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Lignocellulosic enzymatic hydrolysis

Anderson Albino Gomes, Elisa Pazinatto Telli, Luiz Claudio Miletti, Everton Skoronski, Marcos Gomes Ghislandi, Gustavo Felippe da Silva, Maria de Lourdes Borba Magalhães
Optimization of cellulose enzymatic hydrolysis is crucial for cost effective bioethanol production from lignocellulosic biomass. Enzyme immobilization in solid support allows enzyme recycling for reuse, lowering hydrolysis costs. Graphene is a nanomaterial isolated in 2004, which possesses exceptional properties for biomolecule immobilization. This study evaluates the potential for β-glucosidase recycling by immobilization on graphene nanosheets. Data reported here demonstrated that graphene immobilized β-glucosidase can be recycled for at least eight cycles...
June 21, 2017: Biotechnology and Applied Biochemistry
Thiago Rodrigues Dutra, Valéria Monteze Guimarães, Ednilson Mascarenhas Varela, Lílian da Silva Fialho, Adriane Maria Ferreira Milagres, Daniel Luciano Falkoski, José Cola Zanuncio, Sebastião Tavares de Rezende
Low cost and high efficiency cellulolytic cocktails can consolidate lignocellulosic ethanol technologies. Sugarcane bagasse (SCB) is a low cost agro-industrial residue, and its use as a carbon source can reduce the costs of fungi cultivation for enzyme production. Chrysoporthe cubensis grown under solid state fermentation (SSF) with wheat bran has potential to produce efficient enzymatic extracts for SCB saccharification. This fungus was grown under submersed fermentation (SmF) and SSF with in natura SCB, pretreated with acid or alkali and with others carbon sources...
June 20, 2017: Scientific Reports
Hiroshi Teramura, Kengo Sasaki, Hideo Kawaguchi, Fumio Matsuda, Jun Kikuchi, Tomokazu Shirai, Takashi Sazuka, Masanori Yamasaki, Shigeo Takumi, Chiaki Ogino, Akihiko Kondo
Bio-refinery processes require use of the most suitable lignocellulosic biomass for enzymatic saccharification and microbial fermentation. Glucose yield from biomass solid fractions obtained after dilute sulfuric acid (1%) pretreatment (at 180 °C) was investigated using 14, 8, and 16 varieties of rice, wheat, and sorghum, respectively. Biomass solid fractions of each crop showed similar cellulose content. However, glucose yield after enzymatic hydrolysis (cellulase loading at 6.6 filter paper unit/g-biomass) was different among the varieties of each crop, indicating genotypic differences for rice, wheat, and sorghum...
June 16, 2017: Bioscience, Biotechnology, and Biochemistry
Di Huang, Jia Liu, Yanfei Qi, Kexin Yang, Yingying Xu, Lu Feng
Lignocellulosic biomass from various types of wood has become a renewable resource for production of biofuels and biobased chemicals. Because xylan is the major component of wood hemicelluloses, highly efficient enzymes to enhance xylan hydrolysis can improve the use of lignocellulosic biomass. In this study, a xylanolytic gene cluster was identified from the crude oil-degrading thermophilic strain Geobacillus thermodenitrificans NG80-2. The enzymes involved in xylan hydrolysis, which include two xylanases (XynA1, XynA2), three β-xylosidases (XynB1, XynB2, XynB3), and one α-L-arabinofuranosidase (AbfA), have many unique features, such as high pH tolerance, high thermostability, and a broad substrate range...
June 14, 2017: Applied Microbiology and Biotechnology
Rameshwar Tiwari, Lata Nain, Nikolaos E Labrou, Pratyoosh Shukla
Second generation biofuel production has been appeared as a sustainable and alternative energy option. The ultimate aim is the development of an industrially feasible and economic conversion process of lignocellulosic biomass into biofuel molecules. Since, cellulose is the most abundant biopolymer and also represented as the photosynthetically fixed form of carbon, the efficient hydrolysis of cellulose is the most important step towards the development of a sustainable biofuel production process. The enzymatic hydrolysis of cellulose by suites of hydrolytic enzymes underlines the importance of cellulase enzyme system in whole hydrolysis process...
June 13, 2017: Critical Reviews in Microbiology
Phisit Seesuriyachan, Arthitaya Kawee-Ai, Thanongsak Chaiyaso
In this study, the pressures at 50-500MPa were evaluated at different time to pretreat and further enzyme hydrolysis. The ultra-high pressure (UHP) pretreatment at 100MPa for 10min led to improved accessibility of enzyme for conversion of xylan to xylooligosaccharide (XOS). The maximum XOS yield of 35.6mg/g substrate was achieved and firstly reported at 10% (w/v) of substrate, 100U of endo-xylanase/g corncobs and incubation time of 18h. The enzymatic hydrolysis efficiency was increased by 180.3% and released a high amount of xylobiose...
