Cellulase production by mixed fungi in solid-substrate fermentation of bagasse

Abstract

Ammonia-treated bagasse with 80%(w/w) moisture content was subjected to mixed-culture solid-substrate fermentation (SSF) with Trichoderma reesei LM-UC4 and Aspergillus phoenicis QM 329, in flask or pot fermenters, for cellulase production. Significantly higher activities of all the enzymes of the cellulase complex were achieved in 4 days of mixed-culture SSF than in single-culture (T. reesei) SSF. The highest filter-paper-cellulase and β-glucosidase activities seen in mixed-culture SSF were 18.7 and 38.6 IU/g dry wt, respectively, representing approx. 3- and 6-fold increases over the activities attained in single-culture SSF. The mixed-culture SSF process also converted about 46% of the cellulose and hemicellulose to reducing sugars and enriched the product with 13% fungal protein. The biomass productivity, 0.29 gl(-1).h, and enzyme productivity, 28.0 IU I(-1).h, were about twice as high in the mixed-culture than in the single-culture.

Influence of various fermentation variables on exo-glucanase production in Cellulomonas flavigena

“…Indicated that maximum growth in terms of dry cell biomass was significantly higher on α−cellulose while minimum values was obtained following growth on CMC. The Y x/s of 0.55 g cells/ g cellulose utilized was 98% of the maximum theoretical (0.565) of Y x/s from cellulose (Duenas et al 1995). Over all, the values of all substrate consumption parameters were reasonably high.…”

“…Cellulase system of C. flavigena which produced high activities of cellulases and xylanases during growth on kallar grass showed end-product inhibition-resistance and thermal stability at room temperature of 25ºC (Rajoka, 1990). These enzyme characteristics prompted to further investigate the production potential of FPase, cellobiohydrolase or exoglucanase (EC 3.2.1.91) as it measures the complete cellulase complex (Duenas et al 1995). Celluloses and the cellulosic components in LC substrates are essential for formation of mRNA to support maximum formation of cellulases at the transcription level (Gutierrez-Nova et al 2003).…”

El camino de la biotecnología en la Universidad Nacional Agraria La Molina, Perú

“…Hasta el año 2000, las investigaciones que realizamos estuvieron referidas al desarrollo de sistemas de producción de enzimas con cultivos mixtos y biorreactores de estado sólido, siendo pioneras en esta área y los artículos publicados siguen siendo citados con bastante frecuencia (Castillo et al 1994, Dueñas et al 1995, Gutiérrez-Correa 1999, Gutiérrez-Correa & Tengerdy 1997, 1998, 1999). …”

Expresión diferencial de los genes de algunas enzimas lignocelulolíticas en biopelículas de Aspergillus niger

“…Cellulase as filter paper activity (FPA) and xylanase (XYL) were measured from the fermentation broth as previously reported (Dueñas et al, 1995). One international unit (IU) of enzyme activity was defined as the amount of enzyme that releases 1 µmol product per min (glucose equivalents for FPA and xylose equivalents for XYL).…”