Artigos de 2024

  • Genome sequence of the marine alphaproteobacterium Lentilitoribacter sp. EG35 isolated from the temperate octocoral Eunicella gazella

    Tina Keller-Costa, Selene Madureira, Ana S. Fernandes, Lydia Kozma, Jorge M.S. Gonçalves, Cristina Barroso, Conceição Egas, Rodrigo Costa

    Abstract: We report the genome sequence of Lentilitoribacter sp. strain EG35 isolated from the octocoral Eunicella gazella sampled off the coast of Portugal. We reveal the coding potential for the biosynthesis of polyhydroxyalkanoates — biodegradable polyesters that may serve bioplastics production, diverse homoserine lactone-like communication signals, and four putatively novel natural products.

    https://doi.org/10.1128/mra.00872-24

  • Carotenoids from cyanobacteria modulate iNOS and inhibit the production of inflammatory mediators: Promising agents for the treatment of inflammatory conditions

    Janaína Morone, Guilherme Hentschke, Eugénia Pinto, João Morais, Pedro Cruz, Vitor Vasconcelos, Rosário Martins, Graciliana Lopes

    Abstract: Cyanobacteria are green multiproduct refineries of increasing interest for different industrial prospects. In this work, eleven cyanobacteria strains isolated from the Cape Verde archipelago were explored for their biotechnological applications in the field of inflammation. A biorefinery approach was employed to produce carotenoidtargeted extracts, further profiled by HPLC-PDA and explored for their ability to i) scavenge important physiological free radicals of oxygen (superoxide anion radical, O2•-) and nitrogen (nitric oxide, •NO) involved in the
    inflammatory process ii) slow-down post-inflammatory hyperpigmentation and iii) modulate the activity of inflammatory cytokine-producing enzymes, in enzymatic and cell systems comprising RAW 264.7 cells. The studied strains turned out to be important carotenoid producers (70.47–186.71 μg mg􀀀 1dry extract), mainly represented by β-carotene and zeaxanthin. The targeted-extracts stood-out for their potential to slow-down the inflammatory process through a multitarget approach: scavenging •NO and O2•-, reducing inflammatory cytokines
    production through lipoxygenase inhibition, and modulating the inducible nitric oxide synthase in LPSstimulated RAW 264.7 cells, with strains of the order Nodosilineales revealing to be worth of further biotechnological exploitation.

    https://doi.org/10.1016/j.algal.2024.103729

  • Cellulamides: A New Family of Marine-Sourced Linear Peptides from the Underexplored Cellulosimicrobium Genus

    Mariana Girão, José Murillo-Alba, Jesús Martín, Ignacio Pérez-Victoria, Ricardo B. Leite, Ralph Urbatzka , Pedro N. Leão, Maria F. Carvalho and Fernando Reyes

    Abstract: Bioprospecting the secondary metabolism of underexplored Actinomycetota taxa is a prolific route to uncover novel chemistry. In this work, we report the isolation, structure elucidation, and bioactivity screening of cellulamides A and B (1 and 2), two novel linear peptides obtained from the culture of the macroalga-associated Cellulosimicrobium funkei CT-R177. The host of this microorganism, the Chlorophyta Codium tomentosum, was collected in the northern Portuguese coast and, in the scope of a bioprospecting study focused on its associated actinobacterial community, strain CT-R177 was isolated, taxonomically identified, and screened for the production of antimicrobial and anticancer compounds. Dereplication of a crude extract of this strain using LC-HRMS(/MS) analysis unveiled a putative novel natural product, cellulamide A (1), that was isolated following mass spectrometry-guided fractionation. An additional analog, cellulamide B (2) was obtained during the chromatographic process and chemically characterized. The chemical structures of the novel linear peptides, including their absolute configurations, were elucidated using a combination of HRMS, 1D/2D NMR spectroscopy, and Marfey’s analysis. Cellulamide A (1) was subjected to a set of bioactivity screenings, but no significant biological activity was observed. The cellulamides represent the first family of natural products reported from the Actinomycetota genus Cellulosimicrobium, showcasing not only the potential of less-explored taxa but also of host-associated marine strains for novel chemistry discovery.

