Cellulases are o- glycosyl hydrolases (GHs) that hydrolyse β-1,4 glucosidic bonds in cellulose. Cellulase system is grouped into “glycoside hydrolases (GH) family” classified by different means, according to their substrate specifities, reaction, mechanisms or structural similarities. The cellulase complex is found to contain three basic components which may be present either as single polypeptide or can be grouped together into multienzyme complex known as cellulosome. Cellulase system is composed of three main classes based on their activity toward a wide range of substrates. This is rather difficult, since the enzymes have overlapping specificities toward substrates which themselves are poorly defined. The three main classes are:
a) Endoglucanases (endo-1, 4- β- glucanases or 1, 4- β-D-glucan 4-glucanohydrolases EC 3.2.1.4) hydrolyze cellulose chains at random positions in less crystal regions, to generate principally short chain oligosaccharides producing free ends with a rapid change in degree of polymerization. The substrates are amorphous cellulose, such as carboxymethylcellulose, H3PO4 or alkali-swollen cellulose, instead of crystalline cellulose.
b) Exoglucanases or cellobiohydrolases (exo-1, 4- β- glucanases or 1, 4- β-D glucan cellobiohydrolases EC 3.2.1.19) produce cellobiose by attacking free chain ends. They are thought to work processively, that is, one enzyme molecule can release several cellobiose units from the cellulose chain without leaving the substrate.
c) β- glucosidases or cellobiases (β- D glucoside glucohydrolases, EC 3.2.1.21)are very important components of the cellulase system in that they complete the hydrolysis to glucose of short-chain oligosaccharides and cellobiose which are released by the ot...
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...id, acetic acid, formic acid, H₂ and CO₂ as fermentation products which increases ecological, industrial and basic bioenergetics interests in this particularly thermophilic bacterial specie.
Thermophiles produce number of enzymes e.g. cellulases, xylanases, mannases etc which have many applications in various industrial processes including food, detergents, textile, paper, tanneries and biorefining sectors. However, usage of cellulases in industries faces a major setback due to high production cost and low enzymatic activity. This has encouraged investigation of novel cellulase from thermophiles with minimum cost and improved activity.
With the aim of prospecting for new cellulolytic enzymes more suitable for industrial needs, we described here the cloning and high level expression of the novel β-glucosidase BglB, of Clostridium thermocellum in Escherichia coli.
Purpose: The purpose of this lab is to explore the different factors which effect enzyme activity and the rates of reaction, such as particle size and temperature.
Cytosolic β-Glucosidase (hCBG) is a xenobiotic-metabolizing enzyme that hydrolyses certain flavonoid glucosides. This type of enzymes play a role in the metabolic detoxification, with a series of enzymatic reactions that neutralize and solubilize toxins, and then transport them to secretory organs. Flavonoid glusocides is a family of molecules in which a sugar is bound to another functional group by a glycosidic bond, and play numerous roles in living organisms, mainly in plants.
Abstract: Using Ion Exchange Chromatography, cellulase was purified. After purification, it was analyzed using a DNS test. The purified protein did not respond to the DNS the way it was expected to.
Gut microbiota plays an important role in human metabolism. The important sources of energy for human and microbial cells are carbohydrates. Most complex carbohydrates and plant polysaccharides, such as cellulose, xylans, resistance starch and inulin cannot be digested by the human enzymes. The gut micro...
Despite of general properties of enzymes, the properties also varies from where it comes from and how it been produced. For instance, the enzymatic saccharification method in lignocellulosic bioethanol is generated by hydrolyzing cellulose and hemicelluloses. This method gets high attention because of its higher theoretical yield compared to other methods (Taneda et al., 2012). Acremonium cellulolyticus with high activities of cellulase, amylase and pectinase enzymes allow it for the easy separation of solids/liquids in potato pulp, resulting in high saccharification efficiency and a high recovery rate of products (Gao et al., 2014). On the other hand, Enzyme-modified carboxymethyl starch (ECMS) is beneficial in enhancing water holding capacity, emulsion stability and improving sensory characteristics of sausages with a declined fat content (Luo and Xu, 2011). Lipases and phospholipases of dormant cotton seeds have stability in heat, various media and nature of the hydrolysis of the lipids properties (Rakhi...
By taking a Carbon Dioxide, rich substance and mixing it with a yeast, solution fermentation will occur, and then it could be determined if it is a good energy-producer. In this study glacatose, sucrose, glycine, glucose, and water were used to indicate how fast fermentation occurred. The overall result shows that monosaccharides in particular galactose and glucose were the best energy source for a cell.
Lactulose is a synthetic disaccharide which is composed of one molecule of galactose and one molecule of fructose linked by a β1→4 glycosidic bond (2). Because lactulose is not naturally occurring, lactose, which consists of glucose and galactose, is often used as the precursor molecule for lactulose production. In order to produce lactulose from lactose, isomerization of lactose must occur in which the galactose subunit is removed from lactose and joined to a molecule of fructose. Isomerization of lactose can be accomplished using chemical or enzymatic methods. Chemical methods employ an alkaline catalyst, such as sodium hydroxide or potassium hydroxide, in combination with a complexing agent, such as borate or aluminate, that will attach to lactulose and precipitate as an insoluble complex from the reaction system, thus shifting chemical equilibrium in favor of the formation of the lactulose product; lactulose synthesis by this method can result in up to 80% yield of lactulose. Enzymatic methods accomplish isomerization of lactose via transgalactosylation using β-galactosidases, which hydrolyze the β1→4 glycosidic bond of lactose. In the presence of fructose, the galactose subunit of lactose is ideally added to the hydroxyl group of the four prime carbon of fructose to form lactulose. However, the addition of galactose to fructose is not restricted to the four prime carbon because fructose contains other hydroxyl groups on multiple carbon atoms; therefore, enzymatic isomerization of lactose can yield various constitutional isomers of lactulose containing β1→1 or β1→6 glycosidic bonds (3).
