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Bioprocess and biotecnology: effect of xylanase from Aspergillus niger and Aspergillus flavus on pulp biobleaching and enzyme production using agroindustrial residues as substract.

de Alencar Guimaraes NC, Sorgatto M, Peixoto-Nogueira Sde C, Betini JH, Zanoelo FF, Marques MR, de Moraes Polizeli Mde L, Giannesi GC - Springerplus (2013)

Bottom Line: The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives).On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger.That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Biochemistry, CCBS - Universidade Federal de Mato Grosso do Sul/UFMS, Av Costa e Silva s/n°, Campo Grande, MS 79070-900 Brazil.

ABSTRACT
This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of incubation, and A. flavus had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of more than 45 minutes. The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives). On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger. The kappa efficiency corresponded to 36.32 and 25.93, respectively. That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.

No MeSH data available.


Characterization of the xylanases fromA. nigerandA. flavus. Thermostability of the xylanase of A. niger(A) and A. flavus(B) were determined using McIlvaine buffer pH 5.0 at 60°C after incubating the enzymes on temperatures of 45 (■), 50 (●) and 55°C (▲). Thermostability of the xylanases at 55 (A. niger) (C) and 50°C (A. flavus) (D), without additives (■), and with 5% glycerol (●) and polyethyleneglycol (▲). pH stability of A. niger(E) and A. flavus(F) were determined incubating both enzymes at different pHs (3.0 - 8.0) at 0°C, during 1 hour and after the residual activities were determined at 60°C, pH 5.0.
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Fig1: Characterization of the xylanases fromA. nigerandA. flavus. Thermostability of the xylanase of A. niger(A) and A. flavus(B) were determined using McIlvaine buffer pH 5.0 at 60°C after incubating the enzymes on temperatures of 45 (■), 50 (●) and 55°C (▲). Thermostability of the xylanases at 55 (A. niger) (C) and 50°C (A. flavus) (D), without additives (■), and with 5% glycerol (●) and polyethyleneglycol (▲). pH stability of A. niger(E) and A. flavus(F) were determined incubating both enzymes at different pHs (3.0 - 8.0) at 0°C, during 1 hour and after the residual activities were determined at 60°C, pH 5.0.

Mentions: The xylanases produced by A. niger and A. flavus remained totally stable at 45°C. At 50°C both xylanases were stable for the first twenty minutes, where the xylanase of A. niger (Figure 1A) still retained 85.72% activity with 2 hours of incubation, and A. flavus (Figure 1B) had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of approximately 45 minutes. In studies with A. casielus (Kronbauer et al., [2007]), A. phoenicis (Chipeta et al., [2005]) and A. giganteus (Coelho and Carmona, [2003]) the xylanases had half-life of only 50, 25 and 13 minutes at 50°C, respectively. The xylanase produced by A. terreus FSS129 had a residual activity of only 70% approximately with 2 hours of incubation at 50°C, and just retained 25.4% activity at 55°C after 1 hour exposure, while our A. niger still retained 38.2% activity (Bakri et al., [2010]). And at 55°C the xylanase of A. casielus had a half-life of only 17 minutes (Kronbauer et al., [2007]).Figure 1


Bioprocess and biotecnology: effect of xylanase from Aspergillus niger and Aspergillus flavus on pulp biobleaching and enzyme production using agroindustrial residues as substract.

de Alencar Guimaraes NC, Sorgatto M, Peixoto-Nogueira Sde C, Betini JH, Zanoelo FF, Marques MR, de Moraes Polizeli Mde L, Giannesi GC - Springerplus (2013)

Characterization of the xylanases fromA. nigerandA. flavus. Thermostability of the xylanase of A. niger(A) and A. flavus(B) were determined using McIlvaine buffer pH 5.0 at 60°C after incubating the enzymes on temperatures of 45 (■), 50 (●) and 55°C (▲). Thermostability of the xylanases at 55 (A. niger) (C) and 50°C (A. flavus) (D), without additives (■), and with 5% glycerol (●) and polyethyleneglycol (▲). pH stability of A. niger(E) and A. flavus(F) were determined incubating both enzymes at different pHs (3.0 - 8.0) at 0°C, during 1 hour and after the residual activities were determined at 60°C, pH 5.0.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3755788&req=5

Fig1: Characterization of the xylanases fromA. nigerandA. flavus. Thermostability of the xylanase of A. niger(A) and A. flavus(B) were determined using McIlvaine buffer pH 5.0 at 60°C after incubating the enzymes on temperatures of 45 (■), 50 (●) and 55°C (▲). Thermostability of the xylanases at 55 (A. niger) (C) and 50°C (A. flavus) (D), without additives (■), and with 5% glycerol (●) and polyethyleneglycol (▲). pH stability of A. niger(E) and A. flavus(F) were determined incubating both enzymes at different pHs (3.0 - 8.0) at 0°C, during 1 hour and after the residual activities were determined at 60°C, pH 5.0.
Mentions: The xylanases produced by A. niger and A. flavus remained totally stable at 45°C. At 50°C both xylanases were stable for the first twenty minutes, where the xylanase of A. niger (Figure 1A) still retained 85.72% activity with 2 hours of incubation, and A. flavus (Figure 1B) had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of approximately 45 minutes. In studies with A. casielus (Kronbauer et al., [2007]), A. phoenicis (Chipeta et al., [2005]) and A. giganteus (Coelho and Carmona, [2003]) the xylanases had half-life of only 50, 25 and 13 minutes at 50°C, respectively. The xylanase produced by A. terreus FSS129 had a residual activity of only 70% approximately with 2 hours of incubation at 50°C, and just retained 25.4% activity at 55°C after 1 hour exposure, while our A. niger still retained 38.2% activity (Bakri et al., [2010]). And at 55°C the xylanase of A. casielus had a half-life of only 17 minutes (Kronbauer et al., [2007]).Figure 1

Bottom Line: The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives).On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger.That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Biochemistry, CCBS - Universidade Federal de Mato Grosso do Sul/UFMS, Av Costa e Silva s/n°, Campo Grande, MS 79070-900 Brazil.

ABSTRACT
This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of incubation, and A. flavus had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of more than 45 minutes. The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives). On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger. The kappa efficiency corresponded to 36.32 and 25.93, respectively. That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.

No MeSH data available.