facility, Clemson University, Clemson, SC 29634, United States.
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Contrasted enzymatic cocktails reveal the importance of cellulases and hemicellulases activity ratios for the hydrolysis of cellulose in presence of xylans. AMB Express 2016; 6:24. [PMID: 27001439 PMCID: PMC4801825 DOI: 10.1186/s13568-016-0196-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 03/11/2016] [Indexed: 11/18/2022] Open
Abstract
Various enzymatic cocktails were produced from two Trichoderma reesei strains, a cellulase hyperproducer strain and a strain with β-glucosidase activity overexpression. By using various carbon sources (lactose, glucose, xylose, hemicellulosic hydrolysate) for strains growth, contrasted enzymatic activities were obtained. The enzymatic cocktails presented various levels of efficiency for the hydrolysis of cellulose Avicel into glucose, in presence of xylans, or not. These latter were also hydrolyzed with different extents according to cocktails. The most efficient cocktails (TR1 and TR3) on Avicel were richer in filter paper activity (FPU) and presented a low ratio FPU/β-glucosidase activity. Cocktails TR2 and TR5 which were produced on the higher amount of hemicellulosic hydrolysate, possess both high xylanase and β-xylosidase activities, and were the most efficient for xylans hydrolysis. When hydrolysis of Avicel was conducted in presence of xylans, a decrease of glucose release occurred for all cocktails compared to hydrolysis of Avicel alone. Mixing TR1 and TR5 cocktails with two different ratios of proteins (1/1 and 1/4) resulted in a gain of efficiency for glucose release during hydrolysis of Avicel in presence of xylans compared to TR5 alone. Our results demonstrate the importance of combining hemicellulase and cellulase activities to improve the yields of glucose release from Avicel in presence of xylans. In this context, strategies involving enzymes production with carbon sources comprising mixed C5 and C6 sugars or combining different cocktails produced on C5 or on C6 sugars are of interest for processes developed in the context of lignocellulosic biorefinery.
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22
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Classification, mode of action and production strategy of xylanase and its application for biofuel production from water hyacinth. Int J Biol Macromol 2016; 82:1041-54. [DOI: 10.1016/j.ijbiomac.2015.10.086] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 10/26/2015] [Accepted: 10/27/2015] [Indexed: 01/07/2023]
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Song W, Han X, Qian Y, Liu G, Yao G, Zhong Y, Qu Y. Proteomic analysis of the biomass hydrolytic potentials of Penicillium oxalicum lignocellulolytic enzyme system. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:68. [PMID: 26997974 PMCID: PMC4797192 DOI: 10.1186/s13068-016-0477-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/02/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND The mining of high-performance enzyme systems is necessary to develop industrial lignocellulose bioconversion. Large amounts of cellulases and hemicellulases can be produced by Penicillium oxalicum. Hence, the enzyme system of this hypercellulolytic fungus should be elucidated to help design optimum enzyme systems for effective biomass hydrolysis. RESULTS The cellulolytic and xylanolytic activities of an SP enzyme system prepared from P. oxalicum JU-A10 were comparatively analyzed. Results indicated that the fungus possesses a complete cellulolytic-xylanolytic enzyme system. The cellobiohydrolase- and xylanase-specific activities of this system were higher than those of two other enzyme systems, i.e., ST from Trichoderma reesei SN1 and another commercial preparation Celluclast 1.5L. Delignified corncob residue (DCCR) could be hydrolyzed by SP to a greater extent than corncob residue (CCR). Beta-glucosidase (BG) supplemented in SP increased the ability of the system to hydrolyze DCCR and CCR, and resulted in a 64 % decrease in enzyme dosage with the same glucose yield. The behaviors of the enzyme components in the hydrolysis of CCR were further investigated by monitoring individual enzyme dynamics. The total protein concentrations and cellobiohydrolase (CBH), endoglucanase (EG), and filter paper activities in the supernatants significantly decreased during saccharification. These findings were more evident in SP than in the other enzyme systems. The comparative proteomic analysis of the enzyme systems revealed that both SP and ST were rich in carbohydrate-degrading enzymes and multiple non-hydrolytic proteins. A larger number of carbohydrate-binding modules 1 (CBM1) were also identified in SP than in ST. This difference might be linked to the greater adsorption to substrates and lower hydrolysis efficiency of SP enzymes than ST during lignocellulose saccharification, because CBM1 not only targets enzymes to insoluble cellulose but also leads to non-productive adsorption to lignin. CONCLUSIONS Penicillium oxalicum can be applied to the biorefinery of lignocellulosic biomass. Its ability to degrade lignocellulosic substrates could be further improved by modifying its enzyme system on the basis of enzyme activity measurement and proteomic analysis. The proposed strategy may also be applied to other lignocellulolytic enzyme systems to enhance their hydrolytic performances rationally.
