Delignification of banana pseudostem by the enzymatic culture broth of Pleurotus sajor-caju

The lignocellulosic materials from plant biomass are composed of cellulose, hemicellulose and lignin and must be decomposed for use in the industry, since they have compact fibrillar formation of difficult degradation. The decomposition can be carried out using acids, bases, or lignocellulolytic enzymes. In this work, delignification of the banana pseudostem was accessed using acid and enzymatic treatment with enzymes produced by the fungus Pleurotus sajor-caju. The culture was carried out in Erlenmeyer flasks containing Manachini solution with 10 g L-1 of pseudostem bran as substrate. The flasks were inoculated with P. sajor-caju and after 14 days of incubation the suspension was vacuum filtered to obtain the enzyme culture broth. In the first treatment (PAE - pseudostem with acid and enzymatic treatment), thermogravimetric results indicated a mass loss of 59% relative to cellulose and hemicellulose and the release of 8.23 g L-1 of reducing sugars. In the second treatment (PAEI - pseudostem with acid treatment and inactivated enzyme), the thermogravimetric results indicated loss of mass of 54.5% of cellulose and hemicellulose and the release of 5.18 g L-1 of reducing sugars. In the third treatment (PE - pseudostem without acid treatment and with enzymatic treatment), the action of the enzymatic broth of P. sajor-caju promoted loss of mass of 56.6% of cellulose and hemicellulose and 6.12 g L-1 reducing sugars. Compared with the FP sample (pseudostem bran without acid or enzymatic treatment), there was a 25.85% and 43.4% reduction in the lignin content in PAE and PE samples, respectively. The results point to the potential of the enzymatic broth of P. sajor-caju in the delignification of the banana pseudostem.