Abstract
Cyanobacteria, also known as blue-green (micro)algae, are able to sustain many types of chemical stress because of metabolic adaptations that allow them to survive and successfully compete in a variety of ecosystems, including polluted ones. As photoautotrophic bacteria, these microorganisms synthesize aromatic amino acids, which are precursors for a large variety of substances that contain aromatic ring(s) and that are naturally formed in the cells of these organisms. Hence, the transformation of aromatic secondary metabolites by cyanobacteria is the result of the possession of a suitable “enzymatic apparatus” to carry out the biosynthesis of these compounds according to cellular requirements. Another crucial aspect that should be evaluated using varied criteria is the response of cyanobacteria to the presence of extracellular aromatic compounds. Some aspects of the relationship between aromatic compounds and cyanobacteria such as the biosynthesis of aromatic compounds, the influence of aromatic compounds on these organisms and the fate of aromatic substances inside microalgal cells are presented in this paper. The search for this information has suggested that there is a lack of knowledge about the regulation of the biosynthesis of aromatic substances and about the transport of these compounds into cyanobacterial cells. These aspects are of pivotal importance with regard to the biotransformation of aromatic compounds and understanding them may be the goals of future research.
Highlights
Cyanobacteria, which are microorganisms known as blue-greenalgae, are one of the phylogenetically oldest lineages and have continuously existed in the biosphere of the Earth for billions of years
This study examined the impact of hydroxylated chalcones (4′′-hydroxychalcone, 2′hydroxychalcone and 2′′-hydroxychalcone at 20 mg/L) on one halophilic strain (Arthrospira platensis) and seven freshwater strains (Anabaena sp., A. laxa, A. klebahnii, N. moravica, Ch. minutus, Merismopedia glauca, and Synechocystis aquatilis)
The natural production of a wide range of secondary metabolites, including aromatic ones, is a common adaptation of cyanobacteria that allows them to successfully compete in a variety of ecosystems. Because of their phototrophic lifestyle and constant exposure to high oxygen and radical stresses, these organisms possess a high capacity for producing plentiful and efficient chemicals to protect against oxidative and radical stressors. This ability is especially important for cyanobacteria because the energy supply, the key factor that enables chemical transformations in cellular systems, naturally induces the formation of radicals
Summary
Cyanobacteria, which are microorganisms known as blue-green (micro)algae, are one of the phylogenetically oldest lineages and have continuously existed in the biosphere of the Earth for billions of years. Samanthakamani and Thangaraju (2015) indicated that phenol is susceptible to decomposition by other blue-green algae species of the genera Anabaena, Nostoc, Oscillatoria and Spirulina, which can use phenol to meet their needs for a carbon source and energy (Samanthakamani and Thangaraju 2015) Another interesting observation was in a study by Wurster et al (2003), in which another taxon, Synechococcus PCC 7002, was shown to be capable of degrading phenol under non-photosynthetic conditions in darkness, but the cells were not able to use phenol for growth. This activity leads to the formation of cis-, cis-muconic acid, which is formed by the ring cleavage of the compound, providing the first record of the ortho-fission of a phenolic substance by cyanobacteria. It is worth noting that the formation of 1,4-naphthoquinone is a key factor in the generation of excessive reactive oxygen species (Cheng et al 2017)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
