<i>Echinicola vietnamensis</i> sp. nov., a member of the phylum <i>Bacteroidetes</i> isolated from seawater

The taxonomic position of a novel marine, heterotrophic, gliding, halotolerant and light-pink-pigmented bacterium, designated strain KMM 6221T, was examined by using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain KMM 6221T is affiliated with the genus Echinicola, a member of the phylum Bacteroidetes, with levels of similarity of 94.7–95.0 % to strains of Echinicola pacifica. Growth of strain KMM 6221T was observed with 0–15 % NaCl and at 6–44 °C. The DNA G+C content of strain KMM 6221T was 45.9 mol%. On the basis of molecular distinctiveness supported by phenotypic and chemotaxonomic data, strain KMM 6221T is considered to represent a novel species of the genus Echinicola, for which the name Echinicola vietnamensis sp. nov. is proposed. The type strain is KMM 6221T (=DSM 17526T=LMG 23754T)

Acidification increases abundances of Vibrionales and Planctomycetia associated to a seaweed-grazer system: potential consequences for disease and prey digestion efficiency

Ocean acidification significantly affects marine organisms in several ways, with complex interactions. Seaweeds might benefit from rising CO2 through increased photosynthesis and carbon acquisition, with subsequent higher growth rates. However, changes in seaweed chemistry due to increased CO2 may change the nutritional quality of tissue for grazers. In addition, organisms live in close association with a diverse microbiota, which can also be influenced by environmental changes, with feedback effects. As gut microbiomes are often linked to diet, changes in seaweed characteristics and associated microbiome can affect the gut microbiome of the grazer, with possible fitness consequences. In this study, we experimentally investigated the effects of acidification on the microbiome of the invasive brown seaweed Sargassum muticum and a native isopod consumer Synisoma nadejda. Both were exposed to ambient CO2 conditions (380 ppm, pH 8.16) and an acidification treatment (1,000 ppm, pH 7.86) for three weeks. Microbiome diversity and composition were determined using high-throughput sequencing of the variable regions V5-7 of 16S rRNA. We anticipated that as a result of acidification, the seaweed-associated bacterial community would change, leading to further changes in the gut microbiome of grazers. However, no significant effects of elevated CO2 on the overall bacterial community structure and composition were revealed in the seaweed. In contrast, significant changes were observed in the bacterial community of the grazer gut. Although the bacterial community of S. muticum as whole did not change, Oceanospirillales and Vibrionales (mainly Pseudoalteromonas) significantly increased their abundance in acidified conditions. The former, which uses organic matter compounds as its main source, may have opportunistically taken advantage of the possible increase of the C/N ratio in the seaweed under acidified conditions. Pseudoalteromonas, commonly associated to diseased seaweeds, suggesting that acidification may facilitate opportunistic/pathogenic bacteria. In the gut of S. nadejda, the bacterial genus Planctomycetia increased abundance under elevated CO2. This shift might be associated to changes in food (S. muticum) quality under acidification. Planctomycetia are slow-acting decomposers of algal polymers that could be providing the isopod with an elevated algal digestion and availability of inorganic compounds to compensate the shifted C/N ratio under acidification in their food. In conclusion, our results indicate that even after only three weeks of acidified conditions, bacterial communities associated to ungrazed seaweed and to an isopod grazer show specific, differential shifts in associated bacterial community. These have potential consequences for seaweed health (as shown in corals) and isopod food digestion. The observed changes in the gut microbiome of the grazer seem to reflect changes in the seaweed chemistry rather than its microbial composition.Erasmus Mundus Doctoral Programme MARES on Marine Ecosystem Health Conservation [MARES_13_08]; FCT (Foundation for Science and Technology, Portugal) [SFRH/BPD/63703/2009, SFRH/BPD/107878/2015, SFRH/BPD/116774/2016]; EU SEAS-ERA project INVASIVES [SEAS-ERA/0001/2012]; [CCMAR/Multi/04326/2013

Hemolymph microbiome of Pacific oysters in response to temperature, temperature stress and infection

Microbiota provide their hosts with a range of beneficial services, including defense from external pathogens. However, host-associated microbial communities themselves can act as a source of opportunistic pathogens depending on the environment. Marine poikilotherms and their microbiota are strongly influenced by temperature, but experimental studies exploring how temperature affects the interactions between both parties are rare. To assess the effects of temperature, temperature stress and infection on diversity, composition and dynamics of the hemolymph microbiota of Pacific oysters (Crassostrea gigas), we conducted an experiment in a fully-crossed, three-factorial design, in which the temperature acclimated oysters (8 or 22 °C) were exposed to temperature stress and to experimental challenge with a virulent Vibrio sp. Strain. We monitored oyster survival and repeatedly collected hemolymph of dead and alive animals to determine the microbiome composition by 16s rRNA gene amplicon pyrosequencing. We found that the microbial dynamics and composition of communities in healthy animals (including infection survivors) were significantly affected by temperature and temperature stress, but not by infection. The response was mediated by changes in the incidence and abundance of operational taxonomic units (OTUs) and accompanied by little change at higher taxonomic levels, indicating dynamic stability of the hemolymph microbiome. Dead and moribund oysters, on the contrary, displayed signs of community structure disruption, characterized by very low diversity and proliferation of few OTUs. We can therefore link short-term responses of host-associated microbial communities to abiotic and biotic factors and assess the potential feedback between microbiota dynamics and host survival during disease

Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

© 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

THE PSYCHOPROFILE OF LISTERIA MONOCYTOGENES AND ITS ECOLOGOEPIDEMIOLOGICAL IMPORTANCE

For the first time it has been established, that Listeria possess the ability to the hemolithoautotrophic nutrition, assimilating the carbon from the non-organic compounds. For the first time, it has been established, that Listeria are the C-strategists, using the advantages of the K-selection. When studying the hemotaxis, first the number of the attractants and repellents of the Listeria have been revealed. For the first time, the fact of the Listeria multiplication at 6 to 8 degrees C has been proved with the aid of introduction of the radioactive mark into the cultivation medium. It has been shown, that the low temperature of cultivation intensifies the appearance of the Listeria pathogenic properties. It has been shown, that at low temperatures (6 to 8 degrees C) the Listeria metabolism flows more economically. The effective nutrient and selective medium for the growth and isolation of the Listeria from the different objects has been developed, on which 29 strains have been isolated in Primorje. The rational diagram of the Listeria identification has been developedAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Echinicola vietnamensis sp nov, a member of the phylum Bacteroidetes isolated from seawater

The taxonomic position of a novel marine, heterotrophic, gliding, halotolerant and light-pink-pigmented bacterium, designated strain KMM 6221(T), was examined by using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain KMM 6221(T) is affiliated with the genus Echinicola, a member of the phylum Bacteroidetes, with levels of similarity of 94.7-95.0% to strains of Echinicola pacifica. Growth of strain KMM 6221(T) was observed with 0-15% NaCl and at 6-44 degrees C. The DNA G + C content of strain KMM 6221(T) was 45.9 mol%. On the basis of molecular distinctiveness supported by phenotypic and chemotaxonomic data, strain KMM 6221(T) is considered to represent a novel species of the genus Echinicola, for which the name Echinicola vietnamensis sp. nov. is proposed. The type strain is KMM 6221(T) (= DSM 17526(T) = LMG 23754(T))