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Statistical Optimization of Laccase Production and Delignification of Sugarcane Bagasse by Pleurotus ostreatus in Solid-State Fermentation.

Karp SG, Faraco V, Amore A, Letti LA, Thomaz Soccol V, Soccol CR - Biomed Res Int (2015)

Bottom Line: Laccases are oxidative enzymes related to the degradation of phenolic compounds, including lignin units, with concomitant reduction of oxygen to water.Among eight variables (pH, water activity, temperature, and concentrations of CuSO4, (NH4)2SO4, KH2PO4, asparagine, and yeast extract), copper sulfate and ammonium sulfate concentrations were demonstrated to significantly influence laccase production.Lignin content in sugarcane bagasse was reduced from 31.89% to 26.36% after 5 days and to 20.79% after 15 days by the biological treatment of solid-state fermentation.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioprocess Engineering and Biotechnology, Federal University of Paraná, Coronel Francisco H. dos Santos Avenue, 210, 81531-990 Curitiba, PR, Brazil ; Biotechnology Program, Positivo University, Pedro Viriato Parigot de Souza Street, 5300, 81280-330 Curitiba, PR, Brazil.

ABSTRACT
Laccases are oxidative enzymes related to the degradation of phenolic compounds, including lignin units, with concomitant reduction of oxygen to water. Delignification is a necessary pretreatment step in the process of converting plant biomass into fermentable sugars. The objective of this work was to optimize the production of laccases and to evaluate the delignification of sugarcane bagasse by Pleurotus ostreatus in solid-state fermentation. Among eight variables (pH, water activity, temperature, and concentrations of CuSO4, (NH4)2SO4, KH2PO4, asparagine, and yeast extract), copper sulfate and ammonium sulfate concentrations were demonstrated to significantly influence laccase production. The replacement of ammonium sulfate by yeast extract and the addition of ferulic acid as inducer provided increases of 5.7- and 2.0-fold, respectively, in laccase activity. Optimization of laccase production as a function of yeast extract, copper sulfate, and ferulic acid concentrations was performed by response surface methodology and optimal concentrations were 6.4 g/L, 172.6 μM, and 1.86 mM, respectively. Experimentally, the maximum laccase activity of 151.6 U/g was produced at the 5th day of solid-state fermentation. Lignin content in sugarcane bagasse was reduced from 31.89% to 26.36% after 5 days and to 20.79% after 15 days by the biological treatment of solid-state fermentation.

No MeSH data available.


Kinetics of laccase production on solid-state fermentation of sugarcane bagasse by P. ostreatus 22 Em under optimized conditions: 6.4 g/L yeast extract, 172.6 μM CuSO4, and 1.86 mM ferulic acid.
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Related In: Results  -  Collection


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fig1: Kinetics of laccase production on solid-state fermentation of sugarcane bagasse by P. ostreatus 22 Em under optimized conditions: 6.4 g/L yeast extract, 172.6 μM CuSO4, and 1.86 mM ferulic acid.

Mentions: Figure 1 presents the kinetics of laccase production under optimized conditions. The peak of laccase activity (151.6 U/g) was obtained between the 4th day and the 5th day of solid-state fermentation. Other values of laccase productivity reported in the literature are 80 U/mL after 12 days in liquid culture of P. ostreatus hybrids without exogenous inducers [6], 12.2 U/mL after 18 days of liquid fermentation by P. ostreatus [32], 90 U/g of sugarcane bagasse produced by Pycnoporus cinnabarinus after 14 days of solid-state fermentation in columns and activities near 80 U/g after 6 days [33], and 70 U/g of sugarcane bagasse, produced by Pycnoporus cinnabarinus after 10 days [30]. The maximum value of laccase production achieved with the strain P. ostreatus Pl 22 Em in this study (151.6 U/g) after 5 days of solid-state fermentation was promising in terms of enzyme activity and productivity.


Statistical Optimization of Laccase Production and Delignification of Sugarcane Bagasse by Pleurotus ostreatus in Solid-State Fermentation.

Karp SG, Faraco V, Amore A, Letti LA, Thomaz Soccol V, Soccol CR - Biomed Res Int (2015)

Kinetics of laccase production on solid-state fermentation of sugarcane bagasse by P. ostreatus 22 Em under optimized conditions: 6.4 g/L yeast extract, 172.6 μM CuSO4, and 1.86 mM ferulic acid.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4477062&req=5

fig1: Kinetics of laccase production on solid-state fermentation of sugarcane bagasse by P. ostreatus 22 Em under optimized conditions: 6.4 g/L yeast extract, 172.6 μM CuSO4, and 1.86 mM ferulic acid.
Mentions: Figure 1 presents the kinetics of laccase production under optimized conditions. The peak of laccase activity (151.6 U/g) was obtained between the 4th day and the 5th day of solid-state fermentation. Other values of laccase productivity reported in the literature are 80 U/mL after 12 days in liquid culture of P. ostreatus hybrids without exogenous inducers [6], 12.2 U/mL after 18 days of liquid fermentation by P. ostreatus [32], 90 U/g of sugarcane bagasse produced by Pycnoporus cinnabarinus after 14 days of solid-state fermentation in columns and activities near 80 U/g after 6 days [33], and 70 U/g of sugarcane bagasse, produced by Pycnoporus cinnabarinus after 10 days [30]. The maximum value of laccase production achieved with the strain P. ostreatus Pl 22 Em in this study (151.6 U/g) after 5 days of solid-state fermentation was promising in terms of enzyme activity and productivity.

Bottom Line: Laccases are oxidative enzymes related to the degradation of phenolic compounds, including lignin units, with concomitant reduction of oxygen to water.Among eight variables (pH, water activity, temperature, and concentrations of CuSO4, (NH4)2SO4, KH2PO4, asparagine, and yeast extract), copper sulfate and ammonium sulfate concentrations were demonstrated to significantly influence laccase production.Lignin content in sugarcane bagasse was reduced from 31.89% to 26.36% after 5 days and to 20.79% after 15 days by the biological treatment of solid-state fermentation.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioprocess Engineering and Biotechnology, Federal University of Paraná, Coronel Francisco H. dos Santos Avenue, 210, 81531-990 Curitiba, PR, Brazil ; Biotechnology Program, Positivo University, Pedro Viriato Parigot de Souza Street, 5300, 81280-330 Curitiba, PR, Brazil.

ABSTRACT
Laccases are oxidative enzymes related to the degradation of phenolic compounds, including lignin units, with concomitant reduction of oxygen to water. Delignification is a necessary pretreatment step in the process of converting plant biomass into fermentable sugars. The objective of this work was to optimize the production of laccases and to evaluate the delignification of sugarcane bagasse by Pleurotus ostreatus in solid-state fermentation. Among eight variables (pH, water activity, temperature, and concentrations of CuSO4, (NH4)2SO4, KH2PO4, asparagine, and yeast extract), copper sulfate and ammonium sulfate concentrations were demonstrated to significantly influence laccase production. The replacement of ammonium sulfate by yeast extract and the addition of ferulic acid as inducer provided increases of 5.7- and 2.0-fold, respectively, in laccase activity. Optimization of laccase production as a function of yeast extract, copper sulfate, and ferulic acid concentrations was performed by response surface methodology and optimal concentrations were 6.4 g/L, 172.6 μM, and 1.86 mM, respectively. Experimentally, the maximum laccase activity of 151.6 U/g was produced at the 5th day of solid-state fermentation. Lignin content in sugarcane bagasse was reduced from 31.89% to 26.36% after 5 days and to 20.79% after 15 days by the biological treatment of solid-state fermentation.

No MeSH data available.