초록
<P><B>Abstract</B></P> <P>We evaluated the production of bioH<SUB>2</SUB> from Cassava Processing Wastewater (CPW) using three microbial consortia (<B> <I>Vac, Esg,</I> </B> and <B> <I>Lod</I> </B>) from different Brazilian environments. These consortia consisted of bacteria of the genera <I>Clostridium, Sporanaerobacter, Coprococcus, Enterococcus,</I> and others. The CPW was supplemented with nitrogen and used raw or hydrolyzed and sterilized or not. Four independent variables were optimized (Box-Behnken design): pH, temperature, C/N ratio, and inoculum ratio. Three quadratic models were obtained and explain production of bioH<SUB>2</SUB> (R<SUP>2</SUP> of 0.93, 0.87 and 0.82 for the consortia <I>Vac</I>, <I>Esg</I> and <I>Lod,</I> respectively). The quadratic effects were the most significant in comparison to linear effects and interactions. The optimal conditions were: pH: 5.5–7.0; temperature 37-39 °C; inoculum ratio 15%, and C/N ratio 5-3,5. After 48 h, the maximum yields of hydrogen obtained with hydrolyzed and sterilized CPW were 1.82, 1.7 and 1.68 mols of H<SUB>2</SUB>/mol of maltose for <I>Lod</I>, <I>Esg</I> and <I>Vac</I>, respectively. While, for the only sterilized substrate the yields are in the range 1.33–1.54 mol H<SUB>2</SUB>/mol maltose.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three new thermally treated microbial consortia were used to produce bioH<SUB>2</SUB>. </LI> <LI> The conditions for the production of bioH<SUB>2</SUB> were optimized for each consortium. </LI> <LI> Linear and quadratic effects were much more important than interaction effects. </LI> <LI> In the consortia, the <I>Clostridum</I> genus had significant relatively high abundance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>