초록
<P><B>Abstract</B></P><P>During the fermentative processes with <I>R</I><I>hizopus oryzae</I> CCT 7560 and <I>T</I><I>richoderma reesei</I> QM 9414, the effects of rice hull and moisture content on the endoglucanase and total cellulase activities were investigated by response surface methodology, employing a central composite rotatable design. The nutrient solution and bioreactor design were also studied. In tray bioreactors maximum cellulase activity was achieved with 82.5% of rice hull and 17.5% of rice bran, with an initial moisture content of 30% for <I>R</I><I>hizopus</I>, while 100% of rice hull with an initial moisture content of 50% was used for <I>T</I><I>richoderma</I> in Erlenmeyer bioreactors. The results obtained for <I>R</I><I>hizopus</I> were 91% higher for endoglucanase when compared with <I>T</I><I>richoderma</I>, confirming the potential of the newly isolated <I>R</I><I>. oryzae</I> CCT 7560 for cellulase production. In addition, this provided an economical and environmentally viable destination for one of the biggest wastes resulting from the rice industry, the rice hull.</P><P><B>Practical Applications</B></P><P>Most cellulases related in the literature are obtained from fermentative processes employing genetically modified microorganisms during extensive time to achieve maximum activity. The microorganism studied in this work (<I>R</I><I>hizopus oryzae</I> CCT 7560) exhibited rapid enzymatic production indicating its use to obtain digestible carbohydrates from agribusiness waste in a quick and safe way.</P>