Ability of 10 fungi strains for the degradation of ferulic acid and production of vanillic acid was examined. The findings suggested that all the fungi were able to degrade ferulic acid via different pathways producing variety of products. Vanillic acid was the main bioconversion product for all the fungi strains. Aspergillus niger K8 was chosen as a more suitable fungus for conversion of ferulic acid to vanillic acid, due to its highest potential to produce high concentration of vanilic acid (116 mg/l) compared to other fungi. Bioconversion proves was further carried out with Phanerochaetechrysosporium ATCC 24725 for production of vanillin from vanillic acid produced by A. niger K8. The vanillin production (44.8 mg/l) was significant from the economical aspect, due to the cheapness and available source of ferulic acid as a substrate and short time for bioconversion of ferulic acid to vanillic acid.

Rubberwood (Hevea brasiliensis), a potential raw material for bioethanol production due to its high cellulose content, was used as a novel feedstock for enzymatic hydrolysis and bioethanol production using biological pretreatment. To improve ethanol production, rubberwood was pretreated with white rot fungus Ceriporiopsis subvermispora to increase fermentation efficiency. The effects of particle size of rubberwood (1 mm, 0.5 mm, and 0.25 mm) and pretreatment time on the biological pretreatment were first determined by chemical analysis and X-ray diffraction and their best condition obtained with 1 mm particle size and 90 days pretreatment. Further morphological study on rubberwood with 1 mm particle size pretreated by fungus was performed by FT-IR spectra analysis and SEM observation and the result indicated the ability of this fungus for pretreatment. A study on enzymatic hydrolysis resulted in an increased sugar yield of 27.67% as compared with untreated rubberwood (2.88%). The maximum ethanol concentration and yield were 17.9 g/L and 53% yield, respectively, after 120 hours. The results obtained demonstrate that rubberwood pretreated by C. subvermispora can be used as an alternative material for the enzymatic hydrolysis and bioethanol production.