scholarly journals Optimization of β-1,4-endoxylanase production by a new Aspergillus niger strain growing on wheat straw and application in xylooligosaccharides production

2020 ◽  
Author(s):  
Zahra AZZOUZ ◽  
Azzeddine Bettache ◽  
Nawel Boucherba ◽  
Laura de Eugenio ◽  
Maria Martinez ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Wheat Straw ◽  
Physicochemical Parameters ◽  
Plant Biomass ◽  
Xylanase Activity ◽  
Residual Activity ◽  
Glycosyl Hydrolases ◽  
Xylan Hydrolysis ◽  
Rsm Optimization ◽  
Single Carbon Source

Plant biomass constitutes the main resource of renewable carbon in the planet and its valorization has traditionally been focused on the use of cellulose, although hemicellulose is the second most abundant group of polysaccharides on earth. Enzymes involved in its degradation are usually glycosyl hydrolases and filamentous fungi are good producers of these enzymes. In this study, a new strain of Aspergillus niger was utilized for hemicellulase production under solid state fermentation using wheat straw as a single carbon source. Physicochemical parameters for production of an endoxylanase were optimized by using one factor at a time approach and response surface methodology (RSM). Maximum xylanase yield after RSM optimization was increased 3-fold. The enzyme was purified by ultrafiltration and ion-exchange chromatography1.41-fold, with 6.2 % yield. Highest xylanase activity was observed at 50 °C and pH 6. A high pH and thermal stability were found, greater than 90% residual activity between pH 3.0-9.0 and between 30-40°C, after 24 h of incubation, presenting half-lives of 30 min at 50 and 60°C. Enzyme was mostly active for wheat arabinoxylan, and displayed the following kinetic parameters Km of 26.06 mg•ml-1 and Vmax of 5,647 U•mg-1min-1.Wheat straw xylan hydrolysis with the purified β-1,4 endoxylanase showed that it was able to release xylooligosaccharides, making it suitable for different applications in food technology.

scholarly journals Optimization of β-1,4-Endoxylanase Production by an Aspergillus niger Strain Growing on Wheat Straw and Application in Xylooligosaccharides Production

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2527
Author(s):  
Zahra Azzouz ◽  
Azzeddine Bettache ◽  
Nawel Boucherba ◽  
Alicia Prieto ◽  
Maria Jesus Martinez ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Wheat Straw ◽  
Plant Biomass ◽  
Residual Activity ◽  
Exchange Chromatography ◽  
Glycosyl Hydrolases ◽  
Biomass Degradation ◽  
Xylan Hydrolysis ◽  
Rsm Optimization ◽  
Single Carbon Source

Plant biomass constitutes the main source of renewable carbon on the planet. Its valorization has traditionally been focused on the use of cellulose, although hemicellulose is the second most abundant group of polysaccharides on Earth. The main enzymes involved in plant biomass degradation are glycosyl hydrolases, and filamentous fungi are good producers of these enzymes. In this study, a new strain of Aspergillus niger was used for hemicellulase production under solid-state fermentation using wheat straw as single-carbon source. Physicochemical parameters for the production of an endoxylanase were optimized by using a One-Factor-at-a-Time (OFAT) approach and response surface methodology (RSM). Maximum xylanase yield after RSM optimization was increased 3-fold, and 1.41- fold purification was achieved after ultrafiltration and ion-exchange chromatography, with about 6.2% yield. The highest activity of the purified xylanase was observed at 50 °C and pH 6. The enzyme displayed high thermal and pH stability, with more than 90% residual activity between pH 3.0–9.0 and between 30–40 °C, after 24 h of incubation, with half-lives of 30 min at 50 and 60 °C. The enzyme was mostly active against wheat arabinoxylan, and its kinetic parameters were analyzed (Km = 26.06 mg·mL−1 and Vmax = 5.647 U·mg−1). Wheat straw xylan hydrolysis with the purified β-1,4 endoxylanase showed that it was able to release xylooligosaccharides, making it suitable for different applications in food technology.

scholarly journals Blocking utilization of major plant biomass polysaccharides leads Aspergillus niger towards utilization of minor components

