Description of two cultivated and two uncultivated new Salinibacter species, one named following the rules of the bacteriological code: Salinibacter grassmerensis sp. nov.; and three named following the rules of the SeqCode: Salinibacter pepae sp. nov., Salinibacter abyssi sp. nov., and Salinibacter pampae sp. nov.

Current -omics methods allow the collection of a large amount of information that helps in describing the microbial diversity in nature. Here, and as a result of a culturomic approach that rendered the collection of thousands of isolates from 5 different hypersaline sites (in Spain, USA and New Zealand), we obtained 21 strains that represent two new Salinibacter species. For these species we propose the names Salinibacter pepae sp. nov. and Salinibacter grassmerensis sp. nov. (showing average nucleotide identity (ANI) values < 95.09% and 87.08% with Sal. ruber M31T, respectively). Metabolomics revealed species-specific discriminative profiles. Sal. ruber strains were distinguished by a higher percentage of polyunsaturated fatty acids and specific N-functionalized fatty acids; and Sal. altiplanensis was distinguished by an increased number of glycosylated molecules. Based on sequence characteristics and inferred phenotype of metagenome-assembled genomes (MAGs), we describe two new members of the genus Salinibacter. These species dominated in different sites and always coexisted with Sal. ruber and Sal. pepae. Based on the MAGs from three Argentinian lakes in the Pampa region of Argentina and the MAG of the Romanian lake Fara Fund, we describe the species Salinibacter pampae sp. nov. and Salinibacter abyssi sp. nov. respectively (showing ANI values 90.94% and 91.48% with Sal. ruber M31T, respectively). Sal. grassmerensis sp. nov. name was formed according to the rules of the International Code for Nomenclature of Prokaryotes (ICNP), and Sal. pepae, Sal. pampae sp. nov. and Sal. abyssi sp. nov. are proposed following the rules of the newly published Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode). This work constitutes an example on how classification under ICNP and SeqCode can coexist, and how the official naming a cultivated organism for which the deposit in public repositories is difficult finds an intermediate solution.

Corrigendum: Resolving the abundance and air-sea fluxes of airborne microorganisms in the North Atlantic Ocean.

[This corrects the article on p. 557 in vol. 5, PMID: 25400625.].

Long-range transport of airborne microbes over the global tropical and subtropical ocean.

The atmosphere plays a fundamental role in the transport of microbes across the planet but it is often neglected as a microbial habitat. Although the ocean represents two thirds of the Earth's surface, there is little information on the atmospheric microbial load over the open ocean. Here we provide a global estimate of microbial loads and air-sea exchanges over the tropical and subtropical oceans based on the data collected along the Malaspina 2010 Circumnavigation Expedition. Total loads of airborne prokaryotes and eukaryotes were estimated at 2.2 × 1021 and 2.1 × 1021 cells, respectively. Overall 33-68% of these microorganisms could be traced to a marine origin, being transported thousands of kilometres before re-entering the ocean. Moreover, our results show a substantial load of terrestrial microbes transported over the oceans, with abundances declining exponentially with distance from land and indicate that islands may act as stepping stones facilitating the transoceanic transport of terrestrial microbes.The extent to which the ocean acts as a sink and source of airborne particles to the atmosphere is unresolved. Here, the authors report high microbial loads over the tropical Atlantic, Pacific and Indian oceans and propose islands as stepping stones for the transoceanic transport of terrestrial microbes..

Response to Comment on "Dilution limits dissolved organic carbon utilization in the deep ocean".

Our recent finding that dilution limits dissolved organic carbon (DOC) utilization in the deep ocean has been criticized based on the common misconception that lability equates to rapid and complete utilization. Even when considering the redefinition of recalcitrant DOC recently proposed by Jiao et al., the dilution hypothesis best explains our experimental observations.

Ocean chemistry. Dilution limits dissolved organic carbon utilization in the deep ocean.

Oceanic dissolved organic carbon (DOC) is the second largest reservoir of organic carbon in the biosphere. About 72% of the global DOC inventory is stored in deep oceanic layers for years to centuries, supporting the current view that it consists of materials resistant to microbial degradation. An alternative hypothesis is that deep-water DOC consists of many different, intrinsically labile compounds at concentrations too low to compensate for the metabolic costs associated to their utilization. Here, we present experimental evidence showing that low concentrations rather than recalcitrance preclude consumption of a substantial fraction of DOC, leading to slow microbial growth in the deep ocean. These findings demonstrate an alternative mechanism for the long-term storage of labile DOC in the deep ocean, which has been hitherto largely ignored.

Resolving the abundance and air-sea fluxes of airborne microorganisms in the North Atlantic Ocean.

Airborne transport of microbes may play a central role in microbial dispersal, the maintenance of diversity in aquatic systems and in meteorological processes such as cloud formation. Yet, there is almost no information about the abundance and fate of microbes over the oceans, which cover >70% of the Earth's surface and are the likely source and final destination of a large fraction of airborne microbes. We measured the abundance of microbes in the lower atmosphere over a transect covering 17° of latitude in the North Atlantic Ocean and derived estimates of air-sea exchange of microorganisms from meteorological data. The estimated load of microorganisms in the atmospheric boundary layer ranged between 6 × 10(4) and 1.6 × 10(7) microbes per m(2) of ocean, indicating a very dynamic air-sea exchange with millions of microbes leaving and entering the ocean per m(2) every day. Our results show that about 10% of the microbes detected in the boundary layer were still airborne 4 days later and that they could travel up to 11,000 km before they entered the ocean again. The size of the microbial pool hovering over the North Atlantic indicates that it could play a central role in the maintenance of microbial diversity in the surface ocean and contribute significantly to atmospheric processes.

Global unbalance in seaweed production, research effort and biotechnology markets.

Exploitation of the world's oceans is rapidly growing as evidenced by a booming patent market of marine products including seaweed, a resource that is easily accessible without sophisticated bioprospecting technology and that has a high level of domestication globally. The investment in research effort on seaweed aquaculture has recently been identified to be the main force for the development of a biotechnology market of seaweed-derived products and is a more important driver than the capacity of seaweed production. Here, we examined seaweed patent registrations between 1980 and 2009 to assess the growth rate of seaweed biotechnology, its geographic distribution and the types of applications patented. We compare this growth with scientific investment in seaweed aquaculture and with the market of seaweed production. We found that both the seaweed patenting market and the rate of scientific publications are rapidly growing (11% and 16.8% per year respectively) since 1990. The patent market is highly geographically skewed (95% of all registrations belonging to ten countries and the top two holding 65% of the total) compared to the distribution of scientific output among countries (60% of all scientific publications belonging to ten countries and the top two countries holding a 21%), but more homogeneously distributed than the production market (with a 99.8% belonging to the top ten countries, and a 71% to the top two). Food industry was the dominant application for both the patent registrations (37.7%) and the scientific publications (21%) followed in both cases by agriculture and aquaculture applications. This result is consistent with the seaweed taxa most represented. Kelp, which was the target taxa for 47% of the patent registrations, is a traditional ingredient in Asian food and Gracilaria and Ulva, which were the focus of 15% and 13% of the scientific publications respectively, that are also used in more sophisticated applications such as cosmetics, chemical industry or bioremediation. Our analyses indicate a recent interest of non-seaweed producing countries to play a part in the seaweed patenting market focusing on more sophisticated products, while developing countries still have a limited share in this booming market. We suggest that this trend could be reverted by promoting partnerships for R and D to connect on-going efforts in aquaculture production with the emerging opportunities for new biotech applications of seaweed products.