This work describes the use of nutrient limitations with Trichoderma reesei Rut C-30 to obtain a prolonged
stationary phase cellulase production. This period of non-growth may allow for dependable cellulase production,
extended fermentation periods, and the possibility to use pellet morphology for easy product
separation. Phosphorus limitation was successful in halting growth and had a corresponding specific
cellulase production of 5 ± 2 FPU/g-h. Combined with the addition of Triton X-100 for fungal pellet formation
and low shear conditions, a stationary phase cellulase production period in excess of 300 h was
achieved, with a constant enzyme production rate of 7 ± 1 FPU/g-h. While nitrogen limitation was also
effective as a growth limiter, it, however, also prevented cellulase production.