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Maibam PD, Goyal A. Approach to an efficient pretreatment method for rice straw by deep eutectic solvent for high saccharification efficiency. BIORESOURCE TECHNOLOGY 2022; 351:127057. [PMID: 35337995 DOI: 10.1016/j.biortech.2022.127057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
Deep eutectic solvent comprising choline chloride (ChCl) and acetic acid (AA) was used for rice straw (RS) pretreatment. Effect of ChCl: AA molar ratio, time and temperature on lignin removal and retainment of total carbohydrate content (TCC) in pretreatment process were evaluated by central composite design (CCD) approach. The pretreatment temperature and molar ratio of AA to ChCl played a significant role in delignification. The optimized conditions for RS pretreatment were 1:3.59 (ChCl:AA molar ratio), 126 °C and 150 min. ChCl:AA pretreated RS (CApRS) gave 83.1% delignification, 679 mg/gCApRS TCC and 83.7% pretreatment efficiency. CApRS contained enriched cellulose content, 0.73 g/gCApRS as compared with 0.43 g/graw RS in raw RS. CApRS showed 31% higher crystallinity index, 17-fold higher surface area than raw RS. The morphological study of CApRS displayed porous surface. Saccharification of CApRS by commercial cellulase gave total reducing sugar of 18.8 g/L in hydrolysate with saccharification efficiency, 92.2%.
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Affiliation(s)
- Premeshworii Devi Maibam
- School of Energy Sciences and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Arun Goyal
- School of Energy Sciences and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India.
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Gavande PV, Nath P, Kumar K, Ahmed N, Fontes CMGA, Goyal A. Highly efficient, processive and multifunctional recombinant endoglucanase RfGH5_4 from Ruminococcus flavefaciens FD-1 v3 for recycling lignocellulosic plant biomasses. Int J Biol Macromol 2022; 209:801-813. [PMID: 35421411 DOI: 10.1016/j.ijbiomac.2022.04.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/18/2022] [Accepted: 04/08/2022] [Indexed: 11/26/2022]
Abstract
Gene encoding endoglucanase, RfGH5_4 from R. flavefaciens FD-1 v3 was cloned, expressed in Escherichia coli BL21(DE3) cells and purified. RfGH5_4 showed molecular size 41 kDa and maximum activity at pH 5.5 and 55 °C. It was stable between pH 5.0-8.0, retaining 85% activity and between 5 °C-45 °C, retaining 75% activity, after 60 min. RfGH5_4 displayed maximum activity (U/mg) against barley β-D-glucan (665) followed by carboxymethyl cellulose (450), xyloglucan (343), konjac glucomannan (285), phosphoric acid swollen cellulose (86), beechwood xylan (21.7) and carob galactomannan (16), thereby displaying the multi-functionality. Catalytic efficiency (mL.mg-1 s-1) of RfGH5_4 against carboxymethyl cellulose (146) and konjac glucomannan (529) was significantly high. TLC and MALDI-TOF-MS analyses of RfGH5_4 treated hydrolysates of cellulosic and hemicellulosic polysaccharides displayed oligosaccharides of degree of polymerization (DP) between DP2-DP11. TLC, HPLC and Processivity-Index analyses revealed RfGH5_4 to be a processive endoglucanase as initially, for 30 min it hydrolysed cellulose to cellotetraose followed by persistent release of cellotriose and cellobiose. RfGH5_4 yielded sufficiently high Total Reducing Sugar (TRS, mg/g) from saccharification of alkali pre-treated sorghum (72), finger millet (62), sugarcane bagasse (38) and cotton (27) in a 48 h saccharification reaction. Thus, RfGH5_4 can be considered as a potential endoglucanase for renewable energy applications.
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Affiliation(s)
- Parmeshwar Vitthal Gavande
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Priyanka Nath
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Krishan Kumar
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Nazneen Ahmed
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Carlos M G A Fontes
- CIISA - Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal; NZYTech - Genes & Enzymes, Estrada do Paço do Lumiar, Campus do Lumiar, Edifício, Lisbon, Portugal
| | - Arun Goyal
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
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Chandrakant Khaire K, Suryakant Moholkar V, Goyal A. Alkaline pretreatment and response surface methodology based recombinant enzymatic saccharification and fermentation of sugarcane tops. BIORESOURCE TECHNOLOGY 2021; 341:125837. [PMID: 34461408 DOI: 10.1016/j.biortech.2021.125837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/20/2021] [Accepted: 08/21/2021] [Indexed: 06/13/2023]
Abstract
In present study, the water-soluble extractives removal prior to alkali pretreatment of sugarcane tops (SCT) was carried out. The solid alkali pretreated SCT (apSCT) recovered on Field-emission scanning electron microscopy (FE-SEM) analysis showed exposure of cellulosic fibres as compared with raw SCT. The analyses of apSCT by Fourier Transform Infrared (FT-IR) Spectroscopy, X-ray diffraction (XRD) and High performance liquid chromatography (HPLC) analysis also confirmed the enhanced cellulose content in apSCT. Optimum conditions for response surface methodology based saccharification of apSCT at 40 °C, 150 rpm were 2.14% (w/v) apSCT loading in citrate-phosphate buffer (50 mM, pH 6.0), recombinant hydrolytic enzymes (from Clostridium/Hungateiclostridium thermocellum) loading for endo-1,4-β-glucanase (CtCel8A) = 213.2 U/g, cellobiohydrolase (CtCBH5A) = 272.5 U/g and β-glucosidase (HtBg1) = 299.8 U/g for 49.2 h. Under optimized saccharification conditions, the total reducing sugar yield was 265 mg/g (glucose 214 mg/g) of apSCT. Fermentation of produced glucose by S. cerevisiae gave 0.19 g/g glucose of bioethanol.
