• Bacterial degradation
• Flame retardants
• Liquid chromatography coupled to mass spectrometry (LC-MS/MS)
• OPEs-FR-PL
• Organophosphate esters
• Plasticizers
• Seawater
• Solvent demulsification-dispersive liquid-liquid microextraction

• Seawater/microbiology
• Seawater/chemistry
• Plasticizers/metabolism
• Plasticizers/analysis
• Biodegradation, Environmental
• Organophosphates/metabolism
• Organophosphates/analysis
• Water Pollutants, Chemical/metabolism
• Water Pollutants, Chemical/analysis
• Flame Retardants/metabolism
• Flame Retardants/analysis
• Bacteria/metabolism
• Esters/metabolism

• Adiposity
• inflammation
• microflora
• probiotics
• serum lipids

• antagonism
• challenge test
• fish microbiota
• larviculture
• microbiology

In the traditional fermentation process of strong-aroma Baijiu, a fermentation pit mud (FPM) provides many genera of microorganisms for fermentation. However, the functional microorganisms that have an important effect on the quality of Baijiu and their changes with the age of fermentation pit (FP) are poorly understood. Herein, the Roche 454 pyrosequencing technique and a phospholipid fatty-acid analysis were employed to reveal the structure and diversity of prokaryotic communities in FPM samples that have been aged for 5, 30, and 100 years. The results revealed an increase in total prokaryotic biomass with an FP age; however, Shannon’s diversity index decreased significantly (p < 0.01). These results suggested that a unique microbial community structure evolved with uninterrupted use of the FP. The number of functional microorganisms, which could produce the flavor compounds of strong-aroma Baijiu, increased with the FP age. Among them, Clostridium and Ruminococcaceae are microorganisms that directly produce caproic acid. The increase of their relative abundance in the FPM might have improved the quality of strong-aroma Baijiu. Syntrophomonas, Methanobacterium, and Methanocorpusculum might also be beneficial to caproic acid production. They are not directly involved but provide possible environmental factors for caproic acid production. Overall, our study results indicated that an uninterrupted use of the FP shapes the particular microbial community structure in the FPM. This research provides scientific support for the concept that the aged FP yields a high-quality Baijiu.

• And Denaturing Gradient Gel Electrophoresis (DGGE)
• Nitrifying bacterial consortia (NBC)
• Nitrifying bioreactor (NBC)
• Recirculating aquaculture system (RAS)

Isolation of marine microorganisms is fundamental to gather information about their physiology, ecology and genomic content. To date, most of the bacterial isolation efforts have focused on the photic ocean leaving the deep ocean less explored. We have created a marine culture collection of heterotrophic bacteria (MARINHET) using a standard marine medium comprising a total of 1561 bacterial strains, and covering a variety of oceanographic regions from different seasons and years, from 2009 to 2015. Specifically, our marine collection contains isolates from both photic (817) and aphotic layers (744), including the mesopelagic (362) and the bathypelagic (382), from the North Western Mediterranean Sea, the North and South Atlantic Ocean, the Indian, the Pacific, and the Arctic Oceans. We described the taxonomy, the phylogenetic diversity and the biogeography of a fraction of the marine culturable microorganisms to enhance our knowledge about which heterotrophic marine isolates are recurrently retrieved across oceans and along different depths.

The partial sequencing of the 16S rRNA gene of all isolates revealed that they mainly affiliate with the classes Alphaproteobacteria (35.9%), Gammaproteobacteria (38.6%), and phylum Bacteroidetes (16.5%). In addition, Alteromonas and Erythrobacter genera were found the most common heterotrophic bacteria in the ocean growing in solid agar medium. When comparing all photic, mesopelagic, and bathypelagic isolates sequences retrieved from different stations, 37% of them were 100% identical. This percentage increased up to 59% when mesopelagic and bathypelagic strains were grouped as the aphotic dataset and compared to the photic dataset of isolates, indicating the ubiquity of some bacterial isolates along different ocean depths. Finally, we isolated three strains that represent a new species, and the genome comparison and phenotypic characterization of two of these strains (ISS653 and ISS1889) concluded that they belong to a new species within the genus Mesonia.

Overall, this study highlights the relevance of culture-dependent studies, with focus on marine isolated bacteria from different oceanographic regions and depths, to provide a more comprehensive view of the culturable marine bacteria as part of the total marine microbial diversity.

