Kinetics of Aspergillus niger Cellulase Inhibition by Reducing Sugar Produced by the Hydrolysis of Carboxymethylcellulose

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Sulaiman Al-Zuhair ◽  
Yu Ling Fan ◽  
Kit Soon Chui ◽  
Sarmad Rizwan
Keyword(s):  
Experimental Data ◽  
Aspergillus Niger ◽  
Competitive Inhibition ◽  
Batch Reactor ◽  
Product Inhibition ◽  
Reducing Sugar ◽  
Wood Shavings ◽  
Initial Substrate ◽  
Competitive Model ◽  
Hydrolysis Of

Hydrolysis of two types of cellulose, namely, totally amorphous Carboxymethylcellulose (CMC) and highly crystalline wood shavings, by Aspergillus niger cellulase was studied in a stirred batch reactor at 50oC. Two kinetic models were devised to predict the rate of reducing sugar production assuming competitive and non-competitive product inhibition of the enzyme. The applicability of the models was tested by comparing experimental results with those predicted by the models. Both models followed the experimental data fairly well, giving standard deviation of 13.3 and 7.9 for the competitive and the non-competitive inhibition models, respectively. However the non-competitive inhibition model showed more realistic behaviour than the non-competitive model and represented better the experimental data. The significance of crystallinity was determined by comparing the production of reducing sugar from wood shavings to the production from CMC. At same initial substrate concentration, it was found that the production of reducing sugar ceased at much shorter times for wood shavings in comparison to that for CMC.

scholarly journals Thimet oligopeptidase specificity: evidence of preferential cleavage near the C-terminus and product inhibition from kinetic analysis of peptide hydrolysis

1995 ◽  
Vol 308 (1) ◽  
pp. 145-150 ◽  
Author(s):  
C G Knight ◽  
P M Dando ◽  
A J Barrett
Keyword(s):  
Competitive Inhibition ◽  
Product Inhibition ◽  
Water Soluble ◽  
Peptide Hydrolysis ◽  
First Order ◽  
Preferential Cleavage ◽  
C Terminus ◽  
Initial Substrate ◽  
Thimet Oligopeptidase ◽  
Sequential Mechanism

The substrate-size specificity of human thimet oligopeptidase (EC 3.4.24.15) was investigated with oligomers of glycyl-prolyl-leucine (GPL)n where n = 2, 3, 4 and 5. These peptides were cleaved only at Leu-Gly bonds to give GPL as the single final product. Hydrolysis was most rapid with (GPL)3 and slowest with (GPL)5. The more water-soluble oligomers of Gly-Hyp-Leu showed the same trend. (Gly-Hyp-Leu)6 was not hydrolysed, consistent with the previous finding that substrates larger than 17 amino acids are not cleaved by thimet oligopeptidase. The cleavage of (GPL)3 to GPL fitted a sequential first-order model. First-order kinetics were unexpected as the initial substrate concentration was greater than Km. The anomaly was also seen during the cleavage of bradykinin and neurotensin, and in these cases first-order behaviour was due to potent competitive inhibition by the C-terminal product. The sequential mechanism for (GPL)3 breakdown by thimet oligopeptidase does not discriminate between initial cleavages towards the N- or C-terminus. As isoleucine is an unfavourable residue in P1, substrates were made in which selected leucine residues were replaced by isoleucine. GPL--GPI--GPL (where--represents the bond between the tripeptide units) was resistant to hydrolysis and GPI--GPL--GPL was cleaved only at the -Leu-Gly- bond. Experiments with isoleucine-containing analogues of (Gly-Hyp-Leu)4 showed that thimet oligopeptidase preferred to cleave these peptides near the C-terminus.

scholarly journals Hydrolysis of Cellulose from Oil Palm Empty Fruit Bunch using Aspergillus niger

2021 ◽  
Vol 226 ◽  
pp. 00042
Author(s):  
Sri Sugiwati ◽  
Suaidah Suaidah ◽  
Eka Triwahyuni ◽  
Muryanto Muryanto ◽  
Yosie Andriani ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Oil Palm ◽  
Hydrolytic Activity ◽  
Reducing Sugar ◽  
Empty Fruit Bunch ◽  
Hydrolysis Time ◽  
Glucose Assay ◽  
Optimum Ph ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Oil palm empty fruit bunch (OPEFB) constitutes a great source of lignocellulosic biomass, mainly comprising of 66.97 % of holocellulose (cellulose and hemicellulose) and 24.45 % of lignin. This present work aimed to hydrolyze cellulose present in OPEFB to form glucose with the aid of Aspergillus niger. A. niger is a type of filamentous fungi able to produce cellulase, a multi-enzyme complex consisting of an endoglucanase, exoglucanase, and β-glucosidase, able to converting cellulose into glucose. The glucose produced is then fermented to produce bioethanol. The present study compared hydrolytic activity of cellulose between OPEFB with pretreatment using NaOH 10 % and OPEFB without pretreatment, concerning temperature, pH, and hydrolysis time. The concentration of reducing sugar derived from cellulosic hydrolysis was determined by using a glucose assay of 3.5-dinitrosalicylic acid. The results showed that the optimum temperature for hydrolysis of cellulose OPEFB (pretreated and untreated) was at 40 °C and the optimum pH was 5.0 for OPEFB-untreated and 5.5 for OPEFB-pretreated. Hydrolysis of cellulose at 40 °C and 3 d yielded reducing sugar 13.01 mg mL−1 and 1.16 mg mL−1 for OPEFB-untreated and OPEFB-pretreated, respectively.

