Mapping the polysaccharide degradation potential of Aspergillus niger

BMC Genomics. 2012 Jul 16;13:313. doi: 10.1186/1471-2164-13-313.

Abstract

Background: The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For each type of hemicellulose, a complex mixture of enzymes is required for complete conversion to fermentable monosaccharides. In plant-biomass degrading fungi, these enzymes are regulated and released by complex regulatory structures. In this study, we present a methodology for evaluating the potential of a given fungus for polysaccharide degradation.

Results: Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from Aspergillus niger, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan.

Conclusions: The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in A. niger.

MeSH terms

  • Aspergillus niger / enzymology
  • Aspergillus niger / genetics*
  • Aspergillus niger / metabolism
  • Avena / metabolism
  • Biomass
  • Carbohydrate Sequence
  • Cluster Analysis
  • Enzymes / genetics
  • Enzymes / metabolism
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Gene Expression Profiling
  • Molecular Sequence Data
  • Polysaccharides / chemistry
  • Polysaccharides / metabolism*

Substances

  • Enzymes
  • Fungal Proteins
  • Polysaccharides