Analysis of the Biotechnological Potential of a Lentinus crinitus Isolate in the Light of Its Secretome

Analysis of fungal secretomes is
a prospection tool for the discovery
of new catalysts with biotechnological applications. Since enzyme
secretion is strongly modulated by environmental factors, evaluation
of growth conditions is of utmost importance to achieve optimal enzyme
production. In this work, a nonsequenced wood-rotting fungus, Lentinus crinitus, was used for secretome analysis
by enzymatic assays and a proteomics approach. Enzyme production was
assessed after the fungus was cultured in seven different carbon sources
and three nitrogen-containing compounds. The biomass yields and secreted
protein arrays differed drastically among growing conditions. A mixture
of secreted extracts derived from solid and liquid cultures was inspected
by shotgun mass spectrometry and two-dimensional gel electrophoresis
(2-DE) prior to analysis via LC–MS/MS. Proteins were identified
using mass spectrometry (MS)-driven BLAST. The spectrum of secreted
proteins comprised CAZymes, oxidase/reductases, proteases, and lipase/esterases.
Although preseparation by 2-DE improved the number of identifications
(162) compared with the shotgun approach (98 identifications), the
two strategies revealed similar protein patterns. Culture media with
reduced water content stimulated the expression of oxidases/reductases,
while hydrolases were induced during submerged fermentation. The diversity
of proteins observed within both the CAZyme and oxidoreductase groups
revealed in this fungus a powerful arsenal of enzymes dedicated to
the breakdown and consumption of lignocellulose.