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Microalgae I: Origin, Distribution and Morphology
Published in Arun Kumar, Jay Shankar Singh, Microalgae in Waste Water Remediation, 2021
Cyanobacteria are omnipresent microalgal communities and found in freshwater, marine and terrestrial ecosystems as free living or symbiotic with lichens, bryophytes, cycad roots and marine animals (Castenholz and Waterbury 1989, Castenholz 2001). Ultraplanktonic cyanobacterial species like Synechococcus proved to have a more potential role in oceanic primary production in comparison to any individual group of microalgae (Fogg 1987, Waterbury et al. 1979). There are filamentous cyanobacteria such as Nostoc, Anabaena, Oscillatoria, Microcoleus and Mastigocladus, known for their dominance in microbial mats or cyanobacterial mats; existing in brackish waters, hot springs, deserts and paddy fields (Metting 1981, Roger and Kulasooriya 1980). Prochlorophytes (e.g., Prochloron) were first discovered five decades ago and considered as symbionts with marine didemnids and holothurians. But now it is clearer that they are free living communities in the pelagic naoplankton; which includes their distribution and importance in this habitat (Chishom et al. 1992).
Spirulina sp. and Biomass Used as Animal Feed Supplement
Published in Bakrudeen Ali Ahmed Abdul, Microbial Biofilms, 2020
M. Karthik, K. Ashokkumar, N. Arunkumar, R. Krishnamoorthy, P. Arjun
The important factor for selection of strain is production of biomass, reduces the pollutant concentration, which is suited to the environmental and cultivation conditions. The genus Spirulina belongs to Oscillatoriaceae family, and it consists of filamentous cyanobacteria, characterized by spiral-shaped chains of cells (trichomes) enclosed in a thin sheath. Spirulina oscillariodes is the first species of Spirulina isolated from freshwater stream (Turpin 1827). Based on the growth and environmental conditions, Spirulina characteristics could vary within the species. Presently, various species of Spirulina have been reported from relatively different environments such as soil, sand, marshes, brackish water, seawater, freshwater, thermal springs, warm waters from power plants, and fish ponds. Domestic wastewater has been used for first wastewater treatment by using Spirulina platensis (Kosaric et al. 1974). However, the filamentous cyanobacteria Spirulina platensis is a suitable strain used for cultivation and bioremediation of agroindustrial wastewater treatment by several environmental and operational features to removal of pollutants and biomass production (Table 11.2).
Hydrogen Photoproduction by Oxygenic Photosynthetic Microorganisms
Published in Farshad Darvishi Harzevili, Serge Hiligsmann, Microbial Fuels, 2017
Fabrice Franck, Bart Ghysels, Damien Godaux
Nitrogenases catalyze the reduction of molecular nitrogen N2 into ammonium NH3 in diazotrophic bacteria. Since they are inactivated by oxygen, these enzymes are found only in bacterial cells in which an anaerobic environment can be kept. For filamentous cyanobacteria, this condition is achieved in heterocyst cells of diazotrophic species, such as Anabaena sp., which served as experimental species in the first studies on cyanobacterial hydrogen photoproduction (Benemann and Weare, 1974; Weissman and Benemann, 1977). For diazotrophic unicellular cyanobacteria, nitrogenase activity generally occurs during the night period, when oxygenic photosynthesis is inactive. An example of this kind is Cyanothece sp., which has been used more recently to achieve high rates of nitrogenase-based H2 photoproduction (Bandyopadhyay et al., 2010).
Biotechnique for nitrogen and phosphorus removal: a possible insight
Published in Chemistry and Ecology, 2020
Anne Bhambri, Santosh Kumar Karn
The basic removal of nitrogen and phosphorus depends on the initial concentration and the amount of biomass applied. As the light intensity increases, it leads to increase the microalgae activity and growth and also affects the transformation of nutrients in the wastewater [88]. Microalgae (Scenedesmus obliquus) were firstly immobilised by Chevalier and de la Noüe [89] for wastewater treatment in carrageenan beads that further catch up the microalgae in gel beads for the nitrogen and phosphorus removal from the wastewater. Acevedo et al. [28] indicated that the microflora that naturally present in water removed 16 mg/l of phosphorus in darkness and also conducted an experimental trial by using synthetic wastewater and removed nitrogen and phosphorus 46.65 and 55.98 mg/l, respectively and while by using real domestic wastewater, removed 9.2 mg/l of phosphorus and 16.1 mg/l of nitrogen. Sukacova and Cerveny [90] reported the removal of nitrogen and phosphorus 158 g/m2/d 95% and 0.73 g/m2/d 84%, respectively by using biofilm that consists of the mixture of species i.e. Anabaena flos-aquae; Microcystis aeruginosa; Chlorella pyrenoidosa; Synechococcus elongatus and Scenedesmus obliquus from stimulated wastewater throughout a four-day cycle, whereas Boelee et al. [91] determined that after cultivated microalgal biofilm on PVC plastic sheets dominated by filamentous cyanobacteria (Phormidium and Pseudanabaena) and coccal green algae (Scenedesmus sp.) removed 0.13 g/m2 per day and 1 g/m2per day phosphorus and nitrogen, respectively under continuous illumination.