Production of Extracellular Water-Soluble Polysaccharides and Hydrolytic Enzymes

2021 ◽  
Vol 26 (4) ◽  
pp. 153-160
Author(s):  
Woo-Jin Jung ◽  
Yong-Su Song
Keyword(s):  
Hydrolytic Enzymes ◽  
Water Soluble ◽  
Extracellular Water

Stabilisation and mineralisation of sludge in reed bed systems after 10–20 years of operation

2013 ◽  
Vol 69 (3) ◽  
pp. 539-545 ◽  
Author(s):  
Steen Nielsen ◽  
Eleonora Peruzzi ◽  
Cristina Macci ◽  
Serena Doni ◽  
Grazia Masciandaro
Keyword(s):  
Organic Matter ◽  
Extracellular Enzymes ◽  
Wastewater Treatment Plants ◽  
Hydrolytic Enzymes ◽  
Biochemical Properties ◽  
Water Soluble ◽  
Biochemical Processes ◽  
C And N ◽  
Reed Bed ◽  
Urban Wastewater Treatment

Sludge stabilisation and mineralisation during periods of operation between 10 and 21 years were investigated in three different systems receiving sludge from urban wastewater treatment plants situated in Denmark. Samples were taken along the entire profiles, in order to compare the effectiveness of the sludge stabilisation process. Particular attention was given to the stabilisation process occurring within the reed beds; in fact, parameters correlated to biochemical properties of organic sludge matter were determined. Statistical procedures were used to evaluate how the biochemical processes influence the quality of sludge organic matter. The level of total organic carbon and total nitrogen had a similar trend along the profile: their concentration decreased with increasing depth, reaching very low levels at the deepest layers. The same trend was also observed for the water-soluble carbon, N-NH3, β-glucosidase and urease activities, and hydrolytic enzymes linked to C and N cycles: their values decreased dramatically with increasing depth, meaning that the level of mineralisation of the organic matter was higher in the deepest layers. The determination of extracellular enzymes bound to humic substances and humic carbon permitted evaluation of the stabilisation of organic sludge matter, and also allowed individuation of the ways in which the sludge was stabilised, in terms of mineralisation and humification of the organic matter.

scholarly journals Assimilation of Cellooligosaccharides by a Cell Surface-Engineered Yeast Expressing β-Glucosidase and Carboxymethylcellulase from Aspergillus aculeatus

1998 ◽  
Vol 64 (12) ◽  
pp. 4857-4861 ◽  
Author(s):  
Toshiyuki Murai ◽  
Mitsuyoshi Ueda ◽  
Takashi Kawaguchi ◽  
Motoo Arai ◽  
Atsuo Tanaka
Keyword(s):  
Cell Surface ◽  
Rhizopus Oryzae ◽  
Signal Sequence ◽  
Hydrolytic Enzymes ◽  
Water Soluble ◽  
Aspergillus Aculeatus ◽  
Cellulosic Materials ◽  
Secretion Signal ◽  
Engineered Yeast ◽  
Secretion Signal Sequence

ABSTRACT Since Saccharomyces cerevisiae lacks the cellulase complexes that hydrolyze cellulosic materials, which are abundant in the world, two types of hydrolytic enzymes involved in the degradation of cellulosic materials to glucose were genetically co-immobilized on its cell surface for direct utilization of cellulosic materials, one of the final goals of our studies. The genes encoding FI-carboxymethylcellulase (CMCase) and β-glucosidase from the fungusAspergillus aculeatus were individually fused with the gene encoding the C-terminal half (320 amino acid residues from the C terminus) of yeast α-agglutinin and introduced into S. cerevisiae. The delivery of CMCase and β-glucosidase to the cell surface was carried out by the secretion signal sequence of the native signal sequence of CMCase and by the secretion signal sequence of glucoamylase from Rhizopus oryzae for β-glucosidase, respectively. The genes were expressed by the glyceraldehyde-3-phosphate dehydrogenase promoter from S. cerevisiae. The CMCase and β-glucosidase activities were detected in the cell pellet fraction, not in the culture supernatant. The display of CMCase and β-glucosidase proteins on the cell surface was confirmed by immunofluorescence microscopy. The cells displaying these cellulases could grow on cellobiose or water-soluble cellooligosaccharides as the sole carbon source. The degradation and assimilation of cellooligosaccharides were confirmed by thin-layer chromatography. This result showed that the cell surface-engineered yeast with these enzymes can be endowed with the ability to assimilate cellooligosaccharides. This is the first step in the assimilation of cellulosic materials by S. cerevisiae expressing heterologous cellulase genes.

scholarly journals Dynamic Production of Soluble Extracellular Polysaccharides byStreptococcus mutans