June 1, 2017: Bioresource Technology
Linfeng Kou, Yanliang Song, Xu Zhang, Tianwei Tan
In order to utilize energy grasses as substrates for production of biofuels and expand the diversity of lignocellulosic feedstocks, this work developed an evaluation system considering 16 kinds of parameters related to the contents of three main compositions (cellulose, hemicellulose and lignin), inhibitors generated from the pretreatment, the extent of enzymatic hydrolysis and microbial fermentation. Giant reed, corn stalks, switch grass, pennisetum and silvergrass were investigated. Comprehensive utilization indexes of giant reed (55...
May 18, 2017: Bioresource Technology
Repson Gama, J Susan Van Dyk, Mike H Burton, Brett I Pletschke
The enzymatic degradation of lignocellulosic biomass such as apple pomace is a complex process influenced by a number of hydrolysis conditions. Predicting optimal conditions, including enzyme and substrate concentration, temperature and pH can improve conversion efficiency. In this study, the production of sugar monomers from apple pomace using commercial enzyme preparations, Celluclast 1.5L, Viscozyme L and Novozyme 188 was investigated. A limited number of experiments were carried out and then analysed using an artificial neural network (ANN) to model the enzymatic hydrolysis process...
June 2017: 3 Biotech
Chang Dou, Wilian F Marcondes, Jessica E Djaja, Renata Bura, Rick Gustafson
BACKGROUND: Feedstock cost is a substantial barrier to the commercialization of lignocellulosic biorefineries. Poplar grown using a short rotation coppice (SRC) system has the potential to provide a low-cost feedstock and economically viable sugar yields for fuels and chemicals production. In the coppice management regime, poplars are harvested after 2 years' growth to develop the root system and establish the trees. The biomass from these 2-year-old trees is very heterogeneous, and includes components of leaf, bark, branch, and wood chip...
2017: Biotechnology for Biofuels
Juan He, Caoxing Huang, Chenhuan Lai, Chen Huang, Qiang Yong
Lignocellulosics pretreatment is intended to dismantle biomass' natural recalcitrance. Chemical and morphological changes of lignocellulosic materials would occur through varying pretreatment processes. In order to figure out why the acid-pretreated and Kraft-cooked bamboo residues showed very different enzymatic digestibility, the surface properties of pretreated bamboo residues were characterized in this work. It was found that analyzed surface properties were considered to be associating with each corresponding enzymatic digestibility of the pretreated samples...
June 6, 2017: Applied Biochemistry and Biotechnology
M Saritha, Rameshwar Tiwari, Surender Singh, Pawan K S Nain, Sarika Rana, Anurup Adak, Anju Arora, Lata Nain
A successful lignocellulosic ethanol production process needs to address the technological impediments such as cost-competitiveness and sustainability of the process. Effective biomass utilization requires a repertoire of enzymes including various accessory enzymes. Developing an enzyme preparation with defined hydrolytic activities can circumvent the need for supplementing cellulases with accessory enzymes for enhanced hydrolysis. With this objective, mixture design approach was used in the present study to enhance glycoside hydrolase production of a fungal isolate, Aspergillus terreus CM20, by determining the proportion of different lignocellulosic components as enzyme inducers in the culture medium...
August 2016: Indian Journal of Experimental Biology
Ausra Peciulyte, Maria Pisano, Ronald P de Vries, Lisbeth Olsson
OBJECTIVES: To evaluate the potential of enzyme cocktails produced by five filamentous fungi to supplement the industrial cellulase cocktail, Celluclast 1.5L, in order to improve the efficiency of saccharification. RESULTS: The fungi were cultivated on wheat bran and the resulting supernatants were combined with Celluclast in enzymatic hydrolysis experiments to test their ability to hydrolyze wheat bran and five cellulose-rich substrates. The supernatant showing the best performance was that from an Aspergillus niger cellulase mutant...
June 1, 2017: Biotechnology Letters
Irina S Druzhinina, Christian P Kubicek
Lignocellulosic biomass, which mainly consists of cellulose, hemicellulose and lignin, is the most abundant renewable source for production of biofuel and biorefinery products. The industrial use of plant biomass involves mechanical milling or chipping, followed by chemical or physicochemical pretreatment steps to make the material more susceptible to enzymatic hydrolysis. Thereby the cost of enzyme production still presents the major bottleneck, mostly because some of the produced enzymes have low catalytic activity under industrial conditions and/or because the rate of hydrolysis of some enzymes in the secreted enzyme mixture is limiting...
