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Rehman F, Sajjad M, Akhtar MW. Orientation of Cel5A and Xyn10B in a fusion construct is important in facilitating synergistic degradation of plant biomass polysaccharides. J Biosci Bioeng 2023; 135:274-281. [PMID: 36828688 DOI: 10.1016/j.jbiosc.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/26/2022] [Accepted: 11/03/2022] [Indexed: 02/25/2023]
Abstract
One approach to achieve efficient and economical saccharification of plant biomass would be using thermostable and multifunctional enzymes from hyperthermophiles such as Thermotoga maritima. Thus, the bifunctional constructs, Cel5A-Xyn10B and Xyn10B-Cel5A, were produced by fusing cellulase Cel5A at the N- and C-terminals of xylanase Xyn10B, respectively. The Cel5A-Xyn10B fusion construct showed cellulase activity of 1483 U μmol-1 against carboxymethyl cellulose, which was nearly the same as that of Cel5A in the free form. However, xylanase activity of this construct increased by 2-fold against beechwood xylan as compared to that of Xyn10B in free form. The synergistic effect between Cel5A and Xyn10B in the form of Cel5A-Xyn10B fusion resulted an overall increase in the release of reducing sugars. However, Xyn10B-Cel5A showed about 60% decrease in activities of both the component enzymes as compared to their activities in the free form. Both the fusion constructs were active in a wide range of pH from 4.0 to 9.0 and temperatures from 50 to 90 °C. Nearly 80% of cellulase and xylanase activities were retained in Cel5A-Xyn10B fusion after incubation at 60 °C for 1 h. Secondary structures of the component enzymes were retained in the Cel5A-Xyn10B fusion as observed by circular dichroism spectroscopy. Docking and simulation studies suggested that the enhanced xylanase activity in Cel5A-Xyn10B was due to the high binding energy, favorable orientation of the active sites, as well as relative positioning of the active site residues of Cel5A and Xyn10B in closer vicinity, which facilitated the substrate channeling.
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Affiliation(s)
- Fatima Rehman
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan
| | - Muhammad Sajjad
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan
| | - Muhammad Waheed Akhtar
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan.
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El-Sheekh M, Elshobary M, Abdullah E, Abdel-Basset R, Metwally M. Application of a novel biological-nanoparticle pretreatment to Oscillatoria acuminata biomass and coculture dark fermentation for improving hydrogen production. Microb Cell Fact 2023; 22:34. [PMID: 36814252 PMCID: PMC9948338 DOI: 10.1186/s12934-023-02036-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 02/07/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Energy is the basis and assurance for a world's stable development; however, as traditional non-renewable energy sources deplete, the development and study of renewable clean energy have emerged. Using microalgae as a carbon source for anaerobic bacteria to generate biohydrogen is a clean energy generation system that both local and global peers see as promising. RESULTS Klebsiella pneumonia, Enterobacter cloacae, and their coculture were used to synthesize biohydrogen using Oscillatoria acuminata biomass via dark fermentation. The total carbohydrate content in O. acuminata was 237.39 mg/L. To enhance the content of fermentable reducing sugars, thermochemical, biological, and biological with magnesium zinc ferrite nanoparticles (Mg-Zn Fe2O4-NPs) pretreatments were applied. Crude hydrolytic enzymes extracted from Trichoderma harzianum of biological pretreatment were enhanced by Mg-Zn Fe2O4-NPs and significantly increased reducing sugars (230.48 mg/g) four times than thermochemical pretreatment (45.34 mg/g). K. pneumonia demonstrated a greater accumulated hydrogen level (1022 mLH2/L) than E. cloacae (813 mLH2/L), while their coculture showed superior results (1520 mLH2/L) and shortened the production time to 48 h instead of 72 h in single culture pretreatments. Biological pretreatment + Mg-Zn Fe2O4 NPs using coculture significantly stimulated hydrogen yield (3254 mLH2/L), hydrogen efficiency)216.9 mL H2/g reducing sugar( and hydrogen production rate (67.7 mL/L/h) to the maximum among all pretreatments. CONCLUSION These results confirm the effectiveness of biological treatments + Mg-Zn Fe2O4-NPs and coculture dark fermentation in upregulating biohydrogen production.
