Centre for Environmental and Marine Studies

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Marine sponge and octocoral-associated bacteria show versatile secondary metabolite biosynthesis potential and antimicrobial activities against human pathogens

Publication . Almeida, João F.; Marques, Matilde; Oliveira, Vanessa; Egas, Conceição; Mil-Homens, Dalila; Viana, Romeu; Cleary, Daniel F. R.; Huang, Yusheng M.; Fialho, Arsénio M.; Teixeira, Miguel C.; Gomes, Newton C. M.; Costa, Rodrigo; Keller-Costa, Tina

Marine microbiomes are prolific sources of bioactive natural products of potential pharmaceutical value. This study inspected two culture collections comprising 919 host-associated marine bacteria belonging to 55 genera and several thus-far unclassified lineages to identify isolates with potentially rich secondary metabolism and antimicrobial activities. Seventy representative isolates had their genomes mined for secondary metabolite biosynthetic gene clusters (SM-BGCs) and were screened for antimicrobial activities against four pathogenic bacteria and five pathogenic Candida strains. In total, 466 SM-BGCs were identified, with antimicrobial peptide- and polyketide synthase-related SM-BGCs being frequently detected. Only 38 SM-BGCs had similarities greater than 70% to SM-BGCs encoding known compounds, highlighting the potential biosynthetic novelty encoded by these genomes. Cross-streak assays showed that 33 of the 70 genome-sequenced isolates were active against at least one Candida species, while 44 isolates showed activity against at least one bacterial pathogen. Taxon-specific differences in antimicrobial activity among isolates suggested distinct molecules involved in antagonism against bacterial versus Candida pathogens. The here reported culture collections and genome-sequenced isolates constitute a valuable resource of understudied marine bacteria displaying antimicrobial activities and potential for the biosynthesis of novel secondary metabolites, holding promise for a future sustainable production of marine drug leads.

2022Journal article

Open Access

T-wave propagation from the Pacific to the Atlantic: The 2020 Mw7.4 Kermadec Trench earthquake case

Publication . Oliveira, Tiago C. A.; Lin, Ying-Tsong; Kushida, Noriyuki; Jesus, Sergio; Nielsen, Peter

An Mw7.4 submarine earthquake occurred in the Kermadec Trench, northeast of New Zealand, on 18 June, 2020. This powerful earthquake triggered energetic tertiary waves (T-waves) that propagated through the South Pacific Ocean into the South Atlantic Ocean, where the T-waves were recorded by a hydrophone station near Ascension Island, 15 127 km away from the epicenter. Different T-wave arrivals were identified during the earthquake period with arrival angles deviating from the geodesic path. A three-dimensional sound propagation model has been utilized to investigate the cause of the deviation and confirm the horizontal diffraction of the T-waves at the Drake Passage. VC 2021 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). [Editor: Gopu R Potty]

2021-12Journal article

Open Access

Multi-Omic profiling of macrophages treated with phospholipids containing Omega-3 and Omega-6 fatty acids reveals complex immunomodulatory adaptations at protein, lipid and metabolic levels

Publication . Maurício, Tatiana; Aveiro, Susana; Guedes, Sofia; Lopes, Diana; Melo, Tânia; Neves, Bruno M.; Domingues, Rosário; Domingues, Pedro

In recent years, several studies have demonstrated that polyunsaturated fatty acids have strong immunomodulatory properties, altering several functions of macrophages. In the present work, we sought to provide a multi-omic approach combining the analysis of the lipidome, the proteome, and the metabolome of RAW 264.7 macrophages supplemented with phospholipids containing omega-3 (PC 18:0/22:6; omega 3-PC) or omega-6 (PC 18:0/20:4; omega 6-PC) fatty acids, alone and in the presence of lipopolysaccharide (LPS). Supplementation of macrophages with omega 3 and omega 6 phospholipids plus LPS produced a significant reprogramming of the proteome of macrophages and amplified the immune response; it also promoted the expression of anti-inflammatory proteins (e.g., pleckstrin). Supplementation with the omega 3-PC and omega 6-PC induced significant changes in the lipidome, with a marked increase in lipid species linked to the inflammatory response, attributed to several pro-inflammatory signalling pathways (e.g., LPCs) but also to the pro-resolving effect of inflammation (e.g., PIs). Finally, the metabolomic analysis demonstrated that supplementation with omega 3-PC and omega 6-PC induced the expression of several metabolites with a pronounced inflammatory and anti-inflammatory effect (e.g., succinate). Overall, our data show that supplementation of macrophages with omega 3-PC and omega 6-PC effectively modulates the lipidome, proteome, and metabolome of these immune cells, affecting several metabolic pathways involved in the immune response that are triggered by inflammation.

