Legacy Metal Contaminants and Excess Nutrients in Low Flow Estuarine Embayments Alter Composition and Function of Benthic Bacterial Communities

Coastal systems such as estuaries are threatened by multiple anthropogenic stressors worldwide. However, how these stressors and estuarine hydrology shape benthic bacterial communities and their functions remains poorly known. Here, we surveyed sediment bacterial communities in poorly flushed embayments and well flushed channels in Sydney Harbour, Australia, using 16S rRNA gene sequencing. Sediment samples were collected monthly during the Austral summer-autumn 2014 at increasing distance from a large storm drain in each channel and embayment. Bacterial communities differed significantly between sites that varied in proximity to storm drains, with a gradient of change apparent for sites within embayments. We explored this pattern for embayment sites with analysis of RNA-Seq gene expression patterns and found higher expression of multiple genes involved in bacterial stress response far from storm drains, suggesting that bacterial communities close to storm drains may be more tolerant of localised anthropogenic stressors. Several bacterial groups also differed close to and far from storm drains, suggesting their potential utility as bioindicators to monitor contaminants in estuarine sediments. Overall, our study provides useful insights into changes in the composition and functioning of benthic bacterial communities as a result of multiple anthropogenic stressors in differing hydrological conditions.

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Dichotomy between regulation of coral bacterial communities and calcification physiology under ocean acidification conditions

Applied and Environmental Microbiology ◽

10.1128/aem.02189-20 ◽

2021 ◽

Author(s):

A. Shore ◽

R. D. Day ◽

J. A. Stewart ◽

C.A. Burge

Keyword(s):

Ocean Acidification ◽

Bacterial Communities ◽

16S Rrna Gene Sequencing ◽

Ph Gradient ◽

Rrna Gene ◽

Seawater Ph ◽

Coral Health ◽

And Function ◽

The Impact

Ocean acidification (OA) threatens the growth and function of coral reef ecosystems. A key component to coral health is the microbiome, but little is known about the impact of OA on coral microbiomes. A submarine CO2 vent at Maug Island in the Northern Marianas Islands provides a natural pH gradient to investigate coral responses to long-term OA conditions. Three coral species (Pocillopora eydouxi, Porites lobata, and Porites rus) were sampled from three sites where mean seawater pH is 8.04, 7.98, and 7.94. We characterized coral bacterial communities (using 16S rRNA gene sequencing) and determined pH of the extracellular calcifying fluid (ECF) (using skeletal boron isotopes) across the seawater pH gradient. Bacterial communities of both Porites species stabilized (decreases in community dispersion) with decreased seawater pH, coupled with large increases in the abundance of Endozoicomonas, an endosymbiont. P. lobata experienced a significant decrease in ECF pH near the vent, whereas P. rus experienced a trending decrease in ECF pH near the vent. By contrast, Pocillopora exhibited bacterial community destabilization (increases in community dispersion), with significant decreases in Endozoicomonas abundance, while its ECF pH remained unchanged across the pH gradient. Our study shows that OA has multiple consequences on Endozoicomonas abundance and suggests that Endozoicomonas abundance may be an indicator of coral response to OA. We reveal an interesting dichotomy between two facets of coral physiology (regulation of bacterial communities and regulation of calcification), highlighting the importance of multidisciplinary approaches to understanding coral health and function in a changing ocean. IMPORTANCE Ocean acidification (OA) is a consequence of anthropogenic CO2 emissions that is negatively impacting marine ecosystems such as coral reefs. OA affects many aspects of coral physiology, including growth (i.e. calcification) and disrupting associated bacterial communities. Coral-associated bacteria are important for host health, but it remains unclear how coral-associated bacterial communities will respond to future OA conditions. We document changes in coral-associated bacterial communities and changes to calcification physiology with long-term exposure to decreases in seawater pH that are environmentally relevant under mid-range IPCC emission scenarios (0.1 pH units). We also find species-specific responses that may reflect different responses to long-term OA. In Pocillopora, calcification physiology was highly regulated despite changing seawater conditions. In Porites spp., changes in bacterial communities do not reflect a breakdown of coral-bacterial symbiosis. Insights into calcification and host-microbe interactions are critical to predicting the health and function of different coral taxa to future OA conditions.

