Microbial fuel cell (MFC) is an alternative way for household organic waste treatment as it produces sustainable clean energy. Chemical parameters of the cauliflower leaf waste before treatment were 143.5 mg/g COD, 0.90 mg/g ammoniacal nitrogen, 67.8 mg/g phosphorous, 214.8 mg/g total reducing sugar and 0.53 mg/g soluble reducing sugar. After eight days of treatment in MFC at the optimised condition of multiwalled carbon nanotubules (MWCNT)’ coated graphite as anode and potassium ferricyanide added phosphate buffer as catholyte with an external resistance of 1000 Ω showed a reduction in COD, ammoniacal nitrogen, phosphorous and total reducing sugar by 24.7, 76.9, 22.5 and 53.4%, respectively, along with a maximum power density of 10.1 W/m³. Scanning electron microscopy (SEM) showed bacterial adherence in the graphite electrode and its molecular characterisation using 16S rRNA sequencing confirmed as Bacillus sps.

In view of crude oil prices, and its environmental issues, utilization of sustainable renewable alternative energies such as biofuels is rapidly progressing in many countries. The increasing global energy demand and depleting fossils fuels sources has led to search alternative clean and renewable fuels. One of the best alternatives to the gasoline is lignocellulosic bioethanol. Recent researches on lignocellulosic bioethanol focuses on advancement of pretreatment techniques for improved sugar yields and decreased inhibitors production. Pretreatment technique with no or less use of chemicals and cost effectiveness is the main purpose of most of the researches. Biological pretreatment techniques produce less fermentation inhibitors than chemical pretreatments. In order to cope with fermentation inhibitors different strategies can be adopted during pretreatment processes. In the course of time, advancements in production process over separate hydrolysis and fermentation have been introduced. Simultaneous saccharification and co/fermentation; and consolidated bioprocessing for bioethanol production are gaining popularity among researchers. Int. J. Appl. Sci. Biotechnol. Vol 10(1): 1-11.

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.