“…The metabolic capacities presented by these organisms made them notoriously ubiquitous, being found in every continent and presenting ecological, evolutionary, biochemical, biotechnological and ecotoxicological adaptations in several terrestrial and aquatic environments. As one of the most megadiverse countries in the tropics, Brazil and its environments harbour a large but under-explored diversity of cyanobacteria, among which several potential novel taxa are yet to be described [17,18], most likely including a considerable number of unknown nostocacean cyanobacteria.…”
The cyanobacterial genus
Nostoc
is an important contributor to carbon and nitrogen bioavailability in terrestrial ecosystems and a frequent partner in symbiotic relationships with non-diazotrophic organisms. However, since this currently is a polyphyletic genus, the diversity of
Nostoc
-like cyanobacteria is considerably underestimated at this moment. While reviewing the phylogenetic placement of previously isolated
Nostoc
-like cyanobacteria originating from Brazilian Amazon, Caatinga and Atlantic forest samples, we detected 17 strains isolated from soil, freshwater, rock and tree surfaces presenting patterns that diverged significantly from related strains when ecological, morphological, molecular and genomic traits were also considered. These observations led to the identification of the evaluated strains as representative of three novel nostocacean genera and species: Amazonocrinis nigriterrae gen. nov., sp. nov.; Atlanticothrix silvestris gen. nov., sp. nov.; and Dendronalium phyllosphericum gen. nov., sp. nov., which are herein described according to the rules of the International Code of Nomenclature for algae, fungi and plants. This finding highlights the great importance of tropical and equatorial South American ecosystems for harbouring an unknown microbial diversity in the face of the anthropogenic threats with which they increasingly struggle.
“…The metabolic capacities presented by these organisms made them notoriously ubiquitous, being found in every continent and presenting ecological, evolutionary, biochemical, biotechnological and ecotoxicological adaptations in several terrestrial and aquatic environments. As one of the most megadiverse countries in the tropics, Brazil and its environments harbour a large but under-explored diversity of cyanobacteria, among which several potential novel taxa are yet to be described [17,18], most likely including a considerable number of unknown nostocacean cyanobacteria.…”
The cyanobacterial genus
Nostoc
is an important contributor to carbon and nitrogen bioavailability in terrestrial ecosystems and a frequent partner in symbiotic relationships with non-diazotrophic organisms. However, since this currently is a polyphyletic genus, the diversity of
Nostoc
-like cyanobacteria is considerably underestimated at this moment. While reviewing the phylogenetic placement of previously isolated
Nostoc
-like cyanobacteria originating from Brazilian Amazon, Caatinga and Atlantic forest samples, we detected 17 strains isolated from soil, freshwater, rock and tree surfaces presenting patterns that diverged significantly from related strains when ecological, morphological, molecular and genomic traits were also considered. These observations led to the identification of the evaluated strains as representative of three novel nostocacean genera and species: Amazonocrinis nigriterrae gen. nov., sp. nov.; Atlanticothrix silvestris gen. nov., sp. nov.; and Dendronalium phyllosphericum gen. nov., sp. nov., which are herein described according to the rules of the International Code of Nomenclature for algae, fungi and plants. This finding highlights the great importance of tropical and equatorial South American ecosystems for harbouring an unknown microbial diversity in the face of the anthropogenic threats with which they increasingly struggle.
“…Brazil geographically contains six terrestrial biomes (Amazon, Atlantic Forest, Caatinga, Cerrado, Pantanal, and Pampa) and one marine biome (Atlantic Ocean). Despite the high diversity of cyanobacteria in the Brazilian biomes, the biotechnological applications and diversity of cyanobacteria in tropical environments are poorly explored …”
Rationale
Mycosporine‐like amino acids (MAAs) are UV‐absorbing compounds produced by fungi, algae, lichens, and cyanobacteria when exposed to UV radiation. These compounds have photoprotective and antioxidant functions and have been widely studied for possible use in sunscreens and anti‐aging products. This study aims to identify MAA‐producing cyanobacteria with potential application in cosmetics.
Methods
A method for the identification of MAAs was developed using ultrahigh‐performance liquid chromatography with diode array detection coupled to quadrupole time‐of‐flight mass spectrometry (UHPLC‐DAD/QTOFMS). Chromatographic separation was carried out using a Synergi 4 μ Hydro‐RP 80A column (150 × 2,0 mm) at 30°C with 0.1% formic acid aqueous solution + 2 mM ammonium formate and acetonitrile/water (8:2) + 0.1% formic acid as a mobile phase.
Results
Out of the 69 cyanobacteria studied, 26 strains (37%) synthesized MAAs. Nine different MAAs were identified using UHPLC‐DAD/QTOFMS. Iminomycosporines were the major group detected (7 in 9 MAAs). In terms of abundance, the most representative genera for MAA production were heterocyte‐forming groups. Oscilatoria sp. CMMA 1600, of homocyte type, produced the greatest diversity of MAAs.
Conclusions
The UHPLC‐DAD/QTOFMS method is a powerful tool for identification and screening of MAAs in cyanobacterial strains as well as in other organisms such as dinoflagellates, macroalgae, and microalgae. The different cyanobacterial genera isolated from diverse Brazilian biomes and environments are prolific sources of MAAs.
“…In general, tropical cyanobacteria have been comparatively little investigated [ 99 ]. Estimates suggest that <10% of tropical cyanobacterial diversity is known [ 100 ]. The Amazon Rainforest and River basin, for example, which accounts for some 20% of the world’s freshwater, is largely terra incognita with regards to knowledge of cyanobacteria [ 101 , 102 ].…”
Section: Biology Of the Tolyporphins-producing Culturementioning
Tolyporphins were discovered some 30 years ago as part of a global search for antineoplastic compounds from cyanobacteria. To date, the culture HT-58-2, comprised of a cyanobacterium–microbial consortium, is the sole known producer of tolyporphins. Eighteen tolyporphins are now known—each is a free base tetrapyrrole macrocycle with a dioxobacteriochlorin (14), oxochlorin (3), or porphyrin (1) chromophore. Each compound displays two, three, or four open β-pyrrole positions and two, one, or zero appended C-glycoside (or –OH or –OAc) groups, respectively; the appended groups form part of a geminal disubstitution motif flanking the oxo moiety in the pyrroline ring. The distinct structures and repertoire of tolyporphins stand alone in the large pigments-of-life family. Efforts to understand the cyanobacterial origin, biosynthetic pathways, structural diversity, physiological roles, and potential pharmacological properties of tolyporphins have attracted a broad spectrum of researchers from diverse scientific areas. The identification of putative biosynthetic gene clusters in the HT-58-2 cyanobacterial genome and accompanying studies suggest a new biosynthetic paradigm in the tetrapyrrole arena. The present review provides a comprehensive treatment of the rich science concerning tolyporphins.
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