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Comparative Analysis of the Gut Microbiota of Adult Mosquitoes From Eight Locations in Hainan, China

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2020.596750 ◽

2020 ◽

Vol 10 ◽

Author(s):

Xun Kang ◽

Yanhong Wang ◽

Siping Li ◽

Xiaomei Sun ◽

Xiangyang Lu ◽

...

Keyword(s):

Gut Microbiota ◽

Disease Control ◽

Bacterial Communities ◽

Mosquito Species ◽

Microbial Community Composition ◽

Variable Region ◽

Rrna Gene ◽

Microbial Composition ◽

Quality Filtering ◽

And Function

The midgut microbial community composition, structure, and function of field-collected mosquitoes may provide a way to exploit microbial function for mosquito-borne disease control. However, it is unclear how adult mosquitoes acquire their microbiome, how the microbiome affects life history traits and how the microbiome influences community structure. We analyzed the composition of 501 midgut bacterial communities from field-collected adult female mosquitoes, including Aedes albopictus, Aedes galloisi, Culex pallidothorax, Culex pipiens, Culex gelidus, and Armigeres subalbatus, across eight habitats using the HiSeq 4000 system and the V3−V4 hyper-variable region of 16S rRNA gene. After quality filtering and rarefaction, a total of 1421 operational taxonomic units, belonging to 29 phyla, 44 families, and 43 genera were identified. Proteobacteria (75.67%) were the most common phylum, followed by Firmicutes (10.38%), Bacteroidetes (6.87%), Thermi (4.60%), and Actinobacteria (1.58%). The genera Rickettsiaceae (33.00%), Enterobacteriaceae (20.27%), Enterococcaceae (7.49%), Aeromonadaceae (7.00%), Thermaceae (4.52%), and Moraxellaceae (4.31%) were dominant in the samples analyzed and accounted for 76.59% of the total genera. We characterized the midgut bacterial communities of six mosquito species in Hainan province, China. The gut bacterial communities were different in composition and abundance, among locations, for all mosquito species. There were significant differences in the gut microbial composition between some species and substantial variation in the gut microbiota between individuals of the same mosquito species. There was a marked variation in different mosquito gut microbiota within the same location. These results might be useful in the identification of microbial communities that could be exploited for disease control.

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Spatially-resolved correlative microscopy and microbial identification reveals dynamic depth- and mineral-dependent anabolic activity in salt marsh sediment

10.1101/2020.08.03.234146 ◽

2020 ◽

Author(s):

Jeffrey Marlow ◽

Rachel Spietz ◽

Keun-Young Kim ◽

Mark Ellisman ◽

Peter Girguis ◽

...

Keyword(s):

Salt Marsh ◽

Microbial Communities ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Community Members ◽

