Browsing by Issue Date, starting with "2024-08-13"
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- Batch studies on the biodegradation of paracetamol and 1,4-hydroquinone by novel bacterial strains isolated from extreme environmental samples and the identification of candidate catabolic genesPublication . Lara-Moreno, Alba; Fatma El-Sayed; Cox, Cymon; Costa, Maria Clara; Carlier, JorgeThe emerging pollutant paracetamol (APAP) is one of the most prescribed drugs worldwide. In addition, APAP and its main metabolites, namely, 4-aminophenol (4-AP), hydroquinone (H2Q), benzoquinone (BQ), and 2,5-dihydroxy-1,4-benzoquinone (2,5-OH-BQ), among others, are frequently detected in wastewater treatment plants (WWTPs) influents, effluents, and the environment. Thus, continuous release into the environment, especially aquatic environments, is a source of general concern. Six APAP-degrading bacterial strains were isolated from two mine samples from the Iberian Pyrite Belt (Lousal and Poderosa mines). Mycolicibacterium aubagnense HPB1.1, which was isolated using enrichment cultures from the Poderosa mine sample in the presence of H2Q as the sole carbon source, also showed APAP biodegrading capabilities. Pure cultures of this strain degraded 34.3 mg L-1 of APAP in 5 days and 9.4 mg L-1 of H2Q in 4 days. Interestingly, BQ and 2,5-OH-BQ were detected as metabolites resulting from H2Q abiotic degradation, but these compounds were removed in the strain's cultures. Furthermore, M. aubagnense HPB1.1 whole-genome was sequenced, and its encoded proteins were aligned with enzymes of APAP-degrading bacteria recovered from databases and literature aiming to identify candidate catabolic genes. Putative amidases, deaminases, hydroxylases, and dioxygenases, responsible for the degradation of APAP by the HPB1.1 strain, were identified by similarity, corroborating its ability to transform APAP and its intermediate metabolite H2Q into less toxic metabolic compounds due to their capacity to break the aromatic ring of these molecules.
- Long-term co-occurrence and gregariousness in the migratory common stingray using network analysisPublication . Kraft, Sebastian; Winkler, Alexander; Abecasis, David; Mourier, J.Aggregations and social interactions play an important role in the movement ecology of many animals, including elasmobranchs. Several of these species have shown the capability of carrying out complex social behaviours, and the importance of sociality in this taxon is being realized. Although it is a growing field of study in the case of these organisms, these processes still need to be better understood, especially to support management and conservation policies. In this study, a long-term acoustic telemetry data set collected on Dasyatis pastinaca in a coastal marine protected area was analysed. A co-occurrence network analysis was done to investigate preferential associations among individuals, revealing non-random associations among them. The analysis revealed a few strong and consistent associations that were maintained across inter-migratory periods, as this species performs seasonal migrations to a nearby estuary, suggesting temporal stability of the observed associations. Moreover, individuals had similar average positions and a generally high overlap of space use in both periods, indicating some level of site fidelity to the fully protected area. Groups of up to 64% of tagged individuals were co-detected at a same receiver, particularly in the western side of the array. Despite our limited sample size, likely underestimating associations, these results show that in addition to their large-scale movement pattern, D. pastinaca is likely to also present active partner preference and spatial structure at a finer spatial scale. The nature of such results is relevant to support the protection of these species.
- Cardiorespiratory and muscle oxygenation responses to voluntary hypoventilation at low lung volume in upper body repeated sprintsPublication . Rosa, Cristóvão H.; Monteiro, Cristina P.; Barata, Cláudia; Espada, Mário C.; Valamatos, Maria João; Bento, André; da Palma Minhalma, Ricardo José; Reis, Joana FilipaPurpose To investigate the impact of voluntary hypoventilation at low lung volumes (VHL) during upper body repeated sprints (RS) on performance, metabolic markers and muscle oxygenation in Brazilian Jiu-Jitsu (BJJ) athletes. Methods Eighteen male well-trained athletes performed two randomized RS sessions, one with normal breathing (RSN) and another with VHL (RS-VHL), on an arm cycle ergometer, consisting of two sets of eight all-out 6-s sprints performed every 30 s. Peak (PPO), mean power output (MPO), and RS percentage decrement score were calculated. Arterial oxygen saturation (SpO2), heart rate (HR), gas exchange, and muscle oxygenation of the long head of the triceps brachii were continuously recorded. Blood lactate concentration ([La]) was measured at the end of each set. Bench press throw peak power (BPPP) was recorded before and after the RS protocol. Results Although SpO2 was not diferent between conditions, PPO and MPO were signifcantly lower in RS-VHL. V̇ E, HR, [La], and RER were lower in RS-VHL, and VO2 was higher in RS-VLH than in RSN. Muscle oxygenation was not diferent between conditions nor was its pattern of change across the RS protocol infuenced by condition. [La] was lower in RS-VHL than in RSN after both sets. Conclusion Performance was signifcantly lower in RS-VHL, even though SPO2 was not consistent with hypoxemia. However, the fatigue index was not signifcantly afected by VHL, nor was the neuromuscular upper body power after the RSVHL protocol. Additionally, [La] was lower, and oxygen consumption was higher in RS-VHL, suggesting a higher aerobic contribution in this condition.
- Progress and future directions for seaweed holobiont researchPublication . Saha, Mahasweta; Dittami, Simon M.; Chan, Cheong Xin; Raina, Jean‐Baptiste; Stock, Willem; Ghaderiardakani, Fatemeh; John, Ann Mary Valathuparambil Baby; Corr, Shauna; Schleyer, Guy; Todd, Jonathan; Cardini, Ulisse; Bengtsson, Mia M.; Prado, Soizic; Skillings, Derek; Sonnenschein, Eva C.; Engelen, Aschwin; Wang, Gaoge; Wichard, Thomas; Brodie, Juliet; Leblanc, Catherine; Egan, SuhelenIn the marine environment, seaweeds (i.e. marine macroalgae) provide a wide range of ecological services and economic benefits. Like land plants, seaweeds do not provide these services in isolation, rather they rely on their associated microbial communities, which together with the host form the seaweed holobiont. However, there is a poor understanding of the mechanisms shaping these complex seaweed–microbe interactions, and of the evolutionary processes underlying these interactions. Here, we identify the current research challenges and opportunities in the field of seaweed holobiont biology. We argue that identifying the key microbial partners, knowing how they are recruited, and understanding their specific function and their relevance across all seaweed life history stages are among the knowledge gaps that are particularly important to address, especially in the context of the environmental challenges threatening seaweeds. We further discuss future approaches to study seaweed holobionts, and how we can apply the holobiont concept to natural or engineered seaweed ecosystems.