• Bacterial isolates
• Deep ocean
• Diversity
• Photic ocean

• biofilm constituents
• indication of stenting
• micro-organisms profile
• pancreatic stents
• predisposing factors

• Bioremediation
• DGGE
• Drill cuttings
• Drilling fluids
• Halophilic consortium

Primers targeting the 16S small subunit ribosomal RNA marker gene, used to characterize bacterial and archaeal communities, have recently been re‐evaluated for marine planktonic habitats. To investigate whether primer selection affects the ecological interpretation of bacterioplankton populations and community dynamics, amplicon sequencing with four primer sets targeting several hypervariable regions of the 16S rRNA gene was conducted on both mock communities constructed from cloned 16S rRNA genes and a time‐series of DNA samples from the temperate coastal Santa Barbara Channel. Ecological interpretations of community structure (delineation of depth and seasonality, correlations with environmental factors) were similar across primer sets, while population dynamics varied. We observed substantial differences in relative abundances of taxa known to be poorly resolved by some primer sets, such as Thaumarchaeota and SAR11, and unexpected taxa including Roseobacter clades. Though the magnitude of relative abundances of common OTUs differed between primer sets, the relative abundances of the OTUs were nonetheless strongly correlated. We do not endorse one primer set but rather enumerate strengths and weaknesses to facilitate selection appropriate to a system or experimental goal. While 16S rRNA gene primer bias suggests caution in assessing quantitative population dynamics, community dynamics appear robust across studies using different primers.

• Biliary stents
• Biofilm constituents
• Polybacterial profile
• Predisposing factors
• Underlying causes

• Adult
• Aged
• Aged, 80 and over
• Bacteria/classification
• Bacteria/genetics
• Bacteria/growth & development
• Bacteria/metabolism
• Bacterial Proteins/metabolism
• Biofilms/growth & development
• Cholangiopancreatography, Endoscopic Retrograde/adverse effects
• Cholangiopancreatography, Endoscopic Retrograde/instrumentation
• Cholestasis/diagnosis
• Cholestasis/etiology
• Cholestasis/therapy
• Device Removal
• Female
• Gastrointestinal Microbiome
• Humans
• Male
• Middle Aged
• Polysaccharides, Bacterial/metabolism
• Prospective Studies
• Prosthesis Design
• Prosthesis Failure
• Prosthesis-Related Infections/diagnosis
• Prosthesis-Related Infections/microbiology
• Prosthesis-Related Infections/therapy
• Ribotyping
• Stents/adverse effects
• Stents/microbiology
• Tertiary Care Centers
• Time Factors
• Young Adult

• Electrogenic bacteria
• Electron transfer
• Microbial fuel cell
• Pyrosequencing

• Archaea/chemistry
• Archaea/physiology
• Bacteria/chemistry
• Bacterial Physiological Phenomena
• Bioelectric Energy Sources/microbiology
• Biofilms
• Electrodes/microbiology
• Electron Transport
• Electrons
• Microbiota
• Oxidation-Reduction

• Ministerio de Economía y Competitividad

• Fly ash leachate
• Hexavalent chromium
• Remediation
• Sulphate

Atmospheric bacterial dispersion with aeolian dust has been reported to have a potential impact on public health and ecosystems. Asian dust is a major aeolian event that results in an estimated 4 million tons of Asian dust particles falling in Japan annually, 3,000–5,000 km away from their source regions. However, most studies have only investigated the effects of Asian dust during dust seasons. Therefore, in this study, outdoor bacterial abundance and community composition were determined by 16S rRNA quantitative PCR and amplicon sequencing, respectively, and compared on Asian and non-Asian dust days (2013–2015; 44 samples over four seasons). Seasonal variations in bacterial abundance of non-Asian dust days were not observed. Bacterial abundance of individual samples collected on non-Asian dust days changed dynamically relative to Asian dust days, with bacterial abundance occasionally reaching those of Asian dust days. The bacterial community composition on non-Asian dust days was rather stable seasonally, and did not differ from that on Asian dust days. These results indicate that bacteria in Asian dust does not immediately influence indigenous bacterial communities at the phylum/class level in distant downwind areas; accordingly, further studies of bacterial communities in downwind areas closer to the dust source are warranted.

