Genetic Diversity and Abundance of Flavobacterial Proteorhodopsin in China Seas

Proteorhodopsin (PR) genes related to Flavobacteria were found to be highly diverse in the East and South China seas and displayed a distinct geographic pattern, which appeared to reflect cold versus warm adaptation when Global Oceanic Sampling database metagenomic data were included. Flavobacterial PR genes were more abundant offshore than nearshore, implying that inheritance of the PR gene could be important for Flavobacteria living in the oligotrophic environment.     

Trace element levels in mollusks from clean and polluted coastal marine sites in the Mediterranean, Red and North Seas

The trace element contamination levels in mollusks were evaluated for different marine coastal sites in the Mediterranean (Israeli coast), Red (Israeli coast) and North (German coast) Seas. Three bivalve species (Mactra corallina, Donax sp, and Mytilus edulis) and two gastropod species (Patella sp.and Cellana rota) were sampled at polluted and relatively clean sites, and their soft tissue analyzed for Hg, Cd, Zn, Cu, Mn and Fe concentrations. Representative samples were screened for organic contaminants [(DDE), polychlorinated biphenyls PCBs and polycyclic aromatic hydrocarbons (PAHs)] which exhibited very low concentrations at all sites. In the Red Sea, the gastropod C. rota showed low levels of Hg (below detection limit) and similar Cd concentrations at all the examined sites, while other trace elements (Cu, Zn, Mn, Fe) were slightly enriched at the northern beach stations. Along the Mediterranean coast of Israel, Hg and Zn were enriched in two bivalves (M. corallina and Donax sp.) from Haifa Bay, both species undergoing a long-term decrease in Hg based on previous studies. Significant Cd and Zn enrichment was detected in Patella sp. from the Kishon River estuary at the southern part of Haifa Bay. In general, Patella sp. and Donax sp. specimens from Haifa Bay exhibited higher levels of Cd compared to other sites along the Israeli Mediterranean coast, attributed to the enrichment of Cd in suspended particulate matter. Along the German coast (North Sea) M. edulis exhibited higher concentrations of Hg and Cd at the Elbe and Eider estuaries, but with levels below those found in polluted sites elsewhere. Received: 25 February 1999 / Received in revised form: 22 April 1999 / Accepted: 30 April 1999     

The microcopepod fauna in the Eastern Mediterranean and Arabian Seas: a comparison with the Red Sea fauna

Multiple opening-closing nets of 0.05 mm mesh size were employed to study the community structure and vertical distribution of microcopepods at selected stations in the Red Sea, Arabian Sea and Eastern Mediterranean Sea down to a maximum depth of 1850 m. Calanoids, cyclopoids (Oithona and Paroithona) and poecilostomatoids (mainly Oncaea) were the 3 most abundant orders. In the epipelagic zone (0–100 m), these orders occurred at similar abundance levels, whereas in the meso- and bathypelagic zones the poecilostomatoid genus Oncaea dominated numerically by about 60–80% of all copepodids.The species diversity of Oncaea in the Red Sea is compared with preliminary results from the two adjacent regions. In the deep Eastern Mediterranean Sea, the number of species appears to be similar to that in the deep Red Sea and low as compared to the deep Arabian Sea. In this latter area an extremely speciose Oncaea fauna was found at depth below the oxygen-minimum-zone (900–1850 m). The results are related to the differences in the hydrographic conditions of these 3 areas.     

Lipid Composition of Novel Shewanella Species Isolated from Far Eastern Seas

A comparative study of the lipid composition of 26 strains (including type strains) of marine Gammaproteobacteria belonging to the genera Shewanella, Alteromonas, Pseudoalteromonas, Marinobacterium, Microbulbifer, and Marinobacter was carried out. The bacteria exhibited genus-specific profiles of ubiquinones, phospholipids, and fatty acids, which can serve as reliable chemotaxonomic markers for tentative identification of new isolates. The studied species of the genus Shewanella were distinguished by the presence of two types of isoprenoid quinones, namely, ubiquinones Q-7 and Q-8 and menaquinones MK-7 and MMK-7; five phospholipids typical of this genus, namely, phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), lyso-PE, and acyl-PG; and the fatty acids [15:0, 16:0, 16:1 (n-7), 17:1 (n-8), i-13:0, and i-15:0]. The high level of branched fatty acids (38–45%) and the presence of eicosapentaenoic acid (4%) may serve as criteria for the identification of this genus. Unlike Shewanella spp., bacteria of the other genera contained a single type of isoprenoid quinone: Q-8 (Alteromonas, Pseudoalteromonas, Marinobacterium, and Microbulbifer) or Q-9 (Marinobacter). The phospholipid compositions of these bacteria were restricted to three components: two major phospholipids (PE and PG) and a minor phospholipid, bisphosphatidic acid (Alteromonas and Pseudoalteromonas) or DPG (Marinobacterium, Microbulbifer, and Marinobacter). The bacteria exhibited genus-specific profiles of fatty acids.     

