Otimização da produção de tanase por Aspergillus sp. em fermentação em estado sólido (FES)

Abstract

The production of tannase by Aspergillus sp. under solid-state fermentation (SSF) was investigated using leafy of different plants species, such as Mango (Mangifera indica L.), Jamun (Syzygium cumini), Coffee (Coffea arabica L.) and different agro-industrial residues, such as coffee and rice husks, and wheat bran. Among different substrates used, Jamun leaves showed high content of tannins and yielded high tannase production by Aspergillus sp. Surface response methodology was applied to the optimization in laboratory scale production of tannase using Jamun leaves in SSF for Aspergillus sp. The Plackett-Burman design was conducted to evaluate the effects of some variables, including growth temperature (oC), moisture level (tap water: substrate), tannic acid % (w/w), glucose % (w/w), gallic acid % (w/w), potassium nitrate % (w/w), yeast extract % (w/w), ammonium sulfate % (w/w), substrate quantity (g), inoculum concentration (spores/ g of substrate), incubation time (days) and pH on the production of tannase. Among these variables tested, incubation time, potassium nitrate concentration and tannic acid had significant effects on enzyme production. The best incubation time was evaluated and others variables were optimized using the Central Composite Rotatable Design (22) and surface response methodology. The best conditions for tannase production were: incubation time of two days; tannic acid concentration of 1.53% (w/w) and potassium nitrate concentration of 2.71% (w/w). After the optimization process, the tannase activity increased 4.65-fold.