Marsh Sediment ◽

Anabolic Activity ◽

Salt Marsh Sediment ◽

Rrna Gene Sequencing ◽

And Function

AbstractCoastal salt marshes are key sites of biogeochemical cycling and ideal systems in which to investigate the community structure of complex microbial communities. Here, we clarify structural-functional relationships among microorganisms and their mineralogical environment, revealing previously undescribed metabolic activity patterns and precise spatial arrangements within salt marsh sediment. Following 3.7-day in situ incubations with a non-canonical amino acid that was incorporated into new biomass, samples were embedded and analyzed by correlative fluorescence and electron microscopy to map the microscale arrangements of anabolically active and inactive organisms alongside mineral grains. Parallel sediment samples were examined by fluorescence-activated cell sorting and 16S rRNA gene sequencing to link anabolic activity to taxonomic identity. Both approaches demonstrated a rapid decline in the proportion of anabolically active cells with depth into salt marsh sediment, from ∼60% in the top cm to 10-25% between 2-7 cm. From the top to the bottom, the most prominent active community members shifted from sulfur cycling phototrophic consortia, to sulfate-reducing bacteria likely oxidizing organic compounds, to fermentative lineages. Correlative microscopy revealed more abundant (and more anabolically active) organisms around non-quartz minerals including rutile, orthoclase, and plagioclase. Microbe-mineral relationships appear to be dynamic and context-dependent arbiters of biogeochemical cycling.Statement of SignificanceMicroscale spatial relationships dictate critical aspects of a microbiome’s inner workings and emergent properties, such as evolutionary pathways, niche development, and community structure and function. However, many commonly used methods in microbial ecology neglect this parameter – obscuring important microbe-microbe and microbe-mineral interactions – and instead employ bulk-scale methodologies that are incapable of resolving these intricate relationships.This benchmark study presents a compelling new approach for exploring the anabolic activity of a complex microbial community by mapping the precise spatial configuration of anabolically active organisms within mineralogically heterogeneous sediment through in situ incubation, resin embedding, and correlative fluorescence and electron microscopy. In parallel, active organisms were identified through fluorescence-activated cell sorting and 16S rRNA gene sequencing, enabling a powerful interpretive framework connecting location, identity, activity, and putative biogeochemical roles of microbial community members.We deploy this novel approach in salt marsh sediment, revealing quantitative insights into the fundamental principles that govern the structure and function of sediment-hosted microbial communities. In particular, at different sediment horizons, we observed striking changes in the proportion of anabolically active cells, the identities of the most prominent active community members, and the nature of microbe-mineral affiliations. Improved approaches for understanding microscale ecosystems in a new light, such as those presented here, reveal environmental parameters that promote or constrain metabolic activity and clarify the impact that microbial communities have on our world.

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Diversity of siderophore-producing bacterial cultures from Carlsbad Caverns National Park caves, Carlsbad, New Mexico

Journal of Cave and Karst Studies ◽

10.4311/2019es0118 ◽

2021 ◽

Vol 83 (1) ◽

pp. 29-43

Author(s):

Tammi Duncan ◽

Margaret Werner-Washburne ◽

Diana Northup

Keyword(s):

National Park ◽

Ferric Iron ◽

16S Rrna Gene Sequencing ◽

Siderophore Production ◽

Rrna Gene ◽

Hydroxamate Siderophores ◽

Rrna Gene Sequencing ◽

And Function ◽

Ferromanganese Deposits

Siderophores are microbially-produced ferric iron chelators. They are essential for microbial survival, but their presence and function for cave microorganisms have not been extensively studied. Siderophores are classified based on the common functional groups (catechols, hydroxamates, carboxylates, and mixed) that coordinate to ferric (Fe3+) iron. Cave environments are nutrient-limited and previous evidence suggests siderophore usage in carbonate caves. We hypothesize that siderophores are likely used as a mechanism in caves to obtain critical ferric iron. Cave bacteria were collected from long-term parent cultures (LT PC) or short-term parent cultures (ST PC) inoculated with ferromanganese deposits (FMD) and carbonate secondary minerals from Lechuguilla and Spider caves in Carlsbad Caverns National Park, NM. LT PC were incubated for 10−11 years to identify potential chemolithoheterotrophic cultures able to survive in nutrient-limited conditions. ST PC were incubated for 1−3 days to identify a broader diversity of cave isolates. A total of 170 LT and ST cultures, 18 pure and 152 mixed, were collected and used to classify siderophore production and type and to identify siderophore producers. Siderophore production was slow to develop (>10 days) in LT cultures with a greater number of weak siderophore producers in comparison to the ST cultures that produced siderophores in <10 days, with a majority of strong siderophore producers. Overall, 64% of the total cultures were siderophore producers, with the majority producing hydroxamate siderophores. Siderophore producers were classified into Proteobacteria (Alpha-, Beta-, or Gamma-), Actinobacteria, Bacteroidetes, and Firmicutes phyla using 16S rRNA gene sequencing. Our study supports our hypothesis that cave bacteria have the capability to produce siderophores in the subsurface to obtain critical ferric iron.

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Interplay between Fungal Infection and Bacterial Associates in the Wax Moth Galleria mellonella under Different Temperature Conditions

Journal of Fungi ◽

10.3390/jof6030170 ◽

2020 ◽

Vol 6 (3) ◽

pp. 170

Author(s):

Vadim Yu Kryukov ◽

Elena Kosman ◽

Oksana Tomilova ◽

Olga Polenogova ◽

Ulyana Rotskaya ◽

...

