Multi-Objective Statistical Optimization of Pectinolytic Enzymes Production by an Aspergillus sp. on Dehydrated Coffee Residues in Solid-State Fermentation

Abstract

Pectinolytic enzymes are a group of enzymes widely used in the food industry. They can be obtained through a wide range of by-products and agricultural and agro-industrial waste by the action of fungi, such as Aspergillus spp., by solid-state fermentation (SSF). A wild strain of an Aspergillus sp. isolated in the Universidad Técnica del Norte (UTN) was used to obtain pectinolytic enzymes from dehydrated coffee waste (pulp and husk) derived from coffee cherries cultivated in the Ecuadorian Andean regions. It was possible to find a condition in which the production of pectinases (expressed as Enzymatic Activity (EA)) and the concentration of spores (S) were simultaneously maximized, using the response surface methodology, in a 3-level factorial design, by SSF in simple tray-type bioreactors. After the analysis and optimization of quadratic models, three confirmatory experiments were performed in the unique optimal condition recommended (35 °C and 79% relative humidity), obtaining 29.9 IU/g and 2.64 × 106 #Sp./g for EA and S, respectively; these values coincided with those predicted by the quadratic models, demonstrating their validity. The values obtained in this study are similar to those previously obtained by other authors.

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“…on dehydrated coffee residues in solid-state fermentation was employed to produce pectinase and spores under optimal conditions. The results reached were 29.9 IU/g and 2.64•10 6 spores/g for enzymatic activity and spore count, respectively, like those obtained by other authors [11].…”

“…1 (Figure 5), the novelty consisted of valorizing coffee production wastes and using them as a substrate for producing pectinolytic enzymes and spores of a strain of Aspergillus sp. previously isolated in the biotechnology laboratories at the "Universidad Técnica del Norte" [11].…”

A Method for Improving Microbial Conversion of Diosgenin and Separation and Identification of the Product

“…Then the single spore suspension was obtained using filtration with a syringe stuffed with cotton. The concentration of spores was adjusted to 1 × 10 6 cfu/mL, and it was added to the fermentation medium under the condition of 5% inoculation amount [14]. The germination state of spores was observed every two hours, and the spore solution was taken for the next experiment.…”

Media Optimization by Response Surface Methodology for the Enhanced Production of Acidic Extracellular Pectinase by the Indigenously Isolated Novel Strain Aspergillus cervinus ARS2 Using Solid-State Fermentation

“…The solid-state fermentation media was prepared based on the optimal values of different media parameters obtained from the Minitab optimizer during optimization studies and was validated by conducting experiments in triplicate [38]. The experimental enzyme activity value was compared with the predicted value by the optimizer and the prediction error was calculated.…”

“…Different agricultural and agro-industrial wastes such as orange peel, lemon peel, banana peel, wheat bran, apple pomace, sugarcane bagasse, soy bran, coffee waste, papaya peel, grape pomace, strawberry pomace, mango peel, satkara peel, used tea, pineapple peel, and sunflower heads have been reported as the substrates used for pectinase production using SSF [16][17][18]23,37,38]. Among these, orange peels, with their high pectin content, have been used as a low-cost substrate for pectinase production in both SSF and SmF [39,40].…”