2021 ◽  
Author(s):  
Roland S. Kun ◽  
Sandra Garrigues ◽  
Marcos Di Falco ◽  
Adrian Tsang ◽  
Ronald P. Vries
Keyword(s):  
Aspergillus Niger ◽  
Plant Biomass ◽  
Minor Components

scholarly journals Efficient Plant Biomass Degradation by Thermophilic Fungus Myceliophthora heterothallica

2012 ◽  
Vol 79 (4) ◽  
pp. 1316-1324 ◽  
Author(s):  
Joost van den Brink ◽  
Gonny C. J. van Muiswinkel ◽  
Bart Theelen ◽  
Sandra W. A. Hinz ◽  
Ronald P. de Vries
Keyword(s):  
Wheat Straw ◽  
Plant Biomass ◽  
Hydrolytic Enzymes ◽  
Reaction Times ◽  
Giant Reed ◽  
Thermophilic Fungi ◽  
Biomass Degradation ◽  
Thermostable Enzymes ◽  
Content Type

ABSTRACTRapid and efficient enzymatic degradation of plant biomass into fermentable sugars is a major challenge for the sustainable production of biochemicals and biofuels. Enzymes that are more thermostable (up to 70°C) use shorter reaction times for the complete saccharification of plant polysaccharides compared to hydrolytic enzymes of mesophilic fungi such asTrichodermaandAspergillusspecies. The genusMyceliophthoracontains four thermophilic fungi producing industrially relevant thermostable enzymes. Within this genus, isolates belonging toM. heterothallicawere recently separated from the well-described speciesM. thermophila. We evaluate here the potential ofM. heterothallicaisolates to produce efficient enzyme mixtures for biomass degradation. Compared to the other thermophilicMyceliophthoraspecies, isolates belonging toM. heterothallicaandM. thermophilagrew faster on pretreated spruce, wheat straw, and giant reed. According to their protein profiles andin vitroassays after growth on wheat straw, (hemi-)cellulolytic activities differed strongly betweenM. thermophilaandM. heterothallicaisolates. Compared toM. thermophila,M. heterothallicaisolates were better in releasing sugars from mildly pretreated wheat straw (with 5% HCl) with a high content of xylan. The high levels of residual xylobiose revealed that enzyme mixtures ofMyceliophthoraspecies lack sufficient β-xylosidase activity. Sexual crossing of twoM. heterothallicashowed that progenies had a large genetic and physiological diversity. In the future, this will allow further improvement of the plant biomass-degrading enzyme mixtures ofM. heterothallica.

scholarly journals Rheological Evaluation of Some Commercial Xylanases

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
Mihai OGNEAN ◽  
Claudia Felicia OGNEAN ◽  
Neli DARIE
Keyword(s):  
Xylanase Activity ◽  
Dough Rheology ◽  
Xylan Hydrolysis ◽  
Selection Of

The arabinoxylans play and the xylanases play an important role breadmaking. For a better selection of xylanases, it is necessary to understand how they work in breadmaking. At the same activity, the xylanases have different effect on dough rheology. The xylanases activity measured through birch xylan hydrolysis it is not correlated with extensographic effects. Weak but better correlations were observed when the xylanase activity was measured as the ability to decrease the viscosity of soluble wheat arabinoxylans solution.

scholarly journals Animal Biopolymer-Plant Biomass Composites: Synergism and Improved Sorption Efficiency

2020 ◽  
Vol 4 (1) ◽  
pp. 15 ◽  
Author(s):  
Mohamed H. Mohamed ◽  
Inimfon A. Udoetok ◽  
Lee D. Wilson
Keyword(s):  
Wheat Straw ◽  
Active Sites ◽  
Plant Biomass ◽  
Low Cost ◽  
Aqueous Media ◽  
Dye Adsorption ◽  
Anionic Dyes ◽  
Adsorption Affinity ◽  
Variable Weight ◽  
Composite Pellets