    https://doi.org/10.3390/md22060268

  • The extremophile Eurychoronema bolivianum gen. et sp. nov. (Nodosilineales, Cyanobacteria) and Leptolyngbya aquatica comb. nov

    Guilherme Scotta Hentschke, Jimmy Casto Ciancas Jiménez, Claudia Hoepfner, Daniel Guzmán, Maria João Mesquita & Vitor Vasconcelos

    Abstract: Extreme environments exhibit conditions that are beyond the tolerances of most species. They are characterized by extremes in temperature, pressure, gas concentrations, salinity, radiation, pH or water availability. Despite their harsh conditions, extreme environments are a rich source for discovering new cyanobacterial taxa. The Bolivian Altiplano is an extreme environment characterized by sub-freezing temperatures, high salinity and some of the lowest precipitation rates on Earth. From this environment,
    the homocytous filamentous strain LEGE 231228 was isolated. Our 16S rRNA gene phylogenetic analyses showed that this strain was positioned within a clade, sister to a cluster containing Toxifilum and Sodaleptolyngbya strains, in the Nodosilineales clade. The 16S rRNA gene identity analysis revealed that when comparing LEGE 231228 with Toxifilum and Sodaleptolyngbya, the maximum values reached only 94.3% and 93.6%, respectively. Morphologically, LEGE 231228 differed from Sodaleptolyngbya and Toxifilum primarily by forming fascicles and having sheaths that sometimes envelop more than one trichome. Based on these findings, we propose Eurychoronema bolivianum gen. & sp. nov. Additionally, the 16S rRNA gene phylogenies and identity, alongside morphological and 16S-23S ITS analyses permitted us to transfer the Leptolyngbyaceae genus Radiculonema into Leptolyngbya. Radiculonema was nested within the Leptolyngbya clade and both genera shared 95.1% 16S rRNA identity. There was also no morphological difference between these two genera. We also demonstrate that conclusions based on secondary structures of the 16S-23S ITS region alone can be interpreted in different ways.

    https://doi.org/10.1080/00318884.2024.2412366

  • Description of Pegethrix niliensis sp. nov., a Novel Cyanobacterium from the Nile River Basin, Egypt: A Polyphasic Analysis and Comparative Study of Related Genera in the Oculatellales Order

    Guilherme Scotta Hentschke, Zakaria Mohamed, Alexandre Campos and Vitor M. Vasconcelos

    Abstract: In this paper, we examine the filamentous cyanobacterial strain NILCB16 and describe it as a new species within the genus Pegethrix. The original population was sampled from a mat growing in an irrigation canal in the Nile River, Egypt. Initially classified under Plectonema or Planktolyngbya, the strain is a potential producer of the toxins microcystin and β-N-Methylamino-L-Alanine (BMAA). Additionally, we reviewed the taxonomic relationships between the Oculatellales genera. To describe the new species, we conducted a polyphasic study, encompassing 16S rRNA gene phylogenetic analyses performed using both Maximum Likelihood and Bayesian methods, sequence identity (p-distance) analysis, 16S-23S ITS secondary structures, and morphological and habitat comparisons. The phylogenetic analysis revealed that strain NILCB16 clustered within the Pegethrix clade with strong phylogenetic support, but in a distinct position from other species in the genus. The strain shared a maximum 16S rRNA gene identity of 97.3% with P. qiandaoensis and 96.1% with the type species, P. bostrychoides. Morphologically, NILCB16 can be differentiated from other species in the genus by its lack of false branching. Our phylogenetic analyses also show that Pegethrix, Cartusia, Elainella, and Maricoleus are clustered with strong phylogenetic support. They exhibit high 16S rRNA gene identity and are morphologically indistinguishable, suggesting they could potentially be merged into a single genus in the future.