• Bacterial indicator
• Community structure
• Diversity
• Marine environment
• Pollutant

In Morocco, storage reservoirs are particular systems of water supply in rural areas. These reservoirs are fed with rainwater and/or directly from the river, which are very contaminated by several pathogenic bacteria. They are used without any treatment as a drinking water by the surrounding population. In this context, the aim of this study is to evaluate the impact of consuming contaminated water stored in reservoirs on health status for six rural communities located in Assif El Mal, Southern East of Marrakech. This was investigated using a classical methodology based on population survey and by molecular approach using PCR–DGGE technique to determine the intestinal bacterial diversity of consumers. The survey showed that, the residents of the studied area suffered from numerous health problems (diarrheal diseases, vomiting or hepatitis A) due to the lack of waste management infrastructures. The consumer’s stool analysis by molecular approach revealed that numbers of Escherichia coli, Aeromonas hydrophila and Clostridia, were significantly higher in the diarrheal feces. In addition, PCR–DGGE study of the prevalence and distribution of bacteria causing human diseases, confirmed that, there is a relationship between water bacterial contaminations of storage reservoirs and microbial disease related health status. Therefore, water reservoir consumption is assumed to be the mean way of exposure for this population.

It’s clear that this approach gives a very helpful tool to confirm without any doubt the relationship between water bacterial contamination and health status.

• Bacterial contamination
• Health risk
• PCR–DGGE technique
• Water reservoir

This study investigated the relationship between microbial communities in differently sized colonies of the massive coral Coelastrea aspera at Phuket, Thailand where colony size could be used as a proxy for age. Results indicated significant differences between the bacterial diversity (ANOSIM, R = 0.76, p = 0.001) of differently sized colonies from the same intertidal reef habitat. Juvenile and small colonies (<6cm mean diam) harboured a lower bacterial richness than medium (~10cm mean diam) and large colonies (>28 cm mean diam). Bacterial diversity increased in a step-wise pattern from juveniles<small<medium colonies, which was then followed by a slight decrease in the two largest size classes. These changes appear to resemble a successional process which occurs over time, similar to that observed in the ageing human gut. Furthermore, the dominant bacterial ribotypes present in the tissues of medium and large sized colonies of C. aspera, (such as Halomicronema, an Oscillospira and an unidentified cyanobacterium) were also the dominant ribotypes found within the endolithic algal band of the coral skeleton; a result providing some support for the hypothesis that the endolithic algae of corals may directly influence the bacterial community present in coral tissues.

Manganese is a contaminant in the wastewaters produced by Brazilian mining operations, and the removal of the metal is notoriously difficult because of the high stability of the Mn(II) ion in aqueous solutions. To explore a biological approach for removing excessive amounts of aqueous Mn(II), we investigated the potential of Mn(II) oxidation by both consortium and bacterial isolates from a Brazilian manganese mine. A bacterial consortium was able to remove 99.7% of the Mn(II). A phylogenetic analysis of isolates demonstrated that the predominant microorganisms were members of Stenotrophomonas, Bacillus, and Lysinibacillus genera. Mn(II) removal rates between 58.5% and 70.9% were observed for Bacillus sp. and Stenotrophomonas sp. while the Lysinibacillus isolate 13P removes 82.7%. The catalytic oxidation of Mn(II) mediated by multicopper oxidase was not properly detected; however, in all of the experiments, a significant increase in the pH of the culture medium was detected. No aggregates inside the cells grown for a week were found by electronic microscopy. Nevertheless, an energy-dispersive X-ray spectroscopy of the isolates revealed the presence of manganese in Stenotrophomonas sp. and Lysinibacillus sp. grown in K medium. These results suggest that members of Stenotrophomonas and Lysinibacillus genera were able to remove Mn(II) by a nonenzymatic pathway.

• Philaster
• Vibrio
• antibiotics
• disease

• Bacteroidetes
• Roseobacter
• axenic cultures
• chemical ecology
• cross-kingdom interactions
• macroalgae
• morphogenesis
• seaweed

• Constructed wetlands
• Design factors
• Gravel biofilm examination
• Horizontal subsurface flow
• Municipal wastewater treatment

• Environmental Monitoring
• Environmental Restoration and Remediation/methods
• Phylogeny
• Spain
• Waste Disposal, Fluid/methods
• Water Microbiology
• Wetlands

• Biofilters
• Constructed wetlands
• Domestic wastewater
• Microbial community
• PCR-DGGE

• Bioreactors
• Denaturing Gradient Gel Electrophoresis
• Filtration
• Polymerase Chain Reaction
• Waste Disposal, Fluid/methods
• Water Microbiology
• Wetlands