Pelletized biomaterial composites that contain chitosan (C) and torrefied wheat straw (S) at variable weight composition (C:S) were prepared using a facile blending process. The fractional content of the wheat straw was studied to elucidate the role of biomass on the pelletized product and effects of S-content on the physicochemical properties relevant to adsorption phenomena. Chitosan pellets (with and without S) were characterized by spectroscopic (FT-IR and 13C NMR) and thermal (TGA and DSC) techniques to provide support for their respective C:S composition. Confocal microscopy using fluorescein (FL) as a dye probe revealed the presence and an increase in the accessibility of the active sites for the composite pellets according to the S-content (wt %). Equilibrium and kinetic sorption studies using FL and reactive black (RB) dyes revealed an incremental adsorption affinity of the pellets with anionic dyes in variable charge states (FL and RB). The trend for dye adsorption parallels the incremental S-content (wt %) in the composite pellets. This study reports a first-example of a low-cost, facile, and sustainable approach for the valorization of straw and chitosan suitable for sorption-based applications in aqueous media.

scholarly journals Metabolic engineering of Aspergillus niger via ribonucleoprotein-based CRISPR–Cas9 system for succinic acid production from renewable biomass

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Lei Yang ◽  
Mikkel Møller Henriksen ◽  
Rasmus Syrach Hansen ◽  
Mette Lübeck ◽  
Jesper Vang ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Succinic Acid ◽  
Wheat Straw ◽  
Acid Production ◽  
Value Added ◽  
Fungal Cell ◽  
Renewable Biomass ◽  
Succinic Acid Production ◽  
Wheat Straw Hydrolysate ◽  
Low Culture

Abstract Background Succinic acid has great potential to be a new bio-based building block for deriving a number of value-added chemicals in industry. Bio-based succinic acid production from renewable biomass can provide a feasible approach to partially alleviate the dependence of global manufacturing on petroleum refinery. To improve the economics of biological processes, we attempted to explore possible solutions with a fungal cell platform. In this study, Aspergillus niger, a well-known industrial production organism for bio-based organic acids, was exploited for its potential for succinic acid production. Results With a ribonucleoprotein (RNP)-based CRISPR–Cas9 system, consecutive genetic manipulations were realized in engineering of the citric acid-producing strain A. niger ATCC 1015. Two genes involved in production of two byproducts, gluconic acid and oxalic acid, were disrupted. In addition, an efficient C4-dicarboxylate transporter and a soluble NADH-dependent fumarate reductase were overexpressed. The resulting strain SAP-3 produced 17 g/L succinic acid while there was no succinic acid detected at a measurable level in the wild-type strain using a synthetic substrate. Furthermore, two cultivation parameters, temperature and pH, were investigated for their effects on succinic acid production. The highest amount of succinic acid was obtained at 35 °C after 3 days, and low culture pH had inhibitory effects on succinic acid production. Two types of renewable biomass were explored as substrates for succinic acid production. After 6 days, the SAP-3 strain was capable of producing 23 g/L and 9 g/L succinic acid from sugar beet molasses and wheat straw hydrolysate, respectively. Conclusions In this study, we have successfully applied the RNP-based CRISPR–Cas9 system in genetic engineering of A. niger and significantly improved the succinic acid production in the engineered strain. The studies on cultivation parameters revealed the impacts of pH and temperature on succinic acid production and the future challenges in strain development. The feasibility of using renewable biomass for succinic acid production by A. niger has been demonstrated with molasses and wheat straw hydrolysate.

scholarly journals Endolysins from Antarctic Pseudomonas Display Lysozyme Activity at Low Temperature

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 579
Author(s):  
Marco Orlando ◽  
Sandra Pucciarelli ◽  
Marina Lotti
Keyword(s):  
Low Temperature ◽  
Thermal Inactivation ◽  
Residual Activity ◽  
Heat Stability ◽  
Evolutionary Analysis ◽  
Glycosyl Hydrolases ◽  
Bioinformatics Analyses ◽  
Cold Environments ◽  
Local Flexibility ◽  
Cold Activity

