Eilat

Achievements for each user project

Mina Bizic

Dead organisms are known to form aggregates of particulate organic matter. In both, marine and freshwater systems, organic aggregates and associated microorganisms are involved in the decomposition and cycling of organic matter and inorganic nutrients. Though in pelagic environments aggregates can appear in relatively low numbers, they are considered hotspots for microbial activity, responsible for the rapid recycling of nutrients thus making them available to all the surrounding biota.
The Red Sea provides a unique environment where one can sample aggregates from organic-enriched reef waters as well as pelagic waters. The constant warm temperature of the Gulf of Aqaba also adds a temperature factor of comparison to the oceanic waters sampled by us thus far.
During my stay at the Interuniversity Institute for Marine Sciences of Eilat I collected samples for molecular analysis of the bacterial community. The samples were collected at several time points along two cross shore transects from several depths. Samples were filtered on 3 fraction sizes in duplicates for future phylogenetic analysis (FISH, DGGE, and sequencing). In addition, for the same set of analyses, I collected undisturbed marine snow agglomerates in surface waters using SCUBA.
To measure the activity of the bacteria on aggregates, part of the collected water was incubated with BrdU and sub sampled at various time points. This analysis will be coupled with FISH in order to phylogentically identify the active groups.
A rolling tank experiment was used to simulate organic aggregates formation. The formed aggregates were collected and will undergo similar analyses as mentioned.

Stephen Maberly

This project built on recent work (Maberly, Courcelle, Groben & Gontero 2010. J. Exp. Bot. 61: 735-745) which found that glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was less redox-regulated in marine than freshwater phytoplankton. The aim of this project was to test if this was linked to environmental variability by comparing regulation of GAPDH in photoautotrophs from the Irish Sea, where variation is extreme because of tidal range, from the Mediterranean Sea where environmental variation is intermediate and from the Red Sea where conditions are relatively constant. The work at IUI at Eilat involved setting up the laboratory, familiarizing ourselves with the equipment, and preparing the reagents needed for the assays. Subtidal material was collected from shallow water (0 to 2 m depth) by swimming and from water down to 25 m using the dive team. Assays were performed on two red macroalgae, three brown macroalgae, a green macroalga and an angiosperm (seagrass). During our visit, algal material was more scarce than usual so we were not able to study as many species as we had planned. We have yet to analyse the results fully, and the material from the Mediterranean and Irish Sea is also not fully analysed. However, preliminary analysis suggests that the extent of regulation in these marine taxa is similar to marine phytoplankton and less than that of freshwater phytoplankton, while phylogenetic patterns are consistent with those we observed in phytoplankton. We would like to thank the staff at the laboratory for their kind and efficient help.

Ladislav Nedbal

We significantly advanced the model of CO2 mass transfer between air and sea water. During the preparatory phase of the project, the work progress was so fast that we were able to submit the work results as a journal publication. The manuscript summarizing the results of the preparatory phase of the TEMIC project has been already accepted as Nedbal, Cerveny, Keren and Kaplan (2010) J Industrial Microbiol Biotechnol, DOI 10.1007 / s10295-010-0876-5. This work was continued during the TEMIC project itself. Namely, we identified as decisive the expansion of the pH and salinity range of the model and we choose optimum experimental approach. We introduced in Eilat IUI cultivation of relevant model marine planktonic cyanobacterium Cyanothece sp. and performed methodological experiments on MIMS technique. We have identified optimum workplan for continuation of  these experiments. We also solved numerous technical problems in integration of the MIMS method in the algal photobioreactor. The main result of the project was that we came much closer to turning the algal photobioreactor into an effective tool for marine research. Last, not least, my participation in the ASSEMBLE network resulted in numerous interactions in the host institution (IUI) as well as with other grantees. The TEMIC/ASSEMBLE project initiated an intensive collaboration with the host institute. We anticipate that follow up projects will be formulated shortly so that the impact of the TEMIC project is amplified.

Claudia Steglich

The aim of this project was to find new environmentally important non-coding RNAs, which can be assigned to Prochlorococcus, and to link the physicochemical and nutrient status of sample sites with the abundance of these RNAs by deep sequencing of total RNA extracts. We filtered 50 – 200 l of seawater per depth at 3 consecutive sample days at station A. Sampling included a depth profile as well as sampling at the deep chlorophyll maximum and at 130 m depth. A test sample was further processed to make sure that we filtered sufficient biomass for RNA extraction. All remaining samples will be processed and further analyzed in Germany. To monitor environmental conditions we will be able to use CTD data that were collected simultaneously during sampling. At the same time the monthly cruise at station A took place that will provide us with information about the nutrient state. Furthermore flow cytometry will be performed by Debbie Lindell (who joined the cruise) and will provide information about Prochlorococcus cell numbers and distribution of high-light and low-light ecotypes at respective sample depths. We will conduct quantitative real-time PCR for a more detailed characterization of field populations. In summary, all planned activities could be accomplished. Technical and scientific support on-site were excellent and included all services that were requested for the project.

Peter Kroth

The aim of this project was to find new environmentally important non-coding RNAs, which can be assigned to Prochlorococcus, and to link the physicochemical and nutrient status of sample sites with the abundance of these RNAs by deep sequencing of total RNA extracts. We filtered 50 – 200 l of seawater per depth at 3 consecutive sample days at station A. Sampling included a depth profile as well as sampling at the deep chlorophyll maximum and at 130 m depth. A test sample was further processed to make sure that we filtered sufficient biomass for RNA extraction. All remaining samples will be processed and further analyzed in Germany. To monitor environmental conditions we will be able to use CTD data that were collected simultaneously during sampling. At the same time the monthly cruise at station A took place that will provide us with information about the nutrient state. Furthermore flow cytometry will be performed by Debbie Lindell (who joined the cruise) and will provide information about Prochlorococcus cell numbers and distribution of high-light and low-light ecotypes at respective sample depths. We will conduct quantitative real-time PCR for a more detailed characterization of field populations. In summary, all planned activities could be accomplished. Technical and scientific support on-site were excellent and included all services that were requested for the project.