title: Identification and proteomic analysis of a novel gossypol-degrading fungal strain.
abstract: BACKGROUND
  Cottonseed meal, an important source of feed raw materials, has limited use in the feed industry because of the presence of the highly toxic gossypol. The aim of the current work was to isolate the gossypol-degrading fungus from a soil microcosm and investigate the proteins involved in gossypol degradation.
  
  
  RESULTS
  A fungal strain, AN-1, that uses gossypol as its sole carbon source was isolated and identified as Aspergillus niger. A large number of intracellular proteins were detected using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but no significant difference was observed between the glucose-containing and gossypol-containing mycelium extracts. Two-dimensional gel electrophoresis results showed that the protein spots were concentrated in the 25.0-66.2 kDa range and distributed in different pI gradients. PDQuest software showed that 51 protein spots in the gels were differentially expressed. Of these, 20 differential protein spots, including six special spots expressed in gossypol, were analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
  
  
  CONCLUSIONS
  The fungus AN-1 biodegraded gossypol and the proteomic analysis results indicate that some proteins were involved in the gossypol biodegradation during fungus survival, using gossypol as its sole carbon source.
authors: Microbiology Division, Key Laboratory of Molecular Animal Nutrition of Ministry of Education, College of Animal Science, Zhejiang University, Hangzhou, Zhejiang, China.
authors: Xia
authors: X
authors: Yang
authors: Jian-Yi
authors: JY
authors: Sun
authors: Jian-Lin
authors: JL
authors: Guo
authors: Xiao-Yan
authors: XY
authors: Weng
mesh_terms: D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D001483:Base Sequence; D002681:China; D015180:Electrophoresis, Gel, Two-Dimensional; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D003368:Gossypium / Q000737:chemistry; D006072:Gossypol / Q000378:metabolism* / Q000633:toxicity; D008969:Molecular Sequence Data; D058889:Molecular Typing; D025282:Mycelium / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D016533:Mycological Typing Techniques; D010449:Peptide Mapping; D010802:Phylogeny; D040901:Proteomics / Q000379:methods*; D012337:RNA, Ribosomal, 18S / Q000737:chemistry / Q000235:genetics; D012639:Seeds / Q000009:adverse effects / Q000737:chemistry; D017385:Sequence Homology; D012988:Soil Microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D005656:Fungal Proteins; D012337:RNA, Ribosomal, 18S; D006072:Gossypol