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Eva-Maria Decker ◽  
Ilka Dietrich ◽  
Christian Klein ◽  
Christiane von Ohle
Keyword(s):  
Streptococcus Mutans ◽  
Concanavalin A ◽  
Water Soluble ◽  
Extracellular Polysaccharides ◽  
Extracellular Water ◽  
Enzyme Substrate ◽  
Insoluble Polymers ◽  
Dynamic Production

Caries development in the presence ofStreptococcus mutansis associated not only with the production of extracellular water-insoluble polymers but also is based on water-soluble polysaccharides. The aim of this study was the evaluation of a novel glucan-specific Lectin assay for monitoring water-soluble EPS produced byS. mutansduring several growth periods in different media.S. mutanscultures were grown for 24 h, 48 h, and 144 h in medium deficient of sucrose (A) and medium supplemented with 5% sucrose (B). Microtiter well plates were coated with cell-free supernatants followed by the addition of labeled Concanavalin-A and enzyme substrate. The substrate reactions were kinetically detected at 405 nm. The validation of the assay was performed using carbohydrates dextran, xanthan, and sucrose as reference. This new Concanavalin-A-based assay showed the highest sensitivity for dextran and revealed that the glucan production ofS. mutansreached its maximum at 144 h in medium B according to bacterial maturation.

The concentration of soluble polysaccharides in the rumen contents of sheep fed on hay

1970 ◽  
Vol 75 (3) ◽  
pp. 471-478 ◽  
Author(s):  
P. N. Hobson ◽  
J. K. Thompson
Keyword(s):  
Small Proportion ◽  
Water Soluble ◽  
Hot Water ◽  
Acetate Buffer ◽  
Extracellular Water ◽  
Water Fraction ◽  
Iodine Staining ◽  
Feeding Regimes ◽  
Ad Libitum

SUMMARYOn the feeding regimes examined, i.e. hay ad libitum restricted hay and restricted hay with supplementary glucose, the quantities of extracellular water-soluble polysaccharides in rumen liquor were small (3·6–9·0 mg/100 ml) and could have originated from the diet or the saliva as well as from microbes. The polysaccharides extracted with hot water (fraction B) and acetate buffer (fraction C) were also small in amount in the rumen liquor from sheep on any of these diets (less than 56 mg/100 ml) and were composed of rhamnose—containing polysaccharides, starch-like polysaccharides and xylose polymers. Syntheses of these B and C polysaccharides were found with the hay and glucose diet but the quantities involved were small (12·27 mg/100 ml rumen liquor). Degradation of the polysaccharides occurred at 4–6 h after feeding. The consistently high ratios of rhamnose to hexose in the B and C polysaccharides from rumen liquor suggest that these were microbial in origin. Iodine-staining organisms in the rumen liquor were a small proportion of the total and showed no increases after feeding.

scholarly journals Fractionation of Cynara cardunculus L. by Acidified Organosolv Treatment for the Extraction of Highly Digestible Cellulose and Technical Lignin

2021 ◽  
Vol 13 (16) ◽  
pp. 8714
Author(s):  
Tommaso Giannoni ◽  
Mattia Gelosia ◽  
Alessandro Bertini ◽  
Giacomo Fabbrizi ◽  
Andrea Nicolini ◽  
...  
Keyword(s):  
Lignin Content ◽  
Hydrolytic Enzymes ◽  
Water Soluble ◽  
Cellulolytic Enzymes ◽  
Cellulose Content ◽  
Water Mixture ◽  
Cynara Cardunculus ◽  
Cellulose Pulp ◽  
Lignocellulosic Feedstock ◽  
Technical Lignin

One of the primary targets for the new lignocellulosic feedstock-based biorefinery is the simultaneous valorization of holocellulose and lignin. Acidified organosolv treatment is among the most promising strategy for recovering technical lignin, water-soluble hemicellulose, and cellulose pulp with increased accessibility to hydrolytic enzymes. In this work, a design-of-experiment (DoE) approach was used to increase the cellulose recovery, digestibility, and the delignification of Cynara cardunculus L. feedstock. In the first treatment, the milled biomass was subjected to microwave-assisted extraction using an acidified GVL/water mixture to separate lignin and hemicellulose from cellulose. In the second treatment, the cellulose pulp was hydrolyzed by cellulolytic enzymes to demonstrate the enhanced digestibility. At the optimal condition (154 °C, 2.24% H2SO4, and 0.62 GVL/water ratio), the cellulose pulp showed a cellulose content of 87.59%, while the lignin content was lower than 8%. The cellulose recovery and digestibility were equal to 79.46% and 86.94%, respectively. About 40% of the initial hemicellulose was recovered as monosaccharides. This study demonstrated the effectiveness of the two-step organosolv treatment for biomass fractionation; however, as suggested by DoE analysis, a confirmative study at a low temperature (<154 °C) should be performed to further increase the cellulose recovery.

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