Pyrosequencing revealed shifts of prokaryotic communities between healthy and disease-like tissues of the Red Sea sponge Crella cyathophora.

Sponge diseases have been widely reported, yet the causal factors and major pathogenic microbes remain elusive. In this study, two individuals of the sponge Crella cyathophora in total that showed similar disease-like characteristics were collected from two different locations along the Red Sea coast separated by more than 30 kilometers. The disease-like parts of the two individuals were both covered by green surfaces, and the body size was much smaller compared with adjacent healthy regions.

Effect of polybrominated diphenyl ether (PBDE) treatment on the composition and function of the bacterial community in the sponge Haliclona cymaeformis.

Marine sponges play important roles in benthic environments and are sensitive to environmental stresses. Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants since the 1970s and are cytotoxic and genotoxic to organisms. In the present study, we studied the short-period effect of PBDE-47 (2,2',4,4'-tetrabromodiphenyl ether) treatment on the community structure and functional gene composition of the bacterial community inhabiting the marine sponge Haliclona cymaeformis.

Pyrosequencing reveals the microbial communities in the Red Sea sponge Carteriospongia foliascens and their impressive shifts in abnormal tissues.

Abnormality and disease in sponges have been widely reported, yet how sponge-associated microbes respond correspondingly remains inconclusive. Here, individuals of the sponge Carteriospongia foliascens under abnormal status were collected from the Rabigh Bay along the Red Sea coast. Microbial communities in both healthy and abnormal sponge tissues and adjacent seawater were compared to check the influences of these abnormalities on sponge-associated microbes.

Toward understanding the dynamics of microbial communities in an estuarine system.

Community assembly theories such as species sorting theory provide a framework for understanding the structures and dynamics of local communities. The effect of theoretical mechanisms can vary with the scales of observation and effects of specific environmental factors. Based on 16S rRNA gene tag pyrosequencing, different structures and temporal succession patterns were discovered between the surface sediments and bottom water microbial communities in the Pearl River Estuary (PRE).

Microbial sulfur cycle in two hydrothermal chimneys on the Southwest Indian Ridge.

Unlabelled: Sulfur is an important element in sustaining microbial communities present in hydrothermal vents. Sulfur oxidation has been extensively studied due to its importance in chemosynthetic pathways in hydrothermal fields; however, less is known about sulfate reduction. Here, the metagenomes of hydrothermal chimneys located on the ultraslow-spreading Southwest Indian Ridge (SWIR) were pyrosequenced to elucidate the associated microbial sulfur cycle.

Molecular techniques revealed highly diverse microbial communities in natural marine biofilms on polystyrene dishes for invertebrate larval settlement.

Biofilm microbial communities play an important role in the larval settlement response of marine invertebrates. However, the underlying mechanism has yet to be resolved, mainly because of the uncertainties in characterizing members in the communities using traditional 16S rRNA gene-based molecular methods and in identifying the chemical signals involved. In this study, pyrosequencing was used to characterize the bacterial communities in intertidal and subtidal marine biofilms developed during two seasons.

In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system.

Using microscopic and molecular techniques combined with computational analysis, this study examined the structure and composition of microbial communities in biofilms that formed on different artificial substrates in a brine pool and on a seep vent of a cold seep in the Red Sea to test our hypothesis that initiation of the biofilm formation and spreading mode of microbial structures differs between the cold seep and the other aquatic environments. Biofilms on different substrates at two deployment sites differed morphologically, with the vent biofilms having higher microbial abundance and better structural features than the pool biofilms. Microbes in the pool biofilms were more taxonomically diverse and mainly composed of various sulfate-reducing bacteria whereas the vent biofilms were exclusively dominated by sulfur-oxidizing Thiomicrospira.

Adaptation of intertidal biofilm communities is driven by metal ion and oxidative stresses.

Marine organisms in intertidal zones are subjected to periodical fluctuations and wave activities. To understand how microbes in intertidal biofilms adapt to the stresses, the microbial metagenomes of biofilms from intertidal and subtidal zones were compared. The genes responsible for resistance to metal ion and oxidative stresses were enriched in both 6-day and 12-day intertidal biofilms, including genes associated with secondary metabolism, inorganic ion transport and metabolism, signal transduction and extracellular polymeric substance metabolism.

Artifactual pyrosequencing reads in multiple-displacement-amplified sediment metagenomes from the Red Sea.

