Importance of free-living and particle-associated bacteria for the growth of the harmful dinoflagellate Prorocentrum minimum: evidence in culture stages

2018 ◽  
Vol 69 (2) ◽  
pp. 290 ◽  
Author(s):  
Bum Soo Park ◽  
Ruoyu Guo ◽  
Weol-Ae Lim ◽  
Jang-Seu Ki
Keyword(s):  
Bacterial Community ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Bacterial Community Composition ◽  
Hierarchical Cluster ◽  
Prorocentrum Minimum ◽  
Growth Stages ◽  
Roseobacter Clade ◽  
Free Living ◽  
Associated Bacteria

The marine dinoflagellate Prorocentrum minimum is the cause of harmful algal blooms and may grow in association with co-occurring bacteria as ectosymbiotic, endosymbiotic and free-living forms. In the present study we investigated the bacterial community composition of both free-living bacteria (FLB) and particle-associated bacteria (PAB) in the lag, exponential and stationary growth stages of P. minimum using pyrosequencing. Metagenomics, hierarchical cluster and non-metric multidimensional scaling analyses revealed that FLB and PAB had significantly different bacterial community compositions. The PAB community had greater taxonomic richness and diversity than the FLB community. In addition, the shared bacteria identified were clearly dominant in both the FLB (≥98.2%) and PAB (≥89.9%) communities. Among shared bacteria, the genera Seohaeicola (P. minimum operational taxonomic unit (OTU) #1) and Roseovarius (P. minimum OTU #6), belonging to the Roseobacter clade, were predominant in FLB (42–57%) and PAB (11–14%) communities respectively. In the PAB community, the Marinobacter clade (P. minimum OTU #13 and #15) was also a dominant taxon. Interestingly, in response to the growth of P. minimum, the proportion of the Roseobacter clade increased gradually, whereas the genus Marinobacter decreased in both the FLB and PAB communities. These results suggest that Roseobacter and Marinobacter clades are intimately associated with host dinoflagellate.

scholarly journals Different Cultivation Environments Affect the Yield, Bacterial Community and Metabolites of Cordyceps cicadae

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhaoying Zeng ◽  
Dan Mou ◽  
Li Luo ◽  
Wenlin Zhong ◽  
Lin Duan ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Natural Habitat ◽  
Bacterial Community Composition ◽  
Pinus Massoniana ◽  
Growth Stages ◽  
Natural Habitats ◽  
Entomogenous Fungus ◽  
Cordyceps Cicadae ◽  
Glass Bottles ◽  
Different Growth Stages

Cordyceps cicadae is an entomogenous fungus with important uses in traditional Chinese medicine. However, its wild resources have not met consumers’ demand due to excessive harvesting practices. Artificial cultivation is therefore an important alternative, but research on cultivating C. cicadae in natural habitats has not been reported. In this study, we aimed to explore the viability of cultivating C. cicadae in a natural habitat, in the soil of Pinus massoniana forest. We assessed and compared the yield, metabolite contents and bacterial community composition of C. cicadae grown in the Antheraea pernyi pupae at different growth stages, and under different cultivation conditions, in the soil of a natural habitat and in sterile glass bottles. Our results showed that cultivating C. cicadae in a natural habitat is feasible, with up to 95% of pupae producing C. cicadae fruiting bodies. The content of nitrogen compounds (amino acids) in C. cicadae cultivated in a natural habitat was significantly higher than in glass bottles, while the yield and carbon compound (mannitol and polysaccharide) and nucleoside (cordycepin and adenosine) contents were lower. Different bacterial genera were enriched in C. cicadae at different growth stages and cultivation environments, and these bacterial genera were closely related to metabolites contents during growth. This study demonstrated the viability of a novel cultivation method of C. cicadae, which could be used as an alternative to wild stocks of this fungus. These findings provided new insights into the growth mechanism of C. cicadae and its interaction with soil microorganisms.

scholarly journals Isolation of axenic cyanobacterium and the promoting effect of associated bacterium on axenic cyanobacterium

2020 ◽  
Author(s):  
Suqin Gao ◽  
Yun Kong ◽  
Jing Yu ◽  
Lihong Miao ◽  
Lipeng Ji ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Specific Interaction ◽  
Organic Substrates ◽  
Health Issues ◽  
Promoting Effect ◽  
Associated Bacteria ◽  
Purification Technique ◽  
Solid Liquid ◽  
Water Quality Deterioration

