scholarly journals Multifunctional alkalophilic α-amylase with diverse raw seaweed degrading activities

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaoqian Gu ◽  
Liping Fu ◽  
Aihong Pan ◽  
Yuanyuan Gui ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Reducing Sugars ◽  
Metagenomic Library ◽  
Alginate Lyase ◽  
Enzymatic Digestion ◽  
Alkali Resistance ◽  
Functional Domains ◽  
Associated Bacteria ◽  
Multiple Substrates ◽  
Chondrus Ocellatus ◽  
One Step

AbstractUncultured microbes are an important resource for the discovery of novel enzymes. In this study, an amylase gene (amy2587) that codes a protein with 587 amino acids (Amy2587) was obtained from the metagenomic library of macroalgae-associated bacteria. Recombinant Amy2587 was expressed in Escherichia coli BL21 (DE3) and was found to simultaneously possess α-amylase, agarase, carrageenase, cellulase, and alginate lyase activities. Moreover, recombinant Amy2587 showed high thermostability and alkali resistance which are important characteristics for industrial application. To investigate the multifunctional mechanism of Amy2587, three motifs (functional domains) in the Amy2587 sequence were deleted to generate three truncated Amy2587 variants. The results showed that, even though these functional domains affected the multiple substrates degrading activity of Amy2587, they did not wholly explain its multifunctional characteristics. To apply the multifunctional activity of Amy2587, three seaweed substrates (Grateloupia filicina, Chondrus ocellatus, and Scagassum) were digested using Amy2587. After 2 h, 6 h, and 24 h of digestion, 121.2 ± 4 µg/ml, 134.8 ± 6 µg/ml, and 70.3 ± 3.5 µg/ml of reducing sugars were released, respectively. These results show that Amy2587 directly and effectively degraded three kinds of raw seaweeds. This finding provides a theoretical basis for one-step enzymatic digestion of raw seaweeds to obtain seaweed oligosaccharides.

scholarly journals Multifunctional Alkalophilic α-Amylase With Diverse Raw Seaweed Degrading Activities

2021 ◽  
Author(s):  
xiaoqian gu ◽  
Liping Fu ◽  
Aihong Pan ◽  
Yuanyuan Gui ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Reducing Sugars ◽  
Metagenomic Library ◽  
Alginate Lyase ◽  
Enzymatic Digestion ◽  
Alkali Resistance ◽  
Functional Domains ◽  
Associated Bacteria ◽  
Multiple Substrates ◽  
Chondrus Ocellatus ◽  
One Step

Abstract Uncultured microbes are an important resource for the discovery of novel enzymes. In this study, an amylase gene (amy2587) that codes a protein with 587 amino acids (Amy2587) was obtained from the metagenomic library of macroalgae-associated bacteria. Recombinant Amy2587 was expressed in Escherichia coli BL21 (DE3) and was found to simultaneously possess α-amylase, agarase, carrageenase, cellulase, and alginate lyase activities, moreover, recombinant Amy2587 showed high thermostability and alkali resistance which are important characteristics for industrial application. To investigate the multifunctional mechanism of Amy2587, three motifs (functional domains) in the Amy2587 sequence were deleted to generate three truncated Amy2587 variants. The results showed that, although these functional domains affected the multiple substrates degrading activity of Amy2587, they did not wholly explain its multifunctional characteristics. To apply the multifunctional activity of Amy2587, three seaweed substrates (Grateloupia filicina, Chondrus ocellatus, and Scagassum) were digested using Amy2587. After 2 h, 6 h, and 24 h of digestion, 121.2 ± 4 µg/ml, 134.8 ± 6 µg/ml, and 70.3 ± 3.5 µg/ml of reducing sugars were released, respectively. These results show that Amy2587 directly and effectively degraded three kinds of raw seaweeds. This finding provides a theoretical basis for one-step enzymatic digestion of raw seaweeds to obtain seaweed oligosaccharides.

scholarly journals Highly efficient single-step pretreatment to remove lignin and hemicellulose from softwood