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Affiliation(s)
- Wenxia Song
- />State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
| | - Xiaolong Han
- />State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
| | - Yuanchao Qian
- />State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
| | - Guodong Liu
- />State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
| | - Guangshan Yao
- />State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
| | - Yaohua Zhong
- />State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
| | - Yinbo Qu
- />State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
- />National Glycoengineering Research Center, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong China
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White biotechnology: State of the art strategies for the development of biocatalysts for biorefining. Biotechnol Adv 2015; 33:1653-70. [PMID: 26303096 DOI: 10.1016/j.biotechadv.2015.08.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/31/2015] [Accepted: 08/17/2015] [Indexed: 12/31/2022]
Abstract
White biotechnology is a term that is now often used to describe the implementation of biotechnology in the industrial sphere. Biocatalysts (enzymes and microorganisms) are the key tools of white biotechnology, which is considered to be one of the key technological drivers for the growing bioeconomy. Biocatalysts are already present in sectors such as the chemical and agro-food industries, and are used to manufacture products as diverse as antibiotics, paper pulp, bread or advanced polymers. This review proposes an original and global overview of highly complementary fields of biotechnology at both enzyme and microorganism level. A certain number of state of the art approaches that are now being used to improve the industrial fitness of biocatalysts particularly focused on the biorefinery sector are presented. The first part deals with the technologies that underpin the development of industrial biocatalysts, notably the discovery of new enzymes and enzyme improvement using directed evolution techniques. The second part describes the toolbox available by the cell engineer to shape the metabolism of microorganisms. And finally the last part focuses on the 'omic' technologies that are vital for understanding and guide microbial engineering toward more efficient microbial biocatalysts. Altogether, these techniques and strategies will undoubtedly help to achieve the challenging task of developing consolidated bioprocessing (i.e. CBP) readily available for industrial purpose.
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25
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Xue S, Uppugundla N, Bowman MJ, Cavalier D, Da Costa Sousa L, E Dale B, Balan V. Sugar loss and enzyme inhibition due to oligosaccharide accumulation during high solids-loading enzymatic hydrolysis. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:195. [PMID: 26617670 PMCID: PMC4662034 DOI: 10.1186/s13068-015-0378-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 11/09/2015] [Indexed: 05/03/2023]
Abstract
BACKGROUND Accumulation of recalcitrant oligosaccharides during high-solids loading enzymatic hydrolysis of cellulosic biomass reduces biofuel yields and increases processing costs for a cellulosic biorefinery. Recalcitrant oligosaccharides in AFEX-pretreated corn stover hydrolysate accumulate to the extent of about 18-25 % of the total soluble sugars in the hydrolysate and 12-18 % of the total polysaccharides in the inlet biomass (untreated), equivalent to a yield loss of about 7-9 kg of monomeric sugars per 100 kg of inlet dry biomass (untreated). These oligosaccharides represent a yield loss and also inhibit commercial hydrolytic enzymes, with both being serious bottlenecks for economical biofuel production from cellulosic biomass. Very little is understood about the nature of these oligomers and why they are recalcitrant to commercial enzymes. This work presents a robust method for separating recalcitrant oligosaccharides from high solid loading hydrolysate in gramme quantities. Composition analysis, recalcitrance study and enzyme inhibition study were performed to understand their chemical nature. RESULTS Oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, and ammonia fibre expansion: AFEX). The methodology for large-scale separation of recalcitrant oligosaccharides from 25 % solids-loading AFEX-corn stover hydrolysate using charcoal fractionation and size exclusion chromatography is reported for the first time. Oligosaccharides with higher degree of polymerization (DP) were recalcitrant towards commercial enzyme mixtures [Ctec2, Htec2 and Multifect pectinase (MP)] compared to lower DP oligosaccharides. Enzyme inhibition studies using processed substrates (Avicel and xylan) showed that low DP oligosaccharides also inhibit commercial enzymes. Addition of monomeric sugars to oligosaccharides increases the inhibitory effects of oligosaccharides on commercial enzymes. CONCLUSION The carbohydrate composition of the recalcitrant oligosaccharides, ratios of different DP oligomers and their distribution profiles were determined. Recalcitrance and enzyme inhibition studies help determine whether the commercial enzyme mixtures lack the enzyme activities required to completely de-polymerize the plant cell wall. Such studies clarify the reasons for oligosaccharide accumulation and contribute to strategies by which oligosaccharides can be converted into fermentable sugars and provide higher biofuel yields with less enzyme.
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Affiliation(s)
- Saisi Xue
- />DOE Great Lakes Bioenergy Research Center, Biomass Conversion Research Lab (BCRL), Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, Lansing, MI 48910 USA
| | - Nirmal Uppugundla
- />DOE Great Lakes Bioenergy Research Center, Biomass Conversion Research Lab (BCRL), Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, Lansing, MI 48910 USA
| | - Michael J. Bowman
- />USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Bioenergy Research Unit, Peoria, IL 61604 USA
| | - David Cavalier
- />DOE Great Lakes Bioenergy Research Center, Biomass Conversion Research Lab (BCRL), Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, Lansing, MI 48910 USA
- />DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
| | - Leonardo Da Costa Sousa
- />DOE Great Lakes Bioenergy Research Center, Biomass Conversion Research Lab (BCRL), Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, Lansing, MI 48910 USA
| | - Bruce. E Dale
- />DOE Great Lakes Bioenergy Research Center, Biomass Conversion Research Lab (BCRL), Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, Lansing, MI 48910 USA
| | - Venkatesh Balan
- />DOE Great Lakes Bioenergy Research Center, Biomass Conversion Research Lab (BCRL), Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, Lansing, MI 48910 USA
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Expression and characterization of a novel endo-1,4-β-xylanase produced by Streptomyces griseorubens JSD-1 isolated from compost-treated soil. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-1016-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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27
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Wang W, Wei H, Alahuhta M, Chen X, Hyman D, Johnson DK, Zhang M, Himmel ME. Heterologous expression of xylanase enzymes in lipogenic yeast Yarrowia lipolytica. PLoS One 2014; 9:e111443. [PMID: 25462572 PMCID: PMC4251831 DOI: 10.1371/journal.pone.0111443] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 09/26/2014] [Indexed: 11/19/2022] Open
Abstract
To develop a direct microbial sugar conversion platform for the production of lipids, drop-in fuels and chemicals from cellulosic biomass substrate, we chose Yarrowia lipolytica as a viable demonstration strain. Y. lipolytica is known to accumulate lipids intracellularly and is capable of metabolizing sugars to produce lipids; however, it lacks the lignocellulose-degrading enzymes needed to break down biomass directly. While research is continuing on the development of a Y. lipolytica strain able to degrade cellulose, in this study, we present successful expression of several xylanases in Y. lipolytica. The XynII and XlnD expressing Yarrowia strains exhibited an ability to grow on xylan mineral plates. This was shown by Congo Red staining of halo zones on xylan mineral plates. Enzymatic activity tests further demonstrated active expression of XynII and XlnD in Y. lipolytica. Furthermore, synergistic action in converting xylan to xylose was observed when XlnD acted in concert with XynII. The successful expression of these xylanases in Yarrowia further advances us toward our goal to develop a direct microbial conversion process using this organism.
