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Production of eco-friendly and better-quality sugarcane bagasse paper using crude xylanase and pectinase biopulping strategy. 3 Biotech 2023; 13:61. [PMID: 36714548 PMCID: PMC9880078 DOI: 10.1007/s13205-023-03484-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 01/18/2023] [Indexed: 01/27/2023] Open
Abstract
This research aimed to investigate the efficiency of crude xylanase-pectinase in pulping of sugarcane bagasse. Optimum biopulping was obtained, using xylanase-pectinase dose 200-60 IU/g, bagasse/liquid ratio 1:10 and 1.0% Tween 80 concentration at 55 °C temperature, pH 8.5 and period of treatment 180 min. Treatment of sugarcane bagasse samples with these enzymes generated pulp with lower rejections (58.76%), total solids (12.64%), kappa number (47.77%), higher screened pulp yield (10.66%), along with enhanced optical and physical properties, in comparison with a chemical pulp. Bagasse biopulping resulted in a 13% decrease in alkali dose to obtain the optical and physical properties similar to those achieved under the 100% alkali dose. The breaking length, burst factor, tear index, double fold, gurley porosity and viscosity were improved by 15.19, 37.64, 2.47, 37.77, 35 and 23.17%, respectively, after bleaching treatment of biopulped samples. Thus, enzymatic pulping is an eco-friendly environmentally sustainable approach, since it reduces the use of pulping chemicals and simultaneously improves the paper quality. This is the first report, showing pulping of sugarcane bagasse, with crude xylanase-pectinase, produced by an isolate.
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An environment-benign approach of bamboo pulp bleaching using extracellular xylanase of strain Bacillus stratosphericus EB-11 isolated from elephant dung. Folia Microbiol (Praha) 2023; 68:135-149. [PMID: 36048323 DOI: 10.1007/s12223-022-01003-1] [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: 03/28/2022] [Accepted: 08/23/2022] [Indexed: 11/30/2022]
Abstract
The use of microbial enzymes is highly encouraged in paper and pulp industries to reduce the excessive use of hazardous chemicals. During the study, xylanase of Bacillus stratosphericus EB-11 was characterized for pulp bleaching applications. The extracellular xylanase was produced under submerged fermentation using bamboo waste as a natural carbon source. There was fast cell division and enzyme production under optimized fermentation conditions in the bioreactor. The highest activity was 91,200U after 30 h of growth with Km and Vmax of 3.52 mg/mL and 391.5 μmol/min per mg respectively. The purified enzyme with molecular mass ~ 60 kDa had conferred positive activity on native PAGE. The strong inhibition by ethylenediaminetetraacetate and SDS showed the metallo-xylanase nature of the purified enzyme. The bacterial xylanase reduces the use of hydrogen peroxide by 0.4%. Similarly, biological oxygen demand and chemical oxygen demand were reduced by 42.6 and 35.2%. The xylanase-hydrogen peroxide combined treatment and conventional chlorine dioxide-alkaline (CDE1D1D2) bleaching showed almost similar improvement in physicochemical properties of bamboo pulp. Xylanase-peroxide bleaching reduces the lignin content to 4.95% from 13.32% unbleached pulp. This content after CDE1D1D2 treatment was 4.21%. The kappa number decreased from 15.2 to 9.46 with increasing the burst factor (15.51), crystallinity index (60.25%), viscosity (20.1 cp), and brightness (65.4%). The overall finding will encourage the development of new cleaner methods of bleaching in the paper and pulp industry.
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Enhanced Production, Cloning, and Expression of a Xylanase Gene from Endophytic Fungal Strain Trichoderma harzianum kj831197.1: Unveiling the In Vitro Anti-Fungal Activity against Phytopathogenic Fungi. J Fungi (Basel) 2022; 8:jof8050447. [PMID: 35628703 PMCID: PMC9144407 DOI: 10.3390/jof8050447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/14/2022] [Accepted: 04/23/2022] [Indexed: 11/25/2022] Open
Abstract
Trichoderma sp. is extensively applied as a beneficial fungus for the management of plant diseases, plant growth promotion, induced resistance, and plays an important role in global sustainable agriculture. This study aimed to enhance the production of microbial xylanase in high titer from the endophytic fungus Trichoderma harzianum kj831197.1, and the cloning of xylanase genes in E. coli DH5α using a pUC19 vector. A combination of glucose, 0.1 mM, Tween 80 with lactose, and 2 mM galactose combined with malt extract boostedthe enzyme production. Xylanase production was maximized at a pH of 5.0, temp. of 30 °C, and agitation of 150 rpm in the presence of malt extract and bagasse as the best nitrogen source and waste, respectively, using submerged fermentation. The molecular weight of highly purified xylanase was 32 KDa, identified using SDS-PAGE. The xylanase gene of T. harzianum kj831197.1 was screened in fungal DNA using definite primers specified in the gene bank database. The identified region was excised using restriction enzymes HindIII and EcoRI and cloned into a pUC19 plasmid vector. Optimization of fermentation conditions improved xylanase production about 23.9-fold.The antifungal efficacy of xylanase toward different phytopathogenic fungi was determined. The highest inhibition was against Corynespora cassiicola, Alternaria sp., Fusarium oxysporum, and Botrytis fabae. This study offered an economical, simple, and efficient method using Trichoderma harzianum kj831197.1 for the production of the xylanase enzyme via the submerged fermentation method.
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An eco-friendly biocatalytic process for producing better quality paper from sugarcane bagasse using ultrafiltered enzymes concoction. Bioprocess Biosyst Eng 2022; 45:741-747. [PMID: 35113232 DOI: 10.1007/s00449-022-02695-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 01/17/2022] [Indexed: 11/30/2022]
Abstract
In the current study, pretreatment of sugarcane bagasse has been carried out with ultrafiltered xylano-pectinolytic enzymes, before conventional chemical bleaching process. Optimized enzymatic dose (4 IU xylanase and 1.2 IU pectinase per g of oven dried pulp) and retention time (180 min) were determined on the basis of maximum decrement in kappa number (from 20.93 to 15.32), release of maximum sugars (7.4 mg/g) as well as attainment of maximum brightness (25.1% ISO), whiteness (from - 57.3 to - 41.9) and minimum yellowness (from 48.7 to 35.3) of the pulp samples. Enzymatically treated samples also showed release of phenolic, lignin and hydrophobic compounds in their filtrates. Nearly 30% decrement in the exhaustion of bleaching chemical dose was detected as compared to control samples. The physical properties such as tear index, burst index, double fold number, breaking length, gurley porosity and viscosity of enzymo-chemically treated bagasse pulp samples were improved by 6.68%, 33.86%, 22.92%, 13.43%, 17.5% and 9.64%, respectively. Additionally, a decrement of 36.75% and 28.29% in the values of BOD and COD of the effluents was also noted, which demonstrated the fact that, inclusion of enzymes in chemical based protocols of paper and pulp industries could be a highly beneficial and eco-friendly approach in upcoming decades. This is the first report mentioning the effect of ultrafiltered xylano-pectinolytic enzymes concoction on sugarcane bagasse pulp.
