Publicações

João Morais, Pedro Cruz, Guilherme Scotta Hentschke, Bruna Silva, Flavio Oliveira, Jorge Neves, Raquel Silva, Vitor Ramos, Pedro N. Leão, Vitor Vasconcelos

Abstract: The aim of this study was to document the biodiversity of cyanobacteria genera isolated from intertidal and subtidal zones in Cabo Verde. The identification of the strains was conducted using a polyphasic study, comprising 16S rRNA gene maximum likelihood and Bayesian inference phylogeny, 16S rRNA identity (p-distance), 16S–23S ITS secondary structure, morphological, and habitat analyses. A total of 51 strains were isolated by micromanipulation and by streaking biomass onto Petri dishes with a solid medium. Seventeen strains were identified as belonging to the Salileptolyngbya genus and five to Leptothoe; sixteen strains were distributed across twelve genera. Thirteen strains were grouped into eight distinct clades, but could not be assigned to any cyanobacterial genus, indicating that they could be described as new cyanobacterial genera in the future. The phylogenies also exhibited isolates LEGE 181157, LEGE 181224, and LEGE 181227 clustered with Gibliniella, but in a separate clade from the G. alaskensis type. The 16S rRNA gene identity values among these new isolates and G. alaskensis ranged from 94.4% to 95.5%. The 16S–23S ITS dissimilarity between LEGE 181224 and G. alaskensis was 9.4%. Morphologically, these three LEGE strains differ from G. alaskensis in that they have trichomes that are never coiled and have diffluent mucilaginous envelopes, whereas G. alaskensis has coiled trichomes with firm sheaths. Based on these strains, we describe here a new species of Gibliniella.

https://doi.org/10.3390/plants14030299

Ana C. Fonseca, Inês Ribeiro, Mariana Girão, Ana Regueiras, Ralph Urbatzka, Pedro Leão, Maria F. Carvalho

Abstract: To combat health conditions, such as multi-resistant bacterial infections, cancer, and metabolic diseases, new drugs need to be urgently found and, in this respect, marine Actinomycetota have a high potential to produce secondary metabolites with pharmacological importance. We aimed to study the cultivable Actinomycetota community associated with a marine sponge from the Portuguese coast, Hymeniacidon perlevis, and investigate the potential of the retrieved isolates to produce compounds with antimicrobial, anticancer and anti-obesity properties

10.1093/jambio/lxaf044

Mariana Girão, Adriana Rego, Ana C. Fonseca, Weiwei Cao, Zhongjun Jia, Ralph Urbatzka, Pedro N. Leão, Maria F. Carvalho

Abstract: Actinomycetota are unrivalled producers of bioactive natural products, with strains living in association with macroalgae representing a prolific—yet largely unexplored—source of specialised chemicals. In this work, we have investigated the bioactive potential of Actinomycetota from macroalgae through culture-dependent and -independent approaches. A bioprospecting pipeline was applied to a collection of 380 actinobacterial strains, recovered from two macroalgae species collected in the Portuguese northern shore—Codium tomentosum and Chondrus crispus—in order to explore their ability to produce antibacterial, antifungal, anticancer and lipid-reducing compounds. Around 43% of the crude extracts showed activity in at least one of the screenings performed: 111 presented antimicrobial activity at 1mg/mL, 83 significantly decreased cancer cells viability at 15μg/mL and 5 reduced lipid content in zebrafish >60% at 15 ug/mL. Dereplication of active extracts unveiled the presence of compounds that could explain most of the recorded results, but also unknown molecules in the metabolome of several strains, highlighting the opportunity for discovery. The bioactive potential of the actinobacterial community from the same macroalgae specimens, which served as the source for the aforementioned Actinomycetota collection, was also explored through metagenomics analysis, allowing to obtain a broader picture of its functional diversity and novelty. A total of 133 biosynthetic gene clusters recovered from metagenomic contigs and metagenome assembled genomes (MAGs). These were grouped into 91 gene cluster families, 83 of which shared less than 30% of similarity to database entries. Our findings provided by culture-dependent and -independent approaches underscore the potential held by actinomycetes from macroalgae as reservoirs for novel bioactive natural products.

