3.2. Influence of enzyme complex production operational conditions
on SFH ethanol fermentation performance
S. cerevisiae Y904 was grown in SFS in SRW medium containing
enzymatic extract produced from A. niger ATCC 16404 at different
solid-state fermentation durations, revealing that 12 h of solidstate
fermentation was required to achieve the maximum ethanol
production. Additionally, the reduction in the ethanol production
after 18 h of solid-state fermentation suggested the presence of
inhibitory metabolites in the medium produced during solid-state
fermentation. Based on these results, 12 h of solid-state fermentation
was selected for further experiments (Table 4).
Table 5 shows the results of ethanol production (30 C, pH 4.5,
12 h) at different temperatures (30e45 C) of solid-state fermentation,
revealing that the highest final ethanol concentration was
obtained at 40 C. The optimal temperature depends on the
microorganism and strain employed. Optimal temperatures
ranging from 25 to 50 C are found in the literature [15e17].