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Extremophilic Prokaryotic Endoxylanases: Diversity, Applicability, and Molecular Insights. Front Microbiol 2021; 12:728475. [PMID: 34566933 PMCID: PMC8458939 DOI: 10.3389/fmicb.2021.728475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
Extremophilic endoxylanases grabbed attention in recent years due to their applicability under harsh conditions of several industrial processes. Thermophilic, alkaliphilic, and acidophilic endoxylanases found their employability in bio-bleaching of paper pulp, bioconversion of lignocellulosic biomass into xylooligosaccharides, bioethanol production, and improving the nutritious value of bread and other bakery products. Xylanases obtained from extremophilic bacteria and archaea are considered better than fungal sources for several reasons. For example, enzymatic activity under broad pH and temperature range, low molecular weight, cellulase-free activity, and longer stability under extreme conditions of prokaryotic derived xylanases make them a good choice. In addition, a short life span, easy cultivation/harvesting methods, higher yield, and rapid DNA manipulations of bacterial and archaeal cells further reduces the overall cost of the product. This review focuses on the diversity of prokaryotic endoxylanases, their characteristics, and their functional attributes. Besides, the molecular mechanisms of their extreme behavior have also been presented here.
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Eco-friendly bleaching of sugarcane bagasse with crude xylanase and pectinase enzymes to reduce the bleaching effluent toxicity. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:42990-42998. [PMID: 34218371 DOI: 10.1007/s11356-021-15122-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Bio-bleaching effect on bagasse pulp using xylano-pectinolytic enzymes produced by a bacterial species was studied in order to evaluate the potential of these enzymes in paper industry. In this study, action of enzymes was maximum with xylanase/pectinase dose 7/1.75 IU/g, pulp consistency 1:12.5 g/L, pH 8.5, temperature 50° C and 180 min of treatment time. Under the optimized bio-bleaching conditions, removal of reducing sugars (6.15±0.05 mg/L), brightness (16.08%), whiteness (25.54%) and release of chromophores (hydrophobic and phenolic compounds and lignin impurities) were maximum, along with decrease in kappa number (26.28%), and yellowness (27.88%) values were obtained. Improvement in the various physical properties like breaking length (10.28%), burst index (29.55%), tear index (5.02%), double fold (14.89%), Gurley porosity (15%) and viscosity (8.6%), along with the reduction of chlorine dioxide dose by 27%, was also observed. There is also reduction in COD and BOD values of bio-bleached effluents by 27.62% and 20.52%, respectively. This is the first report on bio-bleaching of bagasse pulp using xylano-pectinolytic enzymes.
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Pulp Enhancement of Oil Palm Empty Fruit Bunches (OPEFBs) via Biobleaching by Using Xylano-Pectinolytic Enzymes of Bacillus amyloliquefaciens ADI2. Molecules 2021; 26:4279. [PMID: 34299554 PMCID: PMC8304154 DOI: 10.3390/molecules26144279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/09/2021] [Accepted: 07/11/2021] [Indexed: 11/27/2022] Open
Abstract
The present work reports the biobleaching effect on OPEFB pulp upon utilisation of extracellular xylano-pectinolytic enzymes simultaneously yielded from Bacillus amyloliquefaciens ADI2. The impacts of different doses, retention times, pH, and temperatures required for the pulp biobleaching process were delineated accordingly. Here, the OPEFB pulp was subjected to pre-treatment with xylano-pectinolytic enzymes generated from the same alkalo-thermotolerant isolate that yielded those of higher quality. Remarkable enhanced outcomes were observed across varying pulp attributes: for example, enzyme-treated pulp treated to chemical bleaching sequence generated improved brightness of 11.25%. This resulted in 11.25% of less chlorine or chemical consumption required for obtaining pulp with optical attributes identical to those generated via typical chemical bleaching processes. Ultimately, the reduced consumption of chlorine would minimise the organochlorine compounds found in an effluent, resulting in a lowered environmental effect of paper-making processes overall as a consequence. This will undoubtedly facilitate such environmentally-friendly technology incorporation in the paper pulp industry of today.
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Effect of the single mutation N9Y on the catalytical properties of xylanase Xyn11A from Cellulomonas uda: a biochemical and molecular dynamic simulation analysis. Biosci Biotechnol Biochem 2021; 85:1971-1985. [PMID: 34232281 DOI: 10.1093/bbb/zbab124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 06/29/2021] [Indexed: 11/12/2022]
Abstract
Cellulomonas uda produces Xyn11A, moderately thermostable xylanase, with optimal activity at 50 °C and pH 6.5. An improvement in the biochemical properties of Xyn11A was achieved by site-directed mutagenesis approach. Wild-type xylanase, Xyn11A-WT, and its mutant Xyn11A-N9Y were expressed in Escherichia coli, and then both enzymes were purified and characterized. Xyn11A-N9Y displayed optimal activity at 60 °C and pH 7.5, an upward shift of 10 ºC in the optimum temperature, and an upward shift of one unit in optimum pH; also, it manifested an 11-fold increase in thermal stability at 60 ºC, compared to that displayed by Xyn11A-WT. Molecular dynamics (MD) simulations of Xyn11A-WT and Xyn11A-N9Y suggest the substitution N9Y leads to an array of secondary structure changes at the N-terminal end and an increase in the number of hydrogen bonds in Xyn11A-N9Y. Based on the significant improvements, Xyn11A-N9Y may be considered as a candidate for several biotechnological applications.
