Effect of delignification on hemicellulose extraction from switchgrass, poplar, and pine and its effect on enzymatic convertibility of cellulose-rich residues

Hemicellulose is an abundant and underutilized carbohydrate polymer in plants. The objective of this study was to understand the effect of delignification on hemicellulose extraction efficiency with different types of lignocellulosic biomass. In the case of pine, with a prior sodium chlorite or peracetic acid delignification, more than 50% of the original hemicellulose in the biomass could be extracted using a 10% sodium hydroxide solution; without delignification, only 3.4% of hemicellulose could be extracted from pine. In contrast, without prior delignification, acceptable hemicellulose extraction efficiencies (55.5% and 50.7%, respectively) were achieved from switchgrass and poplar. In addition, the effect of hemicellulose extraction processes on the enzymatic convertibility of the cellulose-rich residues after extraction was determined. The cellulose-rich residues from switchgrass after hemicellulose alkali extraction showed high glucose recovery with enzyme hydrolysis with or without prior delignification. For pine and poplar, high glucose recovery with enzyme hydrolysis of the cellulose-rich residues only occurred if the sample had a delignification step prior to hemicellulose extraction. This information on commercially available biomass feedstocks is useful for those considering isolating hemicellulose within a biorefinery concept.

Download Full-text

High glucose recovery from direct enzymatic hydrolysis of bisulfite-pretreatment on non-detoxified furfural residues

Bioresource Technology ◽

10.1016/j.biortech.2015.06.118 ◽

2015 ◽

Vol 193 ◽

pp. 401-407 ◽

Cited By ~ 24

Author(s):

Yang Xing ◽

Lingxi Bu ◽

Dafeng Sun ◽

Zhiping Liu ◽

Shijie Liu ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

High Glucose ◽

Furfural Residues ◽

Glucose Recovery ◽

Hydrolysis Of

Download Full-text

ENZYME HYDROLYSIS OF PURIFIED HCG

Acta Endocrinologica ◽

10.1530/acta.0.061s219 ◽

1969 ◽

Vol 61 (1_Suppl) ◽

pp. S219

Author(s):

Carl Beling ◽

Ronald Stark

Keyword(s):

Enzyme Hydrolysis ◽

Hydrolysis Of

Download Full-text

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.

Download Full-text

Enzyme-catalyzed reactions in different types of high-pressure enzymatic reactors

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq0603159p ◽

2006 ◽

Vol 12 (3) ◽

pp. 159-163

Author(s):

Mateja Primozic ◽

Maja Habulin ◽

Muzafera Paljevac ◽

Zeljko Knez

Keyword(s):

High Pressure ◽

Atmospheric Pressure ◽

Ceramic Membranes ◽

Stirred Tank ◽

Optimal Temperature ◽

Stirred Tank Reactor ◽

Tank Reactor ◽

Humicola Insolens ◽

Different Types ◽

Hydrolysis Of

The enzyme-catalyzed hydrolysis of carboxy-methyl cellulose (CMC) was performed in three different types of reactors; in a batch stirred-tank reactor (BSTR) operating at atmospheric pressure, in a high-pressure batch stirred-tank reactor (HP BSTR) and in a high-pressure continuous tubular-membrane reactor (HP CTMR). In the high-pressure reactors aqueous SC CO2 was used as the reaction medium. The aim of our research was optimization of the reaction parameters for reaction performance. All the reactions were catalyzed by cellulase from Humicola insolens. Glucose production in the high-pressure batch stirred-tank reactor was faster than in the BSTR at atmospheric pressure. The optimal temperature for the reaction performed in the BSTR at atmospheric pressure was 30?C, while the optimal temperature for the reaction performed in SC CO2 was 32?C. The influence of the application of tubular ceramic membranes in the high-pressure reaction system was studied on the model reaction of CMC hydrolysis at atmospheric pressure and in SC CO2. The reaction was catalyzed by cellulase from Humicola insolens covalently linked to the surface of the ceramic membrane. The hydrolysis of CMC in SC CO2 and at atmospheric pressure was performed for a long time period. The reaction carried out in SC CO2 was more productive than the reaction performed at atmospheric pressure.

