Evaluation of Algal Biofilms on Indium Tin Oxide (ITO) for Use in Biophotovoltaic Platforms Based on Photosynthetic Performance

Abstract

In photosynthesis, a very small amount of the solar energy absorbed is transformed into chemical energy, while the rest is wasted as heat and fluorescence. This excess energy can be harvested through biophotovoltaic platforms to generate electrical energy. In this study, algal biofilms formed on ITO anodes were investigated for use in the algal biophotovoltaic platforms. Sixteen algal strains, comprising local isolates and two diatoms obtained from the Culture Collection of Marine Phytoplankton (CCMP), USA, were screened and eight were selected based on the growth rate, biochemical composition and photosynthesis performance using suspension cultures. Differences in biofilm formation between the eight algal strains as well as their rapid light curve (RLC) generated using a pulse amplitude modulation (PAM) fluorometer, were examined. The RLC provides detailed information on the saturation characteristics of electron transport and overall photosynthetic performance of the algae. Four algal strains, belonging to the Cyanophyta (Cyanobacteria) Synechococcus elongatus (UMACC 105), Spirulina platensis. (UMACC 159) and the Chlorophyta Chlorella vulgaris (UMACC 051), and Chlorella sp. (UMACC 313) were finally selected for investigation using biophotovoltaic platforms. Based on power output per Chl-a content, the algae can be ranked as follows: Synechococcus elongatus (UMACC 105) (6.38×10−5 Wm−2/µgChl-a)>Chlorella vulgaris UMACC 051 (2.24×10−5 Wm−2/µgChl-a)>Chlorella sp.(UMACC 313) (1.43×10−5 Wm−2/µgChl-a)>Spirulina platensis (UMACC 159) (4.90×10−6 Wm−2/µgChl-a). Our study showed that local algal strains have potential for use in biophotovoltaic platforms due to their high photosynthetic performance, ability to produce biofilm and generation of electrical power.

Interaction of bacteria and archaea in a microbial fuel cell with ITO anode

“…17 From the level of microbial communities, observing the anode can supplement highthroughput sequencing. From the level of the microstructure of microorganisms, it can provide direct evidence of electrochemically active microbe (EAM) nanowires.…”

Effect of different irradiance levels on bioelectricity generation from algal biophotovoltaic (BPV) devices

“…5 The use of suspension algal cultures to biofilms 6 and finally alginate-immobilized systems 7 resulted in further increase in power density. 5 The use of suspension algal cultures to biofilms 6 and finally alginate-immobilized systems 7 resulted in further increase in power density.…”

“…For the immobilized algae BPV device, the anode had the algal-alginate film (prepared as described in Section 2.2) attached to its surface ( Figure 1) and was sealed with polydimethylsiloxane (PDMS) before 2 mL Bold's Basal Medium was loaded to the device. 5,6,37 Crocodile clips and copper wires were used to connect the anode and cathode to the external circuit. 5,6,37 Crocodile clips and copper wires were used to connect the anode and cathode to the external circuit.…”

“…6 Excess light energy from photosynthesis will not be stored by photosynthetic plants but it will be converted into heat energy to be released. Rapid light curves (RLC) were generated when the algae cells were exposed to actinic light emitted by LEDs at different irradiance levels.…”

Evaluation of Photocurrent Generation from Different Photosynthetic Organisms

“…Earlier a series of photosynthetic organisms were evaluated in BPVs e. g., Ng et al. investigated sixteen different algal strain biofilms on indium tin oxide for photocurrent generation, McCormick et al. reported mediator‐less BPV system based on photosynthetic biofilms in pure culture .…”