Efficient leaching of cellulases produced by Trichoderma harzianum in solid state fermentation

Recovery of cellulases from solid state culture of #Trichoderma harzianum$ was efficiently achieved by hydraulic pressing. Pressing of fermented solids yielded carboxymethyl-cellulase (CMCase) extraction efficiency of 71% and a ratio of leachate to fermented solids of 0.58 (v/w). Addition of water to pressed solids and second pressing improved the efficiency (95%) with simultaneous increase in the ratio to 1.16 (v/w). The overall extraction of filter paper activity was lower (85%) than that of CMCase. This technique is simple and its extraction efficiency is similar to that obtained in multiple-contact counter-current systems. The hydraulic press in its individuality was not used earlier to leach the product from fermented solids. (Résumé d'auteur

Potential of using a single fermenter for biomass build-up, starch hydrolysis, and ethanol production

Data on conversion of starch on biomass and ethanol by #Schwanniomyces castellii in an aerobic-anaerobic solid state fermentation is reported. #Schwanniomyces castellii grew exponentially in the aerobic phase (12h) and simultaneously hydrolyzed nearly half (55%) of the starch initially present. The accumulation of glucose increased up to 12h, whereas maltose was nearly absent beyond 7h. Shift or metabolism from oxidative to fermentative pattern was observed about 10h as a result of the build-up of CO2 level and faster utilization of O2. The ethanol production in the anaerobic phase reached the level of 89.3 mg ethanol/g initial dry matter by the end of 30h. A total of 92.9% of the starch is utilized during the fermentation. The overall ethanol conversion yields are 57.8% of the theoretical value, whereas in the anaerobic phase it was found to be 94.4%. The cell shape, its morphology, and the type of attachment to the solid support were found to be similar in aerobic and anaerobic phases of fermentation. Data given in this work indicate the feasibility of using one single fermenter for aerobic growth to generate inoculum as well as to simultaneously hydrolyze the starch and subsequent anaerobic fermentation to produce ethanol. (Résumé d'auteur

Potential of ensiling for efficient management of spent residue from solid state fermentation system

Studies on ensiling of spent solids from solid state fermentation process for production of cellulases by #Trichoderma harzianum$ showed that good quality ensiled solids can be obtained by using about 43% initial substrate dry matter with 0.3% ensiling additive. (Résumé d'auteur

Maintenance of heat and water balances as a scale-up criterion for the production of ethanol by Schwanniomyces castellii in a solid state fermentation system

The scale-up of column fermenters by 6 to 410 gravimetric scale factors, from 10 g moist substrate size, has been achieved efficiently by maintaining heat and water balances in the media. The data on the patterns of ethanol production, biomass formation, the concentration of different carbohydrates, dry matter and pH values against time were of equal magnitude in 10- and 60-g size column fermenters. The reactors of 60-, 370- and 4100-g sizes also compared well in respect of O2 consumption, CO2 evolution and the specific growth rates in aerobic and anaerobic fermentations phases. The overall productivities of ethanol were similar in all the four column fermenters. The ability to obtain the same results in all the fermenter sizes, in spite of the increases in the diameter and the height of the columns, indicates the high potential of this simple scale-up criterion which has not been used earlier for scale-up of any fermentation process. (Résumé d'auteur

Enzymatic extraction of hydroxycinnamic acids from coffee pulp

Ferulic, caffeic, p-coumaric and chlorogenic acids are classified as hydroxycinnamic acids, presenting anticarcinogenic, anti-inflammatory and antioxidant properties. In this work, enzymatic extraction has been studied in order to extract high value-added products like hydroxycinnamic acids from coffee pulp. A commercial pectinase and enzyme extract produced by Rhizomucor pusillus strain 23aIV in solid-state fermentation using olive oil or coffee pulp (CP) as an inducer of the feruloyl esterase activity were evaluated separately and mixed. The total content (covalently linked and free) of ferulic, caffeic, p-coumaric and chlorogenic acids was 5276 mg per kg of coffee pulp. Distribution was as follows (in %): chlorogenic acid 58.7, caffeic acid 37.6, ferulic acid 2.1 and p-coumaric acid 1.5. Most of the hydroxycinnamic acids were covalently bound to the cell wall (in %): p-coumaric acid 97.2, caffeic acid 94.4, chlorogenic acid 76.9 and ferulic acid 73.4. The content of covalently linked hydroxycinnamic acid was used to calculate the enzyme extraction yield. The maximum carbon dioxide rate for the solid-state fermentation using olive oil as an inducer was higher and it was reached in a short cultivation time. Nevertheless, the feruloyl esterase (FAE) activity (units per mg of protein) obtained in the fermentation using CP as an inducer was 31.8 % higher in comparison with that obtained in the fermentation using olive oil as the inducer. To our knowledge, this is the first report indicating the composition of both esterified and free ferulic, caffeic, p-coumaric and chlorogenic acids in coffee pulp. The highest yield of extraction of hydroxycinnamic acids was obtained by mixing the produced enzyme extract using coffee pulp as an inducer and a commercial pectinase. Extraction yields were as follows (in %): chlorogenic acid 54.4, ferulic acid 19.8, p-coumaric acid 7.2 and caffeic acid 2.3. An important increase in the added value of coffee pulp was mainly due to the extraction of chlorogenic acid

Efficient leaching of cellulases produced by Trichoderma harzianum in solid state fermentation

Recovery of cellulases from solid state culture of #Trichoderma harzianum$ was efficiently achieved by hydraulic pressing. Pressing of fermented solids yielded carboxymethyl-cellulase (CMCase) extraction efficiency of 71% and a ratio of leachate to fermented solids of 0.58 (v/w). Addition of water to pressed solids and second pressing improved the efficiency (95%) with simultaneous increase in the ratio to 1.16 (v/w). The overall extraction of filter paper activity was lower (85%) than that of CMCase. This technique is simple and its extraction efficiency is similar to that obtained in multiple-contact counter-current systems. The hydraulic press in its individuality was not used earlier to leach the product from fermented solids. (Résumé d'auteur