초록
<P><B>Highlights</B></P><P>► This research was focused on the SSF by deoiled <I>Jatropha curcas</I> seed cake for protease productions by <I>Aspergillus oryzae</I>. ► The optimum conditions were attained from the design of experiment via Taguchi method. ► They were moisture (45%), inoculums (10%), incubated temp. (30°C), mixed sub. (cassava bagasse), and incubated time (84h). ► The protease production based on this approach increased up to 4.6 times more than that of the non-optimizing experiment.</P> <P><B>Abstract</B></P><P>The oil extraction of <I>Jatropha curcas</I> created the large amount of the by-product from its seeds. An application of solid-state fermentation (SSF) was considered to be of value to these raw materials. This study investigated the potential of a utilization of deoiled <I>J. curcas</I> seed cake as substrate for protease productions by <I>Aspergillus oryzae</I>. While various parameters for SSF was conventionally individually optimized, five parameters were simultaneously examined based on Taguchi method. The effect of three different levels of five factors, including moisture content of substrate, inoculums size, incubation temperature, type of porous substrate and incubation time were examined. The optimum conditions for the protease production by <I>A. oryzae</I> obtained from this experiment were 45% moisture content of substrate, 10% inoculums size, 30°C incubation temperature, deoiled <I>J. curcas</I> seed cake mixed with cassava bagasse ratio 4:1 as porous substrate at 84h of incubation time. By adjusting the conditions to these optimum levels, the protease production increased up to 4.6 times as many as the protease yield from the non-optimizing experiment. The use of statistical approach, Taguchi method, provided a satisfactory outcome in defining the optimum conditions for protease production by <I>A. oryzae</I>. Further, the utilization of deoiled <I>J. curcas</I> seed cake as substrate for SSF was proven as the suitable practice for this agricultural waste, in order to develop for an industrial use.</P>