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Affiliation(s)
- Wei Wang
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
- * E-mail: (WW); (HW); (MZ)
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
- * E-mail: (WW); (HW); (MZ)
| | - Markus Alahuhta
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
| | - Xiaowen Chen
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
| | - Deborah Hyman
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
| | - David K. Johnson
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
| | - Min Zhang
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
- * E-mail: (WW); (HW); (MZ)
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
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28
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Zhang Y, Xu B, Zhou W. On a novel mechanistic model for simultaneous enzymatic hydrolysis of cellulose and hemicellulose considering morphology. Biotechnol Bioeng 2014; 111:1767-81. [DOI: 10.1002/bit.25244] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 02/07/2014] [Accepted: 03/19/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Yang Zhang
- Department of Chemical Engineering; Michigan Technological University; Houghton Michigan 49931
| | - Bingqian Xu
- Engineering and Nanoscale Science and Engineering Center; University of Georgia; Athens Georgia 30602
| | - Wen Zhou
- Department of Chemical Engineering; Michigan Technological University; Houghton Michigan 49931
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Gao L, Gao F, Jiang X, Zhang C, Zhang D, Wang L, Wu G, Chen S. Biochemical characterization of a new β-glucosidase (Cel3E) from Penicillium piceum and its application in boosting lignocelluloses bioconversion and forming disaccharide inducers: New insights into the role of β-glucosidase. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.02.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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30
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He YC, Gong L, Liu F, Lu T, Qing Q, Wang LQ, Zhang Y, Gao FT, Wang X. Waste Biogas Residue from Cassava Dregs as Carbon Source to Produce Galactomyces sp. Cczu11-1 Cellulase and its Enzymatic Saccharification. Appl Biochem Biotechnol 2014; 173:894-903. [DOI: 10.1007/s12010-014-0899-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/31/2014] [Indexed: 10/25/2022]
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31
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Lau CS, Thoma GJ, Clausen EC, Carrier DJ. Kinetic Modeling of Xylose Oligomer Degradation during Pretreatment in Dilute Acid or in Water. Ind Eng Chem Res 2014. [DOI: 10.1021/ie403722d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ching-Shuan Lau
- Department
of Biological and Agricultural Engineering, University of Arkansas, 203 Engineering Hall, Fayetteville, Arkansas 72701, United States
| | - Greg J. Thoma
- Ralph
E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - Edgar C. Clausen
- Ralph
E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - Danielle J. Carrier
- Department
of Biological and Agricultural Engineering, University of Arkansas, 203 Engineering Hall, Fayetteville, Arkansas 72701, United States
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32
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Bhutto AW, Qureshi K, Harijan K, Zahedi G, Bahadori A. Strategies for the consolidation of biologically mediated events in the conversion of pre-treated lignocellulose into ethanol. RSC Adv 2014. [DOI: 10.1039/c3ra44020f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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33
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Swiątek K, Lewandowska M, Swiątek M, Bednarski W, Brzozowski B. The improvement of enzymatic hydrolysis efficiency of rape straw and Miscanthus giganteus polysaccharides. BIORESOURCE TECHNOLOGY 2014; 151:323-31. [PMID: 24269826 DOI: 10.1016/j.biortech.2013.10.090] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 05/15/2023]
Abstract
The research was carried out with the aim to determine the impact of various combinations of cellulase and hemicellulase preparations on the effectiveness of enzymatic hydrolysis of polysaccharides of rape straw and Miscanthus giganteus after alkaline pretreatment. Their effectiveness was evaluated based on the quantity of saccharides released during enzymatic reaction and yield calculated in respect of the sum of polysaccharides present in native substrates. The complex of preparations produced from Trichoderma longibrachiatum fungi turned out to be the most effective. The study demonstrated a significant effect of xylanases from T. longibrachiatum, the presence of which evoked a 27-45% increase in the effectiveness of polysaccharides hydrolysis compared to the enzymatic complexes without their addition. In addition, results achieved in this study confirmed the necessity of applying the pretreatment in lignocellulose substrates conversion into bioethanol.
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Affiliation(s)
- Karolina Swiątek
- Chair of Food Biotechnology, University of Warmia and Mazury in Olsztyn, Heweliusza 1, 10-718 Olsztyn, Poland.
