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The present study aims to Fabricate a promising Microbial Solar Cell (MSC) for electricity generation using (sludge, wastewater and mixed algae), two single chamber MSCs were applied, firstly the sludge and algae cell (SMSC) was used and factors such as pH, types of light source, temperature, configuration of electrode and mixing ratio have being studied. The best pH, light source, temperature, configuration of electrode, and mixing ratio of the sludge and algae experiment are found to be 7, sun light, 30 oC, square electrode, and 1:1 respectively would be used in the wastewater and algae cell (WWMSC) for finding the most effective substrates for electrical energy generation. By comparing the Voltage resulted from sludge Microbial Solar cell (SMSC) and wastewater Microbial Solar cell (WWMSC). It was found that (SMSC) produce higher electrical energy than (WWMSC) with a voltage equal to 180 mV.

The present study aims to Fabricate a promising Microbial Solar Cell (MSC) for electricity generation using (sludge, wastewater and mixed algae), two single chamber MSCs were applied, firstly the sludge and algae cell (SMSC) was used and factors such as pH, types of light source, temperature, configuration of electrode and mixing ratio have being studied. The best pH, light source, temperature, configuration of electrode, and mixing ratio of the sludge and algae experiment are found to be 7, sun light, 30 oC, square electrode, and 1:1 respectively would be used in the wastewater and algae cell (WWMSC) for finding the most effective substrates for electrical energy generation. By comparing the Voltage resulted from sludge Microbial Solar cell (SMSC) and wastewater Microbial Solar cell (WWMSC). It was found that (SMSC) produce higher electrical energy than (WWMSC) with a voltage equal to 180 mV. [ABSTRACT FROM AUTHOR]

The depletion of fossil fuel for energy production is one of the major problems being faced worldwide. As an alternative to fossil fuels, first and second generation biofuel was developed from corn, grains and lignocellulosic agricultural residues. These generations are inefficient in achieving the desired rate of biofuel production, climate change mitigation and economic growth. Therefore, third generation biofuel specifically derived from microalgae have proved to be a promising unconventional energy source. Microalgae are microscopic organisms that grow in salt or fresh water and have been used for producing metabolites, cosmetics and for energy production. The conventional approaches used for biofuel production include pyrolysis, gasification, direct combustion and thermomechanical liquefaction. The search for biological and eco-friendly approaches led to the emergence of Microbial Fuel Cell (MFC), which provide a new solution to energy crisis. Integration of photosynthetic organisms such as microalgae into MFC resulted in a new approach i.e. Microbial Solar Cell, which can convert solar energy into electrical energy via photosynthesis. Microbial solar cells have broad range application in wastewater treatment, biodiesel processing and intermediate metabolite production.

The depletion of fossil fuel for energy production is one of the major problems being faced worldwide. As an alternative to fossil fuels, first and second generation biofuel was developed from corn, grains and lignocellulosic agricultural residues. These generations are inefficient in achieving the desired rate of biofuel production, climate change mitigation and economic growth. Therefore, third generation biofuel specifically derived from microalgae have proved to be a promising unconventional energy source. Microalgae are microscopic organisms that grow in salt or fresh water and have been used for producing metabolites, cosmetics and for energy production. The conventional approaches used for biofuel production include pyrolysis, gasification, direct combustion and thermomechanical liquefaction. The search for biological and eco-friendly approaches led to the emergence of Microbial Fuel Cell (MFC), which provide a new solution to energy crisis. Integration of photosynthetic organisms such as microalgae into MFC resulted in a new approach i.e. Microbial Solar Cell, which can convert solar energy into electrical energy via photosynthesis. Microbial solar cells have broad range application in wastewater treatment, biodiesel processing and intermediate metabolite production. [ABSTRACT FROM AUTHOR]