Keyword(s):

Fungal Infection ◽

Bacterial Communities ◽

Galleria Mellonella ◽

Fungal Growth ◽

16S Rrna Gene Sequencing ◽

Illumina Miseq ◽

Rrna Gene ◽

Cultivable Bacteria ◽

Stress Related Genes ◽

Rrna Gene Sequencing

Various insect bacterial associates are involved in pathogeneses caused by entomopathogenic fungi. The outcome of infection (fungal growth or decomposition) may depend on environmental factors such as temperature. The aim of this study was to analyze the bacterial communities and immune response of Galleria mellonella larvae injected with Cordyceps militaris and incubated at 15 °C and 25 °C. We examined changes in the bacterial CFUs, bacterial communities (Illumina MiSeq 16S rRNA gene sequencing) and expression of immune, apoptosis, ROS and stress-related genes (qPCR) in larval tissues in response to fungal infection at the mentioned temperatures. Increased survival of larvae after C. militaris injection was observed at 25 °C, although more frequent episodes of spontaneous bacteriosis were observed at this temperature compared to 15 °C. We revealed an increase in the abundance of enterococci and enterobacteria in the midgut and hemolymph in response to infection at 25 °C, which was not observed at 15 °C. Antifungal peptide genes showed the highest expression at 25 °C, while antibacterial peptides and inhibitor of apoptosis genes were strongly expressed at 15 °C. Cultivable bacteria significantly suppressed the growth of C. militaris. We suggest that fungi such as C. militaris may need low temperatures to avoid competition with host bacterial associates.

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Effect of bamboo vinegar powder as an antibiotic alternative on the digesta bacteria communities of finishing pigs

Canadian Journal of Microbiology ◽

10.1139/cjm-2018-0058 ◽

2018 ◽

Vol 64 (10) ◽

pp. 732-743

Author(s):

Huan Qu ◽

Yanjie Huang ◽

Yinghao Shi ◽

Ying Liu ◽

Shenglong Wu ◽

...

Keyword(s):

Bacterial Communities ◽

Metabolic Pathways ◽

Growth And Development ◽

Intestinal Microflora ◽

Gene Sequencing ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Finishing Pigs ◽

Rrna Gene Sequencing ◽

Bacteria Communities

This study investigated the use for bamboo vinegar powder as an antibiotic alternative in the diet of growing–finishing pigs by examining their digestive bacterial communities. Forty-five Duroc × Landrace × Yorkshire growing–finishing pigs were randomly allocated to five diet groups: 0%, 0.5%, 1.0%, or 1.5% bamboo vinegar levels and antibiotics. After 37 days, the digesta in duodenum of four pigs from each treatment were analyzed for their bacterial community compositions using 16S rRNA gene sequencing. The addition of 1.5% bamboo vinegar powder had an effect on the intestinal microflora most similar to that of antibiotics, indicating its potential to promote the growth and development of finishing pigs. We also found the 1.5% bamboo vinegar powder group to have an increased abundance of Firmicutes/Bacteroidetes compared with the other bamboo vinegar powder groups, which may enhance the ability of the host to absorb food energy and store more body fat. Additionally, the effects of bamboo vinegar powder on promoting the abundances of Lactobacillus and Thalassospira and on inhibiting Streptococcus and Prevotella growth revealed it may play an important role in animal production. Moreover, functional predictions of microbes via PICRUSt indicated that feed supplemented with 1.5% bamboo vinegar powder could promote many vital metabolic pathways.

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Loss of bacterial diversity in the sinuses is associated with lower smell discrimination scores

Scientific Reports ◽

10.1038/s41598-020-73396-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Kristi Biswas ◽

Brett Wagner Mackenzie ◽

Charlotte Ballauf ◽

Julia Draf ◽

Richard G. Douglas ◽

...