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Affiliation(s)
- Mostafa El-Sheekh
- grid.412258.80000 0000 9477 7793Department of Botany, Faculty of Science, Tanta University, Tanta, 31527 Egypt
| | - Mostafa Elshobary
- Department of Botany, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
| | - Eman Abdullah
- grid.412258.80000 0000 9477 7793Department of Botany, Faculty of Science, Tanta University, Tanta, 31527 Egypt
| | - Refat Abdel-Basset
- grid.252487.e0000 0000 8632 679XBotany and Microbiology Department, Faculty of Science, Assuit University, Assuit, Egypt
| | - Metwally Metwally
- grid.412258.80000 0000 9477 7793Department of Botany, Faculty of Science, Tanta University, Tanta, 31527 Egypt
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Physicochemical characterisation of barley straw treated with sodium hydroxide or urea and its digestibility and in vitro fermentability in ruminants. Sci Rep 2022; 12:20530. [PMID: 36446835 PMCID: PMC9708690 DOI: 10.1038/s41598-022-24738-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/18/2022] [Indexed: 11/30/2022] Open
Abstract
The development of strategies to overcome the shortage of forage due to persistently low rainfall is becoming a central task for animal nutrition in research and practice. In this study, it was investigated how the treatment of straw with NaOH or feed urea in a practicable procedure for modern farms affects rumen fermentation (gas production and greenhouse gas concentration) as well as the digestibility of feed energy and nutrients. For this purpose, the treatments were tested individually and in different proportions in a total mixed ration (TMR) in ruminal batch cultures in vitro and in a digestibility trial with sheep. In order to explain the observed effects at the molecular level, descriptive data from 13C solid state nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopy were obtained. NaOH treatment of straw increased crude ash (CA), non-fibrous carbohydrates, digestible energy (DE), and metabolizable energy (ME) concentration, whereas the proportion of neutral detergent fibre (aNDFom) and hemicellulose decreased. In urea treated straw, NH3-N and crude protein increased, whereas acid detergent lignin (ADL), DE, and ME decreased. The physically effective fibre (peNDF8) concentration increased in TMR containing 18% of NaOH or urea treated straw (p < 0.01). The application of straw treatments as pure substrates (not as part of a TMR) increased gas production and decelerated ruminal fermentation (p < 0.05). In vitro organic matter digestibility (IVOMD) of the straw (0.31) increased after NaOH (0.51; p < 0.05) and urea treatment (0.41; p > 0.05). As part of a TMR, straw treatments had no distinct effect on gas production or IVOMD. Concentrations of CH4 and CO2 were likewise not affected. Apparent total tract digestibility of aNDFom, acid detergent fibre (ADFom), hemicellulose, and cellulose increased in the TMR by approximately 10% points following NaOH treatment (p < 0.05). The inclusion of urea treated straw did not affect apparent digestibility. Calculated true digestibility of aNDFom was 0.68, 0.74, and 0.79, of ADFom 0.58, 0.57, and 0.65, and of ADL 0.02, 0.13, and 0.08 in TMR including untreated, NaOH treated, and urea treated straw, respectively. 13C NMR and FTIR analyses consistently revealed that the global structure and crystallinity of the carbohydrates (cellulose and hemicellulose) was not altered by treatment and the concentration of lignin was likewise not affected. Depolymerisation of lignin did not occur. However, NMR signals assigned to acetyl groups were significantly altered indicating that straw treatments disrupted linkages between hemicelluloses and lignin. Moreover, the acetates signal was affected. This signal can be assigned to linkages between ferulic acids and hemicelluloses (arabinoxylans). FTIR spectra of straw treatments mainly differed at a wavelength of 1730 cm-1 and 1240 cm-1. Disappearance of the 1730 cm-1 peak suggests removal of hemicelluloses or lignin related compounds by treatment. The disappearance of the lignin peak at 1240 cm-1 could be due to conjugated ketone (phenyl-carbonyl) removal or the removal of ferulic and p-coumaric acid acetyl groups. Both treatments are supposed to release fermentable cell wall components (hemicelluloses) from lignin-associated bonds and as a result, straw fibre can be better fermented in the rumen. This contributes to energy supply and increased fibre digestibility at least in the TMR that contained NaOH treated straw. The alkaline straw treatments probably induced a release of phenolics such as ferulic acid and p-coumaric acid, which can be metabolised in the gut and the liver and metabolites might be excreted with the urine. This could notably contribute to metabolic energy losses.
