Conventional bio-based succinic acid production involves anaerobic bacterial fermentation of pure sugars. This study explored a new route for directly producing succinic acid from minimally-pretreated lignocellulosic biomass via a consolidated bioprocessing technology employing a mixed lignocellulolytic and acidogenic fungal co-culture. The process involved a solid-state pre-fermentation stage followed by a two-phase slurry fermentation stage. During the solid-state pre-fermentation stage, Aspergillus niger and Trichoderma reesei were co-cultured in a nitrogen-rich substrate (e.g., soybean hull) to induce cellulolytic enzyme activity. The ligninolytic fungus Phanerochaete chrysosporium was grown separately on carbon-rich birch wood chips to induce ligninolytic enzymes, rendering the biomass more susceptible to cellulase attack. The solid-state pre-cultures were then combined in a slurry fermentation culture to achieve simultaneous enzymatic cellulolysis and succinic acid production. This approach generated succinic acid at maximum titers of 32.43 g/L after 72 h of batch slurry fermentation (~10 g/L production), and 61.12 g/L after 36 h of addition of fresh birch wood chips at the onset of the slurry fermentation stage (~26 g/L production). Based on this result, this approach is a promising alternative to current bacterial succinic acid production due to its minimal substrate pretreatment requirements, which could reduce production costs.

To improve the efficiency of second-generation bioethanol production, simultaneous Saccharification and Fermentation (SSF) of top agricultural wastes in the Philippines such as rice straw and banana pseudostem was conducted using commercial enzymes and the thermotolerant yeast Kluyveromyces marxianus. Residues were initially subjected to chemical treatment prior to SSF. A constant inoculum loading of 10% vv -1 was introduced during SSF, and mixed with a nutrient supplemented solution. Aside from the enzyme loading, the effect of reaction temperature and reaction time on ethanol concentration was assessed. Among the tested parameters, only reaction time had a significant effect on the bioethanol concentration from both biomasses. For a pre-treated rice straw with 70.93% ww -1 holocellulose, highest ethanol concentration obtained was 6.30+0.44 gL -1 at 45°C, reaction time of 48 h and with enzyme loading of 30 FPUg -1. On the other hand, 5.35+0.29 gL -1 ethanol was achieved from SSF of banana pseudostem with 67.75% ww -1 holocellulose, also at 35°C, at a lower reaction time of 24 h and same enzyme loading of 30 FPUg -1. This study also proves that the thermotolerant K. marxianus was capable of producing bioethanol from lignocellulosics through SSF, thereby considering it as a potential alternative to Saccharomyces cerevisiae for bioethanol production.