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Affiliation(s)
- Kaustubh Chandrakant Khaire
- School of Energy Science and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Vijayanand Suryakant Moholkar
- School of Energy Science and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Arun Goyal
- School of Energy Science and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
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Khaire KC, Moholkar VS, Goyal A. Separation and characterization of cellulose from sugarcane tops and its saccharification by recombinant cellulolytic enzymes. Prep Biochem Biotechnol 2020; 51:811-820. [DOI: 10.1080/10826068.2020.1861011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
| | - Vijayanand Suryakant Moholkar
- Centre for Energy, Indian Institute of Technology Guwahati, Guwahati, India
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India
| | - Arun Goyal
- Centre for Energy, Indian Institute of Technology Guwahati, Guwahati, India
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India
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Ultrasound-assisted alkali-urea pre-treatment of Miscanthus × giganteus for enhanced extraction of cellulose fiber. Carbohydr Polym 2020; 247:116758. [DOI: 10.1016/j.carbpol.2020.116758] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/11/2020] [Accepted: 06/24/2020] [Indexed: 01/24/2023]
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Nedumaran M, Singh S, Jamaldheen SB, Nath P, Moholkar VS, Goyal A. Assessment of combination of pretreatment of Sorghum durra stalk and production of chimeric enzyme (β-glucosidase and endo β-1,4 glucanase, CtGH1-L1- CtGH5-F194A) and cellobiohydrolase ( CtCBH5A) for saccharification to produce bioethanol. Prep Biochem Biotechnol 2020; 50:883-896. [PMID: 32425106 DOI: 10.1080/10826068.2020.1762214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Optimization of pretreatment and saccharification of Sorghum durra stalk (Sds) was carried out. The chimeric enzyme (CtGH1-L1-CtGH5-F194A) having β-glucosidase (CtGH1) and endo β-1,4 glucanase activity (CtGH5-F194A) and cellobiohydrolase (CtCBH5A) from Clostridium thermocellum were used for saccharification. Chimeric enzyme will save production cost of two enzymes, individually. Stage 2 pretreatment by 1% (w/v) NaOH assisted autoclaving + 1.5% (v/v) dilute H2SO4 assisted oven heating gave lower total sugar yield (366.6 mg/g of pretreated Sds) and total glucose yield (195 mg/g of pretreated Sds) in pretreated hydrolysate with highest crystallinity index 55.6% than the other stage 2 pretreatments. Optimized parameters for saccharification of above stage 2 pretreated biomass were 3% (w/v) biomass concentration, enzyme (chimera: cellobiohydrolase) ratio, 2:3 (U/g) of biomass, total enzyme loading (350 U/g of pretreated biomass), 24 h and 30 °C. Best stage 2 pretreated Sds under optimized enzyme saccharification conditions gave maximum total reducing sugar yield 417 mg/g and glucose yield 285 mg/g pretreated biomass in hydrolysate. Best stage 2 pretreated Sds showed significantly higher cellulose, 71.3% and lower lignin, 2.0% and hemicellulose, 12.2% (w/w) content suggesting the effectiveness of method. This hydrolysate upon SHF using Saccharomyces cerevisiae under unoptimized conditions produced ethanol yield, 0.12 g/g of glucose. Abbreviation: Ct-Clostridium thermocellum, Sds-Sorghum durra stalk, TRS-Total reducing sugar, HPLC-High performance liquid chromatography, RI-Refractive index, ADL-acid insoluble lignin, GYE-Glucose yeast extract, MGYP-Malt glucose yeast extract peptone, SHF-separate hydrolysis and fermentation, OD-Optical density, PVDF-Poly vinylidene fluoride, TS-total sugar, FESEM-Field emission scanning electron microscopy, XRD-X-ray diffraction, FTIR-Fourier transform infra-red spectroscopy and CrI-Crystallinity index.