Novel bioactive bromopyrrole alkaloids from the Mediterranean sponge Axinella verrucosa

The Mediterranean sponge Axinella verrucosa has been investigated for its alkaloid composition and has been found to produce a complex mixture of bromopyrrole alkaloids. Along with the previously isolated compounds 5-18, four novel alkaloids of this class, compounds 1-4, have been isolated, and their structures established through spectroscopic methods. Compounds 1-4 were found to display neuroprotective activity against the agonists serotonin and glutamate in vitro.     

Novel polyhydroxysterols from the Red Sea marine sponge Lamellodysidea herbacea

Chemical investigation of the dichloromethane extract of the Red Sea marine sponge Lamellodysidea herbacea led to the isolation of four novel polyhydroxysteroids: cholesta-8-en-3beta,5alpha,6alpha,25-tetrol (1), cholesta-8(14)-en-3beta,5alpha,6alpha,25-tetrol (2), cholesta-8,24-dien-3beta,5alpha,6alpha-triol (3), and cholesta-8(14),24-dien-3beta,5alpha,6alpha-triol (4). Their structures were identified through 1D and 2D NMR studies. Relative stereochemistries were established by analysis of chemical shifts, coupling constants, and NOESY correlations. Compounds 3-4 showed antifungal activity against Candida tropicalis, with an inhibition diameter of 13 and 11 mm at 10 microg/disc, respectively.     

Composition and dynamics of biostimulated indigenous oil-degrading microbial consortia from the Irish, North and Mediterranean Seas: a mesocosm study

Diversity of indigenous microbial consortia and natural occurrence of obligate hydrocarbon-degrading bacteria (OHCB) are of central importance for efficient bioremediation techniques. To investigate the microbial population dynamics and composition of oil-degrading consortia, we have established a series of identical oil-degrading mesocosms at three different locations, Bangor (Menai Straits, Irish Sea), Helgoland (North Sea) and Messina (Messina Straits, Mediterranean Sea). Changes in microbial community composition in response to oil spiking, nutrient amendment and filtration were assessed by ARISA and DGGE fingerprinting and 16Sr RNA gene library analysis. Bacterial and protozoan cell numbers were quantified by fluorescence microscopy. Very similar microbial population sizes and dynamics, together with key oil-degrading microorganisms, for example, Alcanivorax borkumensis, were observed at all three sites; however, the composition of microbial communities was largely site specific and included variability in relative abundance of OHCB. Reduction in protozoan grazing had little effect on prokaryotic cell numbers but did lead to a decrease in the percentage of A.?borkumensis 16S rRNA genes detected in clone libraries. These results underline the complexity of marine oil-degrading microbial communities and cast further doubt on the feasibility of bioaugmentation practices for use in a broad range of geographical locations.     

Non-native fishes in the Mediterranean from the Red Sea,by way of the Suez Canal

The opening of the Suez Canal in 1869 caused a migration generally from the Red Sea to the Mediterranean, rarely the opposite direction, and 63 lessepsian fish species penetrated into the Mediterranean by way of this canal. These species usually spread northward and most of them can establish wide populations in this area, but some of them can not be successful with respect to establishment. Thus, it is clearly seen that there are a lot of factors influencing the success of species with respect to migration, spreading and establishment. So, the lessepsian migration has been formed by the effects of these factors. Lessepsian species also have the ability to adapt to the ecological conditions of their new environment. Therefore, the influential factors, their effectiveness and the observed changes in lessepsian species due to the effects of these factors have been discussed by considering fishes in this paper.     

Novel variants in human and monkey CETP

Variation in CETP has been shown to play an important role in HDL-C levels and cardiovascular disease. To better characterize this variation, the promoter and exonic DNA for CETP was resequenced in 189 individuals with extreme HDL-C or age. Two novel amino acid variants were found in humans (V-12D and Y361C) and an additional variant (R137W) not previously studied in vitro were expressed. D-12 was not secreted and had no detectable activity in cells. C361 and W137 retained near normal amounts of cholesteryl ester transfer activity when purified but were less well secreted than wild type. Torcetrapib, a CETP inhibitor in clinical development with atorvastatin, was found to have a uniform effect on inhibition of wild type CETP versus W137 or C361. In addition, the level of variation in other species was assessed by resequencing DNA from nine cynomolgus monkeys. Numerous intronic and silent SNPs were found as well as two variable amino acids. The amino acid altering SNPs were genotyped in 29 monkeys and not found to be significantly associated with HDL-C levels. Three SNPs found in monkeys were identical to three found in humans with these SNPs all occurring at CpG sites.     