This work studies how extracellular electron transfer (EET) from cyanobacteria-dominated marine microbial biofilms to solid electrodes is affected by the availability of inorganic carbon (Ci). The EET was recorded chronoamperometrically in the form of electrical current by a potentiostat in two identical photo-electrochemical cells using carbon electrodes poised at a potential of +0.6 V versus standard hydrogen electrode under 12/12 h illumination/dark cycles. The Ci was supplied by the addition of NaHCO to the medium and/or by sparging CO gas. At high Ci conditions, EET from the microbial biofilm to the electrodes was observed only during the dark phase, indicating the occurrence of a form of night-time respiration that can use insoluble electrodes as the terminal electron acceptor. At low or no Ci conditions, however, EET also occurred during illumination suggesting that, in the absence of their natural electron acceptor, some cyanobacteria are able to utilise solid electrodes as an electron sink. This may be a natural survival mechanism for cyanobacteria to maintain redox balance in environments with limiting CO and/or high light intensity. Graphical Abstract: [Figure not available: see fulltext.][Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The electrochemical activity of two seawater microbial consortia were investigated in three-electrode bioelectrochemical cells. Two seawater inocula – from the Sunshine Coast (SC) and Gold Coast (GC) shores of Australia – were enriched at +0.6 V vs. SHE using 12/12 h day/night cycles. After re-inoculation, the SC consortium developed a fully-reversible cathodic/anodic current, with a max. of −62 mA m −2 during the day and +110 mA m −2 at night, while the GC exhibited negligible daytime output but +98 mA m −2 at night. Community analysis revealed that both enrichments were dominated by cyanobacteria, indicating their potential as biocatalysts for indirect light conversion to electricity. Moreover, the presence of γ-proteobacterium Congregibacter in SC biofilm was likely related to the cathodic reductive current, indicating its effectiveness at catalysing cathodic oxygen reduction at a surprisingly high potential. For the first time a correlation between a dual microbial community and fully reversible current is reported. [ABSTRACT FROM AUTHOR]

The shortage of sustainable energy and the extensive environmental pollution along with the global warming effect caused by CO 2 emissions are major problems facing the world today. The use of microalgae to overcome these problems has gained enormous research interests in recent years, primarily due to their ability to convert CO 2 by photosynthesis into potential biomass. The merging of such phototrophic organisms into microbial fuel cells (MFCs) is an interesting option since they can act as efficient in situ oxygenators, thus facilitating the cathodic reaction of photosynthetic microbial fuel cells (PMFCs). Also, microalgae can support the efficient removal of phosphorus and nitrogen, as the MFC technology cannot stand-up alone in this field. But such PMFC configurations does possess several challenges, among which PMFC design, output current and sustainability are the major bottlenecks encountering large scale implementation for electricity generation in a cost-effective way. This review goes beyond previous research work by providing not only a detailed update on the current PMFC configurations, but also the critical operational parameters of PMFC, with a scope that extends to cover all types of direct or indirect integration of phototrophic microbes within MFC technology. [ABSTRACT FROM AUTHOR]

Biological energy-conversion systems are attractive in terms of their self-organizing and self-sustaining properties and are expected to be applied towards environmentally friendly bioenergy processes. Recent studies have demonstrated that sustainable light/electricity-conversion systems, termed microbial solar cells (MSCs), can be constructed using naturally occurring microbial communities. To better understand the energy-conversion mechanisms in microbial communities, the present study attempted to construct model MSCs comprised of defined cocultures of a green alga, Chlamydomonas reinhardtii, and an iron-reducing bacterium, Geobacter sulfurreducens, and examined their metabolism and interactions in MSCs. When MSC bioreactors were inoculated with these microbes and irradiated on a 12-h light/dark cycle, periodic current was generated in the dark with energy-conversion efficiencies of 0.1%. Metabolite analyses revealed that G. sulfurreducens generated current by oxidizing formate that was produced by C. reinhardtii in the dark. These results demonstrate that the light/electricity conversion occurs via syntrophic interactions between phototrophs and electricity-generating bacteria. Based on the results and data in literatures, it is estimated that the excretion of organics by the phototroph was the bottleneck step in the syntrophic light/electricity conversion. We also discuss differences between natural-community and defined-coculture MSCs. [Copyright &y& Elsevier]

Biological energy-conversion systems are attractive in terms of their self-sustaining and self-organizing nature and are expected to be applied to low-cost and environment-friendly processes. Here we show a biofilm-based light/electricity-conversion system that was self-organized from a natural microbial community. A bioreactor equipped with an air cathode and graphite-felt anode was inoculated with a green hot-spring microbial mat. When the reactor was irradiated with light, electric current was generated between the anode and cathode in accordance with the formation of green biofilm on the anode. Fluorescence microscopy of the green biofilm revealed the presence of chlorophyll-containing microbes of ∼10 µm in size, and these cells were abundant close to the surface of the biofilm. The biofilm community was also analyzed by sequencing of polymerase chain reaction-amplified small-subunit rRNA gene fragments, showing that sequence types affiliated with Chlorophyta, Betaproteobacteria, and Bacteroidetes were abundantly detected. These results suggest that green algae and heterotrophic bacteria cooperatively converted light energy into electricity. [ABSTRACT FROM AUTHOR]

The article focuses on a research regarding the use of algal biomass for electricity generation. It informs that researchers developed a mixture of Lactobacillus, an alga-digesting microorganism, and Geobacter, an iron-reducing, for generating electricity from photo-grown Clamydomonas cells. Other topics included microbial fuel cells (MFCs), microbial solar cell (MSCs) and power conversion efficiency (PCE).