scholarly journals Improvement of Enzymatic Saccharification of Cellulose-Containing Raw Materials Using Aspergillus niger

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1360
Author(s):  
Ekaterina Budenkova ◽  
Stanislav Sukhikh ◽  
Svetlana Ivanova ◽  
Olga Babich ◽  
Vyacheslav Dolganyuk ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Aspergillus Niger ◽  
Filter Paper ◽  
Raw Materials ◽  
Enzymatic Saccharification ◽  
Wood Chip ◽  
Cellulase Activity ◽  
Wood Chips ◽  
Acid Pretreatment ◽  
Hydrolysis Of

Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial enzymes (8.6 versus 9.1 IU), in some cases. Under stationary hydrolysis at 37 °C, pH = 4.7, the enzymatic activity of A. niger UV120 + CH30 was 24.9 IU. The enzymatic hydrolysis of secondary raw materials, using treated A. niger strains, was themost effective at 37 °C. Similarly, the most effective treatment of miscanthus cellulose and wood chips occurred at 50 °C. The maximum conversion of cellulose to glucose was observed using miscanthus cellulose (with alkaline pretreatment), and the minimum conversion was observed when using wood chips. The greatest value of cellulase activity was evidenced in the starch-containing raw materials, indicating that A. niger can ferment not only through cellulase activity, but also via an amylolytic one.

scholarly journals Encapsulated NOLA™ Fit 5500 Lactase—An Economically Beneficial Way to Obtain Lactose-Free Milk at Low Temperature

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 527
Author(s):  
Katarzyna Czyzewska ◽  
Anna Trusek
Keyword(s):  
Low Temperature ◽  
Storage Temperature ◽  
Competitive Inhibition ◽  
Caloric Content ◽  
Substrate Diffusion ◽  
Galactose Inhibition ◽  
The Subject ◽  
And Storage ◽  
Food Processes ◽  
Hydrolysis Of

The current requirements of industrial biocatalysis are related to economically beneficial and environmentally friendly processes. Such a strategy engages low-temperature reactions. The presented approach is essential, especially in food processes, where temperature affects the quality and nutritional value foodstuffs. The subject of the study is the hydrolysis of lactose with the commercial lactase NOLA™ Fit 5500 (NOLA). The complete decomposition of lactose into two monosaccharides gives a sweeter product, recommended for lactose intolerant people and those controlling a product’s caloric content. The hydrolysis reaction was performed at 15 °C, which is related to milk transportation and storage temperature. The enzyme showed activity over the entire range of substrate concentrations (up to 55 g/L lactose). For reusability and easy isolation, the enzyme was encapsulated in a sodium alginate network. Its stability allows carrying out six cycles of the complete hydrolysis of lactose to monosaccharides, lasting from two to four hours. During the study, the kinetic description of native and encapsulated NOLA was conducted. As a result, the model of competitive galactose inhibition and glucose mixed influence (competitive inhibition and activation) was proposed. The capsule size does not influence the reaction rate; thus, the substrate diffusion into capsules can be omitted from the process description. The prepared 4 mm capsules are easy to separate between cycles, e.g., using sieves.

The Formation of Plasma Acid at Atmospheric Pressure and its Application in Hydrolysis of Microcrystalline Cellulose

2013 ◽  
Vol 750-752 ◽  
pp. 1626-1629
Author(s):  
Bo Yuan ◽  
Ying Wang ◽  
Ying Chao Ji ◽  
Qiu Hong Wang
Keyword(s):  
Microcrystalline Cellulose ◽  
Atmospheric Pressure ◽  
High Performance ◽  
Barrier Discharge ◽  
Ph Value ◽  
Reducing Sugar ◽  
Dielectric Barrier ◽  
Integrated Optical ◽  
Hydrolysis Of ◽  
Single Factor Experiment