Red cell NADH diaphorase variants in Japanese

Human red cell NADH diaphorase isozyme patterns were examined in 5,046 healthy adult Japanese by starch gel electrophoresis. Twenty had Dia 2-1 and 3 had Dia 4-1 phenotypes. The incidence of Dia variants in patients with mental retardation, cerebral palsy, epilepsy and Down's syndrome was also examined and compared with that of healthy people. It was noticed that thin-layer isoelectric focusing on polyacrylamide gel was very useful for discriminating variant bands from 'aging bands'.     

Life-history traits of the marbled electric ray,Torpedo marmorata Risso, 1810, from the Greek Seas,north-eastern Mediterranean Sea

Environmental Biology of Fishes - This work presents new information on the morphological aspects, reproductive biology and diet of the marbled electric ray Torpedo marmorata Risso 1810, in the...     

Characterization of the Photochemical Reaction Cycle of Proteorhodopsin

Absorption changes in the photocycle of the recently described retinal protein, proteorhodopsin, are analyzed. The transient spectra at pH 9.5, where it acts as a light-driven proton pump, reveal the existence of three spectrally different intermediates, K, M, and N, named in analogy with the photointermediates of bacteriorhodopsin. Model analysis based on time-dependent absorption kinetic signals at four wavelengths suggested the existence of two more spectrally silent intermediates and lead to a sequential reaction scheme with five intermediates, K, M₁, M₂, N, and PR′, before decay to the initial state PR. An L-like intermediate was not observed, probably for kinetic reasons. By measuring the light-generated electric signal of an oriented sample, the electrogenicity of each intermediate could be determined. The electrogenicities of the first three intermediates (K, M₁, and M₂) have small negative value, but the last three components, corresponding to the N and PR′ intermediates and PR, are positive and two-orders-of-magnitude larger. These states give the major contributions to the proton translocation across the membrane. The energetic scheme of the photocycle was calculated from the temperature-dependence of the absorption kinetic signals.     

Strain variation in Mediterranean and Red Sea Mycobacterium marinum isolates

Four different PCR fingerprinting techniques were tested to distinguish possible strain variations in fourteen Mycobacterium marinum isolates, thirteen from Mediterranean and Red Sea fishes and one from a patient in Sardinia, Italy. PCR ribotyping and ERIC (enterobacterial repetitive consensus sequences)-PCR were found to be non-discriminative, whereas IS (insertion sequences)-PCR and GTG (GTG sequences repeats)-PCR could distinguish the clinical isolate from the piscine isolates, two Italian piscine isolates from all other isolates, but not the Greek isolates from the Israeli isolates. Our results indicate that GTG-PCR and IS-PCR have superior discriminative properties and are thus useful molecular tools for epidemiological studies of M. marinum.     

Ecological traits and environmental affinity explain Red Sea fish introduction into the Mediterranean

Alien species are considered one of the prime threats to biodiversity, driving major changes in ecosystem structure and function. Identifying the traits associated with alien introduction has been largely restricted to comparing indigenous and alien species or comparing alien species that differ in abundance or impact. However, a more complete understanding may emerge when the entire pool of potential alien species is used as a control, information that is rarely available. In the eastern Mediterranean, the marine environment is undergoing an unparalleled species composition transformation, as a flood of aliens have entered from the Red Sea following the opening of the Suez Canal in 1869. In this study, we compile data on species traits, geographical distribution, and environmental affinity of the entire pool of reef‐associated fish species in the Red Sea and more generally across the Indo‐Pacific. We use this extensive data to identify the prime characteristics separating Red Sea species that have become alien in the Mediterranean from those that have not. We find that alien species occupy a larger range of environments in their native ranges, explaining their ability to colonize the seasonal Mediterranean. Red Sea species that naturally experience high maximum temperatures in their native range have a high probability of becoming alien. Thus, contrary to predictions of an accelerating number of aliens following increased water temperatures, hotter summers in this region may prevent the establishment of many alien species. We further find that ecological trait diversity of alien species is substantially more evenly spaced and more divergent than random samples from the pool of Red Sea species, pointing at additional processes, such as competition, promoting ecological diversity among alien species. We use these results to provide a first quantitative ranking of the potential of Red Sea species to become established in the eastern Mediterranean.