Extraction and purification of tannase produced by the filamentous fungus Aspergillus fumigatus CAS-21 using aqueous two-phase systems with ionic liquids

Abstract

The enzyme tannin acyl hydrolase (EC 3.1.1.20), commonly known as Tanase, is responsible for catalyzing the hydrolysis of tannins, such as tannic acid, in gallic acid and glucose. Tannins are phenolic compounds with high solubility in water that have the ability to precipitate proteins, which may be present in several plants. Tannase can be produced by different microorganisms, such as bacteria, yeasts and filamentous fungi. Among these, the filamentous fungi of the genus Aspergillus and Penicillium present great capacities of tannase production. Tannase has important applications in the pharmaceutical industry for the production of trimethoprim (an antibacterial agent used with sulfonamide), in the food and beverage industry, in the treatment of effluents, in the production of antioxidant compounds and as an additive in animal feed. The use of pure (or partially purified) enzymes present high specificity, higher productivity and ease of product isolation. Due to these advantages, the search for new techniques of extraction and purification of tannase is of great importance for the obtaining of enzymes with greater biological activities, with lower production costs and with good stability in wide ranges of pH and temperature. The ability of aqueous two-phase systems (ATPS) with ionic liquids (ILs) to recover and purify the enzyme produced by the fungus Aspergillus fumigatus will be evaluated, aiming the search for more sustainable alternative tanase extraction and purification processes. The use of ILs, as substitutes or additives in the formation of ATPS aims to adjust the polarities of the coexisting aqueous phases in equilibrium, and thus, to improve the efficiencies and selectivities of the tanase extraction processes. With this project we intend to develop a model platform for the extraction of tanase, which guarantees adequate purification for future pharmaceutical and food applications. In addition, it is expected to define a more sustainable, inert and selective process, which allows to improve purification yields with respect to the methods currently used. At the same time, the capacity of the LIs in the maintenance (or improvement) of the catalytic activity of the purified tannases will be also evaluated.