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34
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Gao L, Gao F, Zhang D, Zhang C, Wu G, Chen S. Purification and characterization of a new β-glucosidase from Penicillium piceum and its application in enzymatic degradation of delignified corn stover. BIORESOURCE TECHNOLOGY 2013; 147:658-661. [PMID: 24025854 DOI: 10.1016/j.biortech.2013.08.089] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/13/2013] [Accepted: 08/14/2013] [Indexed: 05/07/2023]
Abstract
A new β-glucosidase (Cel3B) was first isolated from cellulytic fungi, designated as PpCel3B. Although PpCel3B was classified to GH family 3 based on the homology sequence, PpCel3B had different biological functions in cellulose degradation and signaling molecules production. PpCel3B was constitutive and could form multiple soluble lignocellulose inducers for cellulase and hemicellulase synthesis via high tranglycosylation activity and new enzymatic activity. Moreover, PpCel3B showed apparent synergism with cellulases by removing several inhibitors. Supplementing low doses of PpCel3B (52 μg/g substrate) increased saccharification efficiency of cellulase produced by Trichoderma reesei and Penicillium piceum by 15% and 35%, respectively on delignified corn stover. PpCel3B had important application in boosting cellulase yield and efficiency.
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Affiliation(s)
- Le Gao
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Feng Gao
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Dongyuan Zhang
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Can Zhang
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Gaihong Wu
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Shulin Chen
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
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35
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Kont R, Kurašin M, Teugjas H, Väljamäe P. Strong cellulase inhibitors from the hydrothermal pretreatment of wheat straw. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:135. [PMID: 24053778 PMCID: PMC3849272 DOI: 10.1186/1754-6834-6-135] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 09/13/2013] [Indexed: 05/03/2023]
Abstract
BACKGROUND The use of the enzymatic hydrolysis of lignocellulose with subsequent fermentation to ethanol provides a green alternative for the production of transportation fuels. Because of its recalcitrant nature, the lignocellulosic biomass must be pretreated before enzymatic hydrolysis. However, the pretreatment often results in the formation of compounds that are inhibitory for the enzymes or fermenting organism. Although well recognized, little quantitative information on the inhibition of individual cellulase components by identified inhibitors is available. RESULTS Strong cellulase inhibitors were separated from the liquid fraction of the hydrothermal pretreatment of wheat straw. HPLC and mass-spectroscopy analyses confirmed that the inhibitors were oligosaccharides (inhibitory oligosaccharides, IOS) with a degree of polymerization from 7 to 16. The IOS are composed of a mixture of xylo- (XOS) and gluco-oligosaccharides (GOS). We propose that XOS and GOS are the fragments of the xylan backbone and mixed-linkage β-glucans, respectively. The IOS were approximately 100 times stronger inhibitors for Trichoderma reesei cellobiohydrolases (CBHs) than cellobiose, which is one of the strongest inhibitors of these enzymes reported to date. Inhibition of endoglucanases (EGs) by IOS was weaker than that of CBHs. Most of the tested cellulases and hemicellulases were able to slowly degrade IOS and reduce the inhibitory power of the liquid fraction to some extent. The most efficient single enzyme component here was T. reesei EG TrCel7B. Although reduced by the enzyme treatment, the residual inhibitory power of IOS and the liquid fraction was strong enough to silence the major component of the T. reesei cellulase system, CBH TrCel7A. CONCLUSIONS The cellulase inhibitors described here may be responsible for the poor yields from the enzymatic conversion of the whole slurries from lignocellulose pretreatment under conditions that do not favor complete degradation of hemicellulose. Identification of the inhibitory compounds helps to design better enzyme mixtures for their degradation and to optimize the pretreatment regimes to minimize their formation.
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Affiliation(s)
- Riin Kont
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
| | - Mihhail Kurašin
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
| | - Hele Teugjas
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
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Heterologous expression of endo-1,4-β-xylanase A from Schizophyllum commune in Pichia pastoris and functional characterization of the recombinant enzyme. Enzyme Microb Technol 2013; 52:170-6. [DOI: 10.1016/j.enzmictec.2012.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/27/2012] [Accepted: 12/31/2012] [Indexed: 11/17/2022]
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Ferrer A, Requejo A, Rodríguez A, Jiménez L. Influence of temperature, time, liquid/solid ratio and sulfuric acid concentration on the hydrolysis of palm empty fruit bunches. BIORESOURCE TECHNOLOGY 2013; 129:506-511. [PMID: 23266852 DOI: 10.1016/j.biortech.2012.10.081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 10/15/2012] [Accepted: 10/16/2012] [Indexed: 06/01/2023]
Abstract
The influence of temperature (150-190 °C), time (0-20 min), liquid/solid ratio (6-8) and sulfuric acid concentration (0.1-0.5%), on the hydrolysis of palm empty fruit bunches (EFBs) was studied and the liquid and solid fractions were analyzed. Polynomial models were found to reproduce the experimental results with errors less than 15% in most of the cases (except for xylose concentration). Operating conditions of 190 °C for 15 min at a liquid/solid ratio of 6 and a sulfuric acid concentration of 0.1% resulted in the production of 3.12, 4.0, 2.35 and 2.28 g/L of glucose, xylose, arabinose and acetic acid, respectively, starting with 1000 g of EFBs. The yield was 67.96%. Soda-anthraquinone, ethanol and ethanolamine pulping of the solid fraction provided pulps with brightness values (63.24%, 28.78%, 48.76%), but with poor resistance properties (6.57-8.54 Nm/g for tensile index, 0.38-0.44 k N/g for burst index and 0.96-1.02 mN m2/g for tear index). Therefore it is advisable to use the pulps for speciality papers or for bioethanol-production.
