Characteristic microcrystalline cellulose extracted by combined acid and enzyme hydrolysis of sweet sorghum

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.

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The role of cellulase concentration in determining the degree of synergism in the hydrolysis of microcrystalline cellulose

Biochemical Journal ◽

10.1042/bj2550895 ◽

1988 ◽

Vol 255 (3) ◽

pp. 895-899 ◽

Cited By ~ 73

Author(s):

J Woodward ◽

M Lima ◽

N E Lee

Keyword(s):

Microcrystalline Cellulose ◽

Apparent Relationship ◽

Beta Glucosidase ◽

Hydrolysis Of

Microcrystalline cellulose (10 mg of Avicel/ml) was hydrolysed to glucose by different concentrations of the purified cellulase components endoglucanase (EG) II and cellobiohydrolases (CBH) I and II, alone and in combination with each other, in the presence of excess beta-glucosidase. At a concentration of 360 micrograms/ml (160 micrograms of EG II/ml, 100 micrograms of CBH I/ml and 100 micrograms of CBH II/ml) the degree of synergism among them was negligible. As the concentration of cellulase decreased, the degree of synergism increased, reaching an optimum at 20 micrograms/ml (5 micrograms of EG II/ml, 10 micrograms of CBH I/ml and 5 micrograms of CBH II/ml). There was no apparent relationship between the ratio of the components and the degree of synergism. The latter is probably due, though it could not be proved, to the level of saturation of the substrate with each component. Inhibition of Avicel hydrolysis was observed when the substrate was incubated with saturating and nonsaturating concentrations of a mixture of EG II and CBH I respectively. A similar result was also observed with a combination of EG I and EG II.

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Evaluation of thermomechanical pretreatment for enzymatic hydrolysis of pure microcrystalline cellulose and cellulose from Brewers’ spent grain

Journal of Cereal Science ◽

10.1016/j.jcs.2011.06.004 ◽

2011 ◽

Vol 54 (3) ◽

pp. 305-310 ◽

Cited By ~ 16

Author(s):

Guillaume Pierre ◽

Frédéric Sannier ◽

Romain Goude ◽

Armelle Nouviaire ◽

Zoulikha Maache-Rezzoug ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Microcrystalline Cellulose ◽

Spent Grain ◽

Hydrolysis Of

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Relatively High-Substrate Consistency Hydrolysis of Steam-Pretreated Sweet Sorghum Bagasse at Relatively Low Cellulase Loading

Applied Biochemistry and Biotechnology ◽

10.1007/s12010-011-9317-9 ◽

2011 ◽

Vol 165 (3-4) ◽

pp. 1024-1036 ◽

Cited By ~ 9

Author(s):

Fei Shen ◽

Yuehua Zhong ◽

Jack N. Saddler ◽

Ronghou Liu

Keyword(s):

Sweet Sorghum ◽

Sweet Sorghum Bagasse ◽

High Substrate ◽

Sorghum Bagasse ◽

Hydrolysis Of

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Novel activity of angiotensin-converting enzyme. Hydrolysis of cholecystokinin and gastrin analogues with release of the amidated C-terminal dipeptide

Biochemical Journal ◽

10.1042/bj2620125 ◽

1989 ◽

Vol 262 (1) ◽

pp. 125-130 ◽

Cited By ~ 39

Author(s):

P Dubreuil ◽

P Fulcrand ◽

M Rodriguez ◽

H Fulcrand ◽

J Laur ◽

...

Keyword(s):

Angiotensin Converting Enzyme ◽

Chloride Ion ◽

Peptide Bond ◽

Major Product ◽

Enzyme Hydrolysis ◽

Ion Concentration ◽

Converting Enzyme ◽

Rabbit Lung ◽

Hydrolysis Of

ACE (angiotensin-converting enzyme; peptidyl dipeptidase A; EC 3.4.15.1), cleaves C-terminal dipeptides from active peptides containing a free C-terminus. We investigated the hydrolysis of cholecystokinin-8 [CCK-8; Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2] and of various gastrin analogues by purified rabbit lung ACE. Although these peptides are amidated at their C-terminal end, they were metabolized by ACE to several peptide fragments. These fragments were analysed by h.p.l.c., isolated and identified by comparison with synthetic fragments, and by amino acid analysis. The initial and major site of hydrolysis was the penultimate peptide bond, which generated a major product, the C-terminal amidated dipeptide Asp-Phe-NH2. As a secondary cleavage, ACE subsequently released di- or tri-peptides from the C-terminal end of the remaining N-terminal fragments. The cleavage of CCK-8 and gastrin analogues was inhibited by ACE inhibitors (Captopril and EDTA), but not by other enzyme inhibitors (phosphoramidon, thiorphan, bestatin etc.). Hydrolysis of [Leu15]gastrin-(14-17)-peptide [Boc (t-butoxycarbonyl)-Trp-Leu-Asp-Phe-NH2] in the presence of ACE was found to be dependent on the chloride-ion concentration. Km values for the hydrolysis of CCK-8, [Leu15]gastrin-(11-17)-peptide and Boc-[Leu15]gastrin-(14-17)-peptide at an NaCl concentration of 300 mM were respectively 115, 420 and 3280 microM, and the catalytic constants were about 33, 115 and 885 min-1. The kcat/Km for the reactions at 37 degrees C was approx. 0.28 microM-1.min-1, which is approx. 35 times less than that reported for the cleavage of angiotensin I. These results suggest that ACE might be involved in the metabolism in vivo of CCK and gastrin short fragments.

