| Abstract | U ovom radu korišten je pivski trop kao supstrat za uzgoj Trametes versicolor u uvjetima fermentacije na čvrstim nosačima. Tijekom rasta mikroorganizma, mjerene su aktivnosti hidrolitičkih enzima (ß-glukozidaza, celulaza, ksilanaza i invertaza), koncentracije ukupnih reducirajućih šećera te koncentracije ukupnog organskog ugljika i dušika. Fermentacija na čvrstim nosačima provedena je pri sljedećim početnim procesnim uvjetima: T = 27°C, t = 15 dana, m (supstrat) = 30 g, početni udio vlage = 64,65 %. Gubitak na masi materijala nakon 15 dana fermentacije iznosio je 25,32 %, a pH supstrata se tijekom fermentacije mijenjao od pH 6,14 do pH 6,62. Najveća volumna aktivnost invertaze postignuta je nakon 14. dana fermentacije i iznosila je V.A. = 331,858 U/mL. Najveća volumna aktivnost ksilanaze postignuta je nakon 15. dana fermentacije i iznosila je V.A. = 104,852 U/mL. Najveća volumna aktivnost β-glukozidaze postignuta je nakon 15. dana fermentacije i iznosila je V.A. = 2,239 U/mL, a najveća volumna aktivnost celulaze V.A. = 0,043 ± 0,005 FPU/mL zabilježena je nakon 14. dana fermentacije. Nakon 15 dana fermentacije došlo je do porasta koncentracije ukupnih reducirajućih šećera (2,9 puta), ukupnog organskog ugljika (2,95 puta) i ukupnog organskog dušika (3,6 puta) u biološki modificiranom pivskom tropu u odnosu na početni uzorak pivskog tropa. Međutim, najveća koncentracija ukupnih reducirajućih šećera izmjerena je nakon 6. dana fermentacije i iznosila je 14,379 mgglukoze/gst, pri čemu je došlo do povećanja koncentracije reducirajućih šećera za 3,4 puta u odnosu na početni uzorak pivskog tropa. |
| Abstract (english) | In this work, brewer’s spent grain was used as a substrate for the cultivation of Trametes versicolor under solid-state fermentation conditions. During the growth of microorganisms, the activities of hydrolytic enzymes (ß-glucosidase, cellulase, xylanase and invertase), the concentration of total reducing sugars and the concentration of total organic carbon and nitrogen were measured. Solid-state fermentation was carried out under the following initial process conditions: T = 27°C, t = 15 days, m (substrate) = 30 g, initial moisture content = 64.65%. The mass loss of material after 15 days of fermentation was 25.32%, and the pH of the substrate varied from pH 6.14 to pH 6.62 during fermentation. The highest volume activity of invertase was achieved after the 14th day of fermentation and was V.A. = 331.858 U/mL The highest volume activity of xylanase was achieved after the 15th day of fermentation and was V.A. = 104.852 U/mL. The highest volume activity of β-glucosidase was achieved after the 15th day of fermentation and was V.A. = 2.239 U/mL, while the highest volume activity of cellulase was measured after the 14th day of fermentation as V.A. = 0.043 FPU/mL. After 15 days of fermentation, there was an increase in the concentration of total reducing sugars (2.9 times), total organic carbon (2.95 times) and total organic nitrogen (3.6 times) in the biologically modified brewer’s spent grain compared to the initial brewer’s spent grain sample. However, the highest concentration of total reducing sugars was measured after the 6th day of fermentation and was 14.379 mgglucose/gst, where the concentration of reducing sugars increased by 3.4 times compared to the initial sample of brewer’s spent grain. |