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Affiliation(s)
- Ana Ferrer
- Chemical Engineering Department, Campus of Rabanales, Building Marie Curie (C-3), University of Córdoba, 14071 Córdoba, Spain
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Harun S, Balan V, Takriff MS, Hassan O, Jahim J, Dale BE. Performance of AFEX™ pretreated rice straw as source of fermentable sugars: the influence of particle size. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:40. [PMID: 23514037 PMCID: PMC3648367 DOI: 10.1186/1754-6834-6-40] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 03/12/2013] [Indexed: 05/18/2023]
Abstract
BACKGROUND It is widely believed that reducing the lignocellulosic biomass particle size would improve the biomass digestibility by increasing the total surface area and eliminating mass and heat transfer limitation during hydrolysis reactions. However, past studies demonstrate that particle size influences biomass digestibility to a limited extent. Thus, this paper studies the effect of particle size (milled: 2 mm, 5 mm, cut: 2 cm and 5 cm) on rice straw conversion. Two different Ammonia Fiber Expansion (AFEX) pretreament conditions, AFEX C1 (low severity) and AFEX C2 (high severity) are used to pretreat the rice straw (named as AC1RS and AC2RS substrates respectively) at different particle size. RESULTS Hydrolysis of AC1RS substrates showed declining sugar conversion trends as the size of milled and cut substrates increased. Hydrolysis of AC2RS substrates demonstrated opposite conversion trends between milled and cut substrates. Increasing the glucan loading to 6% during hydrolysis reduced the sugar conversions significantly in most of AC1RS and AC2RS except for AC1RS-2 mm and AC2RS-5 cm. Both AC1RS-2 mm and AC2RS-5 cm indicated gradual decreasing trends in sugar conversion at high glucan loading. Analysis of SEM imaging for URS and AFEX pretreated rice straw also indicated qualitative agreement with the experimental data of hydrolysis. The largest particle size, AC2RS-5 cm produced the highest sugar yield of 486.12 g/kg of rice straw during hydrolysis at 6% glucan loading equivalent to 76.0% of total theoretical maximum sugar yield, with an average conversion of 85.9% from total glucan and xylan. In contrast, AC1RS-5 cm gave the lowest sugar yield with only 107.6 g/kg of rice straw, about 16.8% of total theoretical maximum sugar yield, and equivalent to one-quarter of AC2RS-5 cm sugar yield. CONCLUSIONS The larger cut rice straw particles (5 cm) significantly demonstrated higher sugar conversion when compared to small particles during enzymatic hydrolysis when treated using high severity AFEX conditions. Analysis of SEM imaging positively supported the interpretation of the experimental hydrolysis trend and kinetic data.
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Affiliation(s)
- Shuhaida Harun
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor, 43600 UKM, Malaysia
| | - Venkatesh Balan
- Department of Chemical Engineering and Materials Science, DOE Great Lakes Bioenergy Research Center, Michigan State University, Lansing, MI, 48823, USA
| | - Mohd Sobri Takriff
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor, 43600 UKM, Malaysia
| | - Osman Hassan
- School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, 43600 UKM, Malaysia
| | - Jamaliah Jahim
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor, 43600 UKM, Malaysia
| | - Bruce E Dale
- Department of Chemical Engineering and Materials Science, DOE Great Lakes Bioenergy Research Center, Michigan State University, Lansing, MI, 48823, USA
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Separation of xylose oligomers using centrifugal partition chromatography with a butanol-methanol-water system. J Ind Microbiol Biotechnol 2012; 40:51-62. [PMID: 23114992 DOI: 10.1007/s10295-012-1209-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 10/05/2012] [Indexed: 10/27/2022]
Abstract
Xylose oligomers are the intermediate products of xylan depolymerization into xylose monomers. An understanding of xylan depolymerization kinetics is important to improve the conversion of xylan into monomeric xylose and to minimize the formation of inhibitory products, thereby reducing ethanol production costs. The study of xylan depolymerization requires copious amount of xylose oligomers, which are expensive if acquired commercially. Our approach consisted of producing in-house oligomer material. To this end, birchwood xylan was used as the starting material and hydrolyzed in hot water at 200 °C for 60 min with a 4 % solids loading. The mixture of xylose oligomers was subsequently fractionated by a centrifugal partition chromatography (CPC) with a solvent system of butanol:methanol:water in a 5:1:4 volumetric ratio. Operating in an ascending mode, the butanol-rich upper phase (the mobile phase) eluted xylose oligomers from the water-rich stationary phase at a 4.89 mL/min flow rate for a total fractionation time of 300 min. The elution of xylose oligomers occurred between 110 and 280 min. The yields and purities of xylobiose (DP 2), xylotriose (DP 3), xylotetraose (DP 4), and xylopentaose (DP 5) were 21, 10, 14, and 15 mg/g xylan and 95, 90, 89, and 68 %, respectively. The purities of xylose oligomers from this solvent system were higher than those reported previously using tetrahydrofuran:dimethyl sulfoxide:water in a 6:1:3 volumetric ratio. Moreover, the butanol-based solvent system improved overall procedures by facilitating the evaporation of the solvents from the CPC fractions, rendering the purification process more efficient.
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Pryor SW, Karki B, Nahar N. Effect of hemicellulase addition during enzymatic hydrolysis of switchgrass pretreated by soaking in aqueous ammonia. BIORESOURCE TECHNOLOGY 2012; 123:620-626. [PMID: 22960121 DOI: 10.1016/j.biortech.2012.07.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/11/2012] [Accepted: 07/13/2012] [Indexed: 06/01/2023]
Abstract
The focus of this study was to determine the effect of supplementing cellulase with hemicellulase during enzymatic hydrolysis of switchgrass pretreated by soaking in aqueous ammonia (SAA) under a range of conditions. SAA was performed using 15% aqueous ammonia for 8 or 24h at temperatures of 40 or 60°C. The combined effect of cellulase and hemicellulase loadings on glucose yield during enzymatic hydrolysis was modeled for each pretreatment condition. Glucose yields greater than 85% of theoretical were achieved for pretreatment at 40°C for 24h and for 60°C for 8h. Hemicellulase supplementation was not sufficient to achieve these glucose yields at lower severity SAA pretreatment. High severity SAA pretreatment also led to low yields despite improved delignification.
