Hydrolysis of sunflower seed meal lignocellulosic fraction by free and immobilized cellulases

Lignocellulosic biomass is widely abundant in nature and recognized aspotential renewable energy source. Its efficient transformation into bio-basedfuels is enabled only after adequate pretreatment, followed by enzymaticsacharification and microbial fermentation. Hereby we present application of twocellulase preparations – from Aspergillus niger and Trichoderma reesei (Celluclast®)in treating sunflower seed meal lignocellulosic fraction (SSMLF). Temperature andpH optimums of two enzymes were determined – 52 °C and pH4.8 for A. nigercellulase and 55 °C and pH4.5 for Celluclast®. At optimized conditions, milledSSMLF was hydrolyzed by both biocatalysts. With A. niger cellulase higher initialreaction rates were accomplished and yield of 70 mM glucose equivalent wasobtained with 6 % (w/v) of enzyme after 6 hours. On the other hand, applicationof Celluclast® led to lower initial reaction rates and yielded 25 mM of glucoseequivalent with 10 % (v/v) of enzyme. To ensure cost-effective application ofA. niger cellulase, the possibility of its immobilization on different supports wasinvestigated. By using porous methacrylate-based carrier with C6 spacer arm andprimary amino groups – LifetechTM ECR8409, preparation with highest activity wasproduced. This preparation was successfully applied in saccharification of SSMLFand showed unchanged catalytic efficiency comparing to free enzyme.

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Immobilization of Aspergillus Niger cellulase onto Lifetech TM carriers and its application in the hydrolysis of sunflower seed meal lignocellulosic fraction

Food and Feed Research ◽

10.5937/ffr1902161c ◽

2019 ◽

Vol 46 (2) ◽

pp. 161-169

Author(s):

Marija Ćorović ◽

Milica Simović ◽

Ana Milivojević ◽

Katarina Banjanac ◽

Katarina Katić ◽

...

Keyword(s):

Aspergillus Niger ◽

Sunflower Seed ◽

Seed Meal ◽

Hydrolysis Of

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KINETIC STUDIES ON THE HYDROLYSIS OF BENZOYLCHOLINE BY HUMAN SERUM CHOLINESTERASE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y56-068 ◽

1956 ◽

Vol 34 (1) ◽

pp. 637-653 ◽

Cited By ~ 6

Author(s):

W. Kalow ◽

K. Genest ◽

N. Staron

Keyword(s):

Kinetic Studies ◽

Reaction Rates ◽

Serum Cholinesterase ◽

Initial Reaction ◽

Ultraviolet Spectrophotometry ◽

First Order ◽

Low Concentrations ◽

Kinetics Of ◽

Hydrolysis Of ◽

Substrate Concentrations

Benzoylcholine stands out from other known substrates of serum cholinesterase because of its high apparent affinity for this enzyme combined with a rapid rate of destruction. The reaction kinetics of the hydrolysis of benzoylcholine can be studied by ultraviolet spectrophotometry, since the absorbance decreases in proportion to the concentration of substrate. Kinetic data obtained by measuring initial reaction rates, and by analyzing continuous hydrolysis curves, are the same within the range of experimental error. The enzymatic data are compatible with the assumption that in the presence of high substrate concentrations a complex consisting of esterase and two substrate molecules is formed. This complex is hydrolyzed more slowly than the complex containing one molecule of substrate which is formed at low concentrations of benzoylcholine. Alkaline hydrolysis of benzoylcholine follows the kinetics of a first order reaction.

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Kinetics of individual steps in reaction network ethanol-diethyl ether-ethylene-water on alumina

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19860763 ◽

1986 ◽

Vol 51 (4) ◽

pp. 763-773 ◽

Cited By ~ 6

Author(s):

Vladimír Morávek ◽

Miloš Kraus

Keyword(s):

Diethyl Ether ◽

Reaction Network ◽

Reaction Rates ◽

Rate Equations ◽

Initial Reaction ◽

Ethanol Dehydration ◽

Partial Pressures ◽

Type Rate ◽

Kinetics Of ◽

Hydrolysis Of

The rates of single reactions have been measured at 250 °C in the complex reaction of ethanol dehydration to ethylene and to diethyl ether involving also hydrolysis of the ether, its disproportionation to ethanol and ethylene and its dehydration to ethylene. The found dependences of the initial reaction rates on partial pressures of the reactants were correlated by semiempirical Langmuir-Hinshelwood type rate equations.