In this paper, plasma acid was obtained by treating distilled water with dielectric barrier discharge at atmospheric pressure in order to hydrolyze cellulose. The acidity of plasma acid was studied through a single factor experiment. A plasma acid with pH value of 1.42 was obtained and used to hydrolyze microcrystalline cellulose at 80°C for 60min. Under this condition, the integrated optical density (IOD) of the hydrolysis sample was 0.589. Based on standard glucose curve, the total reducing sugar (TRS) was calculated to be 53.75mg and the TRS yield was 53.75%. The filtrate was evaporated to get the solid hydrolysis sample to be analyzed by High-performance liquid chromatography (HPLC). The results showed that the sample mainly consisted of glucose, which proved that microcrystalline cellulose could be hydrolyzed by plasma acid. Therefore, it could be concluded that it was an environmentally friendly and economical method to hydrolyze the microcrystalline cellulose by plasma acid.

scholarly journals Low-temperature thermal hydrolysis of sludge prior to anaerobic digestion: principal component analysis (PCA) of experimental data

Data in Brief ◽  
2021 ◽  
pp. 107323
Author(s):  
Mohamed N.A. Meshref ◽  
Seyed Mohammad Mirsoleimani Azizi ◽  
Wafa Dastyar ◽  
Rasha Maal-Bared ◽  
Bipro Ranjan Dhar
Keyword(s):  
Experimental Data ◽  
Principal Component Analysis ◽  
Anaerobic Digestion ◽  
Low Temperature ◽  
Principal Component ◽  
Component Analysis ◽  
Thermal Hydrolysis ◽  
Hydrolysis Of

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

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

scholarly journals Enzymatic hydrolysis of oil palm empty fruit bunch to produce reducing sugar and its kinetic Hidrolisis enzimatik tandan kosong kelapa sawit untuk menghasilkan gula pereduksi dan kinetikanya

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Vera BARLIANTI ◽  
Deliana DAHNUM ◽  
. MURYANTO ◽  
Eka TRIWAHYUNI ◽  
Yosi ARISTIAWAN ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Oil Palm ◽  
Volume Ratio ◽  
Enzyme Concentration ◽  
Reducing Sugar ◽  
Economic Feasibility ◽  
First Order ◽  
Empty Fruit Bunches ◽  
Hydrolysis Process ◽  
Hydrolysis Of

Abstrak Sebagai salah satu Negara penghasil minyak kelapa sawit mentah (CPO), Indonesia juga menghasilkan tandan kosong kelapa sawit (TKKS) dalam jumlah besar. TKKS terdiri dari-tiga-komponen utama, yaitu selulosa, hemiselulosa, dan lignin. Pengolahan awal TKKS secara alkalindi ikuti dengan hidrolisis TKKS secara enzimatik menggunakan kombinasi enzim selulase dan β-glukosidase akan menghasilkan gula-gula yang mudah difermentasi.  Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi substrat, kon-sentrasi enzim, dan suhu selama proses hidrolisis berlangsung.  Hasil yang diperoleh menunjukkan bahwa konsentrasi gula maksimum (194,78 g/L) dicapai pada konsentrasi TKKS 20% (b/v), konsentrasi campuran enzim yang terdiri dari selulase dan β-1,4 glukosidase sebesar 3,85% (v/v), dan suhu 50oC. Perbandingan antara selulase dan β-1,4 glukosidase adalah 5:1 dengan masing-masing aktivitas enzim sebesar 144.5 FPU/mL dan 63 FPU/mL. Hasil penelitian juga menunjukkan bahwa model kinetika yang sesuai untuk proses hidrolisis TKKS secara enzimatik adalah model kinetika Shen dan Agblevor dengan reakside aktivasi enzim orde satu.  Hasil ini mendukung studi kelayakan ekonomi dalam pemanfaatan TKKS untuk produksi bioetanol.AbstractAs one of the crude palm oil producers, Indonesia also produces empty fruit bunches (EFB)in large quantities. The oil palm EFB consist of cellulose, hemicellulose and lignin. Alkaline pretreatment of EFB, followed by enzymatic hydro-lysis of cellulose using combination of cellulase and β-glucosidase enzymes produce fermentable sugars. This paper reported the effects of substrate loading, enzyme concentration, and temperature of hydrolysis process on reducing sugar production. The  maximum  sugar  concentration (194.78 g/L) was produced at 50oC using 20% (w/v) EFB and 3.85% (v/v) mixed enzymes of cellulase and β-1,4 glucosidase in volume ratio of 5:1 (v/v), with enzyme activity of 144.5 FPU/mL and 63 FPU/mL, respectively. The results also showed that the suitable kinetic model for enzymatic hydrolysis process of oil palm EFB follow Shen and Agblevor model with first order of enzyme deactivation. These results support the economic feasibility study in utilization of EFB of oil palm for bioethanol production.    

Sign in / Sign up

Export Citation Format

Share Document