scholarly journals Substrate specificity and mode of action of the cellulases from the thermophilic fungus Thermoascus aurantiacus

1981 ◽  
Vol 193 (1) ◽  
pp. 67-74 ◽  
Author(s):  
M G Shepherd ◽  
C C Tong ◽  
A L Cole
Keyword(s):  
Filter Paper ◽  
Mode Of Action ◽  
Carboxymethyl Cellulose ◽  
Xylanase Activity ◽  
Rapid Decrease ◽  
Thermoascus Aurantiacus ◽  
Inherent Feature ◽  
Rate Of Hydrolysis ◽  
Beta Glucosidase ◽  
Cellulose Filter

The substrate specificities of three cellulases and a beta-glucosidase purified from Thermoascus aurantiacus were examined. All three cellulases partially degraded native cellulose. Cellulase I, but not cellulase II and cellulase III, readily hydrolyzed the mixed beta-1,3; beta-1,6-polysaccharides such as carboxymethyl-pachyman, yeast glucan and laminarin. Both cellulase I and the beta-glucosidase degraded xylan, and it is proposed that the xylanase activity is an inherent feature of these two enzymes. Lichenin (beta-1,4; beta-1,3) was degraded by all three cellulases. Cellulase II cannot degrade carboxymethyl-cellulose, and with filter paper as substrate the end product was cellobiose, which indicates that cellulase II is an exo-beta-1,4-glucan cellobiosylhydrolase. Degradation of cellulose (filter paper) can be catalysed independently by each of the three cellulases; there was no synergistic effect between any of the cellulases, and cellobiose was the principal product of degradation. The mode of action of one cellulase (cellulase III) was examined by using reduced cellulodextrins. The central linkages of the cellulodextrins were the preferred points of cleavage, which, with the rapid decrease in viscosity of carboxymethyl-cellulose, confirmed that cellulase III was an endocellulase. The rate of hydrolysis increased with chain length of the reduced cellulodextrins, and these kinetic data indicated that the specificity region of cellulase III was five or six glucose units in length.

INHIBITION OF FUNGAL GROWTH BY BACTERIA DURING CELLULOSE-DECOMPOSITION

1961 ◽  
Vol 7 (6) ◽  
pp. 857-863 ◽  
Author(s):  
Y. Henis ◽  
Paulina Keller ◽  
A. Keynan
Keyword(s):  
Bacterial Growth ◽  
Filter Paper ◽  
Vegetative Growth ◽  
Pure Culture ◽  
Carboxymethyl Cellulose ◽  
Agar Medium ◽  
Fungal Growth ◽  
Fungal Development ◽  
Cellulose Decomposition ◽  
Cellulose Filter

The cellulose-decomposing flora developing from soil crumbs on filter paper placed upon an agar medium was studied. Under these conditions fungal development was significantly inhibited by bacterial growth. When cellophane was substituted for filter paper, no inhibition of fungal growth was observed. A pure culture of Cellvibrio inhibited the vegetative growth of Stachybotrys when inoculated simultaneously on media containing carboxymethyl-cellulose, filter paper, or glucose up to 0.1%. This inhibition was shown to be caused by competition for available carbohydrates.

scholarly journals Purification and properties of the cellulases from the thermophilic fungus Thermoascus aurantiacus

1980 ◽  
Vol 191 (1) ◽  
pp. 83-94 ◽  
Author(s):  
C C Tong ◽  
A L Cole ◽  
M G Shepherd
Keyword(s):  
Culture Filtrate ◽  
Filter Paper ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Thermophilic Fungus ◽  
Thermoascus Aurantiacus ◽  
Purification And Properties ◽  
Beta Glucosidase ◽  
Carbohydrate Contents

Three cellulases and a beta-glucosidase were purified from the culture filtrate of the thermophilic fungus Thermoascus aurantiacus. The isolated enzymes were all homogeneous on polyacrylamide-disc-gel electrophoresis. Data from chromatography on Bio-Gel P-60 and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis indicated mol.wts. of 87000 (beta-glucosidase), 78000 (cellulase I), 49000 (cellulase II) and 34000 (cellulase III); the carbohydrate contents of the enzymes were 33.0, 5.5, 2.6 and 1.8% (w/w) respectively. Although the three purified cellulases were active towards filter paper, only cellulases I and III were active towards CM(carboxymethyl)-cellulose. Cellulase I was also active towards yeast glucan. The Km and catalytic-centre-activity values for the enzymes were as follows; 0.52 mumol/ml and 6.5 × 10(4) for beta-glucosidase on p-nitrophenyl beta-D-glucoside, 3.9 mg/ml and 6.3 for cellulase I on CM-cellulose, 1.2 mg/ml and 1.1 for cellulase I on yeast glucan, 35.5 mg/ml and 0.34 for cellulase II on filter paper, and 1.9 mg/ml and 33 for cellulase III on CM-cellulose.

scholarly journals Well-Dispersed Silver Nanoparticles on Cellulose Filter Paper for Bacterial Removal