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3567-3577
Author(s):  
Irma Bernal-Lugo ◽  
Carmen Jacinto-Hernandez ◽  
Miquel Gimeno ◽  
C. Carmina Montiel ◽  
Fausto Rivero-Cruz ◽  
...  
Keyword(s):  
Value Added ◽  
Enzymatic Digestion ◽  
Single Step ◽  
Glucose Yield ◽  
Highly Efficient ◽  
First Case ◽  
Hemicellulose Removal ◽  
One Step ◽  
Low Glucose ◽  
Hydrolysis Of

The use of lignocellulosic softwood residues as feedstock for the production of bioethanol and other value-added chemical products has been limited by its high recalcitrance. Alkaline or organosolvent pretreatments have been used to remove recalcitrance in softwoods. Although these methods partially remove lignin and hemicellulose, they also result in low glucose recovery. In the first case, there is low cellulose hydrolizability, and in the second, there is a loss of cellulose. This study evaluated both methods combined into one step: alkaline hydrolysis of the biomass in the presence of an organosolvent. Different conditions of temperature and residence times were assayed. The efficiency of these conditions was quantified as the percentage of lignin and hemicellulose removed from the biomass without loss of cellulose. The substrate produced with the most efficient conditions removed 91% of the lignin and 89.1% of the hemicellulose with no loss of cellulose. Enzymatic hydrolysis of this biomass was 90% to 95%, with a substrate concentration of 3% and with five filter paper units per gram of cellulose (FPU/g cellulose). These results indicated that this one-step alkaline-organsolvent process, applied as a pretreatment to softwood, allows highly efficient lignin and hemicellulose removal. 100% of cellulose was recovered, and there was between 90 and 95% glucose yield after enzymatic digestion.

scholarly journals Effect of Combinative Pretreatments on Cellulose-to-Glucose Conversion of Empty Palm Fruit Bunch (EFB)

2014 ◽  
Vol 7 ◽  
pp. 81-85
Author(s):  
Yakindra Prasad Timilsena ◽  
Nicolas Brosse
Keyword(s):  
Enzymatic Hydrolysis ◽  
Reducing Sugars ◽  
Dilute Acid ◽  
Palm Fruit ◽  
Step Counter ◽  
Lignin Removal ◽  
One Step ◽  
Total Reducing Sugars ◽  
Hydrolysis Of ◽  
Sugar Conversion

Various methods of pretreatments were investigated to their effect on cellulose to glucose conversion efficiency on enzymatic hydrolysis of a tropical agro-industrial waste residue (empty palm fruit bunch, EFB). Four different kinds of combinative pretreatments (autohydrolysis with and without naphthol, dilute acid prehydrolysis, soda prehydrolysis and enzymatic prehydrolysis) were tested for delignification during the first and the second steps of pretreatment. Each prehydrolysis step was seconded by the organosolv delignification with the same conditions of pretreatment. It was observed that all the combinative methods were far more efficient in delignification and enzymatic hydrolysis ability as compared to its one step counter parts. The combinative pretreatment method involving dilute acid prehydrolysis followed by organosolv delignification revealed the best result with respect to lignin removal and enzymatic hydrolysis. The resultant pulp contained very low Klason lignin (~5%) with high sugar conversion ratio (64% total reducing sugars). DOI: http://dx.doi.org/10.3126/jfstn.v7i0.10613   J. Food Sci. Technol. Nepal, Vol. 7 (81-85), 2012  

Characterization of alginate lyase gene using a metagenomic library constructed from the gut microflora of abalone

2011 ◽  
Vol 39 (4) ◽  
pp. 585-593 ◽  
Author(s):  
Su-Jung Sim ◽  
Keun Sik Baik ◽  
Seong Chan Park ◽  
Han Na Choe ◽  
Chi Nam Seong ◽  
...  
Keyword(s):  
Metagenomic Library ◽  
Alginate Lyase ◽  
Gut Microflora

scholarly journals Biochemical characteristics and synergistic effect of two novel alginate lyases from Photobacterium sp. FC615

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Danrong Lu ◽  
Qingdong Zhang ◽  
Shumin Wang ◽  
Jingwen Guan ◽  
Runmiao Jiao ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Synergistic Effect ◽  
Alginate Lyase ◽  
Enzymatic Digestion ◽  
Biofuel Production ◽  
Molar Ratio ◽  
Brown Macroalgae ◽  
Alginate Oligosaccharides ◽  
Novel Method ◽  
Alginate Lyases