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Characterization of a new bifunctional endo-1,4-β-xylanase/esterase found in the rumen metagenome. Sci Rep 2021; 11:10440. [PMID: 34001974 PMCID: PMC8128909 DOI: 10.1038/s41598-021-89916-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 04/26/2021] [Indexed: 12/13/2022] Open
Abstract
Metagenomic data mining of the Nellore cattle rumen microbiota identified a new bifunctional enzyme, endo-1,4-β-xylanase/esterase, which was subsequently overexpressed in E. coli BL21 (DE3). This enzyme was stable at pH intervals of 5 to 6.5 and temperatures between 30 and 45 °C, and under the test conditions, it had a Vmax of 30.959 ± 2.334 µmol/min/mg, Km of 3.6 ± 0.6 mM and kcat of 2.323 ± 175 s-1. Additionally, the results showed that the enzyme is tolerant to NaCl and organic solvents and therefore is suitable for industrial environments. Xylanases are widely applicable, and the synergistic activity of endo-1,4-β-xylanase/esterase in a single molecule will improve the degradation efficiency of heteroxylans via the creation of xylanase binding sites. Therefore, this new molecule has the potential for use in lignocellulosic biomass processing and as an animal feed food additive and could improve xylooligosaccharide production efficiency.
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Potential of crude xylano-pectinolytic enzymes in bleaching of rice straw pulp for improving paper quality and reducing toxic effluent load generation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:18284-18293. [PMID: 33665692 DOI: 10.1007/s11356-021-13204-1] [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: 04/16/2020] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
The objective of this study was to check the potential of crude xylano-pectinolytic enzymes in bleaching of rice straw pulp, in order to reduce the toxic waste load for managing the environmental pollution. The xylano-pectinolytic enzymatic bleaching step for delignification was found to be most effective at pulp consistency 1:10 g/ml, xylanase:pectinase dose of 9:4 IU/ml, pH 8.5 and treatment time 180 min at temperature of 55 °C, and resulted in lowering of kappa number of the rice straw pulp by 15.29%. In subsequent bleaching stages, this enzymatic pre-bleaching treatment also resulted in 30% reduction of active chlorine dioxide dose without any loss of optical properties. Significant improvement in various physical properties of the enzymes treated pulp, tear index (15.43%), breaking length (11.11%), double fold number (25.92%), burst index (9.88%) and viscosity (13.63%), and Gurley porosity (39.86%) was also noticed. This approach resulted in reduction of BOD and COD values by 21.07% and 26.57%, respectively. This is the first study on the use of crude xylano-pectinolytic enzymes for bio-bleaching of rice straw pulp.
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Biobleaching: An eco-friendly approach to reduce chemical consumption and pollutants generation. PHYSICAL SCIENCES REVIEWS 2020. [DOI: 10.1515/psr-2019-0044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The pulp and paper industry is known to be a large contributor to environmental pollution due to the huge consumption of chemicals and energy. Several chemicals including H2SO4, Cl2, ClO2, NaOH, and H2O2 are used during the bleaching process. These chemicals react with lignin and carbohydrates to generate a substantial amount of pollutants in bleach effluents. Environmental pressure has compelled the pulp and paper industry to reduce pollutant generation from the bleaching section. Enzymes have emerged as simple, economical, and eco-friendly alternatives for bleaching of pulp. The pretreatment of pulp with enzymes is termed as biobleaching or pre-bleaching. Different microbial enzymes such as xylanases, pectinases, laccases, manganese peroxidases (MnP), and lignin peroxidases are used for biobleaching. Xylanases depolymerize the hemicelluloses precipitated on pulp fiber surfaces and improves the efficiency of bleaching chemicals. Xylanase treatment also increases the pulp fibrillation and reduces the beating time of the pulp. Pectinases hydrolyze pectin available in the pulp fibers and improve the papermaking process. Laccase treatment is found more effective along with mediator molecules (as a laccase-mediator system). Biobleaching of pulp results in the superior quality of pulp along with lower consumption of chlorine-based chemicals and lower generation of adsorbable organic halidesadsorbable organic halides (AOX. An enzyme pretreatment reduces the kappa number of pulp and improves ISO brightness significantly. Better physical strength properties and pulp viscosity have also been observed during biobleaching of pulp.
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Synergistic approach using ultrafiltered xylano-pectinolytic enzymes for reducing bleaching chemical dose in manufacturing rice straw paper. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:44637-44646. [PMID: 33063206 DOI: 10.1007/s11356-020-11104-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
In this study, action of ultrafiltered xylano-pectinolytic enzymes from a bacterial strain has been evaluated for bleaching of rice straw soda-anthraquinone pulp. Maximum bio-bleaching effect and release of non-cellulosic impurities were noticed with xylano:pectinolytic enzymes dose of 6.0:2.1-IU/g pulp, treatment time of 180 min at 10% pulp consistency, pH 8.5, and temperature 55 °C. Microscopic images of bio-bleached rice straw pulp also confirmed the efficacy of ultrafiltered enzymes, as bleaching agent. This bio-bleaching treatment resulted in 15.38% and 32% reduction in kappa number and active chlorine dioxide dose, respectively, along with increase in various physical properties, burst index (12.50%), tear index (19.07%), breaking length (14.30%), double fold number (26.31%), Gurley porosity (45.32%) and viscosity (16.17%). This bio-bleaching approach not only improved the pulp quality but also reduced environmental pollution load by decreasing effluent parameters values of BOD and COD by 23.67% and 27.44%, respectively. This study indicates that use of ultrafiltered xylano-pectinolytic synergism for rice straw pulp bleaching will ultimately help in making the process eco-friendly, along with better quality pulp. This is the first report on use of ultrafiltered xylanase and pectinase, produced from a bacterial isolate, for bleaching of rice straw pulp.
