Process Engineering and Morphology Control in Solid-State and Submerged Fermentation of Trichoderma for Biocatalyst Production

Abstract

The production of biocatalysts using Trichoderma spp. is commonly carried out in solid-state (SSF) and submerged fermentation (SmF), two systems with fundamentally different transport and control characteristics. This review examines how heat transfer, oxygen availability, and fungal morphology interact with process performance and scalability. In SSF, low thermal conductivity and limited oxygen diffusion lead to temperature gradients and heterogeneous conditions that restrict scale-up. In SmF, oxygen transfer and operating conditions can be controlled more precisely, although this requires higher energy input and introduces shear effects that influence morphology and viscosity. Key parameters such as the volumetric oxygen transfer coefficient (k?a), apparent viscosity (?_app), and thermal gradients (?T) are analyzed in relation to enzymatic productivity and operational stability. Process selection and scale-up are defined by the interaction between transport phenomena and fungal morphology, which determines the balance between control, energy demand, and process robustness.