https://doi.org/10.1111/1751-7915.70058

Ricardo Calado, Miguel C. Leal, Ruben X. G. Silva, Mara Borba, António Ferro, Mariana Almeida, Diana Madeira and Helena Vieira

Abstract: Over the last decades, bioprospecting of tropical corals has revealed numerous bioactive compounds with potential for biotechnological applications. However, this search involves sampling in natural reefs, and this is currently hampered by multiple ethical and technological constraints. Living coral displays, research laboratories, and biobanks currently offer an opportunity to continue to unravel coral chemodiversity, acting as “Noah’s Arks” that may continue to support the bioprospecting of molecules of interest. This issue is even more relevant if one considers that tropical coral reefs currently face unprecedent threats and irreversible losses that may impair the biodiscovery of molecules with potential for new products, processes, and services. Living coral displays provide controlled environments for studying corals and producing both known and new metabolites under varied conditions, and they are not prone to common bottlenecks associated with bioprospecting in natural coral reefs, such as loss of the source and replicability. Research laboratories may focus on a particular coral species or bioactive compound using corals that were cultured ex situ, although they may differ from wild conspecifics in metabolite production both in quantitative and qualitative terms. Biobanks collect and preserve coral specimens, tissues, cells, and/or information (e.g., genes, associated microorganisms), which offers a plethora of data to support the study of bioactive compounds’ mode of action without having to cope with issues related to access, standardization, and regulatory compliance. Bioprospecting in these settings faces several challenges and opportunities. On one hand, it is difficult to ensure the complexity of highly biodiverse ecosystems that shape the production and chemodiversity of corals. On the other hand, it is possible to maximize biomass production and fine tune the synthesis of metabolites of interest under highly controlled environments. Collaborative efforts are needed to overcome barriers and foster opportunities to fully harness the chemodiversity of tropical corals before in-depth knowledge of this pool of metabolites is irreversibly lost due to tropical coral reefs’ degradation.

https://doi.org/10.3390/md23020089

Madalena Matos, Mónica A. Fernandes, Inês Costa, Natacha Coelho, Tamára F. Santos, Veronica Rossetto, João Varela and Isabel Sá-Correia

Abstract: The marine oleaginous microalga Microchloropsis gaditana (formerly Nannochloropsis gaditana) exhibits a high capacity to thrive in a broad range of environmental conditions, being predominantly utilized as feed in aquaculture. This article reports the characterization of the culturable yeast population present during the scale-up process of M. gaditana cultivation at Necton S.A. facilities, from 5 L flasks until tubular photobioreactors. The 146 yeast isolates obtained, molecularly identified based on D1/D2 and ITS nucleotide sequences, belong to the species Rhodotorula diobovata, R. mucilaginosa, R. taiwanensis, R. sphaerocarpa, Vishniacozyma carnescens, Moesziomyces aphidis, and Meyerozyma guilliermondii. The yeast abundance was found to increase throughout upscaling stages. The yeast populations isolated from microalgal cultures and water samples share phylogenetically close isolates, indicating a possible common source. The impressive high percentage of red yeasts isolated (90%) is consistent with the recognized role of carotenoid pigments in yeast photoprotection. Sixty yeast isolates were tested for lipid (Nile Red staining) and biosurfactant (oil drop dispersion and emulsification index) production. Results revealed that these capacities are common features. Microbial lipids and biosurfactants have promising biotechnological applications. Moreover, biosurfactants can fulfill various physiological roles and provide advantages in natural environments contributing to the promising use of yeasts as probiotics in microalgae production.

