Comparative exo-proteomics of solid and submerged state fermentation using the lignocellulose degrading Ascomycete...

Lignocellulolytic enzyme production typically relies on submerged fungal fermentation (SmF) due to high operational control. However, fungi naturally thrive in environments with higher moisture and solid loadings representative of solid-state fermentation (SSF). This study investigates the secretome of Parascedosporium putredinis NO1 grown in SSF (35% w/v) and SmF (1.5% w/v) on wheat straw using a time-series exo-proteomics approach. Peak enzyme activity between conditions was comparable, however protein production in SSF was six-fold higher. SSF secretomes exhibited lower diversity of CAZYme families but a greater number of total upregulated proteins that included higher fold changes in cellulase CAZYme families such as GH1, GH3, GH6, and GH7 than SmF. Greater volatility in protein expression was observed in SmF, while SSF exhibited temporal stability. Here, it is shown that P. putredinis NO1 secretome is modified with significant changes in production, composition, diversity, and activity as a function of SFF when compared to SmF. These findings highlight SSF as a strategy to enhance fungal enzyme yield for lignocellulosic biomass valorization.