scholarly journals Particle-associated and free-living bacterial communities in an oligotrophic sea are affected by different environmental and anthropogenic factors

2020 ◽  
Author(s):  
Dalit Roth Rosenberg ◽  
Markus Haber ◽  
Joshua Goldford ◽  
Maya Lalzar ◽  
Dikla Aharoonovich ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Environmental Conditions ◽  
Heterotrophic Bacteria ◽  
Environmental Parameters ◽  
Metabolic Potential ◽  
Free Living ◽  
Size Fractions ◽  
Marine Microbial Communities

SummaryIn the oceans and seas, environmental conditions change over multiple temporal and spatial scales. Here, we ask what factors affect the bacterial community structure across time, depth and size fraction during six seasonal cruises (two years) in the ultra-oligotrophic Eastern Mediterranean Sea. The bacterial community varied most between size fractions (free-living vs particle-associated), followed by depth and finally season. The free-living (FL) community was taxonomically richer and more stable than the particle-associated (PA) one, which was characterized by recurrent “blooms” of heterotrophic bacteria such as Alteromonas and Ralstonia. The heterotrophic FL and PA communities were also correlated with different environmental parameters: depth and phytoplankton correlated with the FL population, whereas PA bacteria were correlated primarily with season. A significant part of the variability in community structure could not, however, be explained by the measured environmental parameters. The metabolic potential of the PA community, predicted from 16S amplicon data, was enriched in pathways associated with the degradation and utilization of biological macromolecules, as well as plastics, other petroleum products and herbicides. The FL community was enriched in pathways for the metabolism of inositol phosphate, a potential phosphorus source, and of polycyclic aromatic hydrocarbons.Originality – Significance StatementMarine microbial populations are complex and dynamic, and the environmental drivers of the structure and function of these communities are mostly unclear. Specifically, marine microbial communities change over time, over depth and between particle-associated and free-living size fractions, yet the relative importance of each of these axes of variability is unclear. Our results highlight fundamentally different population dynamics between free-living and particle-associated marine bacteria: free living populations were more similar between seasons, whereas particle-associated populations were highly variable and exhibited “blooms” of specific clades of heterotrophic bacteria. We also suggest that the environmental conditions often measured as part of oceanographic cruises are not enough to explain most of the variability in microbial population structure. We speculate that organismal interactions and the presence of anthropogenic pollution may be also be important yet under-sampled drivers of oligotrophic marine microbial communities.

scholarly journals Divergent Patterns of Bacterial Community Structure and Function in Response to Estuarine Output in the Middle of the Bohai Sea

2021 ◽  
Vol 12 ◽  
Author(s):  
Caixia Wang ◽  
Haikun Zhang ◽  
Pengyuan Liu ◽  
Yibo Wang ◽  
Yanyu Sun ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Environmental Conditions ◽  
Bacterial Community Structure ◽  
Bohai Sea ◽  
Bacterial Community Composition ◽  
Nucleotide Metabolism ◽  
The Yellow Sea ◽  
The Bohai Sea

Understanding environment-community relationships under shifting environmental conditions helps uncover mechanisms by which environmental microbial communities manage to improve ecosystem functioning. This study investigated the microbial community and structure near the Yellow Sea River estuary in 12 stations across the middle of the Bohai Sea for over two seasons to elucidate the influence of estuarine output on them. We found that the dominant phyla in all stations were Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacteria, and Planctomycetes. Alpha-diversity increased near the estuary and bacterial community structure differed with variation of spatiotemporal gradients. Among all the environmental factors surveyed, temperature, salinity, phosphate, silicon, nitrate, and total virioplankton abundance played crucial roles in controlling the bacterial community composition. Some inferred that community functions such as carbohydrate, lipid, amino acid metabolism, xenobiotics biodegradation, membrane transport, and environmental adaptation were much higher in winter; energy and nucleotide metabolism were lower in winter. Our results suggested that estuarine output had a great influence on the Bohai Sea environment and changes in the water environmental conditions caused by estuarine output developed distinctive microbial communities in the middle of the Bohai Sea. The distinctive microbial communities in winter demonstrated that the shifting water environment may stimulate changes in the diversity and then strengthen the predicted functions.

