Fungal pretreatments improve the efficiency of saccharification of Panicum prionitis Ness biomass

ABSTRACT

Second-generation bioethanol derived from native perennial grasses offers a promising alternative for biofuel, especially when the biomass avoids land-use competition for crop production. Panicum prionitis Ness is a native perennial C4 grass predominant in soils of the Delta del Paraná River, Argentina. Its forage quality (palatability and digestibility) for livestock is low because of its substantial lignin content. In this work, we evaluated different pretreatments (phosphoric acid, ligninolytic enzymes and fungal secretomes) aimed to degrade lignin and improve cellulose hydrolysis efficiency. Results show that 2-day pretreatments with fungal secretomes highly improve release of fermentable sugars compared with conventional pretreatments. Although Pycnoporus sanguineus displayed a greater contribution than Ganoderma applanatum to the pretreatment, the latter triggered the highest final yield, achieving a hydrolysis of 47.5% of cellulose when added to green tissue. These results strengthen the feasibility of using Panicum prionitis biomass in a low-polluting bioethanol production process.

KEYWORDS:

• Biomass
• ligninolytic pretreatments
• lignocellulosic materials
• rangelands
• white rot fungi
• Pycnoporus sanguineus
• Ganoderma applanatum

Acknowledgements

We are grateful to Ing. Emiliano Jozami for providing the fungi used in this study. This work was supported with grants from Proyecto de Vinculación Tecnológica ¨Ingeniero Enrique Mosconi (Ministerio de Educación Nacional), SECTeI Provincia de Santa Fe, and D-TEC0001/13 (ANPCYT/MINCYT) and Proyecto de Vinculación Tecnológica (Universidad Nacional de Rosario, CS-131/15). ASL and VEP are fellows of IICAR-CONICET and ANPCYP-MINCYT, respectively. SRF is a professor of UNR and researcher from CIUNR and UNR-IICAR-CONICET. HRP is a professor of UNR and researcher of UNR-IICAR-CONICET.

Disclosure statement

The authors declare that they do not have any conflict of interest.