    https://doi.org/10.3390/toxins16100451

  • Nocardiopsis codii sp. nov., and Rhodococcus chondri sp. nov., two novel actinomycetal species isolated from macroalgae collected in the northern Portuguese coast

    Mariana Girão, Zoé Lequint, Adriana Rego, Isabel Costa, Diogo Neves Proença, Paula V. Morais and Maria F. Carvalho

    Abstract: Two novel actinomycetal strains, designated CC-­R113T and CC-­R104T, were isolated from the tissues of two macroalgae collected on the northern Portuguese coast. Phylogenetic analyses based on the 16S rRNA gene showed that strain CT-­R113T belongs to the genus Nocardiopsis, being closely related to Nocardiopsis umidischolae 66/93T and Nocardiopsis tropica VKM Ac-­1457T, with 98.65 and 98.39 % sequence similarity, respectively. The clade formed between the three type strains was confirmed by phylogenomic analysis. The genome of strain CT-­R113T was 7.27 Mb in size with a G+C content of 71.3 mol %, with average nucleotide identity (ANI) values of 89.59 and 90.14 % with strains 66/93T and VKM Ac-­1457T, respectively. The major cellular fatty acids were identified as C18 : 1 ω9c, iso-­C16 : 0 and anteiso-­C17 : 0. Menaquinone 10 (MK-­10) was the major respiratory quinone. Comparative analysis of 16S rRNA gene sequences showed that strain CC-­R104T belongs to the genus Rhodococcus and is most closely related to Rhodococcus pyridinivorans DSM 44555T, with 98.24 % sequence similarity. However, phylogenomic analysis revealed that strain CC-­R104T establishes a clade with Rhodococcus artemisae DSM 45380T, being more distant from Rhodococcus pyridinivorans DSM 44555T. The genome of strain CC-­R104T was 5.34 Mb in size with a G+C content of 67.01 mol%. The ANI value between strains CC-­R104T and DSM 45380T was 81.2 % and between strains CC-­R104T and DSM 44555T was 81.5 %. The major cellular fatty acids were identified as C18 : 1ω9c, C16 : 0 and summed feature 3. Menaquinone 8 (MK-­8) was the only respiratory quinone. For both CC-­R113T and CC-­R104T, optimum growth was observed at pH 7.0, 28 °C and 0–5 % NaCl and whole-­cell hydrolysates contained meso-­diaminopimelic acid as the cell-­wall diamino acid. On the basis of phenotypic, molecular and chemotaxonomic characteristics, strains CT-­R113T and CC-­R104T are considered to represent novel species, for which the names Nocardiopsis codii sp. nov. (type strain CT-­R113T=LMG33234T=UCCCB172T) and Rhodococcus chondri sp. nov. (type strain CC-­R104T=LMG33233T=UCCCB171T) are proposed.

    https://doi.org/10.1099/ijsem.0.006483

  • Pigments profile and antioxidant potential of extremophile cyanobacteria strains isolated from the Mexican Volcanic Lake Chichonal

    Raquel Silva , Talita Gonçalves, Janaína Morone, Gabriela Alves Moreira, João Morais, Guilherme Scotta Hentschke, Peggy Elizabeth Álvarez-Gutiérrez, Ramón Alberto Batista-García, Vitor Vasconcelos, Graciliana Lopes

