Biosensing of algal‐photosynthetic productivity using nanostructured bioelectrochemical systems

Abstract

BACKGROUND Microalgae have attracted worldwide interest resulting from their extensive applications in renewable energy and biomass production. However, in algal fuel cells, photosynthetically evolved oxygen hinders the use of algal biofilms formed at the anode surface. Here, nanostructured bio‐electrochemical systems have been designed to explore the algal bio‐electrochemistry at different illumination and growth conditions. RESULTS Three algal strains were screened for their exoelectrogenic activity and the possibility of direct electron transfer to the chemically modified surfaces. After adjusting light and dark conditions and medium compositions, oxygen production within the fuel cells was regulated. At the anode surface, the obtained bioelectrochemical responses and the morphological characterizations suggested that Oscillatoria agardhii has the potential to serve as electron donor and the nanostructured surface is the final electron acceptor. To that end, dual‐chamber algal fuel cells were constructed and glucose (10 g L–1) was used as carbon source. CONCLUSION Power density of 26.8 mW m–2 was produced using the biofilm formed by O. agardhii. Eventually, the consumption of organic waste was monitored, whereas the chemical oxygen demand removal reached 82%. © 2019 Society of Chemical Industry

Microbial Sensing and Removal of Heavy Metals: Bioelectrochemical Detection and Removal of Chromium(VI) and Cadmium(II)

“…Cell wall components of microorganisms and pigments could have active metal sorption sites that are able to accumulate cadmium and lead simultaneously [ 26 , 27 , 28 , 29 ]. Amongst biosensors used techniques for online evaluation of microbial activity and intra/extracellular functions, microbial electrochemical systems (MESs) were developed and applied in many applications [ 30 , 31 , 32 , 33 , 34 , 35 ].…”

Microbial Electrochemical Systems: Principles, Construction and Biosensing Applications

“…MESs were shown to be the most effective way for studying and understanding the role of the conductive solid surfaces and the environment in biofilm formation [4,72,73]. Bioelectrochemical analysis of the biofilm formation at different electrode modifiers was conducted to understand the influence of the electrode materials on the biofilm progression [11,74]. In addition to morphological characterization using microscopic techniques, cyclic voltammetry (CV) is another technique that can be used for monitoring the online formation of biofilms and their electrochemical activity [75,76].…”

“…Hence, earlier efforts were made to employ the measurement of dissolved oxygen consumption by living cells as a direct measure of the microbial survival [ 7 ]. Consequently, the electron transfer process from living-microorganisms towards electrodes in MES is exploited in microbial fuel cells [ 8 , 9 ] or diagnostic tools for rapid assessment of microbial activity [ 10 , 11 , 12 ]. In these regards, many MES approaches were designed and tested for biological purposes [ 13 , 14 , 15 , 16 ].…”

“…Basically, in the non-mediated microbial electrochemical systems, metabolically active microorganisms and electrodes are directly communicating together through the formation of electro-active biofilms [ 4 , 11 , 55 , 56 ]. In fact, the biofilms are a mixture of heterogeneous communities of microbial cells surrounded by a condensed layer of exopolysaccharides matrix (EPSs), and are strongly adhered to living tissues or solid surfaces [ 57 , 58 ].…”

“…Owing to their unique characteristics such as high surface-to-volume ratio, electrocatalytic activity, electrical and mechanical properties, nanomaterials have intensively studied for use in MESs particularly for accelerating the electron transfer [ 11 , 155 , 156 ] and promote microbial-electrode adherence and biofilm formation [ 138 , 157 ].…”