• Alphaproteobacteria
• Bacterial isolates
• Bacteroidetes
• Blanes Bay Microbial Observatory
• Diversity
• Gammaproteobacteria
• Microdiversity
• Phylogeny

• Bacterial communities
• DGGE
• Reclaimed water
• Water quality index

• Analysis of Variance
• Bacteroidetes/genetics
• Bacteroidetes/growth & development
• Base Sequence
• Betaproteobacteria/genetics
• Betaproteobacteria/growth & development
• Computational Biology
• DNA Fingerprinting
• Denaturing Gradient Gel Electrophoresis
• Gammaproteobacteria/genetics
• Gammaproteobacteria/growth & development
• Microbiota
• Molecular Sequence Data
• Polymerase Chain Reaction
• RNA, Ribosomal/genetics
• Sequence Analysis, RNA
• Time Factors
• Wastewater/microbiology
• Water Microbiology/standards
• Water Quality/standards

• Biodiversity
• Denaturing Gradient Gel Electrophoresis
• Eukaryota/classification
• Eukaryota/genetics
• Eukaryota/physiology
• Phosphates/analysis
• Phosphates/metabolism
• Plankton/classification
• Plankton/genetics
• Plankton/physiology
• RNA, Ribosomal, 18S/genetics
• Seawater/chemistry
• Seawater/parasitology
• Temperature

PCR and PCR-DGGE techniques have been evaluated to monitor biodiversity indexes within an ATAD (autothermal thermophilic aerobic digestion) system treating domestic sludge for land spread, by examining microbial dynamics in response to elevated temperatures during treatment. The ATAD process utilises a thermophilic population to generate heat and operates at elevated pH due to degradation of sludge solids, thus allowing pasteurisation and stabilisation of the sludge. Genera-specific PCR revealed that Archaea, Eukarya and Fungi decline when the temperature reaches 59°C, while the bacterial lineage constitutes the dominant group at this stage. The bacterial community at the thermophilic stage, its similarity index to the feed material, and the species richness present were evaluated by PCR-DGGE. Parameters such as choice of molecular target (16S rDNA or rpoB genes), and electrophoresis condition, were optimised to maximise the resolution of the method for ATAD. Dynamic analysis of microbial communities was best observed utilising PCR-DGGE analysis of the V6-V8 region of 16S rDNA, while rpoB gene profiles were less informative. Unique thermophilic communities were shown to quickly adapt to process changes, and shown to be quite stable during the process. Such techniques may be used as a monitoring technique for process health and efficiency.

Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS) in the Indo-Pacific and Yellow Band Disease (YBD) in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively). Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is most likely a prerequisite to potential transmission of these pathogens.

The number and prevalence of coral diseases/syndromes are increasing worldwide. Dark Spot Syndrome (DSS) afflicts numerous coral species and is widespread throughout the Caribbean, yet there are no known causal agents. In this study we aimed to characterise the microbial communities (bacteria and fungi) associated with DSS lesions affecting the coral Stephanocoenia intersepta using nonculture molecular techniques. Bacterial diversity of healthy tissues (H), those in advance of the lesion interface (apparently healthy AH), and three sizes of disease lesions (small, medium, and large) varied significantly (ANOSIM R  = 0.052 p<0.001), apart from the medium and large lesions, which were similar in their community profile. Four bacteria fitted into the pattern expected from potential pathogens; namely absent from H, increasing in abundance within AH, and dominant in the lesions themselves. These included ribotypes related to Corynebacterium (KC190237), Acinetobacter (KC190251), Parvularculaceae (KC19027), and Oscillatoria (KC190271). Furthermore, two Vibrio species, a genus including many proposed coral pathogens, dominated the disease lesion and were absent from H and AH tissues, making them candidates as potential pathogens for DSS. In contrast, other members of bacteria from the same genus, such as V. harveyii were present throughout all sample types, supporting previous studies where potential coral pathogens exist in healthy tissues. Fungal diversity varied significantly as well, however the main difference between diseased and healthy tissues was the dominance of one ribotype, closely related to the plant pathogen, Rhytisma acerinum, a known causal agent of tar spot on tree leaves. As the corals’ symbiotic algae have been shown to turn to a darker pigmented state in DSS (giving rise to the syndromes name), the two most likely pathogens are R. acerinum and the bacterium Oscillatoria, which has been identified as the causal agent of the colouration in Black Band Disease, another widespread coral disease.

