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Production of Trametes pubescens laccase under submerged and semi-solid culture conditions on agro-industrial wastes.

Gonzalez JC, Medina SC, Rodriguez A, Osma JF, Alméciga-Díaz CJ, Sánchez OF - PLoS ONE (2013)

Bottom Line: The crude extracts presented two laccase isoforms with molecular mass of 120 (Lac1) and 60 kDa (Lac2).Regardless of the substrate, enzymatic crude extract and purified fractions behaved similarly at different temperatures and pHs, most of them presented the maximum activity at 55 °C and a pH range between 2 and 3.In addition, they showed similar stability and electro-chemical properties.

View Article: PubMed Central - PubMed

Affiliation: Chemical Engineering Department, Universidad de los Andes, Bogotá, Colombia.

ABSTRACT
Laccases are copper-containing enzymes involved in the degradation of lignocellulosic materials and used in the treatment of phenol-containing wastewater. In this study we investigated the effect of culture conditions, i.e. submerged or semi-solid, and copper supplementation on laccase production by Trametespubescens grown on coffee husk, soybean pod husk, or cedar sawdust. The highest specific laccase activity was achieved when the culture was conducted under submerged conditions supplemented with copper (5 mM), and using coffee husk as substrate. The crude extracts presented two laccase isoforms with molecular mass of 120 (Lac1) and 60 kDa (Lac2). Regardless of the substrate, enzymatic crude extract and purified fractions behaved similarly at different temperatures and pHs, most of them presented the maximum activity at 55 °C and a pH range between 2 and 3. In addition, they showed similar stability and electro-chemical properties. At optimal culture conditions laccase activity was 7.69 ± 0.28 U mg(-1) of protein for the crude extract, and 0.08 ± 0.001 and 2.86 ± 0.05 U mg(-1) of protein for Lac1 and Lac2, respectively. In summary, these results show the potential of coffee husk as an important and economical growth medium to produce laccase, offering a new alternative use for this common agro-industrial byproduct.

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Cyclic voltammograms of (a) syringaldazine at pH 5.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on coffee husk, or (b) ABTS at pH 3.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on soybean pod husk.Nomenclature: only mediator (dotted line), crude extract (solid line), Lac1 fraction (dashed line), and Lac2 fraction (dashed and dotted line).
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pone-0073721-g007: Cyclic voltammograms of (a) syringaldazine at pH 5.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on coffee husk, or (b) ABTS at pH 3.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on soybean pod husk.Nomenclature: only mediator (dotted line), crude extract (solid line), Lac1 fraction (dashed line), and Lac2 fraction (dashed and dotted line).

Mentions: For selected crude extracts and purified fractions a cyclic voltammetry characterization was conducted. For each mediator, syringaldazine or ABTS, similar cyclic voltammograms were obtained for the different crude extracts and purified fractions. Voltammograms of the redox reaction for syringaldazine (Figure 7a) and ABTS (Figure 6b) are presented. Two anionic and cationic peaks were observed when syringaldazine was used as mediator. The first pair of peaks showed a reversible performance, with a mean Ia: Ic ratio of 1.09±0.06, 1.06±0.05, and 0.98±0.02, for the crude extracts, Lac1, and Lac2, respectively. The second pair of peaks showed quasi-reversible performance, and the cathodic peak was presented at a potential of +0.62 V (vs Ag/AgCl), while the anodic peak was presented at a potential of +0.60 V (vs Ag/AgCl). No significant difference on the reduction potential (Eo) for syringaldazine was observed for the crude extracts or the purified fractions, obtaining an Eo, of 0.314±0.008 V (vs Ag/AgCl). However, the peak potential separation (ΔEp) showed a different profile depending on the substrate used for the culture. While not significant difference (p > 0.05) on ΔEp value was observed between crude extract (0.045±0.005 V vs Ag/AgCl), Lac1 (0.046±0.005 V vs Ag/AgCl), and Lac2 (0.028±0.001 V vs Ag/AgCl), from cultures with cedar sawdust and soybean pod husk; the ΔEp was considerably higher for the crude extract (0.083±0.004 V vs Ag/AgCl), Lac1 (0.068±0.003 V vs Ag/AgCl) and Lac2 (0.051±0.005 V vs Ag/AgCl) from the coffee husk culture.


Production of Trametes pubescens laccase under submerged and semi-solid culture conditions on agro-industrial wastes.

