Enhanced Extracellular Polysaccharide Production and Self-Sustainable Electricity Generation for PAMFCs byScenedesmussp. SB1

Abstract

In this study, a freshwater microalga, Scenedesmus sp. SB1, was isolated, purified, and identified by its internal transcribed spacer region (ITS1-5.8S-ITS2). Media optimization through the Plackett–Burman Design and response surface methodology (RSM) showed a maximum exopolysaccharide (EPS) production of 48 mg/L (1.8-fold higher than that for unoptimized media). Characterization using gas chromatography–mass spectrometry, Fourier transform infrared, X-ray diffraction, and thermogravimetric analysis reveals that the EPS is a sulfated pectin polysaccharide with a crystallinity index of 15.2% and prompt thermal stability. Furthermore, the photoelectrogenic activity of Scenedesmus sp. SB1 inoculated in BG-11 and RSM-optimized BG-11 (ROBG-11) media was tested by cyclic voltammogram studies, revealing the potential of the inoculated strain in ROBG-11 toward photosynthetic algal microbial fuel cells over normal BG-11. To the best of our knowledge, functional group characterization, physical and thermal property and media optimization for EPS production by RSM and electrogenic activity studies are reported for the first time in Scenedesmus sp. SB1.

Nutrient cycling in supraglacial environments of the Dark Zone of the Greenland Ice Sheet

“…One mechanism of possible retention is the production of extracellular polymeric substances (EPS). Algae and bacteria produce EPS which can alter the physical and chemical environment around their cells (Angelaalincy et al, 2017;Stibal et al, 2012a). For example, it has been shown that EPS are used by cyanobacteria in cryoconite holes to bind mineral particles together creating the cryoconite granules at the bottom of the hole (Yallop et al, 2012;Musilova et al, 2016;Stibal et al, 2012b).…”

Closing the life cycle of the pharmaceutical ingredients from biological origin a green interface to waste management

“…It is reported that increases in bacterial growth generate more exopolysaccharides. 15 RCB contributes increasing lipids and carbohydrates for GS1 to GS3 Figure 5. Frequency displacement observed in AMIDE regions for GS1 to GS3 respect from LB control, indicates a change of protein sources in the media composition, and could be responsible for the higher growing rates obtained in the design media Figure 5.…”

Biofilm Engineering Approaches for Improving the Performance of Microbial Fuel Cells and Bioelectrochemical Systems

“…The types of MFCs that operate with a trielectrode system are commonly employed in electrochemical studies (Angelaalincy et al, 2017). The setup consists of three electrodes: the working electrode which acts as a cathode, mostly made up of glassy carbon or platinum electrode that accommodates the microbial consortium; the counter electrode, that functions as the electricity conductor and the reference electrode which is the standard electrode made up of silver in potassium chloride or silver.…”

“…In such cases, it is inferred that, not the density of the biofilms, but the active electron transferring live organisms present in the outer layer of the biofilms, contribute to the high current generation of the system (Sun et al, 2016). In composition, apart from EPS, the biofim is also comprised of a major portion of polysaccharides and minor portions of glycoproteins, proteins, glycolipids, and negligible amount of nucleotides and in rare cases, some metals (Angelaalincy et al, 2017) that contribute to the structural and functional outlook of the biofilm. However, EPS comprises the major component of the biofilm matrix.…”

“…To be more specific, the lipopolysaccharides (LPS) and exopolysaccharides (EPS) alongs with quorum sensing (QS) signaling molecules prescribe the fate of biofilms formation (Nocelli et al, 2016). Henceforth, it is clear that the factors that externally influence EPS production, quorum sensing signaling molecules production and other stress factors such as heavy metal stress (Chen et al, 2015), salinity (Hong et al, 2016), pH (Christenson, 2011), nutrient starvation (Angelaalincy et al, 2017), nutrient depletion, pathogen invasion, growth substrate, water current in moving water bodies etc. (Angelaalincy et al, 2016) also contribute in influencing biofilm formation.…”