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Effects of Some Alkali and Alkaline Earth Metal Ions on the Initial Reaction Rates of Congregibacter litoralis KT71 β-lactamase Hydrolysis of 4-Nitrophenyl Myristate

Asian Journal of Research in Biochemistry ◽

10.9734/ajrb/2021/v9i330202 ◽

2021 ◽

pp. 23-29

Author(s):

O. M. Iniaghe ◽

O. Ibukun

Keyword(s):

Enzyme Activity ◽

Metal Ions ◽

Alkaline Earth ◽

Earth Metal ◽

Reaction Rates ◽

Alkaline Earth Metal ◽

Alkali Metal Ions ◽

Initial Reaction ◽

Alkaline Earth Metal Ions ◽

Hydrolysis Of

The effects of some alkali metal ions (Na+ and K+) and alkaline earth metal ions (Mg 2+ and Ba2+) on the initial reaction rates of Congregibacter litoralis KT71 β-lactamase hydrolysis of 4-nitrophenyl myristate was investigated by varying the concentrations of the metal ions in the assay mixture which comprised of 100 µl of standard enzyme solution, 200 µl of varying concentration of metal ions, 500 µl of 50 mM sodium phosphate buffer pH 7.5 and 200 µl of 4-nitrophenyl myristate (substrate) which was added last to the assay mixture after an incubation time of 10 minutes at 44 oC. The enzyme activity was measured spectrophotometrically using a UV-780 recording spectrophotometer at a wavelength of 405 nm. The hydrolysis of 4-nitrophenyl myristate to yield 4-nitrophenol was monitored by reading the absorbance at 25 minutes. Results showed that the alkaline earth metal ions (Ba2+ and Mg2+) had higher enzyme activation effect than the alkali metal ions (K+ and Na+) Also, all metal ions except Mg2+ showed enzyme stimulatory effect at low concentrations (<2 mM) but inhibitory at higher ion concentrations (2 mM - 3 mM). Mg 2+ caused a proportionate decrease in enzyme activity from its peak (when metal ion concentration was lowest). Results from this research is of great significance to the industrialist especially where the search for novel lipases with unique characteristics suitable for the industries are inevitable.

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KINETIC STUDIES ON THE HYDROLYSIS OF BENZOYLCHOLINE BY HUMAN SERUM CHOLINESTERASE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o56-068 ◽

1956 ◽

Vol 34 (3) ◽

pp. 637-653 ◽

Cited By ~ 37

Author(s):

W. Kalow ◽

K. Genest ◽

N. Staron

Keyword(s):

Kinetic Studies ◽

Reaction Rates ◽

Serum Cholinesterase ◽

Initial Reaction ◽

Ultraviolet Spectrophotometry ◽

First Order ◽

Low Concentrations ◽

Kinetics Of ◽

Hydrolysis Of ◽

Substrate Concentrations

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Preparation of Magnetic Cross-Linked Amyloglucosidase Aggregates: Solving Some Activity Problems

Catalysts ◽

10.3390/catal8110496 ◽

2018 ◽

Vol 8 (11) ◽

pp. 496 ◽

Cited By ~ 17

Author(s):

Murilo Amaral-Fonseca ◽

Willian Kopp ◽

Raquel Giordano ◽

Roberto Fernández-Lafuente ◽

Paulo Tardioli

Keyword(s):