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Affiliation(s)
- Scott W Pryor
- Department of Agricultural and Biosystems Engineering, North Dakota State University, Fargo, ND 58108, USA.
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Production of a xylose-stimulated β-glucosidase and a cellulase-free thermostable xylanase by the thermophilic fungus Humicola brevis var. thermoidea under solid state fermentation. World J Microbiol Biotechnol 2012; 28:2689-701. [PMID: 22806195 DOI: 10.1007/s11274-012-1079-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 05/05/2012] [Indexed: 10/28/2022]
Abstract
Humicola brevis var. thermoidea cultivated under solid state fermentation in wheat bran and water (1:2 w/v) was a good producer of β-glucosidase and xylanase. After optimization using response surface methodology the level of xylanase reached 5,791.2 ± 411.2 U g(-1), while β-glucosidase production was increased about 2.6-fold, reaching 20.7 ± 1.5 U g(-1). Cellulase levels were negligible. Biochemical characterization of H. brevis β-glucosidase and xylanase activities showed that they were stable in a wide pH range. Optimum pH for β-glucosidase and xylanase activities were 5.0 and 5.5, respectively, but the xylanase showed 80 % of maximal activity when assayed at pH 8.0. Both enzymes presented high thermal stability. The β-glucosidase maintained about 95 % of its activity after 26 h in water at 55 °C, with half-lives of 15.7 h at 60 °C and 5.1 h at 65 °C. The presence of xylose during heat treatment at 65 °C protected β-glucosidase against thermal inactivation. Xylanase maintained about 80 % of its activity after 200 h in water at 60 °C. Xylose stimulated β-glucosidase activity up to 1.7-fold, at 200 mmol L(-1). The notable features of both xylanase and β-glucosidase suggest that H. brevis crude culture extract may be useful to compose efficient enzymatic cocktails for lignocellulosic materials treatment or paper pulp biobleaching.
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Requejo A, Peleteiro S, Garrote G, Rodríguez A, Jiménez L. Biorefinery of olive pruning using various processes. BIORESOURCE TECHNOLOGY 2012; 111:301-307. [PMID: 22386468 DOI: 10.1016/j.biortech.2012.01.156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/24/2012] [Accepted: 01/25/2012] [Indexed: 05/31/2023]
Abstract
Biorefinery developed involve separation of olive pruning into two parts: main (OPM) (stems>1cm diameter), and residual (OPR) (stems<1cm diameter, and leaves). OPM was submitted to hydrothermal treatment, separating: a liquid fraction (HL), rich in products of hemicelluloses decomposition, and other solid (HS), rich in cellulose and lignin. HS is subject to pulping, resulting: a liquid fraction (HPL), rich in lignin, and other solid (HPS), rich in cellulose. Up to 42% of the polysaccharides from OPM were recovered in HL as valuable compounds. HPS can be used for the bioethanol production by saccharification and fermentation, reaching a bioethanol conversion of 90.6% of the theoretical value. In addition, HPS obtained paper with lower strength properties than those of paper obtained from OPM pulp directly. OPR provided 18.70 MkJ/t heating values, 1094-2234°C flame temperature, and 45-53°C dew point temperature, with a cost of the unit of heat (3.20 €/MkJ) much lower than fossil fuels fluids.
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Affiliation(s)
- A Requejo
- Chemical Engineering Department, University of Córdoba, Spain
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Sahu R, Dhepe PL. A one-pot method for the selective conversion of hemicellulose from crop waste into C5 sugars and furfural by using solid acid catalysts. CHEMSUSCHEM 2012; 5:751-761. [PMID: 22411884 DOI: 10.1002/cssc.201100448] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 12/22/2011] [Indexed: 05/31/2023]
Abstract
We present a solid-acid catalyzed one-pot method for the selective conversion of solid hemicellulose without its separation from other lignocellulosic components, such as cellulose and lignin. The reactions were carried out in aqueous and biphasic media to yield xylose, arabinose, and furfural. To overcome the drawbacks posed by mineral acid methods in converting hemicelllulose, we used heterogeneous catalysts that work at neutral pH. In a batch reactor, these heterogeneous catalysts, such as solid acids (zeolites, clays, metal oxides etc.), resulted in >90 % conversion of hemicellulose. It has been shown that the selectivity for the products can be tuned by changing the reaction conditions, for example, a reaction carried out in water at 170 °C for 1 h with HBeta (Si/Al=19) and HUSY (Si/Al=15) catalysts gave yields of 62 and 56 % for xylose and arabinose, respectively. With increased reaction time (6 h) and in presence of only water, HUSY resulted in yields of 30 % xylose + arabinose and 18 % furfural. However, in a biphasic reaction system (water + p-xylene, 170 °C, 6 h) yields of 56 % furfural with 17 % xylose+arabinose could be achieved. It was shown that with the addition of organic solvent the furfural yield could be increased from 18 to 56 %. Under optimized reaction conditions, >90 % carbon balance was observed. The study revealed that catalysts were recyclable with a 20 % drop in activity for each subsequent run. It was observed that temperature, pressure, reaction time, substrate to catalyst ratio, solvent, and so forth had an effect on product formation. The catalysts were characterized by means of X-ray diffraction, temperature-programmed desorption of NH(3), inductively coupled plasma spectroscopy, elemental analysis, and solid-state NMR ((29)Si, (27)Al) spectroscopy techniques.
