Bioethanol Production from Eucalyptus camaldulensis Wood Waste Using Bacillus subtilis and Escherichia coli Isolated from Soil in Afaka Forest Reserve, Kaduna State Nigeria

Abstract

The economic and ecological problems associated with fossil fuel have raised interest in biofuel research in recent times in different parts of the world. The use of Eucalyptus forest waste biomass with no appreciable value to industries or for food as alternative and cost effective feedstock for bioethanol production was evaluated in this study. E. camaldulensis biomass (bark and leaves) were pretreated separately with acid (2M H2SO4) and Microwave irradiation (250V, 50Hz) prior to fermentation with Bacillus subtilis and Escherichia coli isolated from surrounding soil. Higher yield of reducing sugar were obtained from bark (43 %) and leaves (38.5 %) pretreated by microwave irradiation as compared with acid treated plant biomass. Similarly, Bioethanol volume and concentration of 34.89 g/l and 0.51 % respectively were higher in Microwave irradiated bark of E. camaldulensis at 21 days of fermentation when E. coli and B. subtilis were used in synergy The least bioethanol volume yield of 18.79 g/l and concentration of 0.12 % when bark and leaves of E. camaldulensis were combined was obtained on day 7 of fermentation using E. coli. The study concludes that the amount of dried wastes generated (37.8 kg) from one average stand of Eucalyptus tree could yield significant volume (131,884.2 g/l) of bioethanol when B. subtilis and E. coli are used in synergy.