Heterotrophic Bacterial Community Structure of Multistage Biofilters in a Commercial Pufferfish Takifugu rubripes RAS

2013 ◽  
Vol 726-731 ◽  
pp. 1621-1627 ◽  
Author(s):  
Zhu Chen ◽  
Ying Liu ◽  
Liang Zi Liu ◽  
Xiao Jing Wang ◽  
Zhi Pei Liu ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Heterotrophic Bacteria ◽  
Diversity Index ◽  
Community Diversity ◽  
Takifugu Rubripes ◽  
Recirculating Aquaculture ◽  
Microbial Resources

The success of a recirculating aquaculture system (RAS) greatly depends on the structure, dynamics and activities of microbial community. Heterotrophic bacteria as the major members play various roles. The heterotrophic bacterial community structure in threestaged biofilters was studied using four different media. 228 isolates belonging to 77species were obtained and affiliated toGammaproteobacteria,Alphaproteobacteria,Bacteroidetes,Firmicutes,ActinobacteriaandBetaproteobacteria.Gammaproteobacteriawas the predominant group. The concurrence was found between potential pathogens (VibrioandShewanella) and probiotics (BacillusandPseudomonas). On the basis of community diversity index, we could infer that differences existed between stages, and the diversity index increased along the biofilters. A comprehensive understanding of microbial community in RAS will be in favor of utilization of microbial resources and optimizing the culture systems' operation.

scholarly journals Intercropping with Potato-Onion Enhanced the Soil Microbial Diversity of Tomato

2020 ◽  
Vol 8 (6) ◽  
pp. 834
Author(s):  
Naihui Li ◽  
Danmei Gao ◽  
Xingang Zhou ◽  
Shaocan Chen ◽  
Chunxia Li ◽  
...  
Keyword(s):  
Community Structure ◽  
Organic Carbon ◽  
Bacterial Community ◽  
Soil Organic Carbon ◽  
Microbial Communities ◽  
Fungal Community ◽  
Soil Microbial Communities ◽  
Tomato Seedling ◽  
Soil Microbial ◽  
Potato Onion

Intercropping can achieve sustainable agricultural development by increasing plant diversity. In this study, we investigated the effects of tomato monoculture and tomato/potato-onion intercropping systems on tomato seedling growth and changes of soil microbial communities in greenhouse conditions. Results showed that the intercropping with potato-onion increased tomato seedling biomass. Compared with monoculture system, the alpha diversity of soil bacterial and fungal communities, beta diversity and abundance of bacterial community were increased in the intercropping system. Nevertheless, the beta-diversity and abundance of fungal community had no difference between the intercropping and monoculture systems. The relative abundances of some taxa (i.e., Acidobacteria-Subgroup-6, Arthrobacter, Bacillus, Pseudomonas) and several OTUs with the potential to promote plant growth were increased, while the relative abundances of some potential plant pathogens (i.e., Cladosporium) were decreased in the intercropping system. Redundancy analysis indicated that bacterial community structure was significantly influenced by soil organic carbon and pH, the fungal community structure was related to changes in soil organic carbon and available phosphorus. Overall, our results suggested that the tomato/potato-onion intercropping system altered soil microbial communities and improved the soil environment, which may be the main factor in promoting tomato growth.

