Publicações

  • 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

  • Leptochelins A–C, Cytotoxic Metallophores Produced by Geographically Dispersed Leptothoe Strains of Marine Cyanobacteria

    Avalon, N. E., Reis, M. A., Thornburg, C. C., Williamson, R. T., Petras, D., Aron, A. T., Neuhaus, G. F., Al-Hindy, M., Mitrevska, J., Ferreira, L., Morais, J., el Abiead, Y., Glukhov, E., Alexander, K. L., Vulpanovici, F. A., Bertin, M. J., Whitner, S., Choi, H., Spengler, G., … Gerwick, W. H.

    Abstract: Metals are important cofactors in the metabolic processes of cyanobacteria, including photosynthesis, cellular respiration, DNA replication, and the biosynthesis of primary and secondary metabolites. In adaptation to the marine environment, cyanobacteria use metallophores to acquire trace metals when necessary as well as to reduce potential toxicity from excessive metal concentrations. Leptochelins A−C were identified as structurally novel metallophores from three geographically dispersed cyanobacteria of the genus Leptothoe. Determination of the complex structures of these metabolites presented numerous challenges, but they were ultimately solved using integrated data from NMR, mass spectrometry and deductions from the biosynthetic gene cluster. The leptochelins are comprised of
    halogenated linear NRPS-PKS hybrid products with multiple heterocycles that have potential for hexadentate and tetradentate coordination with metal ions. The genomes of the three leptochelin producers were sequenced, and retrobiosynthetic analysis revealed one candidate biosynthetic gene cluster (BGC) consistent with the structure of leptochelin. The putative BGC is highly homologous in all three Leptothoe strains, and all possess genetic signatures associated with metallophores. Postcolumn infusion of metals using an LC-MS metabolomics workflow performed with leptochelins A and B revealed promiscuous binding of iron, copper, cobalt, and zinc, with greatest preference for copper. Iron depletion and copper toxicity experiments support the hypothesis that
    leptochelin metallophores may play key ecological roles in iron acquisition and in copper detoxification. In addition, the leptochelins possess significant cytotoxicity against several cancer cell lines.

    https://pubs.acs.org/doi/10.1021/jacs.4c05399?ref=pdf

     

  • Microbial response to a port fuel spill: community dynamics and potential for bioremediation

    Rafaela Perdigão, Maria Paola Tomasino, Catarina Magalhães, Maria F. Carvalho, C. Marisa R. Almeida and Ana P. Mucha

    Abstract: Following a fuel leakage inside a Portuguese maritime port, we conducted parallel 30-day experiments using contaminated seawater and fuel, sampled five days after the incident. This study aimed to (i)survey the native microbial community response to the spilled fuel and (ii)evaluate the efficacy of bioremediation, both biostimulation and bioaugmentation with a lyophilized bacterial consortium (Rhodococcus erythropolis, Pseudomonas sp.), in accelerating hydrocarbon degradation. Metabarcoding analysis revealed a shift in microbial communities, with increased abundance of hydrocarbon-degraders (e.g. Alcanivorax, Thalassospira). Ninety-five hydrocarbonoclastic bacteria were isolated, including key groups from the enriched communities. The lyophilized bacteria added in bioaugmentation, enhanced the abundance of hydrocarbon-degraders over time and were recovered throughout time. Bioremediation treatments favoured biodegradation, achieving over 60 % removal of total petroleum hydrocarbons after 15 days, contrasting with natural attenuation where almost no TPH was removed. This work highlights the potential of bioremediation technologies to accelerate hydrocarbon-degrading activity, for oil spills inside ports.

    https://www.sciencedirect.com/science/article/pii/S0025326X24004119

  • Unveiling the culturable and non-culturable actinobacterial diversity in two macroalgae from the northern Portuguese coast

    Mariana Girão, Diogo A. M. Alexandrino, Weiwei Cao, Isabel Costa, Zhongjun Jia and Maria F. Carvalho

    Abstract: Actinomycetota, associated with macroalgae, remains one of the least explored marine niches. The secondary metabolism of Actinomycetota, the primary microbial source of compounds relevant to biotechnology, continues to drive research into the distribution, dynamics, and metabolome of these microorganisms. In this study, we employed a combination of traditional cultivation and metagenomic analysis to investigate the diversity of Actinomycetota in two native macroalgae species from the Portuguese coast. We obtained and taxonomically identified a collection of 380 strains, which were distributed across 12 orders, 15 families, and 25 genera affiliated with the Actinomycetia class, with Streptomyces making up approximately 60% of the composition. Metagenomic results revealed the presence of Actinomycetota in both Chondrus crispus and Codium tomentosum datasets, with relative abundances of 11% and 2%, respectively. This approach identified 12 orders, 16 families, and 17 genera affiliated with Actinomycetota, with minimal overlap with the cultivation results. Acidimicrobiales emerged as the dominant actinobacterial order in both macroalgae, although no strain affiliated with this taxonomic group was successfully isolated. Our findings suggest that macroalgae represent a hotspot for Actinomycetota. The synergistic use of both culture-dependent and independent approaches proved beneficial, enabling the identification and recovery of not only abundant but also rare taxonomic members.

    https://pubmed.ncbi.nlm.nih.gov/38627038/