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 595
Author(s):  
Hsiu-Wen Chien ◽  
Ming-Yen Tsai ◽  
Chia-Jung Kuo ◽  
Ching-Lo Lin
Keyword(s):  
Silver Nanoparticles ◽  
Filter Paper ◽  
X Ray Diffraction ◽  
Bacterial Reduction ◽  
Treatment Technology ◽  
Bacterial Removal ◽  
Contaminated Drinking Water ◽  
Gravity Driven ◽  
Filter Papers ◽  
Cellulose Filter

In this study, a polydopamine (PDA) and polyethyleneimine (PEI)-assisted approach was developed to generate well-distributed PDA/PEI/silver (PDA/PEI/Ag) nanocomplexes on the surfaces of commercial cellulose filter papers to achieve substantial bacterial reduction under gravity-driven filtration. PDA can bind to cellulose paper and act as a reducer to produce silver nanoparticles (AgNPs), while PEI can react with oxidative dopamine and act as a dispersant to avoid the aggregation of AgNPs. The successful immobilization of PDA/PEI/Ag nanocomplexes was confirmed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were used as pathogen models to test the efficacy of the PDA/PEI/Ag nanocomplex-incorporated filter papers. The PDA/PEI/Ag nanocomplex-incorporated filter papers provided a substantial bacterial removal of up to 99% by simple gravity filtration. This work may be useful to develop a feasible industrial production process for the integration of biocidal AgNPs into cellulose filter paper and is recommended as a local-condition water-treatment technology to treat microbial-contaminated drinking water.

scholarly journals Robust immobilization of anionic silver nanoparticles on cellulose filter paper toward a low-cost point-of-use water disinfection system with improved anti-biofouling properties

RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 4873-4882
Author(s):  
Gongyan Liu ◽  
Ruiquan Yu ◽  
Jing Jiang ◽  
Zhuang Ding ◽  
Jing Ma ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Filter Paper ◽  
Low Cost ◽  
Water Disinfection ◽  
Point Of Use ◽  
Cellulose Filter

Point-of-use water disinfection by GA@AgNPs-LA-FP.

Imidazolium functionalized cellulose filter paper derived from waste newspaper and its application in removal of chromium(VI)

2020 ◽  
Vol 157 ◽  
pp. 104776
Author(s):  
Wenqi Song ◽  
Miaoxiu Yang ◽  
Yuzhen Zhao ◽  
Min Zhu ◽  
Yanfang Zhu ◽  
...  
Keyword(s):  
Filter Paper ◽  
Chromium Vi ◽  
Cellulose Filter

scholarly journals Influence of Me2SO and incubation time on papain activity studied using fluorogenic substrates.

2001 ◽  
Vol 48 (4) ◽  
pp. 995-1002 ◽  
Author(s):  
M Szabelski ◽  
K Stachowiak ◽  
W Wiczk
Keyword(s):  
Incubation Time ◽  
Active Sites ◽  
Initial Rate ◽  
Substrate Binding ◽  
Rapid Decrease ◽  
Fluorogenic Substrates ◽  
Binding Process ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

Papain activity in a buffer containing Me2SO was studied using fluorogenic substrates. It was found that the number of active sites of papain decreases with increasing Me2SO concentration whereas the incubation time, in a buffer containing 3% Me2SO does not affect the number of active sites. However, an increase of papain incubation time in the buffer with 3% Me2SO decreased the initial rate of hydrolysis of Z-Phe-Arg-Amc as well as Dabcyl-Lys-Phe-Gly-Gly-Ala-Ala-Edans. Moreover, an increase of Me2SO concentration in working buffer decreased the initial rate of papain-catalysed hydrolysis of both substrates. A rapid decrease of the initial rate (by up to 30%) was observed between 1 and 2% Me2SO. Application of the Michaelis-Menten equation revealed that at the higher Me2SO concentrations the apparent values of k(cat)/Km decreased as a result of Km increase and kcat decrease. However, Me2SO changed the substrate binding process more effectively (Km) than the rate of catalysis k(cat).

scholarly journals Fibrous porous carbon electrocatalysts for hydrazine oxidation by using cellulose filter paper as precursor and self-template

Carbon ◽  
2016 ◽  
Vol 102 ◽  
pp. 97-105 ◽  
Author(s):  
Alessandro C. Martins ◽  
Xiaoxi Huang ◽  
Anandarup Goswami ◽  
Katherine Koh ◽  
Yuying Meng ◽  
...  
Keyword(s):  
Filter Paper ◽  
Porous Carbon ◽  
Hydrazine Oxidation ◽  
Cellulose Filter

scholarly journals Phenyl carbamate functionalized zinc oxide nanorods for paper-based thin film microextraction

RSC Advances ◽  
2017 ◽  
Vol 7 (79) ◽  
pp. 50210-50215 ◽  
Author(s):  
Mohammad Saraji ◽  
Narges Mehrafza
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Filter Paper ◽  
Low Cost ◽  
Zinc Oxide Nanorods ◽  
Oxide Nanorods ◽  
Cellulose Filter

In this work, phenyl carbamate functionalized zinc oxide nanorods were fabricated on a cellulose filter paper and employed as a novel and low cost sorbent in a thin film microextraction (TFME) technique.

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