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Ultrafiltered biopulping strategy for the production of good quality pulp and paper from sugarcane bagasse. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:44614-44622. [PMID: 33037542 DOI: 10.1007/s11356-020-11102-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
This research was carried out with an objective to examine the efficacy of ultrafiltered xylano-pectinolytic enzymes in pulping of sugarcane bagasse. Maximum biopulping was achieved with enzyme dose of xylanase (175 IU / g bagasse) and pectinase (75 IU / g bagasse) at treatment period of 180 min. The temperature, pH, and bagasse to liquid ratio for biopulping experiments were kept constant at 55o C, 8.5, and 1:10 (g/ml), respectively. The ultrafiltered biopulping improved chemical pulping, resulted in 25.11%, 9.17% increase in brightness, unscreened pulp production and 11.81, 59.50, and 49.14% decrease in total solids, rejections. and kappa number, respectively. The bagasse biopulping also resulted in 15% decrease of alkali load to attain similar kappa number and optical properties as obtained under 100% alkali dosage. Ultrafiltered biopulped-unbleached samples showed significant increase in breaking length (13.55%), burst index (40.21%), tear index (19.04%), double fold (42.5%), Gurley porosity (28.21%) and viscosity (13.37%) in comparison with non-enzymatically treated control pulp samples. In comparison with non biotreated-bleached pulp samples, ultrafiltered biopulped-bleached samples also resulted in higher burst index (56.80%), breaking length (17.38%), double fold (39.58%), tear index (3.38%), viscosity (30.68%), and Gurley porosity (52.50%). This environmentally sustainable ultrafiltered biopulping approach for sugarcane bagasse has the potential to decrease the demand of chemicals, ultimately pollution along with enhance the quality of paper.
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A combined physical-chemical and microbiological approach to unveil the fabrication, provenance, and state of conservation of the Kinkarakawa-gami art. Sci Rep 2020; 10:16072. [PMID: 33009430 PMCID: PMC7532529 DOI: 10.1038/s41598-020-73226-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/07/2020] [Indexed: 11/09/2022] Open
Abstract
Kinkarakawa-gami wallpapers are unique works of art produced in Japan between 1870 and 1905 and exported in European countries, although only few examples are nowadays present in Europe. So far, neither the wallpapers nor the composing materials have been characterised, limiting the effective conservation–restoration of these artefacts accounting also for the potential deteriogen effects of microorganisms populating them. In the present study, four Kinkarakawa-gami wallpapers were analysed combining physical–chemical and microbiological approaches to obtain information regarding the artefacts’ manufacture, composition, dating, and their microbial community. The validity of these methodologies was verified through a fine in blind statistical analysis, which allowed to identify trends and similarities within these important artefacts. The evidence gathered indicated that these wallpapers were generated between 1885 and 1889, during the so-called industrial production period. A wide range of organic (proteinaceous binders, natural waxes, pigments, and vegetable lacquers) and inorganic (tin foil and pigments) substances were used for the artefacts’ manufacture, contributing to their overall complexity, which also reflects on the identification of a heterogeneous microbiota, often found in Eastern environmental matrices. Nevertheless, whether microorganisms inhabiting these wallpapers determined a detrimental or protective effect is not fully elucidated yet, thus constituting an aspect worth to be explored to deepen the knowledge needed for the conservation of Kinkarakawa-gami over time.
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Greener approach for pulp and paper industry by Xylanase and Laccase. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101604] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Nature and bioprospecting of haloalkaliphilics: a review. World J Microbiol Biotechnol 2020; 36:66. [DOI: 10.1007/s11274-020-02841-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/14/2020] [Indexed: 01/07/2023]
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Statistical Optimization of Biobleaching Efficacy of endo-β-1,4-xylanase from an Actinobacterium Streptomyces olivaceus (MSU3) in Comparison with Zinc Oxide Pretreated Sugarcane Bagasse Pulp Using Box–Behnken Design. SMART SCIENCE 2020. [DOI: 10.1080/23080477.2020.1769977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Compatibility testing and enhancing the pulp bleaching process by hydrolases of the newly isolated thermophilic Isoptericola variabilis strain UD-6. BIOCATAL BIOTRANSFOR 2020. [DOI: 10.1080/10242422.2019.1711067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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A detailed overview of xylanases: an emerging biomolecule for current and future prospective. BIORESOUR BIOPROCESS 2019. [DOI: 10.1186/s40643-019-0276-2] [Citation(s) in RCA: 144] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Xylan is the second most abundant naturally occurring renewable polysaccharide available on earth. It is a complex heteropolysaccharide consisting of different monosaccharides such as l-arabinose, d-galactose, d-mannoses and organic acids such as acetic acid, ferulic acid, glucuronic acid interwoven together with help of glycosidic and ester bonds. The breakdown of xylan is restricted due to its heterogeneous nature and it can be overcome by xylanases which are capable of cleaving the heterogeneous β-1,4-glycoside linkage. Xylanases are abundantly present in nature (e.g., molluscs, insects and microorganisms) and several microorganisms such as bacteria, fungi, yeast, and algae are used extensively for its production. Microbial xylanases show varying substrate specificities and biochemical properties which makes it suitable for various applications in industrial and biotechnological sectors. The suitability of xylanases for its application in food and feed, paper and pulp, textile, pharmaceuticals, and lignocellulosic biorefinery has led to an increase in demand of xylanases globally. The present review gives an insight of using microbial xylanases as an “Emerging Green Tool” along with its current status and future prospective.
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Microbial diversity analysis and screening for novel xylanase enzymes from the sediment of the Lobios Hot Spring in Spain. Sci Rep 2019; 9:11195. [PMID: 31371784 PMCID: PMC6671963 DOI: 10.1038/s41598-019-47637-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/11/2019] [Indexed: 01/28/2023] Open
Abstract
Here, we describe the metagenome composition of a microbial community in a hot spring sediment as well as a sequence-based and function-based screening of the metagenome for identification of novel xylanases. The sediment was collected from the Lobios Hot Spring located in the province of Ourense (Spain). Environmental DNA was extracted and sequenced using Illumina technology, and a total of 3.6 Gbp of clean paired reads was produced. A taxonomic classification that was obtained by comparison to the NCBI protein nr database revealed a dominance of Bacteria (93%), followed by Archaea (6%). The most abundant bacterial phylum was Acidobacteria (25%), while Thaumarchaeota (5%) was the main archaeal phylum. Reads were assembled into contigs. Open reading frames (ORFs) predicted on these contigs were searched by BLAST against the CAZy database to retrieve xylanase encoding ORFs. A metagenomic fosmid library of approximately 150,000 clones was constructed to identify functional genes encoding thermostable xylanase enzymes. Function-based screening revealed a novel xylanase-encoding gene (XynA3), which was successfully expressed in E. coli BL21. The resulting protein (41 kDa), a member of glycoside hydrolase family 11 was purified and biochemically characterized. The highest activity was measured at 80 °C and pH 6.5. The protein was extremely thermostable and showed 94% remaining activity after incubation at 60 °C for 24 h and over 70% remaining activity after incubation at 70 °C for 24 h. Xylanolytic activity of the XynA3 enzyme was stimulated in the presence of β-mercaptoethanol, dithiothreitol and Fe3+ ions. HPLC analysis showed that XynA3 hydrolyzes xylan forming xylobiose with lower proportion of xylotriose and xylose. Specific activity of the enzyme was 9080 U/mg for oat arabinoxylan and 5080 U/mg for beechwood xylan, respectively, without cellulase activity.