https://doi.org/10.3390/jof11030228

Ana C Fonseca, Inês Ribeiro, Mariana Girão, Ana Regueiras, Ralph Urbatzka , Pedro Leão , Maria F Carvalho 

Abstract: To combat health conditions, such as multi-resistant bacterial infections, cancer, and metabolic diseases, new drugs need to be urgently found and, in this respect, marine Actinomycetota have a high potential to produce secondary metabolites with pharmacological importance. We aimed to study the cultivable Actinomycetota community associated with a marine sponge from the Portuguese coast, Hymeniacidon perlevis, and investigate the potential of the retrieved isolates to produce compounds with antimicrobial, anticancer and anti-obesity properties.

https://doi.org/10.1093/jambio/lxaf044

Daniela M. G. da Silva, Matilde Marques, Joana F. Couceiro, Elsa Santos, Núria Baylina, Rodrigo Costa and Tina Keller-Costa

Abstract: This study describes a Gram-stain-negative, rod-shaped, facultatively anaerobic bacterial species isolated from the octocoral Litophyton sp. inhabiting the live coral aquarium at Oceanário de Lisboa in Portugal. Four strains, NE35, NE40T, NE41 and NE43, were classified into the genus Endozoicomonas by means of 16S rRNA gene and whole-genome sequence homologies. We then performed phylogenetic, phylogenomic and biochemical analyses to examine their novel species status within the Endozoicomonas genus, based on comparisons with the designated novel type strain NE40T. The closest 16S rRNA gene relatives to strain NE40T are Endozoicomonas montiporae CL-33T (98.2%), Endozoicomonas euniceicola EF212T (97.6%) and Endozoicomonas gorgoniicola PS125T (97.2%). The four strains show genome-wide average nucleotide identity scores above the species level cut-off (95%) with one another and below the cut-off with all Endozoicomonas type strains with publicly available genomes. Digital DNA–DNA hybridization further supported the classification of the strains as a novel species, showing values below 70% when compared with other Endozoicomonas type strains. The DNA G+C content of NE40T was 49.0 mol%, and its genome size was 5.45 Mb. Strain NE40T grows from 15 to 37 °C, with 1–5% (w/v) NaCl, and between pH 6.0 and 8.0 in marine broth and shows optimal growth at 28–32 °C, 2–3% NaCl and pH 7.0–8.0. The predominant cellular fatty acids are summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c), summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C16 :0 and C14 :0. Strain NE40T presents oxidase, catalase and β-galactosidase activities and can reduce nitrates to nitrites and degrade cellulose, chitin, agarose and xylan. Based on the polyphasic approach employed in this study, we propose the novel species name Endozoicomonas lisbonensis sp. nov. (type strain NE40T=DSM 118084T=UCCCB 212T).

https://doi.org/10.1099/ijsem.0.006696

Guilherme Scotta Hentschke, Claudia Hoepfner, Daniel Guzmán and Vitor M. Vasconcelos

Abstract: This article describes a new genus and species of cyanobacteria isolated from Laguna Pastos Grandes in the Bolivian Altiplano. This discovery marks the first described species of this phylum from this extreme environment. Additionally, the phylogenetic status of the genus Capilliphycus is reassessed. The analyses are based on 16S rRNA gene maximum likelihood and Bayesian phylogenies, identity (p-distance), morphology and habitat comparisons. The new genus is a Lyngbya-like type from a mat at the margin of a brackish–alkaline lake with borax. It is phylogenetically close to Dapis, Tenebriella and Okeania, but compared to these genera, the maximum 16S rRNA gene identity values reached only 90.9%, 91.1% and 92.5%, respectively. The genus Capilliphycus was found to be polyphyletic. The type species Capilliphycus salinus is clustered with C. guerandensis. However, “C. tropicalis” and “C. flaviceps” form a distinct clade, distant from the Capilliphycus type species. Between the two “Capilliphycus” clades, Sirenicapillaria and Limnoraphis are found.

https://doi.org/10.3390/plants14030310