Keyword(s):

Bacterial Diversity ◽

Bacterial Communities ◽

Gene Sequencing ◽

16S Rrna Gene Sequencing ◽

Olfactory Dysfunction ◽

Rrna Gene ◽

Olfactory Loss ◽

Olfactory Impairment ◽

Rrna Gene Sequencing ◽

Normal Sense

Abstract Olfactory impairment affects ~ 20% of the population and has been linked to various serious disorders. Microbes in the nasal cavity play a key role in priming the physiology of the olfactory epithelium and maintaining a normal sense of smell by the host. The aim of this study was to explore the link between olfactory dysfunction and nasal bacterial communities. A total of 162 subjects were recruited for this study from a specialized olfactory dysfunction clinic and placed into one of three groups: anosmia, hyposmia or normosmia. Swabs from the nasal middle meatus were collected from each subject then processed for bacterial 16S rRNA gene sequencing. No overall differences in bacterial diversity or composition were observed between the three cohorts in this study. However, the relative abundances of Corynebacterium spp. and Streptococcus spp. were significantly (p < 0.05) different in subjects with olfactory loss. Furthermore, subjects with deficiencies in discriminating between smells (based on discrimination scores) had a lower bacterial diversity (Simpson’s evenness p < 0.05). While these results are preliminary in nature, potential bacterial biomarkers for olfactory loss were identified. These findings need to be further validated and biologically tested in animal models.

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Heliconius Butterflies Host Characteristic and Phylogenetically Structured Adult-Stage Microbiomes

Applied and Environmental Microbiology ◽

10.1128/aem.02007-20 ◽

2020 ◽

Vol 86 (24) ◽

Cited By ~ 1

Author(s):

Tobin J. Hammer ◽

Jacob C. Dickerson ◽

W. Owen McMillan ◽

Noah Fierer

Keyword(s):

Bacterial Communities ◽

Evolutionary Biology ◽

Adult Stage ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Phylogenetic Structure ◽

Shotgun Metagenomics ◽

Microbiome Composition ◽

Form And Function ◽

Passion Vine

ABSTRACT Lepidoptera (butterflies and moths) are diverse and ecologically important, yet we know little about how they interact with microbes as adults. Due to metamorphosis, the form and function of their adult-stage microbiomes might be very different from those of microbiomes in the larval stage (caterpillars). We studied adult-stage microbiomes of Heliconius and closely related passion-vine butterflies (Heliconiini), which are an important model system in evolutionary biology. To characterize the structure and dynamics of heliconiine microbiomes, we used field collections of wild butterflies, 16S rRNA gene sequencing, quantitative PCR, and shotgun metagenomics. We found that Heliconius butterflies harbor simple and abundant bacterial communities that are moderately consistent among conspecific individuals and over time. Heliconiine microbiomes also exhibited a strong signal of the host phylogeny, with a major distinction between Heliconius and other butterflies. These patterns were largely driven by differing relative abundances of bacterial phylotypes shared among host species and genera, as opposed to the presence or absence of host-specific phylotypes. We suggest that the phylogenetic structure in heliconiine microbiomes arises from conserved host traits that differentially filter microbes from the environment. While the relative importance of different traits remains unclear, our data indicate that pollen feeding (unique to Heliconius) is not a primary driver. Using shotgun metagenomics, we also discovered trypanosomatids and microsporidia to be prevalent in butterfly guts, raising the possibility of antagonistic interactions between eukaryotic parasites and colocalized gut bacteria. Our discovery of characteristic and phylogenetically structured microbiomes provides a foundation for tests of adult-stage microbiome function, a poorly understood aspect of lepidopteran biology. IMPORTANCE Many insects host microbiomes with important ecological functions. However, the prevalence of this phenomenon is unclear because in many insect taxa, microbiomes have been studied in only part of the life cycle, if at all. A prominent example is butterflies and moths, in which the composition and functional role of adult-stage microbiomes are largely unknown. We comprehensively characterized microbiomes in adult passion-vine butterflies. Butterfly-associated bacterial communities are generally abundant in guts, consistent within populations, and composed of taxa widely shared among hosts. More closely related butterflies harbor more similar microbiomes, with the most dramatic shift in microbiome composition occurring in tandem with a suite of ecological and life history traits unique to the genus Heliconius. Butterflies are also frequently infected with previously undescribed eukaryotic parasites, which may interact with bacteria in important ways. These findings advance our understanding of butterfly biology and insect-microbe interactions generally.

