Preservation of mannanase <i>Eupenicillium javanicum</i> (BS4) in solid state fermentation using glycerol and polyol

Abstract

The digestibility of palm kernel meal can be increased using mannanase. Enzyme application in the field requires a preservation process. The aim of this study was to evaluate the stability of liquid Eupenicillium javanicum BS4 mannanase resulting from solid state fermentation with the addition of a preservative (glycerol, sorbitol, or mannitol) at storage temperatures of 4 °C and at room temperature. Enzymes were produced using solid state fermentation with coconut cake as substrate and E. javanicum BS4 inoculum. The preservation evaluated the stability of the enzyme in three conditions: in submerged culture and solid state fermentation, filtration and non-filtration treatments, and different concentrations of the preservative. Each treatment was added with each preservation agent and included a negative control. Enzyme activity (U/mL) and saccharification activity (U/mL) were observed during incubation. The half-life of the enzyme activity was determined by the log curve of the enzyme activity. The half-life of the enzyme under solid state fermentation was longer than enzyme-submerged culture. Filtration treatment produced more stable results. The addition of mannitol and sorbitol (polyol) at a concentration of 20% gave similar results during incubation. Increasing the concentration of mannitol was not possible at it caused crystallization. Although the enzyme activity and saccharification fluctuated over the incubation period, 30% sorbitol was the best preservative. The results of saccharification can be used as a parameter in the field for determining enzyme addition to feed containing high palm kernel meal.