Screening, Selection and Optimization of the Culture Conditions for Tannase Production by Endophytic Fungi Isolated from Caatinga

Abstract

Tannin acyl hydrolase (EC 3.1.1.20), called tannase, is an enzyme of great biotechnological interest for applications in food, chemical, beverage and pharmaceutical industries. Therefore, the objective of this study was to isolate, select and identify strains of endophytic fungi from rich tannin plants collected in the Caatinga, as well as, the optimization of culture conditions for the best producers. Sixteen endophyte fungi were isolated from the barks of mastic (Myracrodruon urundeuva Allemão), angico (Anadenanthera colubrina Vell.), barauna (Schinopsis brasiliensis Engl.), cajueiro (Anacardium occidentale L.) and catingueira (Caesalpinia pyramidalis Tul). All strains showed ability of using tannic acid as carbon source. The species A. niger and A. fumigatus isolated from angico and cajueiro, respectively, presented the highest enzyme production. The optimum conditions for the production of tannase by A. niger were 24 h cultivation in Khanna medium containing 2% tannic acid, in the absence of nitrogen source, at 37 °C. A. fumigatus showed increased production of tannase when cultured in mineral medium for 24 h using 2% tannic acid as carbon source and peptone as additional nitrogen source, at 37 ºC. The optimum apparent temperature and pH of activity for the enzymes produced by both fungal species were 30 ºC and 4.0, respectively.

Screening of Potential Tannase-producing Fungi from Local Agri-industrial By-products using a Plate Assay and Submerged Fermentation

“…The tannase activities show a high correlation with r= 0.9204 between the hydrolytic zone diameter and tannase activity in all 13 fungal isolates. These results are in line with previous studies [10], [23], [24]. Their studies showed a correlation between tannase activity and the diameter of hydrolytic zone produced by isolates on plate assay.…”

Immobilization of the Tannase From Aspergillus fumigatus CAS21: Screening the Best Derivative for the Treatment of Tannery Effluent Using a Packed Bed Reactor

“…The endophytic fungus Aspergillus fumigatus CAS21 was isolated from the bark of the cashew tree ( Anacardium occidentale L.) ( Cavalcanti et al, 2017 ) and stored in the Laboratory of Microbiology of the Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Brazil. The fungus was maintained on potato dextrose agar (PDA) slants at 37°C for 96 h and then stored at 4°C.…”

“…The fungus was maintained on potato dextrose agar (PDA) slants at 37 °C for 96 h and then stored at 4 °C. The liquid cultures were obtained by means of the inoculation of 1 ml of spore suspension (10 5 spores/ ml) of the A. fumigatus CAS21 in 25 ml of mineral medium containing 0.1% (w/v) peptone and 2% (w/v) tannic acid as additional carbon source (Cavalcanti et al, 2017). The culture medium was previously autoclaved at 120 °C and 1.5 atm for 20 min, and the tannic acid was sterilized by microfiltration using a syringe filter (0.22 μm) before the addition to the medium.…”

Stabilization and application of spray-dried tannase from Aspergillus fumigatus CAS21 in the presence of different carriers

“…The endophytic fungus Aspergillus fumigatus CAS21 was isolated from the bark of the cashew tree (Anacardium occidentale L.) (Cavalcanti et al 2017) and stored in the Laboratory of Microbiology of the Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto at the University of São Paulo, Brazil. The fungus was maintained on Potato Dextrose Agar (PDA) slants at 37 ºC for 96 h and then stored at 4 ºC.…”

“…Submerged cultures (SbmF) were obtained with the inoculation of 1-mL spore suspension (10 5 spores mL −1 ) of the Aspergillus in a medium containing 0.1% (w/v) KH 2 PO 4 , 0.2% (w/v) MgSO 4 •7H 2 O, 0.1% (w/v) CaCl 2 , 0.3% (w/v) NH 4 Cl, and 0.1% (w/v) peptone, and 2% (w/v) tannic acid as additional carbon source. The culture medium was previously autoclaved at 120 °C and 1.5 atm for 20 min, and the tannic acid was sterilized by means of microfiltration using a syringe filter (0.22 μm) before being added to the medium (Cavalcanti et al 2017). The cultures were kept at 37 °C for 24 h and shaking at 120 rpm.…”