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A novel endo-β-1,4-xylanase from Pediococcus acidilactici GC25; purification, characterization and application in clarification of fruit juices. Int J Biol Macromol 2019; 129:571-578. [DOI: 10.1016/j.ijbiomac.2019.02.054] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/11/2019] [Accepted: 02/08/2019] [Indexed: 11/28/2022]
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Abstract
Xylan and mannan are the two most abundant hemicelluloses, and enzymes that modify these polysaccharides are prominent hemicellulases with immense biotechnological importance. Among these enzymes, xylanases and mannanases which play the vital role in the hydrolysis of xylan and mannan, respectively, attracted a great deal of interest. These hemicellulases have got applications in food, feed, bioethanol, pulp and paper, chemical, and beverage producing industries as well as in biorefineries and environmental biotechnology. The great majority of the enzymes used in these applications are optimally active in mildly acidic to neutral range. However, in recent years, alkaline active enzymes have also become increasingly important. This is mainly due to some benefits of utilizing alkaline active hemicellulases over that of neutral or acid active enzymes. One of the advantages is that the alkaline active enzymes are most suitable to applications that require high pH such as Kraft pulp delignification, detergent formulation, and cotton bioscouring. The other benefit is related to the better solubility of hemicelluloses at high pH. Since the efficiency of enzymatic hydrolysis is often positively correlated to substrate solubility, the hydrolysis of hemicelluloses can be more efficient if performed at high pH. High pH hydrolysis requires the use of alkaline active enzymes. Moreover, alkaline extraction is the most common hemicellulose extraction method, and direct hydrolysis of the alkali-extracted hemicellulose could be of great interest in the valorization of hemicellulose. Direct hydrolysis avoids the time-consuming extensive washing, and neutralization processes required if non-alkaline active enzymes are opted to be used. Furthermore, most alkaline active enzymes are relatively active in a wide range of pH, and at least some of them are significantly or even optimally active in slightly acidic to neutral pH range. Such enzymes can be eligible for non-alkaline applications such as in feed, food, and beverage industries.This chapter largely focuses on the most important alkaline active hemicellulases, endo-β-1,4-xylanases and β-mannanases. It summarizes the relevant catalytic properties, structural features, as well as the real and potential applications of these remarkable hemicellulases in textile, paper and pulp, detergent, feed, food, and prebiotic producing industries. In addition, the chapter depicts the role of these extremozymes in valorization of hemicelluloses to platform chemicals and alike in biorefineries. It also reviews hemicelluloses and discusses their biotechnological importance.
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A logical and sustainable approach towards bamboo pulp bleaching using xylanase from Aspergillus nidulans. Int J Biol Macromol 2018; 118:452-459. [DOI: 10.1016/j.ijbiomac.2018.06.100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/20/2018] [Accepted: 06/21/2018] [Indexed: 10/28/2022]
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Isolation, Identification and Partial Optimization of Novel Xylanolytic Bacterial Isolates from Bhilai-Durg Region, Chhattisgarh, India. IRANIAN JOURNAL OF BIOTECHNOLOGY 2018; 16:e1333. [PMID: 31457021 PMCID: PMC6697829 DOI: 10.15171/ijb.1333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 09/05/2017] [Accepted: 09/16/2017] [Indexed: 11/22/2022]
Abstract
Background Plant biomass and agricultural waste products disposal is a serious problem in agriculture based countries. These wastes, usually rich in xylan can be satisfactorily converted to industrially important and useful products by efficient biotechnological application of potent xylanase producing bacteria which generally have high temperature and pH optima. Objective The aim was to isolate and identify xylanolytic bacterial isolates from Bhilai-Durg region of Chhattisgarh, India which was otherwise unexplored for isolation of thermoalkalophilic xylanase producing bacteria. Partial scale up of process development was performed. Materials and Methods Xyalanse producing bacteria were isolated from probable samples following three stages of screening procedures. The potent isolates were identified and various parameters affecting xylanase production were optimized using the conventional one-factor-at-a-time approach. Results Two potent indigenous bacterial isolates belonged to genus Bacillus and designated as Bacillus sp. MCC2728 and Bacillus sp. MCC2727 were isolated from forest soils with the ability to degrade xylan. Significant differences were observed in their morphology and phenotypic characters amongst themselves and with its closest type strains implying the novelty of the two isolates. After optimization, maximum xylanase levels were obtained at pH 9.0, 55 °C for Bacillus sp. MCC2728 and 50 °C for Bacillus sp. MCC2727, 5% inoculum, agitation speed (150 rpm). Yeast extract and peptone are best nitrogen sources and wheat bran, the best carbon source. The GenBank/EMBL/DDBJ accession numbers of strains Bacillus sp. MCC2728 and Bacillus sp. MCC2727 are KP742971 and KT444621 respectively. Wheat bran, Yeast extract and peptone proved to be the best carbon and nitrogen sources respectively and xylose as an additive was found to be contributing to maximize the xylanase yields. Conclusion Two potent thermoalkalophilic novel bacterial isolates were successfully isolated with xylan degrading ability which may be used as promising xylanase producing candidates for various industrial purposes using agricultural based waste residues.