Magnetic Particles ◽

Cost Effective ◽

Soluble Enzyme ◽

Amino Groups ◽

Effective Technique ◽

Volumetric Activity ◽

Dextrose Equivalent ◽

Cost Effective Technique ◽

Improved Stability ◽

Hydrolysis Of

The preparation of Cross-Linked Enzyme Aggregates (CLEAs) is a simple and cost-effective technique capable of generating insoluble biocatalysts with high volumetric activity and improved stability. The standard CLEA preparation consists of the aggregation of the enzyme and its further crosslinking, usually with glutaraldehyde. However, some enzymes have too low a content of surface lysine groups to permit effective crosslinking with glutaraldehyde, requiring co-aggregation with feeders rich in amino groups to aid the formation of CLEAs. The co-aggregation with magnetic particles makes their handling easier. In this work, CLEAs of a commercial amyloglucosidase (AMG) produced by Aspergillus niger were prepared by co-aggregation in the presence of polyethyleneimine (PEI) or starch with aminated magnetic nanoparticles (MNPs) or bovine serum albumin (BSA). First, CLEAs were prepared only with MNPs at different glutaraldehyde concentrations, yielding a recovered activity of around 20%. The addition of starch during the precipitation and crosslinking steps nearly doubled the recovered activity. Similar recovered activity (around 40%) was achieved when changing starch by PEI. Moreover, under the same conditions, AMG co-aggregated with BSA was also synthesized, yielding CLEAs with very similar recovered activity. Both CLEAs (co-aggregated with MNPs or BSA) were four times more stable than the soluble enzyme. These CLEAs were evaluated in the hydrolysis of starch at typical industrial conditions, achieving more than 95% starch-to-glucose conversion, measured as Dextrose Equivalent (DE). Moreover, both CLEAS could be reused for five cycles, maintaining a DE of around 90%. Although both CLEAs had good properties, magnetic CLEAs could be more attractive for industrial purposes because of their easy separation by an external magnetic field, avoiding the formation of clusters during the filtration or centrifugation recovery methods usually used.

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Enzyme-assisted Extraction for Optimized Recovery of Phenolic Bioactives from Peganum hermala Leaves Using Response Surface Methodology

Current Topics in Nutraceutical Research ◽

10.37290/ctnr2641-452x.17:349-354 ◽

2018 ◽

Vol 17 (4) ◽

pp. 349-354

Author(s):

Qadir Rahman ◽

Anwar Farooq ◽

Amjad Gilani Mazhar ◽

Nadeem Yaqoob Muhammad ◽

Ahmad Mukhtar

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Enzyme Concentration ◽

Coumaric Acid ◽

Assisted Extraction ◽

Pre Treatment ◽

Optimized Conditions ◽

Enzyme Complexes ◽

Hydrolysis Of ◽

Central Composite

This study investigates the effect of enzyme formulations (Zympex-014, Kemzyme dry-plus and Natuzyme) on recovery of phenolics from Peganum hermala (harmal) leaves, under optimized conditions using response surface methodology. As compared to the other enzyme complexes, the yield (34 g/100g) obtained through Zympex-014-assisted extraction was higher under optimized conditions such as time (75 min), temperature (70°C), pH (6.5) and enzyme concentration (5 g/100 g) using central composite design (CCD). Effectiveness of Zympex-014 towards hydrolysis of P. hermala leaves cell wall was examined by analyzing the control and enzyme-treated leave residues using scanning electron microscope (SEM). GC/MS characterization authenticated the presence of quercetin (1.44), gallic acid (0.23), caffeic acid (0.04), cinnamic acid (0.05), m-coumaric acid (0.23) and p-coumaric acid (0.37 μg/g) as the potent phenolics in Zympex-014 based extract. It can be concluded from the findings of the current work that pre-treatment of P. hermala leaves with Zympex-014 significantly enhanced the recovery of phenolics that supports its potential uses in the nutra-pharamaceutical industry.

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Renal sodium-potassium adenosine triphosphatase. Optical localization and x-ray microanalysis.

Journal of Histochemistry & Cytochemistry ◽

10.1177/23.11.127810 ◽

1975 ◽

Vol 23 (11) ◽

pp. 828-839 ◽

Cited By ~ 28

Author(s):

R Beeuwkes ◽

S Rosen

Keyword(s):

Atpase Activity ◽

Electron Probe ◽

Sequential Analysis ◽

Relative Sensitivity ◽

Initial Reaction ◽

Initial Product ◽

Sodium Potassium ◽

Nitrophenyl Phosphate ◽

Hydrolysis Of ◽

Convoluted Tubules

The distribution of sodium-potassium adenosine triposphatase (Na-K-ATPase) activity in kidney sections has been studied by a method based on the hydrolysis of p-nitrophenyl phosphate in alkaline medium containing dimethyl sulfoxide. The products at each stage in the reaction sequence have been subjected to electron probe microanalysis. The initial product was identified as a mixture of KMgPO4 and Mg(PO4)2, and sequential analysis demonstrated the linearity of conversion of this product to a visible form. In human, rabbit and rat kidneys the distribution of activity was found to be essentially identical, with highest levels located in thick ascending limbs and distal convoluted tubules. The initial reaction was completely potassium dependent and was inhibited by ouabain in concentrations reflecting the relative sensitivity of microsomal Na-K-ATPase in each species. Measurement of initial product phosphorus by means of the electron probe is presented as a practical technique for direct quantitation of Na-K-ATPase activity in identified tubule segments.

