The “Bright Side” of Cyanobacteria: Revising the Nuisance Potential and Prospecting Innovative Biotechnology-Based Solutions to Integrate Water Management Programs

Abstract

Global warming and the anthropogenic degradation of water quality are pointed out as main causes of the worldwide increase in frequency, severity, and duration of harmful algal blooms (HABs). Cyanobacteria, major constituents of HABs, can cause ecological, economic, and human health problems, configuring a "dark side" requiring management attention. Their growth can be potentiated by climate change consequences, highlighting further the urgency of improving HABs management strategies to ensure water quality. An innovative perspective for cyanobacteria management is the exploitation of their "bright side". Several exploitable products produced by cyanobacteria (e.g., bioactive pigments, lipids, proteins) present high market value. Thus, this work provides a critical perspective on how HABs management may be connected with biotechnology in the future. We propose the use of the biomass of cyanobacteria blooms physically removed in traditional control actions (much needed to ensure environmental and even human health safety) as a feedstock for future valorization, thus allying profit to water quality management, in a win-win relationship between economics and environmental sustainability. Such a proposal was validated with an economic analysis, which evidenced a relevant potential for a positive return (hence rendering profit likely to occur), both considering only the delivery of harvested biomass to production units and the full valuation route from harvesting to the selling of the extracted/purified product using phycocyanin as a model.

Extraction and purification of phycobiliproteins from algae and their applications

“…Cyanobacteria are unique photosynthetic organisms present in almost all habitats all over the world, as pointed out by the World Health Organization ( WHO, 2021 ). They have a small cell size and can be unicellular, filamentous, or colonial, being sometimes large enough to be visible by the human eye, especially during the occurrence of natural blooms ( Macário et al, 2021 ). These bacteria have been studied for their morphology, photosynthesis, and nitrogen fixation mechanisms, but also for certain aspects of their structure namely in what concerns the part of the cell driving photosynthesis.…”

Cyanobacteria as Candidates to Support Mars Colonization: Growth and Biofertilization Potential Using Mars Regolith as a Resource

“…Moreover, plants are more demanding with regard to environmental tolerance ranges and require more space and resources; thus, they are more costly than cyanobacteria, particularly when Mars culturing is equated. Besides oxygen, these organisms are able to produce a wide range of other interesting compounds with several applications, e.g., amino acids, pigments, lipids, polysaccharides, and proteins, with applications in the food and pharmaceutical industries ( Eriksen, 2008 ; Sekar and Chandramohan, 2008 ; Macário et al, 2021 ). Different species can also be used directly as food sources (e.g., Arthrospira and Nostoc sp.…”

Caracterização e bioprospecção da biomassa de cianobactérias e microalgas presentes em reservatórios de água visando seu potencial biotecnológico

“…No entanto, devido às mudanças climáticas e à eutrofização dos corpos d'água causada pela atividade humana, tem havido um aumento na frequência, severidade e duração das florações de cianobactérias em todo o mundo (Macário et al, 2021). A análise de imagens de satélite obtidas ao longo de três décadas demonstrou um aumento global nas florações em lagos de água doce e oceanos (Hallegraeff et al, 2021;Ho, Michalak, Pahlevan, 2019).…”

“…O crescente número de episódios de florações de cianobactérias em reservatórios, que também cresce em severidade e duração, exige rápida tomada de decisão por parte dos órgãos de saúde (Macário et al, 2021). Compreender os efeitos dos diversos metabólitos secundários das cianobactérias e atribuir a sua atividade biológica em cenários de exposição ambiental torna-se cada dia mais necessário.…”

“…Como produtores primários, as cianobactérias dependem da luz solar para obter energia e, em condições favoráveis, como alta incidência solar, grande disponibilidade de nutrientes e temperaturas elevadas, podem multiplicar-se rapidamente, resultando em episódios de floração de cianobactérias (CDC, [s.d]). Nas últimas décadas, a eutrofização acelerada dos corpos d'água, causada principalmente pela ação humana e pelas mudanças climáticas, tem contribuído para o aumento na frequência e no volume das florações de cianobactérias em reservatórios de água do mundo todo (Macário et al, 2021). Essas florações impactam a paisagem e o potencial recreativo dos corpos d'água e comprometem a qualidade da água como um todo, devido à redução nos níveis de oxigênio dissolvido (Huisman et al, 2018).…”