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Production and purification of xylanase from alkaliphilic Bacillus licheniformis and its pretreatment of eucalyptus kraft pulp. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.06.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Purification and characterization of a cellulase-free, thermostable endo-xylanase from Streptomyces griseorubens LH-3 and its use in biobleaching on eucalyptus kraft pulp. J Biosci Bioeng 2018; 125:46-51. [DOI: 10.1016/j.jbiosc.2017.08.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 07/16/2017] [Accepted: 08/11/2017] [Indexed: 11/18/2022]
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Cellulase-free-thermo-alkali-solvent-stable xylanase from Bacillus altitudinis DHN8: Over-production through statistical approach, purification and bio-deinking/ bio-bleaching potential. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2017. [DOI: 10.1016/j.bcab.2017.10.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Purification, characterization and thermostability improvement of xylanase from Bacillus amyloliquefaciens and its application in pre-bleaching of kraft pulp. 3 Biotech 2017; 7:20. [PMID: 28401458 PMCID: PMC5388660 DOI: 10.1007/s13205-017-0615-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 01/08/2017] [Indexed: 11/06/2022] Open
Abstract
Xylanases have important industrial applications but are most extensively utilized in the pulp and paper industry as a pre-bleaching agent. We characterized a xylanase from Bacillus amyloliquefaciens strain SK-3 and studied it for kraft pulp bleaching. The purified enzyme had a molecular weight of ~50 kDa with optimal activity at pH 9.0 and 50 °C. The enzyme showed good activity retention (85%) after 2 h incubation at 50 °C and pH 9.0. This enzyme obeyed Michaelis–Menten kinetics with regard to beechwood xylan with Km and Vmax values of 5.6 mg/ml, 433 μM/min/mg proteins, respectively. The enzyme activity was stimulated by Mn2+, Ca2+ and Fe2+ metal ions. Further, it also showed good tolerance to phenolics (2 mM) in the presence of syringic acid (no loss), cinnamic acid (97%), benzoic acid (94%) and phenol (97%) activity retention. The thermostability of xylanase was increased by 6.5-fold in presence of sorbitol (0.75 M). Further, pulp treated with 20U/g of xylanase (20IU/g) alone and with sorbitol (0.75M) reduced kappa number by 18.3 and 23.8%, respectively after 3 h reaction. In summary, presence of xylanase shows good pulp-bleaching activity, good tolerance to phenolics, lignin and metal ions and is amenable to thermostability improvement by addition of polyols. The SEM image showed significant changes on the surface of xylanase-treated pulp fiber as a result of xylan hydrolysis.
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HOT PHENOL EXTRACTION OF TOTAL RNA FROM Thermoascus aurantiacus AND CHARACTERIZATION OF ITS THERMOSTABLE XYLANASE GENE. BORNEO JOURNAL OF RESOURCE SCIENCE AND TECHNOLOGY 2016. [DOI: 10.33736/bjrst.264.2011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Total RNA was successfully isolated using hot phenol extraction method. Three bands representing the 18S, 5.8S and 28S rRNA was observed. No heavy smearing was observed in the RNA band patterns, indicating low levels of polysaccharide contamination, when subjected to 1% agarose gel electrophoresis. Genomic DNA was eliminated using DNase I digestion and lithium chloride (LiCl) precipitation. Two-steps reverse transcriptase polymerase chain reaction (RT-PCR) using M-MuLV Reverse Transcriptase and sequence specific primers for xylanase gene, XynA(F) and XynA(R), successfully generated the target amplicon of 500 base pairs (bp). Sequence analysis of the PCR product indicated as partial sequence of Thermoascus aurantiacus xylanase gene (XynA) deposited in the NCBI GenBank with accession number: AF127529.1 and AJ132635.1. Hot phenol extraction is useful for extracting large quantities of total RNA sufficient for complementary DNA (cDNA) synthesis in shorter period of time.
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A high-molecular-weight, alkaline, and thermostable β-1,4-xylanase of a subseafloor Microcella alkaliphila. Extremophiles 2016; 20:471-8. [DOI: 10.1007/s00792-016-0837-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/15/2016] [Indexed: 10/21/2022]
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Cloning, purification and characterization of a cellulase-free xylanase from Geobacillus thermodenitrificans AK53. APPL BIOCHEM MICRO+ 2016. [DOI: 10.1134/s0003683816030066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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IDENTIFICACIÓN DE MICROORGANISMOS ASOCIADOS A RESIDUOS DE HIGUERILLA (Ricinus communis). REVISTA COLOMBIANA DE QUÍMICA 2016. [DOI: 10.15446/rev.colomb.quim.v44n2.55214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
<p>El objetivo de este artículo fue aislar e identificar los microorganismos presentes en los residuos de fruto y torta de higuerilla. Se utilizaron medios de cultivo selectivos para la caracterización morfológica y bioquímica y para la identificación molecular se usó la técnica de PCR con oligonucleótidos universales RM y RB del gen 16S para bacterias y secuencias intergénicas ITS1 e ITS4 para hongos y levaduras. Las secuencias fueron analizadas identificándose nueve especies de hongos, siendo Penicillium brevicompactu predominante; 12 especies de bacterias, donde el género más recurrente fue y dos especies de levaduras, Rhodosporidium paludigenum y Pichia burtonni. La identificación de la microbiota nativa presente en los residuos de higuerilla es muy promisoria, aportando un amplio conocimiento sobre la versatilidad metabólica de cada una de las cepas aisladas. El mayor número de aislamientos se obtuvieron de la torta probablemente debido al alto contenido de nutrientes presentes en este residuo.</p>
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Novel alkali-thermostable xylanase from Thielaviopsis basicola (MTCC 1467): Purification and kinetic characterization. Int J Biol Macromol 2016; 82:823-9. [DOI: 10.1016/j.ijbiomac.2015.10.055] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/16/2015] [Accepted: 10/19/2015] [Indexed: 10/22/2022]
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Xylan-degrading enzymes from Aspergillus terreus: Physicochemical features and functional studies on hydrolysis of cellulose pulp. Carbohydr Polym 2015; 134:700-8. [DOI: 10.1016/j.carbpol.2015.08.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 08/14/2015] [Accepted: 08/17/2015] [Indexed: 11/22/2022]
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Molecular characterization of a new alkaline-tolerant xylanase from Humicola insolens Y1. BIOMED RESEARCH INTERNATIONAL 2015; 2015:149504. [PMID: 25629035 PMCID: PMC4299769 DOI: 10.1155/2015/149504] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 12/20/2014] [Indexed: 11/28/2022]
Abstract
An endo-1,4-β-xylanase-encoding gene, xyn11B, was cloned from the thermophilic fungus Humicola insolens Y1. The gene encodes a multimodular xylanase that consists of a typical hydrophobic signal sequence, a catalytic domain of glycoside hydrolase (GH) family 11, a glycine-rich linker, and a family 1 carbohydrate binding module (CBM1). Deduced Xyn11B shares the highest identity of 74% with a putative xylanase from Podospora anserina S mat+. Recombinant Xyn11B was successfully expressed in Pichia pastoris and purified to electrophoretic homogeneity. Xyn11B had a high specific activity of 382.0 U mg−1 towards beechwood xylan and showed optimal activity at pH 6.0 and 50°C. Distinct from most reported acidic fungal xylanases, Xyn11B was alkaline-tolerant, retaining 30.7% of the maximal activity at pH 9.0. The Km and Vmax values for beechwood xylan were 2.2 mg mL−1 and 462.8 μmol min−1 mg−1, respectively. The enzyme exhibited a wider substrate specificity and produced a mixture of xylooligosaccharides. All these favorable enzymatic properties make Xyn11B attractive for potential applications in various industries.
