Fungal consortium of a cellulolytic isolate F1 (Aspergillus niger) and/or ligninocellulolytic isolate F2 (Ganoderma sessile) along with Saccharomyces cerevisiae (CDBT2) were used for integrated approach of saccharification, fermentation and electrofermentation of Saccharum spontaneum biomass to produce ethanol. Different consortium sets of these isolates were used to observe fermentation efficiency. All the analysis were done using crude as well as hot water pretreated S. spontaneum powder to compare the ethanol production efficiency. The ethanol yield was found to be higher in crude biomass compared to hot water pretreated S. spontaneum biomass. At 28°C, 80 rpm and 5.0 pH, simultaneous culture with combination of G. sessile and CDBT2 produced higher amount of ethanol (57 mg/g crude biomass) followed by combination of G. sessile, A. niger and CDBT2 (44 ± 0.18 mg/g crude biomass). However, the amount of phenol and furfural generated were very low in both cases. In addition, electro-fermentation enhanced ethanol production by 12% and 18% with a combination culture of G. sessile, CDBT2 and G. sessile, A. niger, CDBT2 respectively. This method of lignocellulosic ethanol production by simultaneous saccharification and electrofermentation can be developed as an alternative approach for cost effective production of bioethanol.

Biogas has long been used as a household cooking fuel in many tropical counties, and it has the potential to be a significant energy source beyond household cooking fuel. In this study, we describe the use of low electrical energy input in an anaerobic digestion process using a microbial electrochemical cell (MEC) to promote methane content in biogas at 18, 28, and 37 °C. Although the maximum amount of biogas production was at 37 °C (25 cm³), biogas could be effectively produced at lower temperatures, i.e., 18 (13 cm³) and 28 °C (19 cm³), with an external 2 V power input. The biogas production of 13 cm³ obtained at 18 °C was ~65-fold higher than the biogas produced without an external power supply (0.2 cm³). This was further enhanced by 23% using carbon-nanotubes-treated (CNT) graphite electrodes. This suggests that the MEC can be operated at as low as 18 °C and still produce significant amounts of biogas. The share of CH₄ in biogas produced in the controls was 30%, whereas the biogas produced in an MEC had 80% CH₄. The MEC effectively reduced COD to 42%, whereas it consumed 98% of reducing sugars. Accordingly, it is a suitable method for waste/manure treatment. Molecular characterization using 16s rRNA sequencing confirmed the presence of methanogenic bacteria, viz., Serratia liquefaciens and Zoballella taiwanensis, in the inoculum used for the fermentation. Consistent with recent studies, we believe that electromethanogenesis will play a significant role in the production of value-added products and improve the management of waste by converting it to energy.