Publications by authors named "Louisi S de Oliveira"
In the last decade, several methods were applied to monitor the impact of oil pollution on marine organisms. Recent studies showed an eminent need to standardize these methods to produce comparable results. Here we present the first thorough systematic review of the literature on oil pollution monitoring methods in the last decade.
View Article and Find Full Text PDFTriterpene cyclases catalyze the first committed step in triterpene biosynthesis, by forming mono- to pentacyclic backbone structures from oxygenated C30 isoprenoid precursors. Squalene epoxidase precedes this cyclization by providing the oxygenated and activated substrate for triterpene biosynthesis. Three squalene epoxidases from Cucurbita pepo (CpSEs) were isolated and shown to have evolved under purifying selection with signs of sites under positive selection in their N- and C-termini.
View Article and Find Full Text PDFArticle Synopsis
- - Marine sponges host complex microbial communities that may be responsible for producing secondary metabolites, like bromopyrrole alkaloids, which have notable biological activities.
- - Research on sponge species Agelas spp. and Tedania brasiliensis revealed distinct microbial halogenases, indicating a species-specific presence and a correlation between halogenase encoding bacteria abundance and bromopyrrole production.
- - The study suggests that sponges with numerous CRISPR sequences, like Agelas spp., may protect themselves from phage infections, while phages can facilitate the horizontal transfer of halogenases among holobionts, especially in more adaptable hosts like Tedania spp.
The ability to recognize and respond to the presence of microbes is an essential strategy for seaweeds to survive in the marine environment, but understanding of molecular seaweed-microbe interactions is limited. clones were inoculated with the marine bacterium . The seaweed RNA was sequenced, providing an unprecedentedly high coverage of the transcriptome of , and the gene expression levels were compared between control and inoculated samples after 24, 48, and 72 h.
View Article and Find Full Text PDFArticle Synopsis
- The study focuses on the diversity and structure of virus assemblages in the Amazon River-ocean continuum, highlighting their importance in global carbon and nutrient cycling.
- Researchers collected viral DNA sequences from 12 locations along the river and plume, yielding 29,358 scaffolds and 15 new complete viral genomes, revealing distinct virome characteristics between the river and plume ecosystems.
- Findings indicate that bacteriophages were widespread, while eukaryotic viruses were more prevalent in the river; the study emphasizes the influence of water physical and chemical parameters, especially salinity, on viral distribution and contributes to understanding the role of viruses in the organic matter cycle.
Article Synopsis
- Corals switch from autotrophic feeding during the day to heterotrophic feeding at night, creating different oxygen conditions that impact the microbial communities living around them.
- Most research on coral reef microbes has focused on daytime samples, leading to a potential bias in understanding these communities.
- The study analyzed microbial communities near the coral over a 48-hour cycle and found that microbial composition was stable between day and night, suggesting that water flow plays a bigger role than coral physiology in shaping these communities.
Background: Microcephaly has become a major public health problem in Brazil. The total number of newborns with microcephaly was reported to be >4000 in June 2016. Studies suggest that Zika Virus is a major cause of new microcephaly cases in Brazil.
View Article and Find Full Text PDFThe red seaweed Laurencia dendroidea belongs to the Rhodophyta, a phylum of eukaryotic algae that is widely distributed across the oceans and that constitute an important source of bioactive specialized metabolites. Laurencia species have been studied since 1950 and were found to contain a plethora of specialized metabolites, mainly halogenated sesquiterpenes, diterpenes and triterpenes that possess a broad spectrum of pharmacological and ecological activities. The first committed step in the biosynthesis of triterpenes is the cyclization of 2,3-oxidosqualene, an enzymatic reaction carried out by oxidosqualene cyclases (OSCs), giving rise to a broad range of different compounds, such as the sterol precursors cycloartenol and lanosterol, or triterpene precursors such as cucurbitadienol and β-amyrin.
View Article and Find Full Text PDFThe red seaweeds belonging to the genus Laurencia are well known as halogenated secondary metabolites producers, mainly terpenoids and acetogennins. Several of these chemicals exhibit important ecological roles and biotechnological applications. However, knowledge regarding the genes involved in the biosynthesis of these compounds is still very limited.
View Article and Find Full Text PDFFive novel strains of Photobacterium (A-394T, A-373, A-379, A-397 and A-398) were isolated from bleached coral Madracis decactis (scleractinian) in the remote St Peter & St Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil. Healthy M. decactis specimens were also surveyed, but no strains were related to them.
View Article and Find Full Text PDFArticle Synopsis
- The study focuses on the red seaweed Laurencia dendroidea, which is known for producing important secondary metabolites, particularly halogenated compounds with potential pharmacological properties.
- Researchers conducted a transcriptomic analysis to uncover the genes associated with terpenoid biosynthesis in L. dendroidea and explored its interactions with the surrounding microbial community.
- Findings highlighted that bacteria, especially nitrogen-fixing Cyanobacteria and aerobic heterotrophic Proteobacteria, were the dominant group in its microbiome, while eukaryotic transcripts were linked to processes like photosynthesis and defense mechanisms, contributing to insights about the seaweed's ecological and chemical roles.