Manno‐oligosaccharide preparation by the hydrolysis of konjac flour with a thermostable endo‐mannanase from Talaromyces cellulolyticus

2019 ◽  
Vol 127 (2) ◽  
pp. 520-532 ◽  
Author(s):  
J.‐K. Yang ◽  
Q.‐C. Chen ◽  
B. Zhou ◽  
X.‐J. Wang ◽  
S.‐Q. Liu
Keyword(s):  
Talaromyces Cellulolyticus ◽  
Konjac Flour ◽  
Hydrolysis Of

scholarly journals Research Article Product Composition Analysis and Process Research of Oligosaccharides Produced from Enzymatic Hydrolysis of High-Concentration Konjac Flour

ACS Omega ◽  
2020 ◽  
Vol 5 (5) ◽  
pp. 2480-2487
Author(s):  
Xianghua Tang ◽  
Xuan Zhu ◽  
Yunjuan Yang ◽  
Zhenxiong Qi ◽  
YueLin Mu ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Process Research ◽  
Composition Analysis ◽  
High Concentration ◽  
Research Article ◽  
Product Composition ◽  
Konjac Flour ◽  
Hydrolysis Of

Hydrolysis of Corn Stover by Talaromyces cellulolyticus Enzymes: Evaluation of the Residual Enzymes Activities Through the Process

2019 ◽  
Vol 188 (3) ◽  
pp. 690-705 ◽  
Author(s):  
Federico Liuzzi ◽  
Silvio Mastrolitti ◽  
Isabella De Bari
Keyword(s):  
Corn Stover ◽  
Enzymes Activities ◽  
Talaromyces Cellulolyticus ◽  
Hydrolysis Of

Effect of β-Mannanase and β-Mannosidase Supplementation on the Total Hydrolysis of Softwood Polysaccharides by the Talaromyces cellulolyticus Cellulase System

2015 ◽  
Vol 176 (6) ◽  
pp. 1673-1686 ◽  
Author(s):  
Hiroyuki Inoue ◽  
Shinichi Yano ◽  
Shigeki Sawayama
Keyword(s):  
Talaromyces Cellulolyticus ◽  
Hydrolysis Of

scholarly journals GH30-7 Endoxylanase C from the Filamentous Fungus Talaromyces cellulolyticus

2019 ◽  
Vol 85 (22) ◽  
Author(s):  
Yusuke Nakamichi ◽  
Tatsuya Fujii ◽  
Thierry Fouquet ◽  
Akinori Matsushika ◽  
Hiroyuki Inoue
Keyword(s):  
Glycoside Hydrolase ◽  
Glucuronic Acid ◽  
Catalytic Domain ◽  
Glycoside Hydrolase Family ◽  
Content Type ◽  
Promising Tool ◽  
Talaromyces Cellulolyticus ◽  
Food And Feed ◽  
Cellulose Binding ◽  
Hydrolysis Of

ABSTRACT Glycoside hydrolase family 30 subfamily 7 (GH30-7) enzymes include various types of xylanases, such as glucuronoxylanase, endoxylanase, xylobiohydrolase, and reducing-end xylose-releasing exoxylanase. Here, we characterized the mode of action and gene expression of the GH30-7 endoxylanase from the cellulolytic fungus Talaromyces cellulolyticus (TcXyn30C). TcXyn30C has a modular structure consisting of a GH30-7 catalytic domain and a C-terminal cellulose binding module 1, whose cellulose-binding ability has been confirmed. Sequence alignment of GH30-7 xylanases exhibited that TcXyn30C has a conserved Phe residue at the position corresponding to a conserved Arg residue in GH30-7 glucuronoxylanases, which is required for the recognition of the 4-O-methyl-α-d-glucuronic acid (MeGlcA) substituent. TcXyn30C degraded both glucuronoxylan and arabinoxylan with similar kinetic constants and mainly produced linear xylooligosaccharides (XOSs) with 2 to 3 degrees of polymerization, in an endo manner. Notably, the hydrolysis of glucuronoxylan caused an accumulation of 22-(MeGlcA)-xylobiose (U4m2X). The production of this acidic XOS is likely to proceed via multistep reactions by putative glucuronoxylanase activity that produces 22-(MeGlcA)-XOSs (XnU4m2X, n ≥ 0) in the initial stages of the hydrolysis and by specific release of U4m2X from a mixture containing XnU4m2X. Our results suggest that the unique endoxylanase activity of TcXyn30C may be applicable to the production of linear and acidic XOSs. The gene xyn30C was located adjacent to the putative GH62 arabinofuranosidase gene (abf62C) in the T. cellulolyticus genome. The expression of both genes was induced by cellulose. The results suggest that TcXyn30C may be involved in xylan removal in the hydrolysis of lignocellulose by the T. cellulolyticus cellulolytic system. IMPORTANCE Xylooligosaccharides (XOSs), which are composed of xylose units with a β-1,4 linkage, have recently gained interest as prebiotics in the food and feed industry. Apart from linear XOSs, branched XOSs decorated with a substituent such as methyl glucuronic acid and arabinose also have potential applications. Endoxylanase is a promising tool in producing XOSs from xylan. The structural variety of XOSs generated depends on the substrate specificity of the enzyme as well as the distribution of the substituents in xylan. Thus, the exploration of endoxylanases with novel specificities is expected to be useful in the provision of a series of XOSs. In this study, the endoxylanase TcXyn30C from Talaromyces cellulolyticus was characterized as a unique glycoside hydrolase belonging to the family GH30-7, which specifically releases 22-(4-O-methyl-α-d-glucuronosyl)-xylobiose from hardwood xylan. This study provides new insights into the production of linear and branched XOSs by GH30-7 endoxylanase.