• Acinetobacter/genetics
• Animals
• Anthozoa/microbiology
• Ascomycota/genetics
• Conservation of Natural Resources
• Coral Reefs
• Corynebacterium/genetics
• DNA, Fungal/genetics
• DNA, Ribosomal Spacer/genetics
• Denaturing Gradient Gel Electrophoresis
• Host-Pathogen Interactions
• Metagenome
• Molecular Typing
• Mycological Typing Techniques
• Oscillatoria/genetics
• RNA, Bacterial/genetics
• RNA, Ribosomal, 16S/genetics
• Vibrio/genetics

Cultures of heterotrophic protists often require co-culturing with bacteria to act as a source of nutrition. Such cultures will contain varying levels of intrinsic bacterial contamination that can interfere with molecular research and cause problems with the collection of sufficient material for sequencing. Measuring the levels of bacterial contamination for the purposes of molecular biology research is non-trivial, and can be complicated by the presence of a diverse bacterial flora, or by differences in the relative nucleic acid yield per bacterial or eukaryotic cell.

Here we describe a duplex PCR-based assay that can be used to measure the levels of contamination from marine bacteria in a culture of loricate choanoflagellates. By comparison to a standard culture of known target sequence content, the assay can be used to quantify the relative proportions of bacterial and choanoflagellate material in DNA or RNA samples extracted from a culture. We apply the assay to compare methods of purifying choanoflagellate cultures prior to DNA extraction, to determine their effectiveness in reducing bacterial contamination. Together with measurements of the total nucleic acid concentration, the assay can then be used as the basis for determining the absolute amounts of choanoflagellate DNA or RNA present in a sample.

The assay protocol we describe here is a simple and relatively inexpensive method of measuring contamination levels in nucleic acid samples. This provides a new way to establish quantification and purification protocols for molecular biology and genomics in novel heterotrophic protist species. Guidelines are provided to develop a similar protocol for use with any protistan culture. This assay method is recommended where qPCR equipment is unavailable, where qPCR is not viable because of the nature of the bacterial contamination or starting material, or where prior sequence information is insufficient to develop qPCR protocols.

• Anti-Bacterial Agents/pharmacology
• Cells, Cultured
• DNA Contamination
• DNA, Bacterial/analysis
• DNA, Complementary/genetics
• Eukaryota/cytology
• Eukaryota/drug effects
• Filtration
• Plasmids/genetics
• Polymerase Chain Reaction/methods
• Reference Standards
• Reproducibility of Results
• Templates, Genetic

• BB/E527604/1 Biotechnology and Biological Sciences Research Council

• Bacteroidetes/classification
• Bacteroidetes/genetics
• DNA Primers
• DNA, Bacterial/analysis
• DNA, Bacterial/genetics
• DNA, Ribosomal/analysis
• DNA, Ribosomal/genetics
• Denaturing Gradient Gel Electrophoresis/methods
• Polymerase Chain Reaction/methods
• RNA, Ribosomal, 16S
• Seawater/microbiology
• Sequence Analysis, DNA
• Species Specificity

The increase in reports of novel diseases in a wide range of ecosystems, both terrestrial and marine, has been linked to many factors including exposure to novel pathogens and changes in the global climate. Prevalence of skin cancer in particular has been found to be increasing in humans, but has not been reported in wild fish before. Here we report extensive melanosis and melanoma (skin cancer) in wild populations of an iconic, commercially-important marine fish, the coral trout Plectropomus leopardus. The syndrome reported here has strong similarities to previous studies associated with UV induced melanomas in the well-established laboratory fish model Xiphophorus. Relatively high prevalence rates of this syndrome (15%) were recorded at two offshore sites in the Great Barrier Reef Marine Park (GBRMP). In the absence of microbial pathogens and given the strong similarities to the UV-induced melanomas, we conclude that the likely cause was environmental exposure to UV radiation. Further studies are needed to establish the large scale distribution of the syndrome and confirm that the lesions reported here are the same as the melanoma in Xiphophorus, by assessing mutation of the EGFR gene, Xmrk. Furthermore, research on the potential links of this syndrome to increases in UV radiation from stratospheric ozone depletion needs to be completed.

