| Abstract | Lignocelulozne sirovine poput drvnih ostataka najčešće ostaju neiskorištene, a jeftina su i lako dostupna sirovina za proizvodnju biokemikalija, npr. bioetanola. Glavni nedostatak upotrebe takvih sirovina je potreba za provođenjem procesa predobrade i hidrolize što poskupljuje proces proizvodnje biokemikalija. U ovome radu provedena je enzimska hidroliza (50°C, pH 5) kiselinski predobrađenog čvrstog dijela bukve u 0,01 M acetatnom puferu, pomoću enzima Viscozyme L (5 % vol volˉ¹) i Cellulase enzyme blend (2 % vol volˉ¹). Dobiveni hidrolizat korišten je za uzgoj kvasca P. stipitis pri različitim uvjetima temperature (25, 29 i 33°C), pH vrijednosti (3,7, 4,4 i 5,1), stupnja aeracije te sastava podloge. Među dobivenim produktima zabilježena je značajnija koncentracija etanola u rasponu od 7,54 do 14,5 g Lˉ¹. |
| Abstract (english) | Lignocellulosic raw materials like wood residues are mostly left unused, but they are cheap and easy available raw material for production of biochemicals, e.g. bioethanol. The main problem with utilization of such raw materials is the necessary pretreatments and hydrolysis that ultimately increase the cost of the production process. In this work, enzymatic hydrolysis (at 50°C, pH 5) of solid phase obtained by acid pretreatment of beech wood chips was preformed, in 0,01 M acetate buffer using Viscozyme L (5 % vol volˉ¹) and Cellulase enzyme blend (2% vol volˉ¹). The resultnig beech hydrolysate was used for cultivation of yeast Pichia stipitits at various pH (3,7, 4,4, 5,1) and temperature (25, 29, 33°C) conditions, as well as various aeration rates and media composition. Among the products obtained, a significant concentration of bioethanol was recorded, in the range from 7,54 to 14,5 g Lˉ¹. |