May 29, 2017: Microbial Biotechnology
Samkelo Malgas, Mariska Thoresen, J Susan van Dyk, Brett I Pletschke
Cellulosic ethanol production relies on the biochemical (enzymatic) conversion of lignocellulose to fermentable sugars and ultimately to bioethanol. However, the cost of lignocellulolytic enzymes is a limiting factor in the commercialisation of this technology. This therefore necessitates the optimisation of lignocellulolytic enzyme cocktails through the elucidation of synergistic interactions between enzymes so as to improve lignocellulose hydrolysis and also lower protein loadings in these reactions. However, many factors affect the synergism that occurs between these lignocellulolytic enzymes, such as enzyme ratios, substrate characteristics, substrate loadings, enzyme loadings and time...
August 2017: Enzyme and Microbial Technology
Vinuselvi Parisutham, Sathesh-Prabu Chandran, Aindrila Mukhopadhyay, Sung Kuk Lee, Jay D Keasling
Complete hydrolysis of cellulose has been a key characteristic of biomass technology because of the limitation of industrial production hosts to use cellodextrin, the partial hydrolysis product of cellulose. Cellobiose, a β-1,4-linked glucose dimer, is a major cellodextrin of the enzymatic hydrolysis (via endoglucanase and exoglucanase) of cellulose. Conversion of cellobiose to glucose is executed by β-glucosidase. The complete extracellular hydrolysis of celluloses has several critical barriers in biomass technology...
September 2017: Bioresource Technology
Thomas Pielhop, Janick Amgarten, Michael H Studer, Philipp Rudolf von Rohr
BACKGROUND: Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. It is however not effective for overcoming the extremely high recalcitrance of softwood to biochemical conversion. Recent fundamental research in small-scale liquid hot water pretreatment has shown, though, that the addition of a carbocation scavenger like 2-naphthol can prevent lignin repolymerization and thus enhance the enzymatic digestibility of softwood cellulose...
2017: Biotechnology for Biofuels
Anthi Karnaouri, Madhu Nair Muraleedharan, Maria Dimarogona, Evangelos Topakas, Ulrika Rova, Mats Sandgren, Paul Christakopoulos
BACKGROUND: Filamentous fungi are among the most powerful cellulolytic organisms in terrestrial ecosystems. To perform the degradation of lignocellulosic substrates, these microorganisms employ both hydrolytic and oxidative mechanisms that involve the secretion and synergism of a wide variety of enzymes. Interactions between these enzymes occur on the level of saccharification, i.e., the release of neutral and oxidized products, but sometimes also reflected in the substrate liquefaction...
2017: Biotechnology for Biofuels
Dan Sun, Aftab Alam, Yuanyuan Tu, Shiguang Zhou, Yanting Wang, Tao Xia, Jiangfeng Huang, Ying Li, Zahoor, Xiaoyang Wei, Bo Hao, Liangcai Peng
In this study, total ten Miscanthus accessions exhibited diverse cell wall compositions, leading to largely varied hexoses yields at 17%-40% (% cellulose) released from direct enzymatic hydrolysis of steam-exploded (SE) residues. Further supplied with 2% Tween-80 into the enzymatic digestion, the Mis7 accession showed the higher hexose yield by 14.8-fold than that of raw material, whereas the Mis10 had the highest hexoses yield at 77% among ten Miscanthus accessions. Significantly, this study identified four wall polymer features that negatively affect biomass saccharification as p<0...
September 2017: Bioresource Technology
Hairui Ji, Yanliang Song, Xu Zhang, Tianwei Tan
In this study, a new pretreatment strategy for lignocellulosic was developed using a fully recyclable solid acid, Toluenesulfonic acid (p-TsOH). A combined hydrolysis factor (CHF) as a pretreatment severity was used to balance enzymatic saccharification and the structural characteristics of lignin. The results from degradation of carbohydrates, enzymatic hydrolysis of cellulose and characterization of lignin by FT-IR, (31)P NMR, GPC, 2D-HSQC NMR indicated that a CHF of approximately 3.90 was the optimal pretreatment severity to facilitate enzymatic saccharification and the potential serviceability of lignin...
August 2017: Bioresource Technology
Shuo-Fu Yuan, Gia-Luen Guo, Wen-Song Hwang
Renewable and low-cost lignocellulosic wastes have attractive applications in bioethanol production. The yeast Saccharomyces cerevisiae is the most widely used ethanol-producing microbe; however, its fermentation temperature (30-35°C) is not optimum (40-50°C) for enzymatic hydrolysis in the simultaneous saccharification and fermentation (SSF) process. In this study, we successfully performed an SSF process at 42°C from a high solid loading of 20% (w/v) acid-impregnated steam explosion (AISE)-treated rice straw with low inhibitor concentrations (furfural 0...
May 5, 2017: Microbial Biotechnology
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