Incised valleys drive distinctive oceanographic processes and biological assemblages within rhodolith beds.

Continental shelves encompass gently sloped seascapes that are highly productive and intensively exploited for natural resources. Islands, reefs and other emergent or quasi-emergent features punctuate these shallow (<100 m) seascapes and are well known drivers of increased biomass and biodiversity, as well as predictors of fishing and other human uses. On the other hand, relict mesoscale geomorphological features that do not represent navigation hazards, such as incised valleys (IVs), remain poorly charted. Consequently, their role in biophysical processes remains poorly assessed and sampled. Incised valleys are common within rhodolith beds (RBs), the most extensive benthic habitat along the tropical and subtropical portions of the mid and outer Brazilian shelf. Here, we report on a multi-proxy assessment carried out in a tropical-subtropical transition region (~20°S) off Eastern Brazil, contrasting physicochemical and biological variables in IVs and adjacent RBs. Valleys interfere in near bottom circulation and function as conduits for water and propagules from the slope up to the mid shelf. In addition, they provide a stable and structurally complex habitat for black corals and gorgonians that usually occur in deeper water, contrasting sharply with the algae-dominated RB. Fish richness, abundance and biomass were also higher in the IVs, with small planktivores and large-bodied, commercially important species (e.g. groupers, snappers and grunts) presenting smaller abundances or being absent from RBs. Overall, IVs are unique and vulnerable habitats that sustain diverse assemblages and important ecosystem processes. As new IVs are detected by remote sensing or bathymetric surveys, they can be incorporated into regional marine management plans as conservation targets and priority sites for detailed in situ surveys.

Taxonomic and Functional Metagenomic Signature of Turfs in the Abrolhos Reef System (Brazil).

Turfs are widespread assemblages (consisting of microbes and algae) that inhabit reef systems. They are the most abundant benthic component in the Abrolhos reef system (Brazil), representing greater than half the coverage of the entire benthic community. Their presence is associated with a reduction in three-dimensional coral reef complexity and decreases the habitats available for reef biodiversity. Despite their importance, the taxonomic and functional diversity of turfs remain unclear. We performed a metagenomics and pigments profile characterization of turfs from the Abrolhos reefs. Turf microbiome primarily encompassed Proteobacteria (mean 40.57% ± s.d. 10.36, N = 1.548,192), Cyanobacteria (mean 35.04% ± s.d. 15.5, N = 1.337,196), and Bacteroidetes (mean 11.12% ± s.d. 4.25, N = 424,185). Oxygenic and anoxygenic phototrophs, chemolithotrophs, and aerobic anoxygenic phototrophic (AANP) bacteria showed a conserved functional trait of the turf microbiomes. Genes associated with oxygenic photosynthesis, AANP, sulfur cycle (S oxidation, and DMSP consumption), and nitrogen metabolism (N2 fixation, ammonia assimilation, dissimilatory nitrate and nitrite ammonification) were found in the turf microbiomes. Principal component analyses of the most abundant taxa and functions showed that turf microbiomes differ from the other major Abrolhos benthic microbiomes (i.e., corals and rhodoliths) and seawater. Taken together, these features suggest that turfs have a homogeneous functional core across the Abrolhos Bank, which holds diverse microbial guilds when comparing with other benthic organisms.

Influência do ciclo de esterilização com calor úmido no papel grau cirúrgico: avaliação microbiológica e microscópica / Influence of sterilization cycle with humid heat on surgical grade paper: microbiological and microscopical evaluation

O objetivo do presente estudo foi avaliar a eficácia do papel grau cirúrgico reutilizado durante o processo de esterilização. Foram utilizadas embalagens de papel grau cirúrgico de 10x10cm: Grupo I - um ciclo de esterilização e Grupo II - dois ciclos de esterilização em autoclave. Para análise microbiológica, os envelopes acondicionaram um indicador biológico, com esporos de Geobacillus stearothermophilus e foram submetidos ao ciclo de esterilização em autoclave. Após o ciclo, os indicadores biológicos foram encubados a 60ºC por 48 horas. Como controle, foram incubados indicadores biológicos que não passaram pelo processo de esterilização. Após o período de encubação foi realizada a leitura visual do crescimento bacteriano. Para avaliar alterações físicas, os papéis foram analisados com microscopia eletrônica de varredura em aumentos de até 500x. Não foi observado crescimento bacteriano nos Grupos I e II. Os indicadores biológicos utilizados como controle apresentaram crescimento bacteriano e não foi observada diferença entre os grupos quanto ao padrão das fibras dos papéis. Pode-se dizer que a embalagem de grau cirúrgico reutilizada por pelo menos uma vez permite a esterilização de artigos médicos/odontológicos.

The aim of this study was to evaluate the efficacy of surgical paper reused during the sterilization process. Packagings of surgical paper 10x10 cm were used: Group I - a cycle of sterilization and Group II - two cycles of autoclaving. For microbiological analysis, biological indicator Geobacillus stearothermophilus spores were packed in the envelopes that were submitted to autoclave sterilization cycle. After the cycle, the biological indicators were incubated at 60°C for 48 hours. For the control group biological indicators that did not undergo sterilization process were incubated. After incubation period visual reading of bacterial growth was carried out. To evaluate physical changes, the roles were analyzed with scanning electron microscope 500 x augmentation. No bacterial growth was observed in Groups I and II. Bacterial growth was observed in the control group and there was no difference among groups regarding the fiber pattern of the paper. It can be said that the surgical grade packaging reused once allows the sterilization of medical/dental articles.

Characterization of the photosynthetic conditions and pigment profiles of the colour strains of Hypnea musciformis from field-collected and in vitro cultured samples

Hypnea musciformis (Wulfen) JV Lamour. is a species of great economic interest as it produces Κ-carrageenan and has shown biological activities against HIV and HSV viruses. This species displays different colour strains in its natural habitat, which may have implications for the biotechnological potential of the species. The aim of this study was to characterize the photosynthetic apparatus and pigment profile of three colour strains of H. musciformis (green, brown and red) in their natural habitat and in culture. Chlorophyll a fluorescence of photosystem II was measured with a pulse-amplitude modulated fluorometer and pigments were quantified by spectrofluorimetry (chlorophyll a) and spectrophotometry (phycobiliproteins). In the natural habitat, we detected significant differences between the colour strains for the following photochemical parameters: the green strain had a higher effective quantum yield (ΦPSII) than the red strain and a higher maximum relative electron transport rate (rETRmax) than the brown and red strains. Saturation irradiances were 1000 µE.m-2.s-1 (green) and 500 µE.m-2.s-1 (brown and red). Concerning in vitro culture, the green strain presented the lowest ΦPSII, rETRmax, and α rETR, while the brown strain presented the highest values for these same parameters. The chlorophyll a content of the cultured green strain was the lowest. The phycoerythrin contents of the three colour strains were unchanged by either natural of in vitro conditions: lower in green, intermediate in brown and higher in the red strain, ensuring the chromatic identity of the strains. Our results suggest that the green strain has a better performance when exposed to high irradiance, but a lower efficiency under low irradiance compared to the brown and red strains.