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Abstract
Haloalkaliphiles are microorganisms requiring Na+concentrations of at least 0.5 mol·L–1and an alkaline pH of 9 for optimal growth. Their unique features enable them to make significant contributions to a wide array of biotechnological applications. Organic compatible solutes produced by haloalkaliphiles, such as ectoine and glycine betaine, are correlated with osmoadaptation and may serve as stabilizers of intracellular proteins, salt antagonists, osmoprotectants, and dermatological moisturizers. Haloalkaliphiles are an important source of secondary metabolites like rhodopsin, polyhydroxyalkanoates, and exopolysaccharides that play essential roles in biogeocycling organic compounds. These microorganisms also can secrete unique exoenzymes, including proteases, amylases, and cellulases, that are highly active and stable in extreme haloalkaline conditions and can be used for the production of laundry detergent. Furthermore, the unique metabolic pathways of haloalkaliphiles can be applied in the biodegradation and (or) biotransformation of a broad range of toxic industrial pollutants and heavy metals, in wastewater treatment, and in the biofuel industry.
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Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:198251. [PMID: 27350996 PMCID: PMC4897549 DOI: 10.1155/2014/198251] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 06/21/2014] [Accepted: 06/23/2014] [Indexed: 11/17/2022]
Abstract
A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0-25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca(2+), Mn(2+), and Mg(2+) but strongly inhibited by heavy metals such as Hg(2+), Fe(3+), Ni(2+), and Zn(2+). Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications.
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Biochemical characterization of a novel thermostable GH11 xylanase with CBM6 domain from Caldicellulosiruptor kronotskyensis. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcatb.2014.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Enhanced production of cellulase-free, thermo-alkali-solvent-stable xylanase from Bacillus altitudinis DHN8, its characterization and application in sorghum straw saccharification. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2014. [DOI: 10.1016/j.bcab.2013.10.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Combined enzymatic and physical deinking methodology for efficient eco-friendly recycling of old newsprint. PLoS One 2013; 8:e72346. [PMID: 23977287 PMCID: PMC3744503 DOI: 10.1371/journal.pone.0072346] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 07/08/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The development in the deinking process has made recycled fiber a major part of the raw material for pulp and paper industry. Enzymes have revolutionized the deinking process obtaining brightness levels surpassing conventional deinking processes. This study explores the deinking efficiencies of bacterial alkalophilic laccase (L) and xylanase (X) enzymes along with physical deinking methods of microwaving (MW) and sonication (S) for recycling of old newsprint (ONP). METHODS AND RESULTS The operational parameters viz. enzyme dose, pH and treatment time for X and L deinking were optimized statistically using Response Surface Methodology. Laccase did not require any mediator supplementation for deinking. Deinking of ONP pulp with a combination of xylanase and laccase enzymes was investigated, and fiber surface composition and morphological changes were studied using X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the pulp deinked with xylanase (47.9%) or laccase (62.2%) individually, the percentage reduction of effective residual ink concentration (ERIC) was higher for the combined xylanase/laccase-deinked pulp (65.8%). An increase in brightness (21.6%), breaking length (16.5%), burst factor (4.2%) tear factor (6.9%), viscosity (13%) and cellulose crystallinity (10.3%) along with decrease in kappa number (22%) and chemical consumption (50%) were also observed. Surface appeared more fibrillar along with changes in surface functional groups. A combination of physical and enzymatic processes (S-MW-XL) for deinking further improved brightness (28.8%) and decreased ERIC (73.9%) substantially. CONCLUSION This is the first report on deinking of ONP with laccase without any mediator supplementation. XL pretreatment resulted in marked improvement in paper quality and a new sequence being reported for deinking (S-MW-XL) will contribute further in decreasing chemical consumption and making the process commercially feasible.
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Biobleaching application of cellulase poor and alkali stable xylanase from Bacillus pumilus SV-85S. 3 Biotech 2013; 3:277-285. [PMID: 28324585 PMCID: PMC3723860 DOI: 10.1007/s13205-012-0096-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 09/27/2012] [Indexed: 11/12/2022] Open
Abstract
The potential of extracellular alkali stable and thermo tolerant xylanase produced by Bacilluspumilus SV-85S through solid state fermentation was investigated in pulp bleaching in association with conventional bleaching using chlorine and chlorine dioxide. The biobleaching of kraft pulp with xylanase was the most effective at an enzyme dose of 10 IU/g oven dried pulp, pH 9.0 and 120 min incubation at 55 °C. Under the optimized conditions, xylanase pretreatment reduced Kappa number by 1.6 points and increased brightness by 1.9 points. Subsequently, chlorine dioxide and alkaline bleaching sequences (CDE1D1D2) finally resulted in brightness gain of 2.7 points as compared with the control. The pretreatment of pulp with xylanase resulted in 29.16 % reduction in chlorine consumption by maintaining the same brightness as in control. An improvement in pulp strength properties was also observed after bleaching of xylanase pretreated pulp. Scanning electron microscopy revealed loosening and swelling of pulp fibers after enzyme treatment. These results clearly demonstrated that the B. pumilus SV-85S xylanase was effective as a pulp biobleaching agent. The decrease in chlorine consumption by pretreatment of pulp with xylanase apparently made the biobleaching process not only economical but also eco-friendly.