Ethanol can be made from many different plant sugars including starch and cellulose. Starch ethanol is the most common biofuel used in the world. It is made from kernels of corn, which is very easy to break down. This means that corn is very easily converted into ethanol. On the other hand, cellulose is not easily broken down into ethanol. Cellulose is found in the cell walls of plants, and resembles plant armor. The cellulose combines with lignin, which makes plants woody. During the process of making ethanol from cellulose, the lignin has to be separated from the cellulose because it is not fermentable. Figure 1 shows the complications of making cellulosic ethanol vs. other biofuels. The question marks indicate where the technology hasn’t
Pectin is a complicated branched structure of acidic structural polysaccharides, established in fruits and bast fibers. Most of the structure consists of homopolymeric partially methylated poly-α-(1-4)-D-galacturonic acid residues, but there are substantial 'hairy' non-gelling areas of alternating α-(1-2)-L-rhamnosyl-α-(1-4)-Dgalacturonosyl sections containing branch-points with mostly neutral side chains (1-20 residues) of mainly L-arabinose and D-galactose (rhamnogalacturonan-I). Pectin is the most hydrophilic compound in plant fibres due to the carboxylic acid groups and is easily degraded by defibration with fungi [27]. Pectin along with lignin and hemicelluloses present in natural fibres can be hydrolysed at elevated temperatures.
Science shows that enzymes work on raw material. Fruit, cereal, milk, beer or wood are some typical products for enzymatic conversion. Enzymes are specific, they usually break down or synthesize one particular compound, and in some cases enzymes limit their actions to specific bonds in the compound with in which they react. An example gluconases is one of the many enzymes used in beer brewing. This enzyme is used in industrial applications of brewing beer and is a very efficient catalyst. It breaks down the wheat and converts the carbohydrates into sugars that speed up the reaction in the aspect of the beer’s fermentation.
present at all times but it must retain some of them. All plant life on Earth benefits from the ability of water to make a hydrogen bond with another substance of similar electronegative charge. Cellulose, the substance that makes up cell walls and paper products, is a hydrophilic substance ("water-loving"). It interacts with water but, unlike other hydrophilic substances, it will not dissolve in it. Cellulose can form strong hydrogen bonds with water molecules. This explains why a paper towel will "wick" water upwards when it comes in contact with it.
Some of the characteristics of Nata de coco are chewy, translucent, jelly-like and it is an indigenous dessert. On top of that, Nata de coco is most commonly sweetened as a candy or dessert, and can accompany many things including pickles, drinks, ice cream, puddings and fruit mixes. It is produced by the bacterial fermentation of coconut water. Nata de coco is produced by the fermentation of coconut water or coconut milk, which gels through the production of microbial cellulose by Acetobacter xylinus. Acetobacter xylinum is the most efficient and widely used cellulose-producing bacterium in fermenting the coconut water to produce the nata de coco. Chemical purities are one of the most important features of microbial cellulose, which distinguishes it from that of plants and is usually associated with hemicelluloses and lignin. Interesting properties of microbial cellulose allow nata de coco to con...
After 30 minutes, another 5 ml of acetic acid was added, followed by 1.5 g of NaClO2the following 30 minutes. These steps were repeated until a total of 6 g of NaClO2 was added. The mixture was heated for a further 30 minutes after the final sodium chlorite addition. The suspension was then cooled in an ice bath before being filtered using sintered glass crucible and rinsed with cold distilled water. A final wash was carried out using acetone. The crucible with holocellulose was air dried in an air-conditioned room until constant weight was achieved for further alpha-cellulose analysis. For hemicellulose determination, the oven-dry weight of cellulose was used for
During my undergraduate research project, I had the opportunity to work under the supervision of Prof. Dr. Mozammel Hoq, My research project focused on the production of cellulase by Trichoderma spp. using submerged fermentation technique at a renowned institution ,Bangladesh Council for Scientific and Industrial Research (BCSIR). Cellulase enzyme has practical application in textile industries. This research experience intensified my interest for pursuing higher education in related fields . After my successful undergraduate research work, I became fascinated by the power of microbes, and the fact t...
...on pathways/kinetics of soluble carbohydrate and proteins when used as a sole electron donor or in mixture i.e., 100% carbohydrate, 100% protein, 50%:50% carbohydrate:protein,75%:25% carbohydrate:protein, and 25%:75% carbohydrate:protein. In order to achieve the objective, I will use different advanced analytical tools, such as (i) microbial ecology tool (such as pyrosequencing, quantitative polymerase chain reaction, and clone library), (ii) electrochemical analyses tools (such as cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy, and chronoamperometry), and (iii) chemical analyses tools (such as high-performance liquid chromatography, gas chromatography, ion chromatography, and chemical oxygen demand measurements) to predict the pathways of organic wastes fermentation as well as studying the hydrolysis and fermentation kinetics