Determinação de condições ideais para a produção de poligalacturonase por Kluyveromyces marxianus

Abstract

Pectinolytic enzymes can be synthesized by bactéria, fungi and yeasts. They present industrial importance, mainly in the proccessing offruit juices and wines, têxtil fiber treatments, in the fermentation of cocoa and coffee. The optimization of growing conditions, associated with the choice of suitable lines can lead to an emproved enzyme production.. This work was developed with a view to screening and defining better parameter concentrations to be utilized in fermemtation media by utilizing a saturated fraction fàctorial planning 2(7-4) and another of2(5"2). The enzyme activity was given in mg ofrealesed galacturonic acid/ml. The parameters selected for the fermentation médium were: sugar cane broth as a carbon source, ammonium sulphate as a nitrogen source and citric pectin as a stimulator. Both pH and shaking were established in constant values of 5,0 and 150 rpm, respectively. In orderto define the best concentrations of the selected parameters, a swkch compost central experimental design ofresponse surface offàctorial 53 and 52 was utilized. According to response surface models employed, it is possible to conclude for maximal activity ofpolygalacturonase enzyme to be obtained sugar cane broth should be utilized at concentrations between 9,17 to 14,83 °Brix, supplemented wfíh ammonium sulphate and pectin at concentrations between 0,40 to 0,58 g/100 ml and 0,50 to 1,05 g/lOOml, respectively