Abstract Background: Harmful algal blooms have attracted wide attention all over the world as they cause water quality deterioration and ecosystem health issues. Microcystis aeruginosa associated with a large number of bacteria is one of the most common and widespread bloom-forming cyanobacteria that secret toxins. These associated bacteria are considered to benefit from organic substrates released by the cyanobacterium. In order to avoid the influence of associated bacteria on the target cyanobacteria for physiological and molecular studies, it is urgent to obtain an axenic M. aeruginosa culture and further investigate the specific interaction between the cyanobacterium-associated bacterium and the cyanobacterium.Results: A traditional and reliable method based on solid-liquid alternate cultivation is carried out to purify the xenic cyanobacterium M. aeruginosa FACHB-905. On the basis of 16S rDNA gene sequences, two associated bacteria named strain B905-1 and strain B905-2, are identified as Pannonibacter sp. and Chryseobacterium sp. with a 99% and 97% similarity value, respectively. The axenic M. aeruginosa FACHB-905A is not able to form colonies on BG11 agar medium without the addition of strain B905-1, while it grows well in BG11 liquid medium. Although the presence of B905-1 is not indispensable for the growth of M. aeruginosa FACHB-905A, B905-1 has a positive effect on promoting the growth of M. aeruginosa FACHB-905A. Conclusions: The associated bacteria are eliminated by solid-liquid alternate cultivation method and the axenic M. aeruginosa FACHB-905A is successfully purified. The associated bacterium B905-1 has the potential to promote the growth of M. aeruginosa FACHB-905A. Moreover, the purification technique for cyanobacteria described in this study is potentially applicable to a wider range of unicellular cyanobacteria.

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.

scholarly journals The Cloacal Microbiome Changes with the Breeding Season in a Wild Bird

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
C Escallón ◽  
L K Belden ◽  
I T Moore
Keyword(s):  
Bacterial Community ◽  
Breeding Season ◽  
Bacterial Community Composition ◽  
Free Living ◽  
Sexually Transmitted ◽  
Zonotrichia Capensis ◽  
Investment In Reproduction ◽  
Successful Establishment ◽  
Breeding Condition ◽  
Breeding Seasons

Abstract The symbiotic microbial communities, or “microbiomes,” that reside on animals are dynamic, and can be affected by the behavior and physiology of the host. These communities provide many critical beneficial functions for their hosts, but they can also include potential pathogens. In birds, bacteria residing in the cloaca form a complex community, including both gut and sexually-transmitted bacteria. Transmission of cloacal bacteria among individuals is likely during the breeding season, when there is direct cloacal contact between individuals. In addition, the major energetic investment in reproduction can draw resources away from immune responses that might otherwise prevent the successful establishment of microbes. We assessed dynamic variation in the cloacal microbiome of free-living rufous-collared sparrows (Zonotrichia capensis) through sequential breeding and non-breeding seasons. We found that the cloacal bacterial communities differed between the sexes when they were in breeding condition. Further, in males, but not in females, the bacterial community became more diverse with the onset of reproduction, and then decreased in diversity as males transitioned to non-breeding condition. Individuals sampled across sequential breeding seasons did not accumulate more bacterial taxa over seasons, but bacterial community composition did change. Our results suggest that the cloacal microbiome in birds is dynamic and, especially in males, responsive to breeding condition.

scholarly journals Environmental Drivers of Free-Living vs. Particle-Attached Bacterial Community Composition in the Mauritania Upwelling System

2018 ◽  
Vol 9 ◽  
Author(s):  
Jennifer Bachmann ◽  
Tabea Heimbach ◽  
Christiane Hassenrück ◽  
Germán A. Kopprio ◽  
Morten Hvitfeldt Iversen ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Environmental Drivers ◽  
Free Living ◽  
Upwelling System

scholarly journals Impacts of Extreme Weather Events on Bacterial Community Composition of a Temperate Humic Lake

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2757
Author(s):  
Alexa Hoke ◽  
Jason Woodhouse ◽  
Luca Zoccarato ◽  
Valerie McCarthy ◽  
Elvira de Eyto ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
Critical Role ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Free Living ◽  
Drought Period ◽  
Weather Events

Extreme weather events are projected to increase in frequency and intensity as climate change continues. Heterotrophic bacteria play a critical role in lake ecosystems, yet little research has been done to determine how they are affected by such extremes. The purpose of this study was to use high-throughput sequencing to explore the bacterial community composition of a humic oligotrophic lake on the North Atlantic Irish coast and to assess the impacts on composition dynamics related to extreme weather events. Samples for sequencing were collected from Lough Feeagh on a fortnightly basis from April to November 2018. Filtration was used to separate free-living and particle-associated bacterial communities and amplicon sequencing was performed for the 16S rRNA V4 region. Two named storms, six high discharge events, and one drought period occurred during the sampling period. These events had variable, context-dependent effects on bacterial communities in Lough Feeagh. The particle-associated community was found to be more likely to respond to physical changes, such as mixing, while the free-living population responded to changes in nutrient and carbon concentrations. Generally, however, the high stability of the bacterial community observed in Lough Feeagh suggests that the bacterial community is relatively resilient to extreme weather events.

scholarly journals A prolonged red tide of Heterocapsa triquetra (Ehrenberg) F. Stein (Dinophyceae) and phytoplankton succession in a eutrophic estuary in Turkey

