Isolation of microorganisms from cassava peels for the production of bioethanol

Abstract

This study investigates the production of bioethanol from cassava peels using the inherent isolated microorganisms. Cassava peels were collected from cassava processing unit in selected towns in Ekiti State. Microorganisms were isolated from the cassava peels by using pour plate method; the isolates were identified by different biochemical tests and molecular characterization. The bacterial isolates include, Sporosarcina terrae, Bacillus cereus, Proteus mirabilis and Pseudomonas taiwanensis; while the fungal isolates include yeast (Wickerhamomyces rabaulensis), Rhizopus and Aspergillus niger. The entire bacterial isolates and A. niger tested positive to degradative test, while only W. rabaulensis tested positive to fermentation test. Four bacterial species were detected using 16S rDNA nucleotide sequence. High yields of the bioethanol was obtained using the combination of different inoculants, however the combination of B. cereus and W. rabaulensis produced the highest yield of 19.3 g/cm3 at a concentration of 38.6% and 17.7 g/cm3 at a concentration of 34.4% from 100g of cassava peels when distilled at 14 days and 21 days respectively. Yields of 562.31g/cm3 (67.0%) and 481.9g/cm3 (65%) of bioethanol were obtained from 5 kilograms (Kg) of cassava peels with a combination of B. cereus and W. rabaulensis and a combination of P. taiwanensis and W. rabaulensis respectively. The results of this study confirmed that bioethanol can be produced from cassava peels using the inherent isolated microorganisms as it is simple to produce, environmental friendly. and reliable therefore, healthy environment, wealth and energy generation from wastes (cassava peels) is assured in Ekiti State.