Abstract

FLOREZ-PARDO, Luz-Marina; PARRA-PAZ, Angela-Sofía; LOPEZ-GALAN, Jorge-Enrique  and  FIGUEROA-OVIEDO, Jersson-Ivan. MEDIATOR SYSTEM TO INCREASE THE DELIGNIFICATION OF SUGARCANE RESIDUES WITH FUNGAL ENZYMES. C.T.F Cienc. Tecnol. Futuro [online]. 2015, vol.6, n.2, pp.81-92. ISSN 0122-5383.

Industrial residues are resources that generate regional energy security but they have not been sufficiently valued. In southern Colombia, the sugar cane sector produces approximately 9'000 000 T/year of residues, mostly represented by tops and leaves. Delignification is a critical step in the process of obtaining ethanol from these residues. The removal of lignin using extracellular enzyme extracts and mediators has not been widely studied. Therefore, a methodology was developed to extract, a cocktail of enzymes consisting of laccase, manganese peroxidase (MnP) and lignoperoxidase (LiP) from Pleurotus ostreatus, which was cultivated by solid substrate fermentation. The extracts with two mediators: 1) ABTS: 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic-acid and 2) vanillin, were tested on two different types of residues: untreated residues and pretreated residues with ultrasound. It was found that the crude enzyme extract contained laccase (0.432 U/mL), LiP (0.116 U/mL) and MnP (0.025 U/mL) activity. Additionally, the results confirmed that this extract was capable of removing 52.7% of lignin from ultrasound pretreated sugar cane residues and ABTS as the laccase mediator. It is important to highlight that the results obtained were very promising mainly if a more concentrated extracellular extract can be used.

Keywords : Enzymatic delignification; Mediators; Laccase; Pleurotus ostreatus; Lignoperoxidase; Ultrasound pretreatment; Tops and leaves.

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