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Affiliation(s)
- Mohanapriya Nedumaran
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India
| | - Shweta Singh
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India.,DBT PAN-IIT Centre for Bioenergy, Indian Institute of Technology Guwahati, Guwahati, India
| | - Sumitha Banu Jamaldheen
- DBT PAN-IIT Centre for Bioenergy, Indian Institute of Technology Guwahati, Guwahati, India.,Centre for Energy, Indian Institute of Technology Guwahati, Guwahati, India
| | - Priyanka Nath
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India.,DBT PAN-IIT Centre for Bioenergy, Indian Institute of Technology Guwahati, Guwahati, India
| | - Vijayanand Suryakant Moholkar
- Centre for Energy, Indian Institute of Technology Guwahati, Guwahati, India.,Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India
| | - Arun Goyal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India.,DBT PAN-IIT Centre for Bioenergy, Indian Institute of Technology Guwahati, Guwahati, India.,Centre for Energy, Indian Institute of Technology Guwahati, Guwahati, India
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Xia J, Shu J, Yao K, Xu J, Yu X, Xue X, Ma D, Lin X. Synergism of cellulase, pectinase and xylanase on hydrolyzing differently pretreated sweet potato residues. Prep Biochem Biotechnol 2019; 50:181-190. [PMID: 31647386 DOI: 10.1080/10826068.2019.1680390] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The synergism of cellulase (C), pectinase (P), and xylanase (X) for the saccharification of sweet potato residues (SPR) was investigated. The removal of starch from SPR was easily achieved by using amylase, but the cellulose conversion of de-starched SPR was relatively low, thus dilute H2SO4, NaOH, and H2O2 pretreatment was conducted to improve the enzymatic digestibility. The lignin content of NaOH pretreated SPR was the lowest, whereas H2SO4 pretreatment resulted in the lowest contents of hemicellulose and pectin. The combination of C, P, and X exhibited different sugar production patterns, C-P displayed synergistic action on glucose and galactose production from each type of SPR, C-X also exhibited synergistic effect on glucose production except when H2SO4 pretreated SPR was used, whereas no synergism between P-X on monosaccharide production was observed. The presence of synergism between cellulase and mixed accessory enzymes [C-(PX)] on glucose formation was determined by C-X, and the degree of synergism between C-P and C-(PX) on glucose production had a positive relationship with pectin content. The highest cellulose conversion of 96.2% was obtained from NaOH pretreated SPR using mixed enzymes comprising C, P, and X with the ratio of 8:1:1.
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Affiliation(s)
- Jun Xia
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, College of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an, Jiangsu, P. R. China
| | - Jingyi Shu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, College of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an, Jiangsu, P. R. China
| | - Kangwei Yao
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, College of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an, Jiangsu, P. R. China
| | - Jiming Xu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, College of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an, Jiangsu, P. R. China
| | - Xinjun Yu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang, P. R. China
| | - Xiang Xue
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, College of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an, Jiangsu, P. R. China
| | - Decao Ma
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, College of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an, Jiangsu, P. R. China
| | - Xueqi Lin
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, College of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an, Jiangsu, P. R. China
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Nath P, Dhillon A, Kumar K, Sharma K, Jamaldheen SB, Moholkar VS, Goyal A. Development of bi-functional chimeric enzyme (CtGH1-L1-CtGH5-F194A) from endoglucanase (CtGH5) mutant F194A and β-1,4-glucosidase (CtGH1) from Clostridium thermocellum with enhanced activity and structural integrity. BIORESOURCE TECHNOLOGY 2019; 282:494-501. [PMID: 30897487 DOI: 10.1016/j.biortech.2019.03.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/08/2019] [Accepted: 03/09/2019] [Indexed: 06/09/2023]
Abstract
Site-directed mutagenesis of β-1,4-endoglucanase from family 5 glycoside hydrolase (CtGH5) from Clostridium thermocellum was performed to develop a mutant CtGH5-F194A that gave 40 U/mg specific activity against carboxymethyl cellulose, resulting 2-fold higher activity than wild-type CtGH5. CtGH5-F194A was fused with a β-1,4-glucosidase, CtGH1 from Clostridium thermocellum to develop a chimeric enzyme. The chimera (CtGH1-L1-CtGH5-F194A) expressed as a soluble protein using E. coli BL-21cells displaying 3- to 5-fold higher catalytic efficiency for endoglucanase and β-glucosidase activities. TLC analysis of hydrolysed product of CMC by chimera 1 revealed glucose as final product confirming both β-1,4-endoglucanase and β-1,4-glucosidase activities, while the products of CtGH5-F194A were cellobiose and cello-oligosaccharides. Protein melting studies of CtGH5-F194A showed melting temperature (Tm), 68 °C and of CtGH1, 79 °C, whereas, chimera showed 78 °C. The improved structural integrity, thermostability and enhanced bi-functional enzyme activities of chimera makes it potentially useful for industrial application in converting biomass to glucose and thus bioethanol.
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Affiliation(s)
- Priyanka Nath
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; DBT PAN-IIT Center for Bioenergy, Indian Institute of Technology Guwahati, India
| | - Arun Dhillon
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Krishan Kumar
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Kedar Sharma
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Sumitha Banu Jamaldheen
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Centre for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Vijayanand Suryakant Moholkar
- Centre for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Arun Goyal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; DBT PAN-IIT Center for Bioenergy, Indian Institute of Technology Guwahati, India; Centre for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
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