Produção de lipase por fungos Aspergillus sp. em fermentação no estado sólido utilizando farelo de casca de banana.

Abstract

The objective of this study was to use the banana peel bran as a substrate for the production of lipase in the solid state fermentation (SSF) with Aspergillus sp.. Thus, the experiments were conducted in accordance with factorial design 22, and analyzed the conditions initial moisture (40%, 50% and 60%) and temperature (28°C, 35°C and 42°C). The fungus used was previously isolated from effluent Monteiro Dairy Industry, located in Monteiro-PB, having been selected by presenting a crop enzymatic index (EI) of 10.75, featuring lipase as a good producer. The concentration of spores were used as inoculum for 108 esporos.mL-1. Fermentations were conducted in Erlenmeyer flasks of 150 mL containing 10 g of wet banana peel bran with distilled water by adding the residual frying oil at a concentration of 1% (m/m) as an inducer. The bottles were incubated in the greenhouse. Cultivation was interrupted every 24 hours to obtain the enzyme extract, which was done with sodium phosphate buffer (50 mM, pH = 7.0) incubation in an orbital shaker for 20 min at 150 rpm and 35°C. The mycelial growth of Aspergillus was evaluated by visual observation according to the standard of ASTM (American Society for Testing Materials) Standard Methods G21-90. In the fermentation process, the test 01 (40% humidity and 28°C) showed the highest enzyme activity (666.250 U.mL-1) with 96 h of cultivation. The test 03 (40% humidity and 42°C) had the second highest enzyme activity (437.250 U.mL-1) with 120 h of cultivation. In 02 tests (60% humidity and 28°C) and 04 (60% humidity and 42°C) lower activities were detected. Analyses conducted planning statistics revealed that between the factors studied, moisture is the most important factor in semisolid fermentation process in banana peel for lipase production using the fungus Aspergillus sp.