Download Full-text

Combination of Autohydrolysis and Catalytic Hydrolysis of Biomass for the Production of Hemicellulose Oligosaccharides and Sugars

Reactions ◽

10.3390/reactions3010003 ◽

2021 ◽

Vol 3 (1) ◽

pp. 30-46

Author(s):

Léa Vilcocq ◽

Agnès Crepet ◽

Patrick Jame ◽

Florbela Carvalheiro ◽

Luis C. Duarte

Keyword(s):

Agricultural Waste ◽

Solid Acid Catalyst ◽

Acid Catalyst ◽

Energy Crop ◽

Catalytic Hydrolysis ◽

Experimental Conditions ◽

Different Types ◽

Hemicellulosic Sugars ◽

Hydrolysis Of

Three different types of biomass sourced from forestry waste (eucalyptus residues), agricultural waste (wheat straw), and energy crop (miscanthus) were used as starting materials to produce hemicellulosic sugars, furans (furfural and hydroxymethylfurfural), and oligosaccharides. A two-step hybrid process was implemented; biomass was first autohydrolysed without any additive to extract hemicelluloses and dissolve it in water. Then, the hydrolysate was treated with a solid acid catalyst, TiO2-WOx, in order to achieve hydrolysis and produce monomeric sugars and furans. This article investigates the role of the biomass type, autohydrolysis experimental conditions, polymerisation degree and composition of hemicelluloses on the performance of the process coupling autohydrolysis and catalytic hydrolysis. The highest global yields of both oligosaccharides and monomeric sugars were obtained from Eucalyptus (37% and 18%, respectively).

Download Full-text

Cold enzyme hydrolysis of wheat starch granules

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.5450760111 ◽

1998 ◽

Vol 76 (1) ◽

pp. 87-93 ◽

Cited By ~ 29

Author(s):

Steven D. Textor ◽

Gordon A. Hill ◽

Douglas G. Macdonald ◽

Earl St. Denis

Keyword(s):

Enzyme Hydrolysis ◽

Wheat Starch ◽

Starch Granules ◽

Hydrolysis Of

Download Full-text

Purification and Identification of an Antioxidative Peptide from Digestive Enzyme Hydrolysis of Cutlassfish Muscle

Journal of Aquatic Food Product Technology ◽

10.1080/10498850.2018.1508532 ◽

2018 ◽

Vol 27 (8) ◽

pp. 934-944 ◽

Cited By ~ 4

Author(s):

Hyun-Soo Kim ◽

WonWoo Lee ◽

Ji-Hyeok Lee ◽

K. K. Asanka Sanjeewa ◽

I. P. Shanura Fernando ◽

...

Keyword(s):

Digestive Enzyme ◽

Enzyme Hydrolysis ◽

Antioxidative Peptide ◽

Hydrolysis Of

Download Full-text

Kinetics of Aspergillus niger growth at high glucose concentrations in different types of the cultures

Advances in Solid State Fermentation ◽

10.1007/978-94-017-0661-2_5 ◽

1997 ◽

pp. 49-58 ◽

Cited By ~ 1

Author(s):

E. Favela-Torres ◽

M. García-Rivero ◽

J. Cordova-López ◽

S. Roussos ◽

G. Viniegra-González ◽

...

Keyword(s):

Aspergillus Niger ◽

High Glucose ◽

Different Types ◽

Kinetics Of

Download Full-text

Enzyme Hydrolysis of 6-Benzylamino-9B D-Ribofuranosylpurine and 6-Hexylamino-9B D-Ribofuranosylpurine

Nature ◽

10.1038/213629a0 ◽

1967 ◽

Vol 213 (5076) ◽

pp. 629-630

Author(s):

M. F. TROUSLOT ◽

J. GUERN

Keyword(s):

Enzyme Hydrolysis ◽

Hydrolysis Of

Download Full-text

Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria

Journal of Molecular Microbiology and Biotechnology ◽

10.1159/000441500 ◽

2016 ◽

Vol 26 (1-3) ◽

pp. 152-164 ◽

Cited By ~ 7

Author(s):

Johann Heider ◽

Karola Schühle ◽

Jasmin Frey ◽

Bernhard Schink

Keyword(s):

Energy Supply ◽

Anaerobic Bacteria ◽

Aerobic Bacteria ◽

Metabolic Intermediate ◽

Present Evidence ◽

Sulfate Reducing ◽

Different Types ◽

Subsequent Degradation ◽

Reducing Bacteria ◽

Hydrolysis Of

Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO<sub>2</sub>-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions.

Download Full-text