Nutrient availability and organic matter quality shape bacterial community structure in a lake biofilm

2020 ◽  
Vol 85 ◽  
pp. 1-18
Author(s):  
RC Seballos ◽  
KH Wyatt ◽  
RJ Bernot ◽  
SP Brown ◽  
S Chandra ◽  
...  
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Heterotrophic Bacteria ◽  
Interspecific Interactions ◽  
Molecular Techniques ◽  
Nitrogen And Phosphorus ◽  
Microbial Composition ◽  
Organic Matter Quality

Heterotrophic bacteria play a key role in ecosystem processes, but little is known about the factors that shape bacterial community structure in aquatic biofilms, especially in lakes. We used molecular techniques (16S rRNA) to evaluate resource controls on biofilm bacterial community structure in an oligotrophic subalpine lake. We manipulated nutrients (nitrogen and phosphorus; NP) and glucose (G) on inorganic (rock) and organic (wood) substrates under light and dark conditions (i.e. with and without autotrophy, respectively) in a full factorial design using nutrient diffusing substrates in situ for 20 d. Distinct patterns of separation in community structure between treatments with nutrients (NP, NP+G) and without nutrients (control, G-only) indicated that community structure was more strongly influenced by nutrients than organic matter irrespective of substrate type or light availability. Further separation in community structure between treatments with nutrients only (NP) and nutrients with glucose (NP+G) on both organic and inorganic substrates indicated that once nutrient limitation was alleviated, organic matter quality played an important role in shaping community structure. Differences in the relative abundance of 6 phyla, 3 classes, and 19 genera among treatments revealed (1) contrasting taxa-specific resource requirements, (2) the influence of interspecific interactions on composition, and (3) the potential for individual taxa to participate in the decomposition of recalcitrant organic matter. Our findings provide insight into the role that nutrients and organic matter quality play in shaping bacterial community structure, which is a critical step in bridging the knowledge gap between microbial composition and ecosystem function within aquatic environments.

Host fruit as a suitable bacteria growth substrate that promotes larval development of Bactrocera dorsalis (Diptera: Tephritidae)

2019 ◽  
Author(s):  
Mazarin Akami ◽  
Xueming Ren ◽  
Yaohui Wang ◽  
Abdelaziz Mansour ◽  
Shuai Cao ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Larval Development ◽  
Bacterial Growth ◽  
Bacterial Community Structure ◽  
Fruit Fly ◽  
Bactrocera Dorsalis ◽  
Significant Shift ◽  
Bacteria Growth

AbstractThe ability of a host plant to act as a substrate or media for larval development may depend on how good it is at offering suitable nutrients for bacterial growth. In this study, we hypothesized that the suitability of a fruit type for fruit fly larval development is positively correlated with the ability of that fruit to act as a substrate/media for fruit fly symbiotic bacterial growth. We allowed a single female fruit fly to lay eggs on five different host fruits, then we monitored the larval development parameters across five generations and analyzed the bacterial community structure of larvae developing in 2 of these hosts (apple and banana) at the first and fifth generations. Results indicate that the larval length and dry weight did not vary significantly across experimental generations, but were greatly affected by fruit types and larval stages. The larval development time was extended considerably in apple and tomato but shortened in banana and mango. There was a significant shift in bacterial community structure and composition across fruits and generations. The bacterial community of larvae within the same fruit (apple and banana) clustered and was similar to the parental female (with the predominance of Proteobacteria), but there was a shift at the fifth generation (dominance of Firmicutes). Banana offered a suitable better development and growth to larvae and bacteria, respectively, compared to apple in which reduced larval development and bacterial growth were recorded. Although additional experiments are needed to adequately show that the differences in microbiome seen in fruit fly larval guts are the actual driver of different developmental outcomes of larvae on the different fruits, at the very least, our study has provided intriguing data suggesting interaction between the diets and gut microbial communities on insect development.Importance and Significance of the studyTephritid fruit flies entertain complex interactions with gut bacteria. These bacteria are known to provide nutritional benefits to their hosts, by supplementing missing nutrients from the host diets and regulating energy balance. Foraging for food is a risky exercise for the insect which is exposed to ecological adversities, including predators. Therefore, making beneficial choice among available food substrates is a question of survival for the flies and bacteria as well. Our study demonstrates interactions between the host fly and its intestinal bacteria in sustaining the larval development while foraging optimally on different fruit types. These findings add a novel step into our understanding of the interactions between the gut microbial communities and B. dorsalis and provide avenues for developing control strategies to limit the devastative incidence of the fly.