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Affiliation(s)
- Ramakanta Sahu
- Catalysis and Inorganic Chemistry Division, National Chemical Laboratory, Pune 411008, India
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Van Dyk JS, Pletschke BI. A review of lignocellulose bioconversion using enzymatic hydrolysis and synergistic cooperation between enzymes--factors affecting enzymes, conversion and synergy. Biotechnol Adv 2012; 30:1458-80. [PMID: 22445788 DOI: 10.1016/j.biotechadv.2012.03.002] [Citation(s) in RCA: 477] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 02/10/2012] [Accepted: 03/06/2012] [Indexed: 02/04/2023]
Abstract
Lignocellulose is a complex substrate which requires a variety of enzymes, acting in synergy, for its complete hydrolysis. These synergistic interactions between different enzymes have been investigated in order to design optimal combinations and ratios of enzymes for different lignocellulosic substrates that have been subjected to different pretreatments. This review examines the enzymes required to degrade various components of lignocellulose and the impact of pretreatments on the lignocellulose components and the enzymes required for degradation. Many factors affect the enzymes and the optimisation of the hydrolysis process, such as enzyme ratios, substrate loadings, enzyme loadings, inhibitors, adsorption and surfactants. Consideration is also given to the calculation of degrees of synergy and yield. A model is further proposed for the optimisation of enzyme combinations based on a selection of individual or commercial enzyme mixtures. The main area for further study is the effect of and interaction between different hemicellulases on complex substrates.
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Affiliation(s)
- J S Van Dyk
- Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, PO Box 94, Grahamstown, 6140, South Africa
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Barr CJ, Mertens JA, Schall CA. Critical cellulase and hemicellulase activities for hydrolysis of ionic liquid pretreated biomass. BIORESOURCE TECHNOLOGY 2012; 104:480-5. [PMID: 22154300 DOI: 10.1016/j.biortech.2011.10.101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 10/27/2011] [Accepted: 10/28/2011] [Indexed: 05/10/2023]
Abstract
Critical cellulase and hemicellulase activities are identified for hydrolysis of ionic liquid (IL) pretreated poplar and switchgrass; hemicellulase rich substrates with largely amorphous cellulose. Enzymes from Aspergillus nidulans were expressed and purified: an endoglucanase (EG) a cellobiohydrolase (CBH), an endoxylanase (EX) and an acetylxylan esterase (AXE). β-Xylosidase (βX) from Selenomonas ruminantium and a commercial β-glucosidase (βG) from Novozyme 188 were admixed with the A. nidulans enzymes. Statistical analysis indicates that βG and βX activities are significant for both glucose and xylose yields for the two substrates. EG is a significant factor for glucan hydrolysis while EX is significant for xylan hydrolysis of the substrates. The CBH, which has activity on crystalline cellulose and negligible activity on amorphous cellulose, was not a significant factor in glucan hydrolysis. EX is significant in glucan hydrolysis for poplar. The addition of AXE significantly improves xylan hydrolysis for poplar but not switchgrass.
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Affiliation(s)
- Christopher J Barr
- Department of Chemical & Environmental Engineering, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606, USA
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Garlock RJ, Balan V, Dale BE, Pallapolu VR, Lee YY, Kim Y, Mosier NS, Ladisch MR, Holtzapple MT, Falls M, Sierra-Ramirez R, Shi J, Ebrik MA, Redmond T, Yang B, Wyman CE, Donohoe BS, Vinzant TB, Elander RT, Hames B, Thomas S, Warner RE. Comparative material balances around pretreatment technologies for the conversion of switchgrass to soluble sugars. BIORESOURCE TECHNOLOGY 2011; 102:11063-71. [PMID: 21524908 DOI: 10.1016/j.biortech.2011.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 04/01/2011] [Accepted: 04/01/2011] [Indexed: 05/02/2023]
Abstract
For this project, six chemical pretreatments were compared for the Consortium for Applied Fundamentals and Innovation (CAFI): ammonia fiber expansion (AFEX), dilute sulfuric acid (DA), lime, liquid hot water (LHW), soaking in aqueous ammonia (SAA), and sulfur dioxide (SO(2)). For each pretreatment, a material balance was analyzed around the pretreatment, optional post-washing step, and enzymatic hydrolysis of Dacotah switchgrass. All pretreatments+enzymatic hydrolysis solubilized over two-thirds of the available glucan and xylan. Lime, post-washed LHW, and SO(2) achieved >83% total glucose yields. Lime, post-washed AFEX, and DA achieved >83% total xylose yields. Alkaline pretreatments, except AFEX, solubilized the most lignin and a portion of the xylan as xylo-oligomers. As pretreatment pH decreased, total solubilized xylan and released monomeric xylose increased. Low temperature-long time or high temperature-short time pretreatments are necessary for high glucose release from late-harvest Dacotah switchgrass but high temperatures may cause xylose degradation.
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Affiliation(s)
- Rebecca J Garlock
- Biomass Conversion Research Laboratory, Department of Chemical Engineering and Materials Science, Michigan State University, 3900 Collins Road, Lansing, MI 48910, USA.
