Anais do Congresso Paranaense de Microbiologia
IV Congress of Microbiology in Paraná

The use of microorganisms in industrial processes has been a common practice in the field of biotechnology. With this, studies addressing the bioprospection of microorganisms with possible potential for the production of bioactive compounds, especially enzymes, have increased in recent years. Xylanases are enzymes that act on the degradation of xylan, the main hemicellulose found in the wall of plant cells. Among the enzymes of biotechnological interest, xylanases are widely studied due to their numerous economic applications, such as in the pulp and paper industries, animal feed production, food, textile, among others. The objective of this work was to establish the optimal conditions for the production of xylanases by Penicillium sp. For this, agroindustrial residues were evaluated as alternative substrates. Penicillium sp. was kept in the laboratory in solid Vogel medium containing glucose 1.5% (m/v) and 1.5% agar (m/v). After inoculation, the cultures were incubated for 7 days at 28 ºC and used as a source of spores or stored at 4 °C. Furthermore, the influence of carbon source concentration, crop pH and time on enzymatic production was evaluated using the Central Rotational Composite Design applicable to the Response Surface Methodology. Suspensions of Penicillium sp. in sterile distilled water containing 1.0 x 107 spores mL-1 were inoculated in Vogel liquid medium with different percentages (m/v) of the evaluated substrate, according to experimental planning. After incubation periods, also specified, mycelium was separated by vacuum filtration and the culture filtrate obtained was used as a source of extracellular xylanases. The xylathanic activity was determined by measuring released reducing sugars, using the acid reagent 3,5-dinhythrolic. Through the results obtained, it was verified that the highest levels of xylanasic activity were obtained using pineapple peel as a carbon source, at the concentration of (2.0%), after 10 days of cultivation, at pH 6.0, corresponding to 109.41 U mL-1. Pineapple peel proved to be a promising substrate for xylanase production, because it is a low cost residue, produced in large quantities. The lineage of Penicillium sp. demonstrated potential for the production of xylanolytic enzymes. Further studies will be carried out in order to aim at future biotechnological applications for these enzymes.