title: Comparative characterization of proteins secreted by Neurospora sitophila in solid-state and submerged fermentation.
abstract: Although submerged fermentation (SmF) accounts for most of current enzyme industries, it has been reported that solid-state fermentation (SSF) can produce higher enzyme yields in laboratory scale. In order to understand the reasons contributing to high enzyme production in SSF, this study compared the cellulase activities and secretomes of Neurospora sitophila cultured in SSF and SmF using steam exploded wheat straw as carbon source and enzyme inducer. The total amounts of protein and biomass (glucosamine content) in SSF were respectively 30 and 2.8 times of those in SmF. The CMCase, FPA and β-glucoside activities in SSF were 53-181 times of those in SmF. Both in SSF and SmF, N. sitophila secreted the most critical cellulases and hemicellulases known for Trichoderma reesei, although a β-xylosidase was exclusively identified in SSF. Six endoglucanases were identified in N. sitophila secretion with the high CMCase activity. The non-enzyme proteins in SSF were involved in fungal mycelia growth and conidiation; while those in SmF were more related to glycometabolism and stress tolerance. This revealed that SSF more likely serves as a natural habitat for filamentous fungi to facilitate the enzyme secretion.
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Peng
authors.forename: Hongzhang
authors.initials: H
authors.lastname: Chen
mesh_terms: D018533:Biomass; D044602:Cellulases / Q000096:biosynthesis / Q000378:metabolism; D004790:Enzyme Induction; D005285:Fermentation; D005656:Fungal Proteins / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D007101:Immersion; D008031:Lignin / Q000378:metabolism; D009491:Neurospora / Q000201:enzymology / Q000378:metabolism*; D014995:Xylosidases / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; C036909:lignocellulose; D008031:Lignin; D044602:Cellulases; D014995:Xylosidases; C026579:exo-1,4-beta-D-xylosidase
keywords: Cellulase activity; Fungal secretome; Lignocellulose; Solid-state fermentation; Submerged fermentation