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Cyanobacteria: A Biocatalyst in Microbial Fuel Cell for Sustainable Electricity Generation
Published in Lakhveer Singh, Durga Madhab Mahapatra, Waste to Sustainable Energy, 2019
Thingujam Indrama, O.N. Tiwari, Tarun Kanti Bandyopadhyay, Abhijit Mondal, Biswanath Bhunia
Cyanobacteria contain mainly two pigments. They are carotenoids and chlorophylls, which are considered antennae for light harvesting. These two antennae can absorb light and are considered centers for photochemical reaction (Colyer et al. 2005). Chloroplast is an organelle where photosynthesis reaction takes place (Fig. 8.2). Photosynthesis happens through light dependent reaction and light independent reaction. In light dependent reaction, adenosine diphosphate (ADP) and inorganic phosphate (P) are used for production of adenosine triphosphate (ATP). However, carbon dioxide is reduced to carbohydrate in light independent reaction (Kruse et al. 2005). In light dependent reactions, the light energy is adsorbed by the phycobilisome and transferred to PSII reaction centers unidirectionally (Arteni et al. 2009). Both photosystems, namely PSI and PSII, exist in cyanobacteria. The phycobilisome (PBS) is a protein complex which is acting as antenna for PSII for cyanobacteria. The PBS comprises rod and core cylinders, which are connected with various protein. They are called phycobilin-binding proteins, which are also linked with various colorless proteins. Generally, phycocyanin (PhC) and allophycocyanin (APC) are the major phycobiliprotein found in the rod and core sub-complex, respectively. The linker protein available between rod–core cylinder is cyanobacterial phycocyanin protein G (CpcG), which plays a crucial role during assembly of the PBS (Watanabe et al. 2014). The reaction center of PSI is composed of a dimer of chlorophylls, which has an absorption peak at 700 nm. However, chlorophyll-b, the only primary pigment, remains at the center of PSII.
Monitoring Ecosystem Toxins in a Water Body for Sustainable Development of a Lake Watershed
Published in Ni-Bin Chang, Kaixu Bai, Multisensor Data Fusion and Machine Learning for Environmental Remote Sensing, 2018
Freshwater algae that quickly spread out in a water body do not accumulate to form dense surface scums or blooms as do some cyanobacteria. Since Microcystis is a bacterium that uses photosynthesis for energy production, high concentrations of Microcystis can be correlated with elevated chlorophyll-a levels. Chlorophyll-a levels in Microcystis blooms are thus related to the amount of microcystin in a water body (WHO, 1999; Rogalus and Watzin, 2008; Rinta-Kanto et al., 2009). Budd et al. (2001) used the Advanced Very High Resolution Radiometer (AVHRR) and Landsat Thematic Mapper (TM) images to determine chlorophyll-a concentrations in a lake, leading to the detection and tracking of the pathways of HABs. Wynne et al. (2008) also employed the surface reflectance of chlorophyll-a values to specifically predict Microcystis blooms. Mole et al. (1997) and Ha et al. (2009) had similar findings in regard to using chlorophyll-a as an indicator for identifying and quantifying microcystin in algae blooms which had reached the late exponential growth and stationary phase. Their studies proved that surface reflectance data may be used to detect and track HABs based upon chlorophyll-a levels. In addition, it was discovered that Microcystis blooms can be distinguished from other cyanobacteria blooms through a spectral analysis of the detected surface reflectance at 681 nm if there is a satellite band covering this wavelength (Ganf et al., 1989). As the surface reflectance at 681 nm is closely related to phycocyanin, phycocyanin may be regarded as an alternative indicator of Microcystis. In fact, phycocyanin is a pigment-protein complex from the light-harvesting, water-soluble phycobiliprotein family and is an accessory pigment to chlorophyll that all cyanobacteria own. Phycocyanin concentrations also share a positive correlation with microcystin levels (Rinta-Kanto et al., 2009).
Microalgae-Based Nutrient Recovery from Urban Wastewater
Published in Shashi Kant Bhatia, Sanjeet Mehariya, Obulisamy Parthiba Karthikeyan, Algal Biorefineries and the Circular Bioeconomy, 2022
Maria Rosa di Cicco, Maria Palmieri, C. Lubritto, C. Ciniglia
Phycocyanin is an important compound that can be obtained from microalgal and cyanobacterial cultures. It is an important phycobiliprotein, a complex of proteins and blue pigment with a maximum absorption between 610–640 nm, and it is found in cyanobacteria and exceptionally in cryptomonads and Rhodophyta (Newsome, Culver, and Van Breemen, 2014). It is used as antioxidant, anti-inflammatory, antimicrobial, anticancer compound, and also as fluorescent marker in biomedical research (Renugadevi et al., 2018). As seen in Table 4.2, it has applications in the food-feed markets and in cosmetic industries. Despite Spirulina platensis being the main source of commercial phycocyanin, this is the major pigment that is produced by the extremophilic microalga G. sulphuraria, which is capable of producing this valuable compound even in the absence of light (heterotrophic metabolism) (Graverholt and Eriksen, 2007). This characteristic is of great importance and has a high impact on industrial applications because phycocyanin production by microalgae usually relies on photosynthetic activity, thus requiring light provision to be carried out. Hirooka and Miyagishima (2016) described phycocyanin production in autotrophic condition, which achieved with G. sulphuraria 107.42 ± 1.81 mg g drybiomass−1 in acidic water supplemented with ammonia, resulting in similar productivity to Spirulina platensis (39.5 vs 37.5 mg phycocyanin L−1 d−1, respectively). With G. sulphuraria, Wan et al. (2016) achieved a biomass productivity of 1.20 g L−1 d−1 containing 13.88% phycocyanin, after 7 days in heterotrophic condition and 8 days in autotrophic condition. Graverholt and Eriksen (2007) described a heterotrophic continuous flow culture on glucose with which it was possible to obtain a phycocyanin productivity of 861 mg L−1 d−1. Phycocyanin production by G. sulphuraria is guided by an imbalance between nitrogen and carbon concentration in the growth medium (excess of nitrogen in carbon-limiting conditions); in fact, the glucose inhibits phycocyanin synthesis in this microalga (Imbimbo et al., 2019). Therefore, the correct balance (or imbalance) among the macronutrients fed to the selected microorganism becomes an additional fundamental parameter to be carefully regulated depending on the expected yield objectives.
Separation of Phycobiliprotein from Nostoc Commune by Using Ion-Exchange Membrane with Quaternary Amine
Published in Solvent Extraction and Ion Exchange, 2023
Takanori Hidane, Tomohiro Fukui, Mikihide Demura, Shintaro Morisada, Keisuke Ohto, Hidetaka Kawakita
Phycobiliprotein (PB) is a water-soluble chromoprotein produced by cyanobacteria. It is used as a colorant for cosmetics and as a fluorescent probe.[1,2] Because PB shows anti-inflammatory and anti-cancer effects, it is expected to have pharmaceutical applications. The global demand for PB is therefore increasing.[3,4] The chromatographic separation of PB from cyanobacteria such as Spirulina sp., Nostoc sp., and Synechococcus sp. has been achieved, e.g., by using packed beds.[5–7] A solution of a cyanobacteria extract was injected in impulse mode into a bead-packed-resin chromatographic column, and PB and other biomolecules X were eluted separately by gradient elution with NaCl solution. During separation, mass transfer of the target PB and other biomolecules X occurs via diffusion through the pores in the packed resin, therefore PB recovery is slow. More sophisticated methods for PB separation at higher capacities and speeds therefore need to be developed.