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Isolation and Cultivation of a Xylanolytic Bacillus subtilis Extracted from the Gut of the Termite Reticulitermes santonensis. Appl Biochem Biotechnol 2013; 171:225-45. [DOI: 10.1007/s12010-013-0337-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 06/17/2013] [Indexed: 10/26/2022]
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Purification, bio-chemical characterization, homology modeling and active site binding mode interactions of thermo-alkali-tolerant β-1,4 endoxylanase from Coprinus cinereus LK-D-NCIM-1369. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2013. [DOI: 10.1016/j.bcab.2013.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Characterization of a thermostable xylanase from a newly isolated Kluyvera species and its application for biobutanol production. BIORESOURCE TECHNOLOGY 2013; 135:309-315. [PMID: 23186668 DOI: 10.1016/j.biortech.2012.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 09/28/2012] [Accepted: 10/02/2012] [Indexed: 05/23/2023]
Abstract
Kluyvera species strain OM3 isolated from spent mushroom substrate could produce a high level of cellulase-free xylanase (5.12 U/mL). This xylanase showed maximum activities at 70 °C and pH 8.0, which could retain 100% and 71% activity after 1h incubation at 60 °C and 70 °C, and maintain stability over a wide range of pHs (5.0-9.0), indicating its thermal and pH stability. Moreover, the xylanase could hydrolyze untreated lignocellulosics (e.g., palm oil fiber) to reducing sugars with a yield of 27.1-46.9 mg/g. A co-culture consisting of Kluyvera sp. strain OM3 and Clostridium sp. strain BOH3 could directly convert birchwood xylan to 1.2g/L butanol, which was comparable to the amount of butanol (1.7 g/L) generated via separate hydrolysis by the xylanase and fermentation by Clostridium sp. strain BOH3. This is the first report on the production, characterization of a xylanase from genus Kluyvera and its application for butanol production directly from hemicelluloses.
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Gene cloning, expression and characterization of a novel xylanase from the marine bacterium, Glaciecola mesophila KMM241. Mar Drugs 2013; 11:1173-87. [PMID: 23567318 PMCID: PMC3705397 DOI: 10.3390/md11041173] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/06/2013] [Accepted: 03/19/2013] [Indexed: 11/16/2022] Open
Abstract
Marine xylanases are rather less studied compared to terrestrial xylanases. In this study, a new xylanase gene, xynB, was cloned from the marine bacterium, Glaciecola mesophila KMM241, and expressed in Escherichia coli. xynB encodes a multi-domain xylanase XynB of glycoside hydrolase (GH) family 8. The recombinant XynB comprises an N-terminal domain (NTD) with unknown function and a catalytic domain, which is structurally novel among the characterized xylanases of GH family 8. XynB has the highest identity (38%) to rXyn8 among the characterized xylanases. The recombinant XynB showed maximal activity at pH 6–7 and 35 °C. It is thermolabile and salt-tolerant. XynB is an endo-xylanase that demands at least five sugar moieties for effective cleavage and to hydrolyze xylohexaose and xylopentaose into xylotetraose, xylotriose and xylobiose. NTD was expressed in Escherichia coli to analyze its function. The recombinant NTD exhibited a high binding ability to insoluble xylan and avicel and little binding ability to chitosan and chitin. Since the NTD shows no obvious homology to any known carbohydrate-binding module (CBM) sequence in public databases, XynB may contain a new type of CBM.
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Thermostable and Alkalistable Endoxylanase of the Extremely Thermophilic Bacterium Geobacillus thermodenitrificans TSAA1: Cloning, Expression, Characteristics and Its Applicability in Generating Xylooligosaccharides and Fermentable Sugars. Appl Biochem Biotechnol 2013; 170:119-30. [DOI: 10.1007/s12010-013-0174-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 03/01/2013] [Indexed: 10/27/2022]
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Enzymatic clarification of fruit juices (Apple, Pineapple, and Tomato) using purified Bacillus pumilus SV-85S xylanase. BIOTECHNOL BIOPROC E 2013. [DOI: 10.1007/s12257-012-0375-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Molecular characterization of a cold-active recombinant xylanase from Flavobacterium johnsoniae and its applicability in xylan hydrolysis. BIORESOURCE TECHNOLOGY 2013; 128:145-155. [PMID: 23196234 PMCID: PMC4106359 DOI: 10.1016/j.biortech.2012.10.087] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 10/16/2012] [Accepted: 10/19/2012] [Indexed: 05/23/2023]
Abstract
A novel xylanase gene, xyn10A, was cloned from Flavobacterium johsoniae, overexpressed in a flavobacterial expression system, the recombinant enzyme purified by Ni-affinity chromatography, and enzyme structure and activity analyzed. Xyn10A was found to be a modular xylanase with an Fn3 accessory domain on its N-terminal and a catalytic region on the C-terminal. The optimum pH and temperature for Xyn10A was 8.0 and 30 °C, but Xyn10A retained 50% activity at 4 °C, indicating that Xyn10A is a cold-active xylanase. A Fn3-deletion xylanase had relative activity ca. 3.6-fold lower than the wild-type, indicating that Fn3 promotes xylanase activity. The Fn3 region also contributed to stability of the enzyme at elevated temperatures. However, Fn3 did not bind this xylanase to insoluble substrates. The enzyme hydrolyzed xylo-oligosaccharides into xylobiose, and xylose with xylobiose as the main product, confirming that Xyn10A is a strict endo-β-1,4-xylanase. Xyn10A also hydrolyzed birchwood and beechwood xylan to yield mainly xylose, xylobiose and xylotriose.
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Production and purification of high levels of cellulase-free bacterial xylanase by Bacillus sp. SV-34S using agro-residue. ANN MICROBIOL 2012. [DOI: 10.1007/s13213-012-0574-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Cloning, Expression, and Characterization of an GHF 11 Xylanase from Aspergillus niger XZ-3S. Indian J Microbiol 2012; 52:682-8. [PMID: 24293731 DOI: 10.1007/s12088-012-0314-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 09/26/2012] [Indexed: 11/28/2022] Open
Abstract
A xylanase gene (xynZF-2) from the Aspergillus niger XZ-3S was cloned and expressed in Escherichia coli. The coding region of the gene was separated by only one intron with the 68 bp in length. It encoded 225 amino acid residues of a protein with a calculated molecular weight of 24.04 kDa plus a signal peptide of 18 amino acids. The amino acid sequence of the xynZF-2 gene had a high similarity with those of family 11 of glycosyl hydrolases reported from other microorganisms. The mature peptide encoding cDNA was subcloned into pET-28a(+) expression vector. The resultant recombinant plasmid pET-28a-xynZF-2 was transformed into E. coli BL21(DE3), and finally the recombinant strain BL21/xynZF-2 was obtained. A maximum activity of 42.33 U/mg was gained from cellular of E. coli BL21/xynZF-2 induced by IPTG. The optimum temperature and pH for recombinant enzyme which has a good stability in alkaline conditions were 40 °C and 5.0, respectively. Fe(3+) had an active effect on the enzyme obviously.
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