The Multiple Displacement Amplification (MDA) protocol is reported to introduce different artifacts into DNA samples with impurities. In this study, we report an artifactual effect of MDA with sediment DNA samples from a deep-sea brine basin in the Red Sea. In the metagenomes, we showed the presence of abundant artifactual 454 pyrosequencing reads over sizes of 50 to 220 bp.

Autotrophic microbe metagenomes and metabolic pathways differentiate adjacent Red Sea brine pools.

In the Red Sea, two neighboring deep-sea brine pools, Atlantis II and Discovery, have been studied extensively, and the results have shown that the temperature and concentrations of metal and methane in Atlantis II have increased over the past decades. Therefore, we investigated changes in the microbial community and metabolic pathways. Here, we compared the metagenomes of the two pools to each other and to those of deep-sea water samples.

Deep sequencing of Myxilla (Ectyomyxilla) methanophila, an epibiotic sponge on cold-seep tubeworms, reveals methylotrophic, thiotrophic, and putative hydrocarbon-degrading microbial associations.

The encrusting sponge Myxilla (Ectyomyxilla) methanophila (Poecilosclerida: Myxillidae) is an epibiont on vestimentiferan tubeworms at hydrocarbon seeps on the upper Louisiana slope of the Gulf of Mexico. It has long been suggested that this sponge harbors methylotrophic bacteria due to its low δ(13)C value and high methanol dehydrogenase activity, yet the full community of microbial associations in M. methanophila remained uncharacterized.

Spatial and species variations in bacterial communities associated with corals from the Red Sea as revealed by pyrosequencing.

Microbial associations with corals are common and are most likely symbiotic, although their diversity and relationships with environmental factors and host species remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with three stony Scleractinea and two soft Octocorallia corals from three locations in the Red Sea. Our results revealed highly diverse bacterial communities in the Red Sea corals, with more than 600 ribotypes detected and up to 1,000 species estimated from a single coral species.

The regulatory role of the NO/cGMP signal transduction cascade during larval attachment and metamorphosis of the barnacle Balanus (=Amphibalanus) amphitrite.

The barnacle Balanus amphitrite is among the most dominant fouling species on intertidal rocky shores in tropical and subtropical areas and is thus a target organism in antifouling research. After being released from adults, the swimming nauplius undertakes six molting cycles and then transforms into a cyprid. Using paired antennules, a competent cyprid actively explores and selects a suitable substratum for attachment and metamorphosis (collectively known as settlement).

Profundibacterium mesophilum gen. nov., sp. nov., a novel member in the family Rhodobacteraceae isolated from deep-sea sediment in the Red Sea, Saudi Arabia.

A slow-growing, strictly aerobic, Gram-negative, coccus bacterial strain, designated KAUST100406-0324(T), was isolated from sea-floor sediment collected from the Red Sea, Saudi Arabia. The catalase- and oxidase-positive strain was non-sporulating and only slightly halophilic. Optimum growth occurred at 20-25 °C and at pH values ranging from 7.

Bacterial niche-specific genome expansion is coupled with highly frequent gene disruptions in deep-sea sediments.

The complexity and dynamics of microbial metagenomes may be evaluated by genome size, gene duplication and the disruption rate between lineages. In this study, we pyrosequenced the metagenomes of microbes obtained from the brine and sediment of a deep-sea brine pool in the Red Sea to explore the possible genomic adaptations of the microbes in response to environmental changes. The microbes from the brine and sediments (both surface and deep layers) of the Atlantis II Deep brine pool had similar communities whereas the effective genome size varied from 7.

Marinobacter xestospongiae sp. nov., isolated from the marine sponge Xestospongia testudinaria collected from the Red Sea.

A Gram-negative, catalase- and oxidase-positive, non-sporulating, rod-shaped and slightly halophilic bacterial strain, designated UST090418-1611(T), was isolated from the marine sponge Xestospongia testudinaria collected from the Red Sea coast of Saudi Arabia. Phylogenetic trees based on the 16S rRNA gene sequence placed strain UST090418-1611(T) in the family Alteromonadaceae with the closest relationship to the genus Marinobacter. The 16S rRNA gene sequence similarity between the strain and the type strains of recognized Marinobacter species ranged from 92.

Erythrobacter pelagi sp. nov., a member of the family Erythrobacteraceae isolated from the Red Sea.