    Abstract: Cyanobacteria are ancient and prolific microorganisms for which the current knowledge remains limited. The present work constitutes the first report on the presence of the cyanobacteria Tolypothrix sp. LEGE 221228, Nostoc sp. LEGE 221229, Scytonema sp. LEGE 221230 and Drouetiella sp. LEGE 221231 in the volcanic crater lake in Chichonal (Chiapas-Mexico), and in the characterization of their pigments profile and antioxidant potential, through the application of biorefinery approaches. The identification of cyanobacteria species was achieved through advanced morphology-based methods for cyanobacterial taxonomy. The HPLC-PDA analysis of the cyanobacteria acetone extracts revealed β-carotene, echinenone and chlorophyll-a as the main pigments. Drouetiella sp. LEGE 221231 presented the highest β-carotene concentration (63.67 μg/mL), total carotenoids (87.92 μg/mL) and chlorophylls (20.88 μg/mL), closely followed by Tolypothrix sp. LEGE 221228 (with 51.37, 75.14 and 14.88 μg/mL, respectively), this being the first report on the carotenoid and chlorophylls profile of these strains. Aqueous extracts revealed the highest content of phycoerythrin in Tolypothrix sp. LEGE 221228 (50.61 mg/g) and of phycocyanin in Nostoc sp. LEGE 221229 (57.66 mg/g), standing out in superoxide anion radical scavenging, while the acetonic ones were more effective in scavenging nitric oxide radical. For both, Tolypothrix sp. LEGE 221228 was the most effective, presenting the lowest IC50 (53.75 and 57.68 μg/mL, respectively). Overall, the present study enriches the knowledge on biodiversity of cyanobacteria from underexplored environments, enhancing their potential biotechnological applications as producers of added value secondary metabolites with interest in food, pharmaceutical and cosmetic industries.

    https://doi.org/10.1016/j.algal.2024.103578

  • Exploring the cyanobacterial diversity in Portugal: Description of four new genera from LEGE-CC using the polyphasic approach

    Flavio Luis de Oliveira, Guilherme Scotta Hentschke, João Morais, Raquel Silva, Pedro Cruz, Vitor M. Vasconcelos

    Abstract: Culture collections such as the Blue Biotechnology and Ecotoxicology Culture Collection (LEGE-CC) hold approximately 1200 cyanobacterial strains and are critical community resources. However, many isolates in this and other collections have not been described with a polyphasic approach, and this limits further study. Here, we employed a polyphasic methodology that integrates 16S rRNA gene phylogenetic analyses, similarity (p-distance), 16S-23S ITS rRNA region secondary structures, morphological analyses, and habitat assessments to describe four novel cyanobacterial genera from the LEGE-CC, Portugal. Pseudolimnococcus planktonicus gen. et sp. nov. (Chroococcales) is phylogenetically and morphologically related to Limnococcus. The 16S rRNA gene similarity between the types of both genera is only 93.1%. Morphologically, Pseudolimnococcus cells do not reach the original spherical shape before the next division or have aerotopes and firm mucilage, while Limnococcus cells reach the original shape, lack aerotopes, and have diffluent mucilage. Eucapsopsis lusitanus gen. et sp. nov. (Chroococcales) is morphologically similar to Eucapsis but differs from it by having aerotopes and diffluent envelope. Eucapsis lacks aerotopes and has firm mucilaginous envelopes, rarely diffluent. Both genera are phylogenetically very distant from each other and have only 90.68% 16S rRNA gene similarity. Pseudoacaryochloris arrabidensis gen. et sp. nov. (Acaryochloridales) differs from Acaryochloris by the lack of mucilaginous envelope, which is present in Acaryochloris. Both genera are phylogenetically distant and have only 94.1% 16S rRNA gene similarity. Moreover, Acaryochloris is marine (sponge symbiont), while Pseudoacaryochloris is from freshwater. Vasconcelosia minhoensis gen. et sp. nov. (Nodosilineales) is phylogenetically related to Cymatolege but has only 94.3% similarity with this genus. Morphologically both genera are distinct. Vasconcelosia has a Romeria-like structure, while Cymatolege has a Phormidium-like structure. In all cases the 16S-23S ITS rRNA region secondary structures are in agreement with the other analyses. These novel genera expand the diversity of cyanobacteria in culture collections.

    https://doi.org/10.1111/jpy.13502

  • A journey through Cyanobacteria in Brazil: a review of novel genera and 16S rRNA sequences

    Scotta HENTSCHKE, G., Renan de Souza SANTOS, K., de MATTOS, L., Oliveira, F., & Vasconcelos, V. M.

