China
Africa
Explore chapters and articles related to this topic
Design and Engineering Parameters of Bioreactors for Production of Bioethanol
Published in Ayerim Y. Hernández Almanza, Nagamani Balagurusamy, Héctor Ruiz Leza, Cristóbal N. Aguilar, Bioethanol, 2023
David Francisco Lafuente-Rincón, Inty Omar Hernández-De Lira, Héctor Hernández-Escoto, María Alejandra Sánchez-Muñoz, Héctor Hugo Molina Correa, Cristian Emanuel Gámez-Alvarado, Perla Araceli Meléndez-Hernández, Javier Ulises Hernández-Beltrán
Polysaccharide hydrolysis involves at least three different enzymes which are simultaneously working to degrade the polymer to its monomer. Enzymatic hydrolysis of cellulose is performed by cellulases or cellulolytic enzymes that catalyzes the cleavage of β-1,4 glycosidic bonds, present in the insoluble cellulose, to produce glucose. Cellulase enzymes comprise endo-1,4-0-D-glucanases, exo-1,4-0-D-glucanases (cellobiohydrolases) and β-glucosidases. The main reaction mechanism of cellulases is depicted in Figure 9.2. First, endoglucanases start breaking 0-1,4 glycosidic bonds by the addition of a water molecule, releasing cellodextrin with a reducing and a non-reducing end from the amorphous regions of the cellulose backbone. Then, exoglucanases hydrolyzes cellodextrins, from its reducing and a non-reducing end, to produce cellobiose (disaccharide of two glucose units). Finally, 0-glucosidases catalyzes the cleavage of cellobiose producing two soluble monomers of glucose [30–33]. Although enzymes are biological catalysts that perform chemical reactions efficiently, its activity is strongly regulated for different factors as temperature and pH, as well as, adsorption, mixing conditions, and solid-liquid ratio that will be further discussed.
Two β-glucanases from bacterium Cellulomonas flavigena: expression in Pichia pastoris, properties, biotechnological potential
Published in Preparative Biochemistry & Biotechnology, 2023
Alexander Lisov, Oksana Belova, Zoya Lisova, Alexey Nagel, Andrey Shadrin, Zhanna Andreeva-Kovalevskaya, Maxim Nagornykh, Marina Zakharova, Alexey Leontievsky
1,3-1,4-β-glucanase is widely used for biotechnological purposes. The enzyme is used in the brewing industry to reduce the haze and viscosity of brewing mash.[14] Treatment of the mash with 1,3-1,4-β-glucanase reduces its filtration time.[15] The enzyme improves the nutritional quality of animal feed. When exposed to water, β-glucans swell and increase the viscosity of the chime, thus preventing intestinal absorption and the interaction of digestive enzymes with the chime.[16] 1,3-1,4-β-glucanase degrades β-glucans, thus eliminating their negative effects. The enzyme improved the nutritional value of the barley-based feed better than that of endo-1,4-β glucanase.[17] Many oligosaccharides are prebiotics that increases the growth of beneficial intestinal microbiota.[18] High molecular weight beta-glucans as well as oligosaccharides from beta-glucans also increase the growth of beneficial bacteria.[19,20] 1,3-1,4-β-glucanase can be used to produce oligosaccharides as food additives.
Weak base pretreatment on coconut coir fibers for ethanol production using a simultaneous saccharification and fermentation process
Published in Biofuels, 2021
Majid Ebrahimi, Alvin R. Caparanga, Oliver B. Villaflores
In enzymatic hydrolysis, cellulase enzymes of three main types (endo-glucanases, exo-glucanases, and β-glucosidase) are mostly employed to break down polysaccharides into simple sugars. The released fermentable sugars obtained from the hydrolysis process can be quickly converted to bioethanol with the help of microorganisms [3]. Bioethanol production can be conducted by applying various methods, namely separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), simultaneous saccharification and co-fermentation (SSCF) and consolidated biomass processing (CBP), as well as the recent novel technique known as simultaneous saccharification, filtration and fermentation (SSFF) [6]. SSF can be accomplished with gratr benefits compared to SHF. These benefits are lower temperature, smaller quantity of enzyme used, shorter working time, lower sugar inhibition, and consequently higher ethanol yield and lower production costs [2,18].
Production and partial characterization of β-1,3-glucanase obtained from Rhodotorula oryzicola
Published in Preparative Biochemistry & Biotechnology, 2018
Mona Liza Santana, Elinalva Maciel Paulo, José Ailton Bispo, Amanda Reges de Sena, Sandra Aparecida de Assis
β-1,3-glucanases have several applications, such as the use in yeast cell wall lyse as well as in food industry, in the production of beverages such as wine, beer, juices, or as food supplement in animal feed.[41] Some plant-derived endogenous β-1,3-glucanases are denatured within minutes when they are exposed to temperatures in industrial processes (60–75°C). On the other hand, exogenous β-1,3-glucanases have better reacting features due to their greater thermal stability and resistance to acidic medium and they may be used to degrade glucan in cereals or in other industry segments.[42]