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Baumann MJ, Borch K, Westh P. Xylan oligosaccharides and cellobiohydrolase I (TrCel7A) interaction and effect on activity. BIOTECHNOLOGY FOR BIOFUELS 2011; 4:45. [PMID: 22035059 PMCID: PMC3257202 DOI: 10.1186/1754-6834-4-45] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 10/31/2011] [Indexed: 05/05/2023]
Abstract
BACKGROUND The well-studied cellulase mixture secreted by Trichoderma reesei (anamorph to Hypocrea jecorina) contains two cellobiohydolases (CBHs), cellobiohydrolase I (TrCel7A) and cellobiohydrolase II (TrCeI6A), that are core enzymes for the solubilisation of cellulose. This has attracted significant research interest because of the role of the CBHs in the conversion of biomass to fermentable sugars. However, the CHBs are notoriously slow and susceptible to inhibition, which presents a challenge for the commercial utilisation of biomass. The xylans and xylan fragments that are also present in the biomass have been suggested repeatedly as one cause of the reduced activity of CHBs. Yet, the extent and mechanisms of this inhibition remain poorly elucidated. Therefore, we studied xylan oligosaccharides (XOSs) of variable lengths with respect to their binding and inhibition of both TrCel7A and an enzyme variant without the cellulose-binding domain (CBM). RESULTS We studied the binding of XOSs to TrCel7A by isothermal titration calorimetry. We found that XOSs bind to TrCel7A and that the affinity increases commensurate with XOS length. The CBM, on the other hand, did not affect the affinity significantly, which suggests that XOSs may bind to the active site. Activity assays of TrCel7A clearly demonstrated the negative effect of the presence of XOSs on the turnover number. CONCLUSIONS On the basis of these binding data and a comparison of XOS inhibition of the activity of the two enzyme variants towards, respectively, soluble and insoluble substrates, we propose a competitive mechanism for XOS inhibition of TrCel7A with phosphoric swollen cellulose as a substrate.
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Affiliation(s)
- Martin J Baumann
- Research Unit for Biomaterials, Roskilde University, NSM, Universitetsvej 1, DK-4000, Roskilde, Denmark
- Novozymes A/S, Krogshøjvej 36, DK-2880, Bagsværd, Denmark
| | - Kim Borch
- Novozymes A/S, Krogshøjvej 36, DK-2880, Bagsværd, Denmark
| | - Peter Westh
- Research Unit for Biomaterials, Roskilde University, NSM, Universitetsvej 1, DK-4000, Roskilde, Denmark
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Siqueira G, Milagres AMF, Carvalho W, Koch G, Ferraz A. Topochemical distribution of lignin and hydroxycinnamic acids in sugar-cane cell walls and its correlation with the enzymatic hydrolysis of polysaccharides. BIOTECHNOLOGY FOR BIOFUELS 2011; 4:7. [PMID: 21410971 PMCID: PMC3068087 DOI: 10.1186/1754-6834-4-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 03/16/2011] [Indexed: 05/10/2023]
Abstract
BACKGROUND Lignin and hemicelluloses are the major components limiting enzyme infiltration into cell walls. Determination of the topochemical distribution of lignin and aromatics in sugar cane might provide important data on the recalcitrance of specific cells. We used cellular ultraviolet (UV) microspectrophotometry (UMSP) to topochemically detect lignin and hydroxycinnamic acids in individual fiber, vessel and parenchyma cell walls of untreated and chlorite-treated sugar cane. Internodes, presenting typical vascular bundles and sucrose-storing parenchyma cells, were divided into rind and pith fractions. RESULTS Vascular bundles were more abundant in the rind, whereas parenchyma cells predominated in the pith region. UV measurements of untreated fiber cell walls gave absorbance spectra typical of grass lignin, with a band at 278 nm and a pronounced shoulder at 315 nm, assigned to the presence of hydroxycinnamic acids linked to lignin and/or to arabino-methylglucurono-xylans. The cell walls of vessels had the highest level of lignification, followed by those of fibers and parenchyma. Pith parenchyma cell walls were characterized by very low absorbance values at 278 nm; however, a distinct peak at 315 nm indicated that pith parenchyma cells are not extensively lignified, but contain significant amounts of hydroxycinnamic acids. Cellular UV image profiles scanned with an absorbance intensity maximum of 278 nm identified the pattern of lignin distribution in the individual cell walls, with the highest concentration occurring in the middle lamella and cell corners. Chlorite treatment caused a rapid removal of hydroxycinnamic acids from parenchyma cell walls, whereas the thicker fiber cell walls were delignified only after a long treatment duration (4 hours). Untreated pith samples were promptly hydrolyzed by cellulases, reaching 63% of cellulose conversion after 72 hours of hydrolysis, whereas untreated rind samples achieved only 20% hydrolyzation. CONCLUSION The low recalcitrance of pith cells correlated with the low UV-absorbance values seen in parenchyma cells. Chlorite treatment of pith cells did not enhance cellulose conversion. By contrast, application of the same treatment to rind cells led to significant removal of hydroxycinnamic acids and lignin, resulting in marked enhancement of cellulose conversion by cellulases.
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Affiliation(s)
- Germano Siqueira
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, CP 116, 12602-810 Lorena, SP, Brasil
| | - Adriane MF Milagres
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, CP 116, 12602-810 Lorena, SP, Brasil
| | - Walter Carvalho
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, CP 116, 12602-810 Lorena, SP, Brasil
| | - Gerald Koch
- Institute of Wood Technology and Wood Biology, Federal Research Institute for Rural Areas, Forestry and Fisheries, D-21031 Hamburg, Germany
| | - André Ferraz
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, CP 116, 12602-810 Lorena, SP, Brasil
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