title: Genome-wide analysis of maltose utilization and regulation in aspergilli.
abstract: Maltose utilization and regulation in aspergilli is of great importance for cellular physiology and industrial fermentation processes. In Aspergillus oryzae, maltose utilization requires a functional MAL locus, composed of three genes: MALR encoding a regulatory protein, MALT encoding maltose permease and MALS encoding maltase. Through a comparative genome and transcriptome analysis we show that the MAL regulon system is active in A. oryzae while it is not present in Aspergillus niger. In order to utilize maltose, A. niger requires a different regulatory system that involves the AmyR regulator for glucoamylase (glaA) induction. Analysis of reporter metabolites and subnetworks illustrates the major route of maltose transport and metabolism in A. oryzae. This demonstrates that overall metabolic responses of A. oryzae occur in terms of genes, enzymes and metabolites when the carbon source is altered. Although the knowledge of maltose transport and metabolism is far from being complete in Aspergillus spp., our study not only helps to understand the sugar preference in industrial fermentation processes, but also indicates how maltose affects gene expression and overall metabolism.
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
authors.forename: Wanwipa
authors.initials: W
authors.lastname: Vongsangnak
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
authors.forename: Margarita
authors.initials: M
authors.lastname: Salazar
authors.affiliation: Novozymes A/S, DK-2880 Bagsvaerd, Denmark.
authors.forename: Kim
authors.initials: K
authors.lastname: Hansen
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
authors.forename: Jens
authors.initials: J
authors.lastname: Nielsen
mesh_terms: D001230:Aspergillus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D001234:Aspergillus niger / Q000235:genetics / Q000378:metabolism; D001236:Aspergillus oryzae / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D005800:Genes, Fungal; D016681:Genome, Fungal; D055106:Genome-Wide Association Study; D008320:Maltose / Q000378:metabolism*; D008954:Models, Biological; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D018085:Regulon; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D000520:alpha-Glucosidases / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D009004:Monosaccharide Transport Proteins; D008320:Maltose; C021534:maltose permease; D000520:alpha-Glucosidases