• Animals
• Cyprinodontiformes/genetics
• Cyprinodontiformes/metabolism
• Fish Diseases/epidemiology
• Fish Diseases/genetics
• Fish Diseases/metabolism
• Fish Diseases/pathology
• Fish Proteins/genetics
• Fish Proteins/metabolism
• Marine Biology/methods
• Melanoma/epidemiology
• Melanoma/genetics
• Melanoma/metabolism
• Melanoma/pathology
• Mutation/radiation effects
• Oceans and Seas
• Ozone Depletion
• Perciformes/genetics
• Perciformes/metabolism
• Receptor Protein-Tyrosine Kinases/genetics
• Receptor Protein-Tyrosine Kinases/metabolism
• Skin Diseases/epidemiology
• Skin Diseases/genetics
• Skin Diseases/metabolism
• Skin Diseases/pathology
• Ultraviolet Rays/adverse effects

In recent years, acetic acid bacteria have been shown to be frequently associated with insects, but knowledge on their biological role in the arthropod host is limited. The discovery that acetic acid bacteria of the genus Asaia are a main component of the microbiota of Anopheles stephensi makes this mosquito a useful model for studies on this novel group of symbionts. Here we present experimental results that provide a first evidence for a beneficial role of Asaia in An. stephensi.

Larvae of An. stephensi at different stages were treated with rifampicin, an antibiotic effective on wild-type Asaia spp., and the effects on the larval development were evaluated. Larvae treated with the antibiotic showed a delay in the development and an asynchrony in the appearance of later instars. In larvae treated with rifampicin, but supplemented with a rifampicin-resistant mutant strain of Asaia, larval development was comparable to that of control larvae not exposed to the antibiotic. Analysis of the bacterial diversity of the three mosquito populations confirmed that the level of Asaia was strongly decreased in the antibiotic-treated larvae, since the symbiont was not detectable by PCR-DGGE (denaturing gradient gel electrophoresis), while Asaia was consistently found in insects supplemented with rifampicin plus the antibiotic-resistant mutant in the diet, and in those not exposed to the antibiotic.

The results here reported indicate that Asaia symbionts play a beneficial role in the normal development of An. stephensi larvae.

• Bacteria/classification
• Bacteria/genetics
• Bacteria/growth & development
• Biofilms/growth & development
• Biofouling/prevention & control
• DNA, Bacterial/analysis
• DNA, Bacterial/genetics
• Diatoms/classification
• Diatoms/genetics
• Diatoms/growth & development
• Ecosystem
• Electrophoresis, Agar Gel
• France
• Mediterranean Sea
• Paint/microbiology
• Polymerase Chain Reaction/methods
• Polystyrenes
• Polytetrafluoroethylene
• Seawater/microbiology
• Surface Properties

Numerous studies have demonstrated the differences in bacterial communities associated with corals versus those in their surrounding environment. However, these environmental samples often represent vastly different microbial micro-environments with few studies having looked at the settlement and growth of bacteria on surfaces similar to corals. As a result, it is difficult to determine which bacteria are associated specifically with coral tissue surfaces. In this study, early stages of passive settlement from the water column to artificial coral surfaces (formation of a biofilm) were assessed. Changes in bacterial diversity (16S rRNA gene), were studied on artificially created resin nubbins that were modelled from the skeleton of the reef building coral Acropora muricata. These models were dip-coated in sterile agar, mounted in situ on the reef and followed over time to monitor bacterial community succession. The bacterial community forming the biofilms remained significantly different (R = 0.864 p<0.05) from that of the water column and from the surface mucus layer (SML) of the coral at all times from 30 min to 96 h. The water column was dominated by members of the α-proteobacteria, the developed community on the biofilms dominated by γ-proteobacteria, whereas that within the SML was composed of a more diverse array of groups. Bacterial communities present within the SML do not appear to arise from passive settlement from the water column, but instead appear to have become established through a selection process. This selection process was shown to be dependent on some aspects of the physico-chemical structure of the settlement surface, since agar-coated slides showed distinct communities to coral-shaped surfaces. However, no significant differences were found between different surface coatings, including plain agar and agar enhanced with coral mucus exudates. Therefore future work should consider physico-chemical surface properties as factors governing change in microbial diversity.

• Animals
• Anthozoa/microbiology
• Bacteria/genetics
• Bacteria/growth & development
• Biofilms/growth & development
• Carbon/analysis
• DNA Fingerprinting
• Denaturing Gradient Gel Electrophoresis
• Mucus/microbiology
• Nitrogen/analysis
• RNA, Ribosomal, 16S/genetics
• Surface Properties