2015 ◽  
Vol 16 (3) ◽  
pp. 621 ◽  
Author(s):  
S. TAS
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Prorocentrum Minimum ◽  
Phytoplankton Succession ◽  
Chl A ◽  
Heterocapsa Triquetra ◽  
Golden Horn ◽  
Moderate Salinity ◽  
Near Future

A prolonged red tide of Heterocapsa triquetra and phytoplankton succession were investigated in a eutrophic estuary (Golden Horn) for a year. Runoff following the rainfall in winter supplied high amounts of nutrients and also created a mesohaline frontal zone in the middle and upper estuary. Red tide of H. triquetra was first observed with an orange-brownish water discoloration at the upper estuary in January. Highest cell density of H. triquetra was 2.7×106 cells l-1 in January and reached to 19.2×106 cells l-1 in April. Successive blooms continued with dinoflagellate Prorocentrum minimum in May and phytoflagellates Eutreptiella marina and Fibrocapsa sp. in summer. High chl-a and dissolved oxygen were measured in the spring depending on algal biomass. Findings indicate that H. triquetra might be adapted to moderate salinity and low temperatures and red tide events should be considered as a response to increasing eutrophication due to high amounts of nutrients. Eutrophication can lead to harmful algal blooms for this area in the near future.

scholarly journals Complexity of Bacterial Communities in a River-Floodplain System (Danube, Austria)

2005 ◽  
Vol 71 (2) ◽  
pp. 609-620 ◽  
Author(s):  
Katharina Besemer ◽  
Markus M. Moeseneder ◽  
Jesus M. Arrieta ◽  
Gerhard J. Herndl ◽  
Peter Peduzzi
Keyword(s):  
Organic Matter ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Temporal Dynamics ◽  
Bacterial Community Composition ◽  
Inorganic Nutrients ◽  
Danube River ◽  
Polymorphism Analysis ◽  
Free Living ◽  
River Floodplain

ABSTRACT Natural floodplains play an essential role in the processing and decomposition of organic matter and in the self-purification ability of rivers, largely due to the activity of bacteria. Knowledge about the composition of bacterial communities and its impact on organic-matter cycling is crucial for the understanding of ecological processes in river-floodplain systems. Particle-associated and free-living bacterial assemblages from the Danube River and various floodplain pools with different hydrological characteristics were investigated using terminal restriction fragment length polymorphism analysis. The particle-associated bacterial community exhibited a higher number of operational taxonomic units (OTUs) and was more heterogeneous in time and space than the free-living community. The temporal dynamics of the community structure were generally higher in isolated floodplain pools. The community structures of the river and the various floodplain pools, as well as those of the particle-associated and free-living bacteria, differed significantly. The compositional dynamics of the planktonic bacterial communities were related to changes in the algal biomass, temperature, and concentrations of organic and inorganic nutrients. The OTU richness of the free-living community was correlated with the concentration and origin of organic matter and the concentration of inorganic nutrients, while no correlation with the OTU richness of the particle-associated assemblage was found. Our results demonstrate the importance of the river-floodplain interactions and the influence of damming and regulation on the bacterial-community composition.

scholarly journals Bacterial Diversity in a Dynamic and Extreme Sub-Arctic Watercourse (Pasvik River, Norwegian Arctic)

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3098
Author(s):  
Maria Papale ◽  
Alessandro Ciro Rappazzo ◽  
Anu Mikkonen ◽  
Carmen Rizzo ◽  
Federica Moscheo ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Algal Blooms ◽  
Heavy Metal Contamination ◽  
Bacterial Community Composition ◽  
Amplicon Sequencing ◽  
The Arctic ◽  
Rrna Gene ◽  
Environmental Perturbations ◽  
Water And Sediment ◽  
Microbial Groups

Microbial communities promptly respond to the environmental perturbations, especially in the Arctic and sub-Arctic systems that are highly impacted by climate change, and fluctuations in the diversity level of microbial assemblages could give insights on their expected response. 16S rRNA gene amplicon sequencing was applied to describe the bacterial community composition in water and sediment through the sub-Arctic Pasvik River. Our results showed that river water and sediment harbored distinct communities in terms of diversity and composition at genus level. The distribution of the bacterial communities was mainly affected by both salinity and temperature in sediment samples, and by oxygen in water samples. Glacial meltwaters and runoff waters from melting ice probably influenced the composition of the bacterial community at upper and middle river sites. Interestingly, marine-derived bacteria consistently accounted for a small proportion of the total sequences and were also more prominent in the inner part of the river. Results evidenced that particular conditions occurring at sampling sites (such as algal blooms, heavy metal contamination and anaerobiosis) may select species at local scale from a shared bacterial pool, thus favoring certain bacterial taxa. Conversely, the few phylotypes specifically detected in some sites are probably due to localized external inputs introducing allochthonous microbial groups.

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