Microbial communities in the deep-sea sediments of the South São Paulo Plateau, Southwestern Atlantic Ocean / Comunidades microbianas en los sedimentos de aguas profundas de la meseta sur de São Paulo, océano Atlántico sudoccidental

Microbial communities play a key role in the ocean, acting as primary producers, nutrient recyclers, and energy providers. The São Paulo Plateau is a region located on the southeastern coast of Brazil within economic importance, due to its oil and gas reservoirs. With this focus, this study examined the diversity and composition of microbial communities in marine sediments located at three oceanographic stations in the southern region of São Paulo Plateau using the HOV Shinkai 6500 in 2013. The 16S rRNA gene was sequenced using the universal primers (515F and 926R) by the Illumina Miseq platform. The taxonomic compositions of samples recovered from SP3 station were markedly distinct from those obtained from SP1 and SP2. Although all three stations exhibited a high abundance of Gammaproteobacteria (> 15%), this taxon dominated more than 90% of composition of the A and C sediment layers at SP3. The highest abundance of the archaeal class Nitrososphaeria was presented at SP1, mainly at layer C (~ 21%), being absent at SP3 station. The prediction of chemoheterotrophy and fermentation as important microbial functions was supported by the data. Additionally, other metabolic pathways related to the cycles of nitrogen, carbon and sulfur were also predicted. The core microbiome analysis comprised only two ASVs. Our study contributes to a better understanding of microbial communities in an economically important little-explored region. This is the third microbiological survey in plateau sediments and the first focused on the southern region.(AU)

Influence of food consumption patterns and Galician lifestyle on human gut microbiota

The proportion of different microbial populations in the human gut is an important factor that in recent years has been linked to obesity and numerous metabolic diseases. Because there are many factors that can affect the composition of human gut microbiota, it is of interest to have information about what is the composition of the gut microbiota in different populations in order to better understand the possibilities for improving nutritional management. A group of 31 volunteers were selected according to established inclusion and exclusion criteria and were asked about their diet history, lifestyle patterns, and adherence to the Southern European Atlantic Diet. Fecal samples were taken and subsequently analyzed by real-time PCR. The results indicated different dietary patterns for subjects who consumed a higher amount of fruits, vegetables, legumes, and fish and a lower amount of bakery foods and precooked foods and snacks compared to Spanish consumption data. Most participants showed intermediate or high adherence to Southern European Atlantic Diet, and an analysis of gut microbiota showed high numbers of total bacteria and Actinobacteria, as well as high amounts of bacteria belonging to the genera Lactobacillus spp. and Bifidobacterium spp. A subsequent statistical comparison also revealed differences in gut microbiota depending on the subject's body weight, age, or degree of adherence to the Southern European Atlantic Diet

Competition for polymers among heterotrophic bacteria, isolated from particles of the Equatorial Atlantic / Competición por polímeros entre bacterias heterótrofas aisladas de partículas en el Atlántico ecuatorial

Three heterotrophic bacterial strains, isolated from organic particles of the upper water column of the Equatorial Atlantic, taken during a cruise on the R/V METEOR (1997), were investigated concerning their physiological and phylogenetic properties using classic microbiological and modern molecular-biological methods. All isolates are gram-negative rods able to use polymers such as cellulose, chitin or starch as sole carbon source. The phylogeny of these isolates was investigated by fluorescence in situ hybridization (FISH) and 16S rDNA sequencing. The three isolated strains belong to the Cytophaga/Flavobacteria, gamma-Proteobacteria (Marinobacter sp.), and alpha-Proteobacteria (Sulfitobacter pontiacus). In order to study succession during growth on polymers naturally occurring in marine habitats, FISH was used as a new approach to detect cells from different phylogenetic clusters in the course of a single growth experiment. Mixed cultures consisting of the isolated strains in equal amounts were incubated with cellulose, chitin or starch. Isolate 4301-10/2, a member of the gamma-Proteobacteria, dominated in mixed cultures growing on cellulose, chitin, or starch after only 10 days, with 55, 60, and 95%, respectively, of cells hybridizing with 4,6-diamidino-2-phenylindole (DAPI) (AU)

Tres cepas de bacterias heterótrofas, aisladas de partículas orgánicas de la parte superior de la columna de agua del Atlántico ecuatorial, tomadas durante un crucero con el R/V Meteor (1997), fueron investigadas respecto a sus propiedades fisiológicas y filogenéticas usando tanto técnicas microbiológicas clásicas como métodos moleculares modernos. Todas las cepas aisladas son bacilos Gram-negativos con capacidad de usar polímeros como celulosa, quitina o almidón como única fuente de carbono. La filogenia de estas cepas se investigó mediante hibridación in situ por fluorescencia (FISH) y secuenciación del rDNA 16S. Las tres cepas aisladas pertenecen a las Cytophaga/Flavobacterias, las gamma-Proteobacterias (Marinobacter sp.), y las alfa-Proteobacterias (Sulfitobacter pontiacus). Para estudiar la sucesión a lo largo del crecimiento con polímeros presentes de forma natural en ambientes marinos, se usó FISH para detectar las células de diferentes grupos filogenéticos a lo largo de un experimento de crecimiento. Cultivos mixtos consistentes en las cepas aisladas en cantidades iguales se incubaron con celulosa, quitina o almidón. Transcurridos sólo 10 días, la cepa 4301-10/2, que es una gamma-Proteobacteria, dominó los cultivos mixtos con celulosa, quitina o almidón, con el 55, 60 y 95 por ciento, respectivamente, de las células hibridadas con 4',6-diamidino-2-fenilindol (DAPI) (AU)