The usage of Cyanobacteria in wastewater treatment: prospects and limitations

Abstract

The applicability of Cyanobacteria executes various roles in the treatment of wastewater, assembling of superfluous food and, thus, produces valued biomass which has various applications. Besides this, they enrich and improve the quality of water as they are photosynthetic autotrophs. Currently, Cyanobacteria gained momentum for remediation of wastewaters because firstly, they enhances the O2 content of waters through photosynthesis and perform bioremediation of some heavy metals. Secondly, Cyanobacteria play significant roles in distressing the biological oxygen demand, chemical oxygen demand, turbidity, minerals and microbes; thirdly, they can be used either as axenic cultures or as mixed cultures both offering distinct advantages. Lastly, some species are tolerant towards extreme temperatures both low and high, acidic pH, high salt concentrations and heavy metals, which makes them outstanding candidates for the wastewater treatment plants. The suitable immobilization methods must evolve, better understanding of their morphological and biochemical parameters is required for the optimum growth, easy methods of harvesting the biomass after the treatment are required and more trials on large‐scale basis are required before they can be launched on full‐fledged basis for wastewater treatments.

Coupling dairy wastewaters for nutritional balancing and water recycling: sustainable heterologous 2-phenylethanol production by engineered cyanobacteria

“…Eukaryotic microalgae biomass produced from these treatments is usually exploited as feedstock for biofuel production since the biomass can contain up to 40%-70% lipids (Kothari et al, 2013;Chokshi et al, 2016;Khalaji et al, 2023;Paulenco et al, 2023). On the other hand, cyanobacteria, which constitute a group of ancient ubiquitous phototrophic bacteria (Abed et al, 2009;Garcia-Pichel, 2009), are resistant to extreme conditions of temperature, pH, heavy metals, and high salinity and, thus, are suitable for bioremediation (Gaurav et al, 2018;Ahmad, 2022;Lakmali et al, 2022). Although cyanobacteria have the ability to successfully remove nitrogen and phosphate from wastewaters (Lincoln et al, 1996;Kumar et al, 2011;El-Sheekh et al, 2011;Jitha and Madhu, 2016;Kabariya and Ramani, 2016;Ouhsassi et al, 2020;Álvarez et al, 2020;Ahmad, 2022), they have been mainly investigated for the production of high-value compounds, both naturally produced and metabolically engineered, thanks to their ease of genetic manipulation.…”

“…On the other hand, cyanobacteria, which constitute a group of ancient ubiquitous phototrophic bacteria (Abed et al, 2009;Garcia-Pichel, 2009), are resistant to extreme conditions of temperature, pH, heavy metals, and high salinity and, thus, are suitable for bioremediation (Gaurav et al, 2018;Ahmad, 2022;Lakmali et al, 2022). Although cyanobacteria have the ability to successfully remove nitrogen and phosphate from wastewaters (Lincoln et al, 1996;Kumar et al, 2011;El-Sheekh et al, 2011;Jitha and Madhu, 2016;Kabariya and Ramani, 2016;Ouhsassi et al, 2020;Álvarez et al, 2020;Ahmad, 2022), they have been mainly investigated for the production of high-value compounds, both naturally produced and metabolically engineered, thanks to their ease of genetic manipulation. These compounds can be extruded or derivatives of biomass, such as pigments (Kabariya and Ramani, 2018;Menin et al, 2019;Arashiro et al, 2020;Thevarajah et al, 2023).…”

Microalgae-based technology for wastewater treatment: exploring organic micropollutants removal

“…So far, the number of studies of microalgae-based technologies for the removal of various OMPs in different types of wastewater or media is not abundant, but slowly increasing (Usmani et al, 2020;Hena et al, 2021;Ali et al, 2023). Also, more species of green microalgae, cyanobacteria, and diatoms are tested in these studies (Sutherland and Ralph, 2019;Ahmad, 2022;Ali et al, 2023). Nevertheless, multiple knowledge gaps need to be addressed for further understanding and applying microalgae-based technology for the removal of OMPs.…”