Abstract
Indonesia is home of approximately 19 million ha of peat soils, where sago palm can grow well without intensive input as other crops do. Due to the increasing of international oil price, Indonesian governments stated national policy to have bioethanol in fuel mixture which may be achieved from sago starch. However, the efficiency of sago starch extraction process is still not adequate. In order to extract 1 kg of starch, 0.6 kg dry matter residue (31% starch and 40% fi ber) will be generated and disposed as polluting materials to the environment. In this study, sago extraction residue (SER) was used for bioethanol production through simultaneous saccharifi cation and fermentation (SSF). The microorganisms involved during SSF experiments were Aspergillus awamori, Trichoderma reesei and Saccharomyces cerevisiae. The bioethanol produced on SSF was 10.9 and 10.4 g/l from 50 g/l of SER solution at cocultures of A. awamori and S. cerevisiae, and cocultures of A. awamori, T. reesei, and S. cerevisiae, respectively. The starch utilization of the SER was about 88%. The fiber was only 5% converted to bioethanol due to the low cellulase activity produced by T. reesei on cocultures. However, the overall results indicated sago extraction residue was a good substrate as bioethanol feedstock.