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Valorization of Bombax ceiba Waste into Bioethanol Production through Separate Hydrolysis and Fermentation and Simultaneous Saccharification and Fermentation. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8080386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, Seed pods of B. ceiba were used as a novel, cheap, and sustainable feedstock for second-generation bioethanol production. B. ceiba waste was pretreated with NaOH under different conditions using a Box–Behnken design (BBD) with three factors and three levels. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to investigate the chemical, structural, and morphological modifications made by pretreatment. NaOH pretreatment followed by steam was more effective as it offered 60% cellulose and 9% lignin at 10% substrate loading, 5% NaOH conc., and 4 h residence time. Samples with maximum cellulose were employed for ethanol production by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) using indigenously produced cellulase as well as commercial cellulase. HPLC analysis revealed the best saccharification (50.9%) at 24 h and the best ethanol yield (54.51 g/L) at 96 h of fermentation in SSF using commercial cellulose by Saccharomyces cerevisiae. SSF offered a better production of bioethanol from seed pods than SHF. The implications of the work support the notion that B. ceiba waste could be utilized for large-scale bioethanol production.
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Bioethanol Production Optimization from KOH-Pretreated Bombax ceiba Using Saccharomyces cerevisiae through Response Surface Methodology. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8040148] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present study was based on the production of bioethanol from alkali-pretreated seed pods of Bombax ceiba. Pretreatment is necessary to properly utilize seed pods for bioethanol production via fermentation. This process assures the accessibility of cellulase to the cellulose found in seedpods by removing lignin. Untreated, KOH-pretreated, and KOH-steam-pretreated substrates were characterized for morphological, thermal, and chemical changes by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Hydrolysis of biomass was performed using both commercial and indigenous cellulase. Two different fermentation approaches were used, i.e., separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). Findings of the study show that the maximum saccharification (58.6% after 24 h) and highest ethanol titer (57.34 g/L after 96 h) were observed in the KOH-steam-treated substrate in SSF. This SSF using the KOH-steam-treated substrate was further optimized for physical and nutritional parameters by one factor at a time (OFAT) and central composite design (CCD). The optimum fermentation parameters for maximum ethanol production (72.0 g/L) were 0.25 g/L yeast extract, 0.1 g/L K2HPO4, 0.25 g/L (NH4)2SO4, 0.09 g/L MgSO4, 8% substrate, 40 IU/g commercial cellulase, 1% Saccharomyces cerevisiae inoculum, and pH 5.
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Wei R, Sakai Y. Improving the properties of botanical concrete based on waste concrete, wood, and kraft lignin powder. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2021.11.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Co-Ensiling of Wheat Straw as an Alternative Pre-Treatment to Chemical, Hydrothermal and Mechanical Methods for Methane Production. ENERGIES 2020. [DOI: 10.3390/en13164047] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Wheat straw without pre-treatment is only converted to methane to a low degree during anaerobic digestion for fuel production due to its low hydrolysis. Current pre-treatment technologies are challenged by high expenses to energy or chemical agents. We examined the low-tech co-ensiling pre-treatment as an alternative pre-treatment of wheat straw, and compared the results with hydrothermal, chemical and mechanical pre-treatment methods. The effects of co-ensiling duration and the mixing ratio between straw and sugar beet root on the methane yields, surface morphology and chemical composition were examined. It was found that co-ensiling could improve production of methane by 34.7%, while a combined hydrothermal and chemical pre-treatment could increase the production of methane by 25.4%. The study demonstrated that the effect of co-ensiling could overlap with hydrothermal and chemical pre-treatment by having similar effects to increase lignocellulosic hydrolysis and improve methane production.
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Zaini NABM, Chatzifragkou A, Charalampopoulos D. Alkaline fractionation and enzymatic saccharification of wheat dried distillers grains with solubles (DDGS). FOOD AND BIOPRODUCTS PROCESSING 2019. [DOI: 10.1016/j.fbp.2019.09.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Jamaldheen SB, Thakur A, Moholkar VS, Goyal A. Enzymatic hydrolysis of hemicellulose from pretreated Finger millet (Eleusine coracana) straw by recombinant endo-1,4-β-xylanase and exo-1,4-β-xylosidase. Int J Biol Macromol 2019; 135:1098-1106. [DOI: 10.1016/j.ijbiomac.2019.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/03/2019] [Accepted: 06/03/2019] [Indexed: 10/26/2022]
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Michelin M, Teixeira JA. Liquid hot water pretreatment of multi feedstocks and enzymatic hydrolysis of solids obtained thereof. BIORESOURCE TECHNOLOGY 2016; 216:862-9. [PMID: 27318165 DOI: 10.1016/j.biortech.2016.06.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/02/2016] [Accepted: 06/03/2016] [Indexed: 05/26/2023]
Abstract
Agricultural feedstocks (brewers' spent grain - BSG, corncob - CC, corn husk - CH, wheat straw - WS and Luffa sponge - LS) were pretreated by liquid hot water (LHW) in order to increase cellulose recovery and enzymatic saccharification. LHW-pretreatment resulted in hemicellulose solubilization, and solids enriched in cellulose. Chemical analysis showed different susceptibilities of the feedstocks to LHW-pretreatment and enzymatic hydrolysis. Pretreated feedstocks presented higher crystallinity (determined through X-ray diffraction) and thermal stability (determined through thermogravimetric analysis) than untreated feedstocks. SEM images confirmed the effect of LHW-pretreatment on structural changes. Moreover, enzymatic hydrolysis and cellulose conversion to glucose (CCG) were improved for pretreated feedstocks, with exception of LS. CCG (in relation to glucose potential on solids) followed the order: BSG>CH>WS>CC>LS. LHW-pretreatment showed to be a good technology to pretreat multi feedstocks and for improving the enzymatic hydrolysis of recalcitrant agricultural feedstocks to sugars, which can be further converted to ethanol-fuel and other value-added chemicals.