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Optimizing Chitin Depolymerization by Lysozyme to Long-Chain Oligosaccharides

Marine Drugs ◽

10.3390/md19060320 ◽

2021 ◽

Vol 19 (6) ◽

pp. 320

Author(s):

Arnaud Masselin ◽

Antoine Rousseau ◽

Stéphanie Pradeau ◽

Laure Fort ◽

Rodolphe Gueret ◽

...

Keyword(s):

Time Course ◽

Water Soluble ◽

Organic Fertilizers ◽

Symbiotic Associations ◽

Egg White Lysozyme ◽

Hen Egg White ◽

Ecological Transition ◽

Optimized Conditions ◽

Hydrolysis Of ◽

Long Chain

Chitin oligosaccharides (COs) hold high promise as organic fertilizers in the ongoing agro-ecological transition. Short- and long-chain COs can contribute to the establishment of symbiotic associations between plants and microorganisms, facilitating the uptake of soil nutrients by host plants. Long-chain COs trigger plant innate immunity. A fine investigation of these different signaling pathways requires improving the access to high-purity COs. Here, we used the response surface methodology to optimize the production of COs by enzymatic hydrolysis of water-soluble chitin (WSC) with hen egg-white lysozyme. The influence of WSC concentration, its acetylation degree, and the reaction time course were modelled using a Box–Behnken design. Under optimized conditions, water-soluble COs up to the nonasaccharide were formed in 51% yield and purified to homogeneity. This straightforward approach opens new avenues to determine the complex roles of COs in plants.

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Prevalence of Aspergillus species on selected Colombian animal feedstuffs and ability of Aspergillus section Flavi to produce aflatoxins

World Mycotoxin Journal ◽

10.3920/wmj2008.1041 ◽

2009 ◽

Vol 2 (1) ◽

pp. 31-34 ◽

Cited By ~ 3

Author(s):

G. Diaz ◽

M. Lozano ◽

A. Acuña

Keyword(s):

Liquid Chromatography ◽

Cottonseed Meal ◽

Sunflower Seed ◽

Seed Meal ◽

Aspergillus Section Flavi ◽

Wheat Middlings ◽

Highperformance Liquid Chromatography ◽

Animal Feedstuffs ◽

Aflatoxin B ◽

Aspergillus Section

A total of 57 samples of feedstuffs commonly used for animal nutrition in Colombia (maize, soybean, sorghum, cottonseed meal, sunflower seed meal, wheat middlings and rice) were analysed for Aspergillus contamination. Aspergillus fungi were identified at species level and their ability to produce aflatoxins was determined by highperformance liquid chromatography. A total of 31 of the feedstuffs analysed (54.4%) were found to contain Aspergillus spp. The most contaminated substrate was maize (100%) followed by cottonseed meal (80%), sorghum (60%) and wheat middlings (60%). Soybean showed lower levels of contamination (10%). No Aspergillus spp. could be isolated from rice or sunflower seed meal. Total Aspergillus strains isolated were 50, with 28 belonging to section Flavi (56%), 17 to section Nigri (34%), 4 to section Circumdati (8%) and 1 to section Fumigati (2%). Among section Flavi, 17 isolates were identified as A. flavus, seven as A. parasiticus, two as A. oryzae and two as A. tamarii. Production of aflatoxins by Aspergillus section Flavi was screened by liquid chromatography. About three quarters of the A. flavus strains (76.5%) produced aflatoxin B1 (0.2 to 240.4 µg/g) and aflatoxin B2 (0.2 to 1.6 µg/g), while all A. parasiticus strains produced the four naturally occurring aflatoxins (aflatoxin B1 from 0.6 to 83.5 µg/g, aflatoxin B2 from 0.3 to 4.8 µg/g, aflatoxin G1 from 0.4 to 19.3 µg/g and aflatoxin G2 from 0.1 to 1.0 µg/g). This is the first study demonstrating the presence of highly toxigenic Aspergillus fungi in Colombian animal feedstuffs.

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