Enzymatic hydrolysis of agar: purification and characterization of neoagarobiose hydrolase and p-nitrophenyl α-galactoside hydrolases

1975 ◽  
Vol 21 (10) ◽  
pp. 1512-1518 ◽  
Author(s):  
D. F. Day ◽  
W. Yaphe
Keyword(s):  
Enzymatic Hydrolysis ◽  
Hydrolytic Enzymes ◽  
Partial Characterization ◽  
Purification And Characterization ◽  
Hydrolysis Of

The mixture of polysaccharides in the gelling component of agar (agarose) is hydrolyzed to D-galactose and 3,6-anhydro-L-galactose by a series of hydrolytic enzymes obtained from Pseudomonas atlantica. The final degradative step in the pathway of agarose decomposition is the hydrolysis of the α-linkage in the dissaccharide neoagarobiose yielding D-galactose and 3,6-anhydro-L-galactose. Pseudomonas atlantica when grown on agar produces two specific enzymes, p-nitrophenyl α-galactose hydrolase and neoagarobiose hydrolase. The purification and partial characterization of both enzymes are presented.

Enzymatic hydrolysis of agar: purification and characterization of β-neoagarotetraose hydrolase from Pseudomonas atlantica

1977 ◽  
Vol 23 (6) ◽  
pp. 672-679 ◽  
Author(s):  
D. Groleau ◽  
W. Yaphe
Keyword(s):  
Cell Wall ◽  
Enzymatic Hydrolysis ◽  
Cytoplasmic Membrane ◽  
Degree Of Polymerization ◽  
Hydrolase Activity ◽  
Wall Region ◽  
Purification And Characterization ◽  
Hydrolysis Of

Agarose is degraded by a β-agarase from Pseudomonas atlantica to neoagarooligosaccharides of degree of polymerization (DP) 4, 6, 8, and 10. A β-neoagarotetraose hydrolase cleaves the central β-linkage in neoagarotetraose and the β-linkage near the nonreducing end in neoagarohexaose and -octaose to yield neoagarobiose. The β-neoagarotetraose hydrolase was localized on or outside the cytoplasmic membrane, in the cell wall region. The enzyme was activated by NaCl, KCl, CaCl2, MnCl2, and MgSO4, has a Km of 3.4 × 10−3 M for neoagarotetraose, was free from β-agarase and α-neoagarobiose hydrolase activity, and showed no transglycosidic activity.

scholarly journals EVALUATION OF ALKALINE PRETREATMENT ON THE ENZYMATIC HYDROLYSIS OF CARNAUBA STRAW RESIDUE

2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Alan De Oliveira Campos ◽  
Francinaldo Leite Da Silva ◽  
Emilianny Rafaely Batista Magalhães ◽  
Gorete Ribeiro De Macedo ◽  
Everaldo Silvino Dos Santos
Keyword(s):  
Enzymatic Hydrolysis ◽  
Cellulosic Ethanol ◽  
Chemical Characterization ◽  
Crystallinity Index ◽  
Biomass Pretreatment ◽  
Cellulose Conversion ◽  
Hydrolysis Of ◽  
Potential Use ◽  
Second Generation Ethanol

Carnauba (Copernicia prunifera) straw residue generated from production of its wax is rich in cellulose, thus showing a potential use in the production of second generation ethanol. However, the high lignin and hemicellulose load associated with cellulose makes it difficult the enzymatic attack, thus having the need of an adequate pretreatment of this material. The objective of this study was to optimize the enzymatic hydrolysis of carnauba straw residue, focusing on the alkaline biomass pretreatment. Therefore, NaOH solutions at concentrations of 1.0% (w/v) (PA1), 2.0% (w/v) (PA2), 3.0% (w/v) (PA3) and 4.0% (w/v) (PA4) were used. The chemical and physical characterization of natural and pre-treated carnauba straw were according to the NREL, and DRX and FTIR performed analyzes. The materials chemical characterization showed that all the used pretreatments were able to remove a significant amount of lignin and hemicellulose, which can improve the enzymes access, favoring the increase of cellulose conversion. In relation to DRX analysis an increase in crystallinity index happens reaching up to 55.15% after the pretreatment PA4, which may be associated to the removal of hemicellulose and amorphous lignin, related to cellulose. After a period of 96 hours of enzymatic hydrolysis, the PA4 pretreated residue showed the best performance with a cellulosic conversion of 78%. Spite of a slightly lower performance of the residue that presented higher cellulose conversion, the pretreated material PA2 is an alternative to reduce costs in the cellulosic ethanol production.

Effects of Rhamnolipids on Enzymatic Hydrolysis of Bamboo Biomass and Mechanism

2020 ◽  
Vol 14 (4) ◽  
pp. 453-460
Author(s):  
Ruyi Sha ◽  
Zhan Yu ◽  
Zhenzhen Wang ◽  
Edwin Menledy Gbor ◽  
Ligang Jiang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Fluorescence Probe ◽  
Economic Losses ◽  
Dilute Acid ◽  
Site Of Action ◽  
The Stability ◽  
Surface Modified ◽  
Hydrolysis Of ◽  
Positive Effect

The lignin present in lignocellulose seriously affects the efficiency of cellulose enzymatic hydrolysis. In addition, lignin adsorbs high-cost cellulase, causing greater economic losses. Lignin can also disturb the site of action of cellulase and reduce the efficiency of hydrolysis. Therefore, if lignin is removed or surface modified before cellulose enzymatic hydrolysis, the enzymatic hydrolysis efficiency of lignocellulosic biomass will be greatly improved. In this paper, the cellulose enzymatic properties of bamboo biomass being treated with dilute acid and alkaline under the intervention of biosurfactant rhamnolipid were evaluated. The effects of rhamnolipids on the adsorption characterization of cellulose on pretreated bamboo were studied. Besides, the inter-communication between rhamnolipids and cellulose was investigated by fluorescence probe. The results showed that rhamnolipids could have a positive effect on the enzymatic hydrolysis of bamboo biomass by reducing the non-productive adsorption of cellulase on the surface of lignocellulose. The outcome illustrated that cellulase could be combined with rhamnolipids micelles, participating in the formation of rhamnolipids micelles, thereby increasing the internal hydrophobicity of the micelles, but could not change the properties of rhamnolipids micelles higher than one CMC (Critical Micelle Concentration). It can be seen that the interaction between rhamnolipids and cellulase is beneficial to enhance the stability and enzymatic activity of cellulase, thereby improving the enzymatic hydrolysis efficiency of cellulose in biomass. Based on these results, a theoretical knowledge about the mechanism of enhancing the enzymatic hydrolysis efficiency of lignocellulose by biosurfactants rhamnolipids is provided.

scholarly journals Characterization of Residual Lignin Obtained by the Enzymatic Hydrolysis of Oil Palm Empty Fruit Bunch Pulps

BioResources ◽  
2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Yin Ying H'ng ◽  
Akiko Nakagawa-Izumi ◽  
Cheu Peng Leh ◽  
Atanu Kumar Das ◽  
Hiroshi Ohi
Keyword(s):  
Enzymatic Hydrolysis ◽  
Oil Palm ◽  
Empty Fruit Bunch ◽  
Residual Lignin ◽  
Hydrolysis Of
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