Physicochemical and Microbial Characterization of Maize Cob for Bioethanol Production

Abstract

The overall efficiency of processes designed to convert lignocellulosic biomass to bioethanol depends on determining the compositions of such material. This paper evaluates the physicochemical and microbial characterization of maize cob for bioethanol production. The proximate analysis of the substrate (maize cob) showed a low moisture content of 3.55% which is favourable for biofuel because high moisture content is associated with lower carbon burn rate. In addition, the low crude lipid of 0.96% and low crude protein of 2.63% favours high yield of bioethanol; the remarkable high carbohydrate content of 87.86% also favours high bioethanol yield. The ultimate analysis of the substrate revealed relatively low nitrogen of 0.42% and sulfur content of 1.13% which implies lower amounts of ammonia (NH₃), Hydrogen cyanide (HCN) and Hydrogen Sulphide (H₂S) which are inhibitory to microorganisms. The lower amount of lignin: 10.43% in the dry matter; amount of extractive of 0.15 g was also recorded from the Lignocellulosic composition of the maize cob. Molecular identification showed that microbial isolates were Pichia kudriavzevii strains; the identified microbial isolates are capable of producing amylase and cellulase enzymes for the production of bioethanol. From the aforementioned, the analyzed maize cob is a very promising feedstock for converting the fermentable sugar to bioethanol.