scholarly journals Colonization in the Photic Zone and Subsequent Changes during Sinking Determine Bacterial Community Composition in Marine Snow

2014 ◽  
Vol 81 (4) ◽  
pp. 1463-1471 ◽  
Author(s):  
Stefan Thiele ◽  
Bernhard M. Fuchs ◽  
Rudolf Amann ◽  
Morten H. Iversen
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Microbial Community Composition ◽  
Marine Snow ◽  
Free Living ◽  
Fluorescence Maximum

ABSTRACTDue to sampling difficulties, little is known about microbial communities associated with sinking marine snow in the twilight zone. A drifting sediment trap was equipped with a viscous cryogel and deployed to collect intact marine snow from depths of 100 and 400 m off Cape Blanc (Mauritania). Marine snow aggregates were fixed and washedin situto prevent changes in microbial community composition and to enable subsequent analysis using catalyzed reporter deposition fluorescencein situhybridization (CARD-FISH). The attached microbial communities collected at 100 m were similar to the free-living community at the depth of the fluorescence maximum (20 m) but different from those at other depths (150, 400, 550, and 700 m). Therefore, the attached microbial community seemed to be “inherited” from that at the fluorescence maximum. The attached microbial community structure at 400 m differed from that of the attached community at 100 m and from that of any free-living community at the tested depths, except that collected near the sediment at 700 m. The differences between the particle-associated communities at 400 m and 100 m appeared to be due to internal changes in the attached microbial community rather thande novocolonization, detachment, or grazing during the sinking of marine snow. The new sampling method presented here will facilitate future investigations into the mechanisms that shape the bacterial community within sinking marine snow, leading to better understanding of the mechanisms which regulate biogeochemical cycling of settling organic matter.

Bacterial community structure in cooling water and biofilm in an industrial recirculating cooling water system

2013 ◽  
Vol 68 (4) ◽  
pp. 940-947 ◽  
Author(s):  
Jinmei Wang ◽  
Min Liu ◽  
Huijie Xiao ◽  
Wei Wu ◽  
Meijuan Xie ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Water System ◽  
Cooling Water ◽  
Water Systems ◽  
Rrna Gene ◽  
Free Living ◽  
Cooling Water System ◽  
Attached Bacteria ◽  
Living Bacteria

Microbial fouling is a serious problem in open recirculating cooling water systems. The bacterial communities that cause it have not been fully understood. In this study, we analyzed the community structure of free-living bacteria and particle-attached bacteria in cooling water, and bacteria in biofilm collected from the wall of the water reservoir in an industrial recirculating cooling water system by construction of a 16S rRNA gene clone library. Based on amplified ribosomal DNA restriction analysis, clones of all three libraries were clustered into 45 operational taxonomic units (OTUs). Thirteen OTUs displaying 91–96% sequence similarity to a type strain might be novel bacterial species. Noted differences in community structure were observed among the three libraries. The relative species richness of the free-living bacteria in cooling water was much lower than that of particle-attached bacteria and bacteria in biofilm. The majority of the free-living bacterial community (99.0%) was Betaproteobacteria. The predominant bacteria in the particle-attached bacterial community were Alphaproteobacteria (20.5%), Betaproteobacteria (27.8%) and Planctomycetes (42.0%), while those in the biofilm bacterial community were Alphaproteobacteria (47.9%), Betaproteobacteria (11.7%), Acidobacteria (13.1%) and Gemmatimonadetes (11.3%). To control microbial fouling in industrial recirculating cooling water systems, additional physiological and ecological studies of these species will be essential.

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