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Affiliation(s)
- Michele Michelin
- Centre of Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.
| | - José António Teixeira
- Centre of Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal
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Haque MA, Barman DN, Kim MK, Yun HD, Cho KM. Cogon grass (Imperata cylindrica), a potential biomass candidate for bioethanol: cell wall structural changes enhancing hydrolysis in a mild alkali pretreatment regime. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2016; 96:1790-1797. [PMID: 26041026 DOI: 10.1002/jsfa.7288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 05/16/2015] [Accepted: 05/30/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Imperata cylindrica is being considered as a biomass candidate for bioethanol. This work aimed to evaluate a mild alkali pretreatment effect on the Imperata recalcitrant structure. Therefore, varied concentrations of NaOH (0, 7.5, 15, 20, and 25 g L(-1) ) were applied as treatments to Imperata at 105 °C for 10 min. RESULTS Scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy studies revealed that 20 to 25 g L(-1) NaOH-treated Imperata exposed amorphous cellulose on surface granules composed of lignin, waxes, and partly hemicelluloses were abolished due to the comprehensive disruption of the linkages between lignin and carbohydrates. The cellulose crystalline index was increased with 7.5 to 20 g L(-1) NaOH treatments and reduced with a 25 g L(-1) NaOH treatment. In fact, the cellulose content in solids increased with the increasing NaOH concentration and was estimated to be 720 and 740 g kg(-1) for the 20 and 25 g L(-1) NaOH treatments, respectively. The yield of the reducing sugar was obtained 805 and 813 mg g(-1) from 20 and 25 g L(-1) NaOH-treated Imperata, respectively. CONCLUSION Considering the cost of pretreatment, the 20 g L(-1) NaOH treatment is judged to be effective for disrupting Imperata recalcitrance in this pretreatment regime.
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Affiliation(s)
- Md Azizul Haque
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju 660-701, Republic of Korea
- Dept of Food Science, Gyeongnam National University of Science and Technology, Jinju 660-758, Republic of Korea
| | - Dhirendra Nath Barman
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju 660-701, Republic of Korea
| | - Min Keun Kim
- Gyeongsangnam-do Agricultural Research and Extension Service, Jinju 660-758, Republic of Korea
| | - Han Dae Yun
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju 660-701, Republic of Korea
- Research Institute of Agriculture and Life Science, Gyeongsang National University, Chinju, 660-701, Republic of Korea
| | - Kye Man Cho
- Dept of Food Science, Gyeongnam National University of Science and Technology, Jinju 660-758, Republic of Korea
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Mohaptra S, Dash PK, Behera SS, Thatoi H. Optimization of delignification of two Pennisetum grass species by NaOH pretreatment using Taguchi and ANN statistical approach. ENVIRONMENTAL TECHNOLOGY 2015; 37:940-951. [PMID: 26584152 DOI: 10.1080/09593330.2015.1093034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In the bioconversion of lignocelluloses for bioethanol, pretreatment seems to be the most important step which improves the elimination of the lignin and hemicelluloses content, exposing cellulose to further hydrolysis. The present study discusses the application of dynamic statistical techniques like the Taguchi method and artificial neural network (ANN) in the optimization of pretreatment of lignocellulosic biomasses such as Hybrid Napier grass (HNG) (Pennisetum purpureum) and Denanath grass (DG) (Pennisetum pedicellatum), using alkali sodium hydroxide. This study analysed and determined a parameter combination with a low number of experiments by using the Taguchi method in which both the substrates can be efficiently pretreated. The optimized parameters obtained from the L16 orthogonal array are soaking time (18 and 26 h), temperature (60°C and 55°C), and alkali concentration (1%) for HNG and DG, respectively. High performance liquid chromatography analysis of the optimized pretreated grass varieties confirmed the presence of glucan (47.94% and 46.50%), xylan (9.35% and 7.95%), arabinan (2.15% and 2.2%), and galactan/mannan (1.44% and 1.52%) for HNG and DG, respectively. Physicochemical characterization studies of native and alkali-pretreated grasses were carried out by scanning electron microscopy and Fourier transformation Infrared spectroscopy which revealed some morphological differences between the native and optimized pretreated samples. Model validation by ANN showed a good agreement between experimental results and the predicted responses.