Gonzalez JC, Medina SC, Rodriguez A, Osma JF, Alméciga-Díaz CJ, Sánchez OF - PLoS ONE (2013)

Cyclic voltammograms of (a) syringaldazine at pH 5.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on coffee husk, or (b) ABTS at pH 3.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on soybean pod husk.Nomenclature: only mediator (dotted line), crude extract (solid line), Lac1 fraction (dashed line), and Lac2 fraction (dashed and dotted line).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3760920&req=5

pone-0073721-g007: Cyclic voltammograms of (a) syringaldazine at pH 5.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on coffee husk, or (b) ABTS at pH 3.0 using the crude extract and purified laccase fractions from semisolid culture of T. pubescens on soybean pod husk.Nomenclature: only mediator (dotted line), crude extract (solid line), Lac1 fraction (dashed line), and Lac2 fraction (dashed and dotted line).
Mentions: For selected crude extracts and purified fractions a cyclic voltammetry characterization was conducted. For each mediator, syringaldazine or ABTS, similar cyclic voltammograms were obtained for the different crude extracts and purified fractions. Voltammograms of the redox reaction for syringaldazine (Figure 7a) and ABTS (Figure 6b) are presented. Two anionic and cationic peaks were observed when syringaldazine was used as mediator. The first pair of peaks showed a reversible performance, with a mean Ia: Ic ratio of 1.09±0.06, 1.06±0.05, and 0.98±0.02, for the crude extracts, Lac1, and Lac2, respectively. The second pair of peaks showed quasi-reversible performance, and the cathodic peak was presented at a potential of +0.62 V (vs Ag/AgCl), while the anodic peak was presented at a potential of +0.60 V (vs Ag/AgCl). No significant difference on the reduction potential (Eo) for syringaldazine was observed for the crude extracts or the purified fractions, obtaining an Eo, of 0.314±0.008 V (vs Ag/AgCl). However, the peak potential separation (ΔEp) showed a different profile depending on the substrate used for the culture. While not significant difference (p > 0.05) on ΔEp value was observed between crude extract (0.045±0.005 V vs Ag/AgCl), Lac1 (0.046±0.005 V vs Ag/AgCl), and Lac2 (0.028±0.001 V vs Ag/AgCl), from cultures with cedar sawdust and soybean pod husk; the ΔEp was considerably higher for the crude extract (0.083±0.004 V vs Ag/AgCl), Lac1 (0.068±0.003 V vs Ag/AgCl) and Lac2 (0.051±0.005 V vs Ag/AgCl) from the coffee husk culture.

Bottom Line: The crude extracts presented two laccase isoforms with molecular mass of 120 (Lac1) and 60 kDa (Lac2).Regardless of the substrate, enzymatic crude extract and purified fractions behaved similarly at different temperatures and pHs, most of them presented the maximum activity at 55 °C and a pH range between 2 and 3.In addition, they showed similar stability and electro-chemical properties.

View Article: PubMed Central - PubMed

Affiliation: Chemical Engineering Department, Universidad de los Andes, Bogotá, Colombia.

ABSTRACT
Laccases are copper-containing enzymes involved in the degradation of lignocellulosic materials and used in the treatment of phenol-containing wastewater. In this study we investigated the effect of culture conditions, i.e. submerged or semi-solid, and copper supplementation on laccase production by Trametespubescens grown on coffee husk, soybean pod husk, or cedar sawdust. The highest specific laccase activity was achieved when the culture was conducted under submerged conditions supplemented with copper (5 mM), and using coffee husk as substrate. The crude extracts presented two laccase isoforms with molecular mass of 120 (Lac1) and 60 kDa (Lac2). Regardless of the substrate, enzymatic crude extract and purified fractions behaved similarly at different temperatures and pHs, most of them presented the maximum activity at 55 °C and a pH range between 2 and 3. In addition, they showed similar stability and electro-chemical properties. At optimal culture conditions laccase activity was 7.69 ± 0.28 U mg(-1) of protein for the crude extract, and 0.08 ± 0.001 and 2.86 ± 0.05 U mg(-1) of protein for Lac1 and Lac2, respectively. In summary, these results show the potential of coffee husk as an important and economical growth medium to produce laccase, offering a new alternative use for this common agro-industrial byproduct.

Show MeSH
Related in: MedlinePlus