Effect of stirring on growth and cellulolytic enzymes production by Trichoderma harzianum in a novel bench-scale solid-state fermentation bioreactor

• Published in: Bioresource technology 2018-10, Vol.265, p.291-298
• Main Authors: Lopez-Ramirez, N., Volke-Sepulveda, T., Gaime-Perraud, I., Saucedo-Castañeda, G., Favela-Torres, E.
• Format: Article
• Language: English
• Subjects: Cellulases; Environmental Engineering; Environmental Sciences; Respirometry; Solid-state fermentation; Stirred bioreactor; Trichoderma harzianum; Xylanases
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2018.06.015

[Display omitted] •A cross-flow stirred bioreactor was assessed for enzymes production by T. harzianum.•T. harzianum grows and produces cellulases and xylanases in SSF from 26 to 36 °C.•Increasing diameters in static bioreactors increase the temperature at 1.08 °C/cm.•Stirring rates of 0.5–1 rpm favor (30%) xylanase activity regarding static reactors.•Cellulase and xylanase production by T. harzianum are associated to CO2 production. A novel bench-scale stirred bioreactor for solid-state fermentation was used to determine the effect of the stirring rate on growth and enzymes production by Trichoderma harzianum PBLA. Lab-scale static tubular bioreactors were first used to assess the effect of bioreactor diameter on heat accumulation, growth, and production of cellulases and xylanases. The increased diameters (1.8–4.2 cm) led to increases in temperature up to 36 °C (at a rate of 1.08 °C/cm), which negatively affected the growth and enzyme production. Afterward, in the bench-scale bioreactor operated at rates up to 3.0 rpm, maximum xylanases production (107 ± 0.3 U/g dm) was attained at rates of 0.5 and 1.0 rpm, reaching a maximum of 34 ± 0.3 °C. Cellulases production was reduced (up to 79%) due to stirring. Therefore, the production of xylanases by T. harzianum can be performed in this cross-flow stirred SSF bioreactor at rates up to 1.0 rpm, avoiding heat accumulation and damage on metabolic activity.