A novel Gram-negative, aerobic, catalase- and oxidase-positive, non-sporulating, non-motile, rod-shaped bacterium, designated strain UST081027-248(T), was isolated from seawater of the Red Sea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain UST081027-248(T) fell within the genus Erythrobacter. Levels of 16S rRNA gene sequence similarity between the novel strain and the type strains of Erythrobacter species ranged from 95.

Hydrothermally generated aromatic compounds are consumed by bacteria colonizing in Atlantis II Deep of the Red Sea.

Hydrothermal ecosystems have a wide distribution on Earth and many can be found in the basin of the Red Sea. Production of aromatic compounds occurs in a temperature window of ∼60-150 °C by utilizing organic debris. In the past 50 years, the temperature of the Atlantis II Deep brine pool in the Red Sea has increased from 56 to 68 °C, whereas the temperature at the nearby Discovery Deep brine pool has remained relatively stable at about 44 °C.

Sponges and sediments as monitoring tools of metal contamination in the eastern coast of the Red Sea, Saudi Arabia.

Sediments and sponges were collected from various locations along the eastern coast of the Red Sea, the Kingdom of Saudi Arabia. Total concentrations of Cd, Zn, Ag, Cu, Pb, As and Hg in the sediments were measured. Metal contamination was not significant in most of the studied sites and only one site was moderately polluted by Zn, Cu, and Pb.

Diversity and quantity of ammonia-oxidizing Archaea and Bacteria in sediment of the Pearl River Estuary, China.

The diversity and abundance of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in the sediment of the Pearl River Estuary were investigated by cloning and quantitative real-time polymerase chain reaction (qPCR). From one sediment sample S16, 36 AOA OTUs (3% cutoff) were obtained from three clone libraries constructed using three primer sets for amoA gene. Among the 36 OTUs, six were shared by all three clone libraries, two appeared in two clone libraries, and the other 28 were only recovered in one of the libraries.

Pyrosequencing reveals highly diverse and species-specific microbial communities in sponges from the Red Sea.

Marine sponges are associated with a remarkable array of microorganisms. Using a tag pyrosequencing technology, this study was the first to investigate in depth the microbial communities associated with three Red Sea sponges, Hyrtios erectus, Stylissa carteri and Xestospongia testudinaria. We revealed highly diverse sponge-associated bacterial communities with up to 1000 microbial operational taxonomic units (OTUs) and richness estimates of up to 2000 species.

Vertical stratification of microbial communities in the Red Sea revealed by 16S rDNA pyrosequencing.

The ecosystems of the Red Sea are among the least-explored microbial habitats in the marine environment. In this study, we investigated the microbial communities in the water column overlying the Atlantis II Deep and Discovery Deep in the Red Sea. Taxonomic classification of pyrosequencing reads of the 16S rRNA gene amplicons showed vertical stratification of microbial diversity from the surface water to 1500 m below the surface.

Copper affects biofilm inductiveness to larval settlement of the serpulid polychaete Hydroides elegans (Haswell).

Copper (Cu) contamination is a potential threat to the marine environment due to the use of Cu-based antifouling paints. Cu stress on larval settlement of the polychaete Hydroides elegans was investigated, and this was linked to Cu stress on biofilms and on the biofilm development process. The inductiveness of young biofilms was more easily altered by Cu stress than that of old biofilms, indicating the relative vulnerability of young biofilms.

Bacterial community succession and chemical profiles of subtidal biofilms in relation to larval settlement of the polychaete Hydroides elegans.

Earlier studies have shown that biofilms can mediate the larval settlement of the polychaete Hydroides elegans and that changes in the bacterial community structure and density of biofilms often alter the larval settlement response. However, the chemical cues that mediate this response remain unknown. In this study, both successional changes in the bacterial community structure and the chemical profiles of subtidal biofilms are described and related to the larval settlement response.

Evidence for vertical transmission of bacterial symbionts from adult to embryo in the Caribbean sponge Svenzea zeai.

The Caribbean reef sponge Svenzea zeai was previously found to contain substantial quantities of unicellular photosynthetic and autotrophic microbes in its tissues, but the identities of these symbionts and their method of transfer from adult to progeny are largely unknown. In this study, both a 16S rRNA gene-based fingerprinting technique (denaturing gradient gel electrophoresis [DGGE]) and clone library analysis were applied to compare the bacterial communities associated with adults and embryos of S. zeai to test the hypothesis of vertical transfer across generations.