2022Journal article

Open Access

Chemical characterization and biological properties assessment of Euphorbia resinifera and Euphorbia officinarum Moroccan Propolis

Publication . Boutoub, Oumaima; El-Guendouz, Soukaina; Matos, Isabel; El Ghadraoui, Lahsen; Costa, Maria Clara; Carlier, Jorge; Faleiro, Maria Leonor; Figueiredo, Ana Cristina; Estevinho, Letícia M.; Miguel, Maria

Although the plants of the genus Euphorbia are largely exploited by therapists in Morocco, the composition and antibacterial activities of propolis from these plants are still unknown. To address this gap, this study aimed to characterize the pollen type, the volatile compounds, and the phenolic and mineral profiles of three Euphorbia propolis samples collected in Morocco and evaluate their antimicrobial activities. The minimum inhibitory concentration of the propolis samples was determined by the microdilution method, and the anti-adherence activity was evaluated by the crystal violet assay. The examination of anti-quorum-sensing proprieties was performed using the biosensor Chromobacterium violaceum CV026. Pollen analysis revealed that Euphorbia resinifera pollen dominated in the P1 sample (58%), while E. officinarum pollen dominated in the P2 and P3 samples (44%). The volatile compounds were primarily composed of monoterpene hydrocarbons, constituting 35% in P1 and 31% in P2, with α-pinene being the major component in both cases, at 16% in P1 and 15% in P2. Calcium (Ca) was the predominant mineral element in both E. resinifera (P1) and E. officinarum (P2 and P3) propolis samples. Higher levels of phenols, flavonoids and dihydroflavonoids were detected in the E. officinarum P2 sample. The minimum inhibitory concentration (MIC) value ranged from 50 to 450 µL/mL against Gram-positive and Gram-negative bacteria. Euphorbia propolis displayed the ability to inhibit quorum sensing in the biosensor C. violaceum CV026 and disrupted bacterial biofilm formation, including that of resistant bacterial pathogens. In summary, the current study evidences the potential use of E. officinarum propolis (P2 and P3) to combat important features of resistant pathogenic bacteria, such as quorum sensing and biofilm formation.

2024-02-29Journal article

Open Access

Megameter propagation and correlation of T-waves from Kermadec Trench and Islands

Publication . Oliveira, Tiago C. A.; Nielsen, Peter; Lin, Ying-Tsong; Kushida, Noriyuki; Jesus, Sergio

On 18 June 2020 and 4 March 2021, very energetic low-frequency underwater T-wave signals (2 to 25 Hz) were recorded at the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) hydrophone stations in the Pacific Ocean (Stations HA11 and HA03) and the South Atlantic Ocean (Station HA10). This work investigates the long-range (megameters) propagation of these T-waves. Their sources were three powerful submarine earthquakes in the Kermadec Trench and Islands, located at approximately 6000, 8800, and 15100 km from Stations HA11, HA03, and HA10, respectively. Arrival time and back azimuth of the recorded T-waves were estimated using the Progressive Multi-Channel Correlation algorithm installed on the CTBT Organization (CTBTO) virtual Data Exploitation Centre (vDEC). Different arrivals within the duration of the earthquake signals were identified, and their correlations were also analyzed. The data analysis at HA03 and HA10 revealed intriguing T-wave propagation paths reflecting, refracting, or even transmitting through continents, as well as T-wave excitation along a chain of seamounts. The analysis also showed much higher transmission loss (TL) in the propagation paths to HA11 than to HA03 and HA10. Moreover, strong discrepancies between expected and measured back azimuths were observed for HA11, and a three-dimensional (3D) parabolic equation model was utilized to identify the cause of these differences. Numerical results revealed the importance of 3D effects induced by the Kermadec Ridge, Fiji archipelago, and Marshall Islands on T-wave propagation to HA11. This analysis can guide future improvements in underwater event localization using the CTBT-IMS hydroacoustic sensor network.

2022Journal article

Open Access