Organisms specialized to thrive in cold environments (so-called psychrophiles) produce enzymes with the remarkable ability to catalyze chemical reactions at low temperature. Cold activity relies on adaptive changes in the proteins’ sequence and structural organization that result in high conformational flexibility. As a consequence of flexibility, several such enzymes are inherently heat sensitive. Cold-active enzymes are of interest for application in a number of bioprocesses, where cold activity coupled with easy thermal inactivation can be of advantage. We describe the biochemical and functional properties of two glycosyl hydrolases (named LYS177 and LYS188) of family 19 (GH19), identified in the genome of an Antarctic marine Pseudomonas. Molecular evolutionary analysis placed them in a group of characterized GH19 endolysins active on lysozyme substrates, such as peptidoglycan. Enzyme activity peaks at about 25–35 °C and 40% residual activity is retained at 5 °C. LYS177 and LYS188 are thermolabile, with Tm of 52 and 45 °C and half-lives of 48 and 12 h at 37 °C, respectively. Bioinformatics analyses suggest that low heat stability may be associated to temperature-driven increases in local flexibility occurring mainly in a specific region of the polypeptide that is predicted to contain hot spots for aggregation.

scholarly journals Screening of a Soil Bacteria Collection for the Production of Alkali Thermostable Xylanases

2018 ◽  
Vol 10 (8) ◽  
pp. 232
Author(s):  
C. R. Sampaio ◽  
C. G. S. Silva ◽  
É. C. T. Anjos ◽  
R. P. M. Fernandes ◽  
M. F. Fernandes
Keyword(s):  
Selection Criteria ◽  
Soil Bacteria ◽  
Solid Medium ◽  
Xylanase Activity ◽  
Relative Activity ◽  
Optimum Activity ◽  
Ph Values ◽  
Xylan Hydrolysis ◽  
Pure Cultures ◽  
The Stability

This work aimed to evaluate a collection of common and rare soil bacteria regarding to extracellular xylanases production and to characterize the stability in contrasting conditions of temperature and pH of these enzymes. This collection consists of 120 isolates belonging to six phyla that were subjected to screening for xylanase activity in pure cultures and in the extracellular proteic extract (EPE). The ratio between the halos diameters of xylan hydrolysis and in the colonies on solid medium (ratio H:C) was used for the evaluation of cultures as selection criteria. EPEs of isolates with highest ratios H:C were evaluated for the specific xylanases activity at 50 °C for 1 h. EPE of the three isolates with the highest potential for activity under this condition were evaluated for optimum activity, stability at 60 °C and different pH values. Twenty-two isolates showed xylanase activity under these conditions. Xylanases from TC21 and TC119 showed high relative activity at temperatures up to 70 °C and were less sensitive to changes in pH. Soil bacteria show high potential as a source of extracellular xylanases adapted to extreme pH and temperature conditions, which are required in agroindustrial processes.

THE INFLUENCE OF BIOCARBON ADDITIVES ON GREASE FUNCTIONALITY

Tribologia ◽  
2020 ◽  
Vol 290 (2) ◽  
pp. 47-53
Author(s):  
Jarosław MOLENDA ◽  
Zbigniew PAWELEC ◽  
Ewa PAWELEC ◽  
Bernadetta KAŹMIERCZAK
Keyword(s):  
Physicochemical Properties ◽  
Wheat Straw ◽  
Physicochemical Parameters ◽  
Mineral Oil ◽  
Natural Origin ◽  
Functional Additives ◽  
Oxidative Resistance ◽  
Beneficial Impact ◽  
The Subject ◽  
Flax Straw

The article presents the results of tests on tribological and physicochemical properties of plastic greases, in which the dispersing phase was highly refined mineral oil and the dispersed phase (thickener) lithium stearate. The functional additives were biocarbon, which were obtained in the pyrolysis process of waste of natural origin, i.e. stems with corn leaves, wheat straw, flax straw, and cherry stones. The compositions containing 5% m/m biocarbon were prepared. Their evaluated on the functional properties of plastic greases was assessed. Tribological characteristics of the greases compositions were determined using the T-02 tester in accordance with the requirements of the subject standards. The effect of biocarbon used on anti-wear (Goz) and anti-seizing (Pt, poz) plastic greases was determined. An assessment was also made of the effect of plant biocarbon on changes in basic physicochemical properties of the composition of plastic greases, i.e. penetration, dropping temperature, and thermo-oxidative stability. It was found that some of the biocarbon significantly improve the tribological properties of plastic greases without significantly affecting the change of key physicochemical parameters. The most beneficial impact of the tested additives on the operational properties of plastic greases was observed when using biocarbon from wheat straw. In some cases, a lower oxidative resistance of biocarbon grease is observed compared to grease without the addition of biocarbon.

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