Navegando por Autor "Gulik, Walter Martin van"

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    Continuous production of enzymes under carbon-limited conditions by Trichoderma harzianum P49P11
    (Elsevier) Gelain, Lucas; Kingma, Esther; Pradella, José Geraldo da Cruz; Costa, Aline Carvalho da; Wielen, Luuk Van Der; Gulik, Walter Martin van
    Carbon-limited chemostat cultures were performed using different carbon sources (glucose, 10 and 20 g/L; sucrose, 10 g/L; fructose/glucose, 5.26/5.26 g/L; carboxymethyl cellulose, 10 g/L; and carboxymethyl cellulose/glucose, 5/5 g/L) to verify the capability of the wild type strain Trichoderma harzianum to produce extracellular enzymes. All chemostat cultures were carried out at a fixed dilution rate of 0.05 h . Experiments using glucose, fructose/glucose and sucrose were performed in duplicate. Glucose condition was found to induce the production of enzymes that can catalyse the hydrolysis of p-nitro- phenyl-b-D-glucopyranoside (PNPGase). A concentration of 20 g/L of glucose in the feed provided the highest productivity (1048 ± 16 U/mol h). Extracellular polysaccharides were considered the source of inducers. Based on the obtained results, a new PNPGase production process was developed using mainly glucose. This process raises interesting possibilities of synthesizing the inducer substrate and the induced enzymes in a single step using an easily assimilated carbon source under carbon-limited conditions.