The influence of Aspergillus niger transcription factors AraR and XlnR in the gene expression during growth in d-xylose, l-arabinose and steam-exploded sugarcane bagasse

详细信息    查看全文

• 作者：Wagner Rodrigo de Souza ; Gabriela Piccolo Maitan-Alfenas ; Paula Fagundes de Gouv锚a ; Neil Andrew Brown ; Marcela Savoldi ; Evy Battaglia ; Maria Helena S. Goldman ; Ronald P. de Vries ; Gustavo Henrique Goldman
• 关键词：Aspergillus niger ; XlnR ; AraR ; Sugarcane bagasse saccharification ; Plant polysaccharide-degrading genes ; Biofuels
• 刊名：Fungal Genetics and Biology
• 出版年：November, 2013
• 年：2013
• 卷：60
• 期：Complete
• 页码：29-45
• 全文大小：2512 K

文摘

The interest in the conversion of plant biomass to renewable fuels such as bioethanol has led to an increased investigation into the processes regulating biomass saccharification. The filamentous fungus Aspergillus niger is an important microorganism capable of producing a wide variety of plant biomass degrading enzymes. In A. niger the transcriptional activator XlnR and its close homolog, AraR, controls the main (hemi-)cellulolytic system responsible for plant polysaccharide degradation. Sugarcane is used worldwide as a feedstock for sugar and ethanol production, while the lignocellulosic residual bagasse can be used in different industrial applications, including ethanol production. The use of pentose sugars from hemicelluloses represents an opportunity to further increase production efficiencies. In the present study, we describe a global gene expression analysis of A. niger XlnR- and AraR-deficient mutant strains, grown on a d-xylose/l-arabinose monosaccharide mixture and steam-exploded sugarcane bagasse. Different gene sets of CAZy enzymes and sugar transporters were shown to be individually or dually regulated by XlnR and AraR, with XlnR appearing to be the major regulator on complex polysaccharides. Our study contributes to understanding of the complex regulatory mechanisms responsible for plant polysaccharide-degrading gene expression, and opens new possibilities for the engineering of fungi able to produce more efficient enzymatic cocktails to be used in biofuel production.