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Changes of Bacterial Communities in Response to Prolonged Hydrodynamic Disturbances in the Eutrophic Water-Sediment Systems

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16203868 ◽

2019 ◽

Vol 16 (20) ◽

pp. 3868

Author(s):

Haomiao Cheng ◽

Ling Cheng ◽

Liang Wang ◽

Tengyi Zhu ◽

Wei Cai ◽

...

Keyword(s):

Relative Abundance ◽

Bacterial Communities ◽

16S Rrna Gene Sequencing ◽

Aquatic Environments ◽

Rrna Gene ◽

Evolutionary Trend ◽

Ecological Evaluation ◽

Eutrophic Water ◽

Rrna Gene Sequencing ◽

Opposite Tendency

The effects of hydrodynamic disturbances on the bacterial communities in eutrophic aquatic environments remain poorly understood, despite their importance to ecological evaluation and remediation. This study investigated the evolution of bacterial communities in the water–sediment systems under the influence of three typical velocity conditions with the timescale of 5 weeks. The results demonstrated that higher bacterial diversity and notable differences were detected in sediment compared to water using the 16S rRNA gene sequencing. The phyla Firmicutes and γ-Proteobacteria survived better in both water and sediment under stronger water disturbances. Their relative abundance peaked at 36.0%, 33.2% in water and 38.0%, 43.6% in sediment, respectively, while the phylum Actinobacteria in water had the opposite tendency. Its relative abundance grew rapidly in static control (SC) and peaked at 44.8%, and it almost disappeared in disturbance conditions. These phenomena were caused by the proliferation of genus Exiguobacterium (belonging to Firmicutes), Citrobacter, Acinetobacter, Pseudomonas (belonging to γ-Proteobacteria), and hgcI_clade (belonging to Actinobacteria). The nonmetric multidimensional scaling (NMDS) and Venn analysis also revealed significantly different evolutionary trend in the three water-sediment systems. It was most likely caused by the changes of geochemical characteristics (dissolved oxygen (DO) and nutrients). This kind of study can provide helpful information for ecological assessment and remediation strategy in eutrophic aquatic environments.

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The Gut Microbial Community of Antarctic Fish Detected by 16S rRNA Gene Sequence Analysis

BioMed Research International ◽

10.1155/2016/3241529 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 18

Author(s):

Wei Song ◽

Lingzhi Li ◽

Hongliang Huang ◽

Keji Jiang ◽

Fengying Zhang ◽

...

Keyword(s):

Microbial Community ◽

16S Rrna ◽

16S Rrna Gene ◽

Bacterial Communities ◽

Antarctic Fish ◽

16S Rrna Gene Sequencing ◽

Physiological Characteristics ◽

Rrna Gene ◽

Rrna Gene Sequencing ◽

Gut Microbial Community

Intestinal bacterial communities are highly relevant to the digestion, nutrition, growth, reproduction, and a range of fitness in fish, but little is known about the gut microbial community in Antarctic fish. In this study, the composition of intestinal microbial community in four species of Antarctic fish was detected based on 16S rRNA gene sequencing. As a result, 1 004 639 sequences were obtained from 13 samples identified into 36 phyla and 804 genera, in which Proteobacteria, Actinobacteria, Firmicutes, Thermi, and Bacteroidetes were the dominant phyla, and Rhodococcus, Thermus, Acinetobacter, Propionibacterium, Streptococcus, and Mycoplasma were the dominant genera. The number of common OTUs (operational taxonomic units) varied from 346 to 768, while unique OTUs varied from 84 to 694 in the four species of Antarctic fish. Moreover, intestinal bacterial communities in individuals of each species were not really similar, and those in the four species were not absolutely different, suggesting that bacterial communities might influence the physiological characteristics of Antarctic fish, and the common bacterial communities might contribute to the fish survival ability in extreme Antarctic environment, while the different ones were related to the living habits. All of these results could offer certain information for the future study of Antarctic fish physiological characteristics.

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