scholarly journals Mode of Action of GH30-7 Reducing-End Xylose-Releasing Exoxylanase A (Xyn30A) from the Filamentous Fungus Talaromyces cellulolyticus

2019 ◽  
Vol 85 (13) ◽  
Author(s):  
Yusuke Nakamichi ◽  
Thierry Fouquet ◽  
Shotaro Ito ◽  
Akinori Matsushika ◽  
Hiroyuki Inoue
Keyword(s):  
Mode Of Action ◽  
Glycoside Hydrolase ◽  
Glycoside Hydrolase Family ◽  
Fungal Enzymes ◽  
Content Type ◽  
Talaromyces Cellulolyticus ◽  
Bacteria And Fungi ◽  
Hydrolysis Of ◽  
Hydrolase Family ◽  
Glycoside Hydrolase Family 30

ABSTRACT In this study, we characterized the mode of action of reducing-end xylose-releasing exoxylanase (Rex), which belongs to the glycoside hydrolase family 30-7 (GH30-7). GH30-7 Rex, isolated from the cellulolytic fungus Talaromyces cellulolyticus (Xyn30A), exists as a dimer. The purified Xyn30A released xylose from linear xylooligosaccharides (XOSs) 3 to 6 xylose units in length with similar kinetic constants. Hydrolysis of branched, borohydride-reduced, and p-nitrophenyl XOSs clarified that Xyn30A possesses a Rex activity. 1H nuclear magnetic resonance (1H NMR) analysis of xylotriose hydrolysate indicated that Xyn30A degraded XOSs via a retaining mechanism and without recognizing an anomeric structure at the reducing end. Hydrolysis of xylan by Xyn30A revealed that the enzyme continuously liberated both xylose and two types of acidic XOSs: 22-(4-O-methyl-α-d-glucuronyl)-xylotriose (MeGlcA2Xyl3) and 22-(MeGlcA)-xylobiose (MeGlcA2Xyl2). These acidic products were also detected during hydrolysis using a mixture of MeGlcA2Xyln (n = 2 to 14) as the substrate. This indicates that Xyn30A can release MeGlcA2Xyln (n = 2 and 3) in an exo manner. Comparison of subsites in Xyn30A and GH30-7 glucuronoxylanase using homology modeling suggested that the binding of the reducing-end residue at subsite +2 was partially prevented by a Gln residue conserved in GH30-7 Rex; additionally, the Arg residue at subsite −2b, which is conserved in glucuronoxylanase, was not found in Xyn30A. Our results lead us to propose that GH30-7 Rex plays a complementary role in hydrolysis of xylan by fungal cellulolytic systems. IMPORTANCE Endo- and exo-type xylanases depolymerize xylan and play crucial roles in the assimilation of xylan in bacteria and fungi. Exoxylanases release xylose from the reducing or nonreducing ends of xylooligosaccharides; this is generated by the activity of endoxylanases. β-Xylosidase, which hydrolyzes xylose residues on the nonreducing end of a substrate, is well studied. However, the function of reducing-end xylose-releasing exoxylanases (Rex), especially in fungal cellulolytic systems, remains unclear. This study revealed the mode of xylan hydrolysis by Rex from the cellulolytic fungus Talaromyces cellulolyticus (Xyn30A), which belongs to the glycoside hydrolase family 30-7 (GH30-7). A conserved residue related to Rex activity is found in the substrate-binding site of Xyn30A. These findings will enhance our understanding of the function of GH30-7 Rex in the cooperative hydrolysis of xylan by fungal enzymes.

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

Lattice imaging and pore structure of β ferric oxyhydroxide

1978 ◽  
Vol 36 (1) ◽  
pp. 264-265
Author(s):  
T. Baird ◽  
J.R. Fryer ◽  
S.T. Galbraith
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bulk Material ◽  
Model Structure ◽  
Bulk Crystals ◽  
Lattice Imaging ◽  
Thin Sections ◽  
Ferric Oxyhydroxide ◽  
Resolution Electron ◽  
Hydrolysis Of

Introduction Previously we had suggested (l) that the striations observed in the pod shaped crystals of β FeOOH were an artefact of imaging in the electron microscope. Contrary to this adsorption measurements on bulk material had indicated the presence of some porosity and Gallagher (2) had proposed a model structure - based on the hollandite structure - showing the hollandite rods forming the sides of 30Å pores running the length of the crystal. Low resolution electron microscopy by Watson (3) on sectioned crystals embedded in methylmethacrylate had tended to support the existence of such pores.We have applied modern high resolution techniques to the bulk crystals and thin sections of them without confirming these earlier postulatesExperimental β FeOOH was prepared by room temperature hydrolysis of 0.01M solutions of FeCl3.6H2O, The precipitate was washed, dried in air, and embedded in Scandiplast resin. The sections were out on an LKB III Ultramicrotome to a thickness of about 500Å.

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