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Affiliation(s)
- Sonali Mohaptra
- a Department of Biotechnology, College of Engineering and Technology , Biju Patnaik University of Technology , Bhubaneswar, India
| | - Preeti Krishna Dash
- a Department of Biotechnology, College of Engineering and Technology , Biju Patnaik University of Technology , Bhubaneswar, India
| | - Sudhanshu Shekar Behera
- b Department of Biotechnology and Medical Engineering , National Institute of Technology , Rourkela, India
| | - Hrudayanath Thatoi
- a Department of Biotechnology, College of Engineering and Technology , Biju Patnaik University of Technology , Bhubaneswar, India
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Kim DU, Kim HJ, Jeong YS, Na HB, Cha YL, Koo BC, Kim J, Yun HD, Lee JK, Kim H. Enhanced saccharification of reed and rice straws by the addition of β-1,3-1,4-glucanase with broad substrate specificity and calcium ion. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13765-015-0013-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Alkaline Pretreatment Improves Saccharification and Ethanol Yield from Waste Money Bills. Biosci Biotechnol Biochem 2014; 77:1397-402. [DOI: 10.1271/bbb.130002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Barmana DN, Haquea MA, Kang TH, Kim GH, Kim TY, Kim MK, Yun HD. Effect of mild alkali pretreatment on structural changes of reed (Phragmites communis Trinius) straw. ENVIRONMENTAL TECHNOLOGY 2014; 35:232-241. [PMID: 24600861 DOI: 10.1080/09593330.2013.824009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The effect of dilute sodium hydroxide (NaOH) on reed straw structural change at 105 degreeC temperature was evaluated in this study. Various concentrations of NaOH (1% to 2.5%) were used for pretreatment of reed straw at 105 degreeC for 10min. Scanning electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy studies showed that 2% and 2.5% NaOH pretreated sample exposed more cellulose fibers compared with other treatments. The cellulose crystalline index was increased by the 1% to 2.0% NaOH treatments and slightly lowered by the 2.5% NaOH treatment due to destructing cellulose fibres. Two per cent NaOH pretreatment caused 69.9% lignin removal, whereas 2.5% NaOH pretreatment removed 72.4% lignin. Besides, reed straw, when pretreated at 2% and 2.5% NaOH, resulted 56.4% and 60.5% hemicellulose removal, respectively. However, the difference in removal of lignin and hemicellulose between 2% and 2.5% NaOH treated reed straw was very marginal. In addition, very negligible increase of cellulose level was estimated, amounting 78.8% and 76.6% in 2.5% and 2% NaOH-treated sample, respectively. Moreover, after 72 h, reducing sugar yield was 81.2% and 83.3% using enzyme loading of 15 FPU (g dry biomass)-' and 30 IU (g dry biomass)- and xylanase 4 FXU (g dry biomass)-1 from 2% and 2.5% NaOH pretreated reed straw, respectively. Reducing sugar yield was increased very marginally when NaOH concentration increased from 2% to 2.5% for reed straw pretreatment. Therefore, 2% NaOH is supposed to be effective for reed straw pretreatment at this mentioned condition.
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Affiliation(s)
- Dhirendra Nath Barmana
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju, Republic of Korea
| | - Md Azizul Haquea
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju, Republic of Korea
| | - Tae Ho Kang
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju, Republic of Korea
| | - Gi Hwan Kim
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju, Republic of Korea
| | - Tae Yang Kim
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju, Republic of Korea
| | - Min Keun Kim
- Gyeongsangnam-do Agricultural Research and Extension Service, Chinju, Republic of Korea
| | - Han Dae Yun
- Division of Applied Life Science (BK21 Program), Gyeongsang National University, Chinju, Republic of Korea
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