Silencing of a BAHD acyltransferase in sugarcane increases biomass digestibility

Biotechnology for Biofuels

Hugo Bruno Correa Molinari¹  Felipe Vinecky¹  Wagner Rodrigo de Souza¹  Adilson Kenji Kobayashi¹  Bárbara Andrade Dias Brito da Cunha¹  Karoline Estefani Duarte¹  Bruno Leite Sampaio¹  Dasciana de Sousa Rodrigues Gambetta¹  Eduardo Fernandes Formighieri¹  Ana Paula Ribeiro¹  Polyana Kelly Martins¹  Thályta Fraga Pacheco¹  Patrícia Abrão de Oliveira Molinari¹  Thaís Ribeiro Santiago¹  Rowan Andrew Craig Mitchell² 

[1] Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE);Plant Sciences, Rothamsted Research;

关键词: Sugarcane;    Cell-wall acylation;    Biomass;    Lignocellulosic feedstock;    Biofuels;   

DOI  :  10.1186/s13068-019-1450-7

来源: DOAJ

【 摘 要 】

Abstract Background Sugarcane (Saccharum spp.) covers vast areas of land (around 25 million ha worldwide), and its processing is already linked into infrastructure for producing bioethanol in many countries. This makes it an ideal candidate for improving composition of its residues (mostly cell walls), making them more suitable for cellulosic ethanol production. In this paper, we report an approach to improving saccharification of sugarcane straw by RNAi silencing of the recently discovered BAHD01 gene responsible for feruloylation of grass cell walls. Results We identified six BAHD genes in the sugarcane genome (SacBAHDs) and generated five lines with substantially decreased SacBAHD01 expression. To find optimal conditions for determining saccharification of sugarcane straw, we tried multiple combinations of solvent and temperature pretreatment conditions, devising a predictive model for finding their effects on glucose release. Under optimal conditions, demonstrated by Organosolv pretreatment using 30% ethanol for 240 min, transgenic lines showed increases in saccharification efficiency of up to 24%. The three lines with improved saccharification efficiency had lower cell-wall ferulate content but unchanged monosaccharide and lignin compositions. Conclusions The silencing of SacBAHD01 gene and subsequent decrease of cell-wall ferulate contents indicate a promising novel biotechnological approach for improving the suitability of sugarcane residues for cellulosic ethanol production. In addition, the Organosolv pretreatment of the genetically modified biomass and the optimal conditions for the enzymatic hydrolysis presented here might be incorporated in the sugarcane industry for bioethanol production.

【 授权许可】

Unknown