Abstract Background Macroalgae and microalgae, as feedstocks for third-generation biofuel, possess competitive strengths in terms of cost, technology and economics. The most important compound in brown macroalgae is alginate, and the synergistic effect of endolytic and exolytic alginate lyases plays a crucial role in the saccharification process of transforming alginate into biofuel. However, there are few studies on the synergistic effect of endolytic and exolytic alginate lyases, especially those from the same bacterial strain. Results In this study, the endolytic alginate lyase AlyPB1 and exolytic alginate lyase AlyPB2 were identified from the marine bacterium Photobacterium sp. FC615. These two enzymes showed quite different and novel enzymatic properties whereas behaved a strong synergistic effect on the saccharification of alginate. Compared to that when AlyPB2 was used alone, the conversion rate of alginate polysaccharides to unsaturated monosaccharides when AlyPB1 and AlyPB2 acted on alginate together was dramatically increased approximately sevenfold. Furthermore, we found that AlyPB1 and AlyPB2 acted the synergistic effect basing on the complementarity of their substrate degradation patterns, particularly due to their M-/G-preference and substrate-size dependence. In addition, a novel method for sequencing alginate oligosaccharides was developed for the first time by combining the 1H NMR spectroscopy and the enzymatic digestion with the exo-lyase AlyPB2, and this method is much simpler than traditional methods based on one- and two-dimensional NMR spectroscopy. Using this strategy, the sequences of the final tetrasaccharide and pentasaccharide product fractions produced by AlyPB1 were easily determined: the tetrasaccharide fractions contained two structures, ΔGMM and ΔMMM, at a molar ratio of 1:3.2, and the pentasaccharide fractions contained four structures, ΔMMMM, ΔMGMM, ΔGMMM, and ΔGGMM, at a molar ratio of ~ 1:1.5:3.5:5.25. Conclusions The identification of these two novel alginate lyases provides not only excellent candidate tool-type enzymes for oligosaccharide preparation but also a good model for studying the synergistic digestion and saccharification of alginate in biofuel production. The novel method for oligosaccharide sequencing described in this study will offer a very useful approach for structural and functional studies on alginate.

scholarly journals Cloning, sequencing and overexpression in Escherichia coli of the alginatelyase-encoding aly gene of Pseudomonas alginovora: identification of three classes of alginate lyases

1996 ◽  
Vol 319 (2) ◽  
pp. 575-583 ◽  
Author(s):  
Frederic CHAVAGNAT ◽  
Colette DUEZ ◽  
Micheline GUINAND ◽  
Philippe POTIN ◽  
Tristan BARBEYRON ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Alginate Lyase ◽  
Wild Type ◽  
E Coli ◽  
Step Procedure ◽  
Amino Acid Precursor ◽  
One Step ◽  
Alginate Lyases ◽  
Pcr Techniques

A gene of Pseudomonas alginovora, called aly, has been cloned in Escherichia coli using a battery of PCR techniques and sequenced. It encodes a 210-amino-acid alginate lyase (EC 4.2.2.3), Aly, in the form of a 233-amino-acid precursor. P. alginovora Aly has been overproduced in E. coli with a His-tag sequence fused at the C-terminal end under conditions in which the formation of inclusion bodies is avoided. His-tagged P. alginovora Aly has the same enzymic properties as the wild-type enzyme and has the specificity of a mannuronate lyase. It can be purified in a one-step procedure by affinity chromatography on Ni2+-nitriloacetate resin. The yield is of 5 mg of enzyme per litre of culture. The amplification factor is 12.5 compared with the level of production by wild-type P. alginovora. The six alginate lyases of known primary structure fall into three distinct classes, one of which comprises the pair P. alginovora Aly and Klebsiella pneumoniae Aly.

An Interactive Minicomputer Program for the Indexing and Simulation of Electron Diffraction Patterns

1976 ◽  
Vol 34 ◽  
pp. 542-543
Author(s):  
R.P. Goehner ◽  
W.T. Hatfield ◽  
Prakash Rao
Keyword(s):  
Electron Diffraction ◽  
Real Time ◽  
Pattern Analysis ◽  
Flow Diagram ◽  
Hard Copy ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Transmission Electron ◽  
One Step ◽  
Diffraction Patterns

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

Sign in / Sign up

Export Citation Format

Share Document