title: Conversion of orange peel waste biomass to bioelectricity using a mediator-less microbial fuel cell.
abstract: Microorganisms have the potential to become a game-changer in sustainable energy production in the coming generations. Microbial fuel cells (MFCs) as an alternative renewable technology can capture bioenergy (electricity) from carbon-based sources by utilizing microorganisms as biocatalysts. This study demonstrated that MFC technology can be explored for bioelectricity production from orange peel waste (OPW), an agricultural byproduct and an organic substrate, without any chemical pretreatment or the addition of extra mediators. A maximum voltage generation of 0.59 ± 0.02 V (at 500 Ω) was achieved in a dual chamber MFC during stable voltage generation stages. The maximum power density and current density obtained were 358.8 ± 15.6 mW/m(2) and 847 ± 18.4 mA/m(2), respectively. Key components of OPW, namely pectin and cellulose, were also tested in their pure form, with pectin giving a stable current, while no significant current generation was achieved using cellulose alone as the substrate, thus demonstrating the absence of cellulose-degrading bacteria. Maximum pectinase and polygalacturonase enzyme activities of 18.55 U/g and 9.04 U/g (per gram of substrate), respectively were achieved during orange peel degradation in MFCs. Bacterial identification using 16S rRNA analysis of the initial inoculum fed to the MFC, the biofilm attached to the anode, and the anode suspension, showed significant diversity in community composition. A well-known exoelectrogen, Pseudomonas, was present among the predominant genera in the anode biofilm.
authors.affiliation: Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
authors.forename: Waheed
authors.initials: W
authors.lastname: Miran
authors.affiliation: Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
authors.forename: Mohsin
authors.initials: M
authors.lastname: Nawaz
authors.affiliation: Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
authors.forename: Jiseon
authors.initials: J
authors.lastname: Jang
authors.affiliation: Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea. Electronic address: daesung@knu.ac.kr.
authors.forename: Dae Sung
authors.initials: DS
authors.lastname: Lee
mesh_terms: D001419:Bacteria; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D018441:Biofilms; D018533:Biomass; D002482:Cellulose; D004560:Electricity; D004566:Electrodes; D012037:Refuse Disposal
chemical_list: D002482:Cellulose
keywords: Bioconversion; Enzyme activity; Microbial community; Microbial fuel cell; Microbial growth; Waste treatment