    Abstract: In this paper we present a bibliographical review of the newly described Brazilian cyanobacterial genera, based on 16S rDNA analysis. Moreover, we discuss their position according to the current classification system of Cyanobacteria. Additionally, in order to comprehend the diversity of Brazilian 16S rDNA sequences deposited in GenBank (NCBI), we constructed a phylogeny based on an alignment of these sequences with cyanobacterial reference strains. The bibliographical review resulted in 26 papers. We identified 30 cyanobacterial genera described from Brazil, distributed across eight orders. The order Nostocales is the most well-represented with 11 genera. The genera described based on Brazilian strains are from terrestrial, aquatic (marine and freshwater), and extreme habitats (alkaline saline lakes). The terrestrial habitat hosts the largest number of genera, with 17 in total. The studies are primarily concentrated in the Atlantic Rainforest, Amazon, Caatinga, and Pantanal Biomes, while the Pampa Biome remains unstudied. Most of the Brazilian genera are monophyletic, with the exception of Brasilonema Fiore, Sant’Anna, de Paiva Azevedo, Komarek, Kaštovský, Sulek & Lorenzi, which is intermixed with Iphinoe Lamprinou & Pantazidou and Symphyonemopsis Tiwari & Mitra; and Capilliphycus Caires, Sant’Anna & Nunes, which is polyphyletic. Genera like Marmoreocelis Machado-de-Lima & Branco, Monilinema Malone, Genuário, Vaz, Fiore & Sant’Anna, Insularia Araújo, Schnadelbach, Nunes & Caires, and Microlinema Araújo, Schnadelbach, Nunes & Caires require revision in their taxonomical classifications. Our findings reveal that numerous Brazilian 16S rDNA sequences in GenBank are unidentified or misidentified, indicating a need for at least 15 genera to be described based on these strains. Here we also elucidate that the Brazilian cyanobacterial diversity is significantly underestimated.

    https://sciencepress.mnhn.fr/en/periodiques/algologie/45/6

  • A phylogenetically distant clade of Nostoc–like (Cyanobacteria) taxa with the description of Reofilinostoc matlalcueyense gen. et sp. nov. from an extreme environment

    Garduño Solorzano, Gloria, MartínezZ-García, M., Hentschke, G., Solorza, L., Vasconcelos, V.

    Abstract: Although species of the order Nostocales have morphological similarities to each other, some Nostoc species have been considered cryptic and are classified in the families Nostocaceae, Nodulariaceae and Aphanizomenaceae. Since then, the phylogenetic and morphological evaluation of Nostoc-like organisms has led to the taxonomic revision of some genera in different families. In the present work a cyanobacterium morphologically identified as Nostoc was isolated from an extreme cold lotic environment, in a high mountain of the Transmexican Volcanic Belt, and was taxonomically and phylogenetically characterized based on a polyphasic approach. Analysis of the 16S rRNA gene sequence references: Reofilinostoc matlalcueyense gen. et sp. nov. Thus, establishing a new genus of the family Nodulariaceae. The morphology of Reofilinostoc in the wild is reminiscent of a mouse ear, it is of 0.4-1.2 cm in length and has a firm cartilaginous texture; colonies can be pale green, brown or dark green in colour. Through a microscopic inspection, the filaments resemble to Komarekiella atlantica, Desikacharya nostocoides and Minunostoc cylindricum. While, the phylogenetic approach yielded similar results and consistently showed that Reofilinostoc matlalcueyense F02 (OR724089) is closely related to D. nostocoides and M. cylindricum in the core clade of Nodulariaceae. This research revealed that some comparisons between genera of Nodulariaceae exhibited similarity values higher than 97%, such as Atlanticothrix vs. Goleter and Cyanocohniella vs. Anabaenopsis. Nevertheless, in comparison to these phylogenetically closer genera, a substantial difference in the length and structure of D1-D1’, Box-B and V3 helix was demostrated; where Reofilinostoc, Desikacharya, and Minunostoc are part of the Nodulariaceae family; leading to the establishment of Reofilinostoc gen. nov., with Reofilinostoc matlalcueyense sp. nov. as the type species.

    https://phytotaxa.mapress.com/pt/article/view/phytotaxa.655.2.2