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Bleaching of Microcrystalline Cellulose Produced by Gas-Phase Hydrolysis

Lesnoy Zhurnal (Forestry Journal) ◽

10.37482/0536-1036-2021-6-173-183 ◽

2021 ◽

pp. 173-183

Author(s):

Alexander I. Sizov ◽

◽

Sergey D. Pimenov ◽

Anastasia D. Stroiteleva ◽

Katherine D. Stroiteleva ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Pharmaceutical Industry ◽

Gas Phase ◽

Sodium Hypochlorite ◽

Microcrystalline Cellulose ◽

High Rate ◽

Subsequent Formation ◽

Hydrolysis Of Cellulose ◽

Yellow Tint ◽

Hydrolysis Of

One of the main consumers of microcrystalline cellulose (MCC) is the pharmaceutical industry, where MCC is used as a binder and filler in direct compression of tablets. MCC is produced by acidic hydrolysis of cellulose, which usually results in a decrease in whiteness. This is due to the destruction of sugars formed during hydrolysis and the subsequent formation of colored products. The composition and properties of these products depend on the method of hydrolysis, acid concentration, temperature, and process duration. One of the most promising methods for producing MCC is gas-phase hydrolysis of cellulose with hydrogen chloride gas-air mixtures. The method has a high rate of hydrolysis, low reagent and energy consumption. The requirements of the pharmaceutical industry determine the need to produce MCC with high whiteness. The research purpose is to select bleaching modes for MCC using sodium hypochlorite and hydrogen peroxide as bleaching agents. MCC produced by gas-phase hydrolysis of bleached wood pulp was used during the study. The whiteness and intensity of the yellow tint of MCC in the bleaching process were determined by digital colorimetry on a flatbed scanner. The paper shows that sodium hypochlorite and hydrogen peroxide allow achieving the whiteness not less than 90 % and the intensity of the yellow tint not more than 3 standard units. High-quality bleaching can be carried out even for MCC samples with an initial whiteness of about 40 %. The most effective bleaching agent is sodium hypochlorite when the pH of the bleaching solution is 2–3. Hydrogen peroxide also provides high whiteness of MCC at pH of 10–11. However, the consumption of active oxygen (AO) for bleaching is more than three times higher in comparison with the consumption of active chlorine (ACh). It was found that the dyes of MCC produced by gas-phase hydrolysis consist of two chromophore groups that decolorize at different rates. The easily oxidized group of components makes up about 90 % of the total amount of dyes, and the resistant to oxidation components make up about 10 % and determine the intensity of the yellow tint of MCC. The modes of bleaching MCC with sodium hypochlorite and hydrogen peroxide to product samples with whiteness comparable to that of imported samples were determined. For citation: Sizov A.I., Pimenov S.D., Stroiteleva A.D., Stroiteleva K.D. Bleaching of Microcrystalline Cellulose Produced by Gas-Phase Hydrolysis. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 173–183. DOI: 10.37482/0536-1036-2021-6-173-183

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Hydrolysis of microcrystalline cellulose isolated from waste seeds of Leucaena leucocephala for glucose production

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v15n2.1165 ◽

2019 ◽

Vol 15 (2) ◽

pp. 200-205

Author(s):

Maryam Husin ◽

Nurnadiah Rahim ◽

Mohd Radzi Ahmad ◽

Ahmad Zafir Romli ◽

Zul Ilham

Keyword(s):

Microcrystalline Cellulose ◽

Leucaena Leucocephala ◽

Acid Treatment ◽

Value Added ◽

Glucose Production ◽

Sugar Composition ◽

Sulfuric Acid Method ◽

Percentage Conversion ◽

Hydrolysis Of ◽

Phenol Sulfuric Acid

The waste seeds of Leucaena leucocephala (LLS) used in this study were unused residues obtained after oil and polysaccharides extraction. The microcrystalline cellulose (MCC) was isolated from LLS by acid treatment. MCC produced was, then, further converted to glucose by using sulphuric acid at 121 °C by varying the acid concentration and reaction time. The sugar composition was analyzed by using the phenol-sulfuric acid method and pre-column derivatization HPLC technique. The yield of glucose ranging from 70–85% could be obtained from MCC hydrolyzates, depending on the hydrolysis factors, which corresponding to around 57-75% of the percentage conversion of MCC to glucose.Cellulose isolated from LLS was, therefore, potentially suitable to be utilized in liquid biofuels and other value-added chemicals such as bioethanol, 5-hydroxymethylfurfural(HMF), and levulinic acid.

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