BioChem - DOS

Silencing of a BAHD acyltransferase in sugarcane increases biomass digestibility

Biotechnology for biofuels

de Souza, Wagner Rodrigo; Pacheco, Thá lyta Fraga; Duarte, Karoline Estefani; Sampaio, Bruno Leite; de Oliveira Molinari, Patrí cia Abrã o; Martins, Polyana Kelly; Santiago, Thaí s Ribeiro; Formighieri, Eduardo Fernandes; Vinecky, Felipe; Ribeiro, Ana Paula; da Cunha, Bá rbara Andrade Dias Brito; Kobayashi, Adilson Kenji; Mitchell, Rowan Andrew Craig; de Sousa Rodrigues Gambetta, Dasciana; Molinari, Hugo Bruno Correa

<P><B>Background</B></P><P>Sugarcane (<I>Saccharum</I> 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 <I>BAHD01</I> gene responsible for feruloylation of grass cell walls.</P><P><B>Results</B></P><P>We identified six <I>BAHD</I> genes in the sugarcane genome (Sac<I>BAHD</I>s) and generated five lines with substantially decreased <I>SacBAHD01</I> 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 <I>Organosolv</I> pretreatment using 30% ethanol for 240&nbsp;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.</P><P><B>Conclusions</B></P><P>The silencing of <I>SacBAHD01</I> 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 <I>Organosolv</I> 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.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (10.1186/s13068-019-1450-7) contains supplementary material, which is available to authorized users.</P>

2019

BioMed Central

cc-by

1754-6834

12

pp.111

10.1186/s13068-019-1450-7

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART105612320

https://biotechnologyforbiofuels.biomedcentral.com/track/pdf/10.1186/s13068-019-1450-7

Sugarcane; Cell-wall acylation; Biomass; Lignocellulosic feedstock; Biofuels