Comparative Analysis of Community Structure Between Attached and Free-living Bacteria in the Meiliang Bay, Taihu Lake*

2011 ◽  
Vol 17 (1) ◽  
pp. 104-108 ◽  
Author(s):  
Juan DONG ◽  
Xiaohong HE ◽  
Daping LI ◽  
Yashu ZHANG ◽  
Yong TAO
Keyword(s):  
Community Structure ◽  
Comparative Analysis ◽  
Taihu Lake ◽  
Free Living ◽  
Meiliang Bay ◽  
Living Bacteria

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.

scholarly journals Dynamics of Free-Living and Attached Bacterial Assemblages in Skeletonema sp. Diatom Cultures at Elevated Temperatures

2021 ◽  
Vol 8 ◽  
Author(s):  
Zichao Deng ◽  
Shouchang Chen ◽  
Ping Zhang ◽  
Xu Zhang ◽  
Jonathan M. Adams ◽  
...  
Keyword(s):  
Community Structure ◽  
Elevated Temperature ◽  
Bacterial Communities ◽  
Elevated Temperatures ◽  
Bacterial Species ◽  
Positive Interactions ◽  
Growth Stages ◽  
Free Living ◽  
Attached Bacteria ◽  
Living Bacteria

In the context of global warming, changes in phytoplankton-associated bacterial communities have the potential to change biogeochemical cycling and food webs in marine ecosystems. Skeletonema is a cosmopolitan diatom genus in coastal waters worldwide. Here, we grew a Skeletonema strain with its native bacterial assemblage at different temperatures and examined cell concentrations of Skeletonema sp. and free-living bacteria, dissolved organic carbon (DOC) concentrations of cultures, and the community structure of both free-living and attached bacteria at different culture stages. The results showed that elevated temperature increased the specific growth rates of both Skeletonema and free-living bacteria. Different growth stages had a more pronounced effect on community structure compared with temperatures and different physical states of bacteria. The effects of temperature on the structure of the free-living bacterial community were more pronounced compared with diatom-attached bacteria. Carbon metabolism genes and those for some specific amino acid pathways were found to be positively correlated with elevated temperature, which may have profound implications on the oceanic carbon cycle and the marine microbial loop. Network analysis revealed evidence of enhanced cooperation with an increase in positive interactions among different bacteria at elevated temperature. This may help the whole community to overcome the stress of elevated temperature. We speculate that different bacterial species may build more integrated networks with a modified functional profile of the whole community to cope with elevated temperature. This study contributes to an improved understanding of the response of diatom-associated bacterial communities to elevated temperature.

scholarly journals Coupling of heterotrophic bacteria to phytoplankton bloom development at different <i>p</i>CO<sub>2</sub> levels: a mesocosm study

2008 ◽  
Vol 5 (4) ◽  
pp. 1007-1022 ◽  
Author(s):  
M. Allgaier ◽  
U. Riebesell ◽  
M. Vogt ◽  
R. Thyrhaug ◽  
H.-P. Grossart
Keyword(s):  
Community Structure ◽  
Heterotrophic Bacteria ◽  
Phytoplankton Bloom ◽  
C:N Ratio ◽  
Life Forms ◽  
Bacterial Activity ◽  
Free Living ◽  
Seawater Chemistry ◽  
Attached Bacteria ◽  
Living Bacteria

Abstract. The predicted rise in anthropogenic CO2 emissions will increase CO2 concentrations and decrease seawater pH in the upper ocean. Recent studies have revealed effects of pCO2 induced changes in seawater chemistry on a variety of marine life forms, in particular calcifying organisms. To test whether the predicted increase in pCO2 will directly or indirectly (via changes in phytoplankton dynamics) affect abundance, activities, and community composition of heterotrophic bacteria during phytoplankton bloom development, we have aerated mesocosms with CO2 to obtain triplicates with three different partial pressures of CO2 (pCO2): 350 μatm (1×CO2), 700 μatm (2×CO2) and 1050 μatm (3×CO2). The development of a phytoplankton bloom was initiated by the addition of nitrate and phosphate. In accordance to an elevated carbon to nitrogen drawdown at increasing pCO2, bacterial production (BPP) of free-living and attached bacteria as well as cell-specific BPP (csBPP) of attached bacteria were related to the C:N ratio of suspended matter. These relationships significantly differed among treatments. However, bacterial abundance and activities were not statistically different among treatments. Solely community structure of free-living bacteria changed with pCO2 whereas that of attached bacteria seemed to be independent of pCO2 but tightly coupled to phytoplankton bloom development. Our findings imply that changes in pCO2, although reflected by changes in community structure of free-living bacteria, do not directly affect bacterial activity. Furthermore, bacterial activity and dynamics of heterotrophic bacteria, especially of attached bacteria, were tightly correlated to phytoplankton development and, hence, may also potentially depend on changes in pCO2.

scholarly journals Coupling of heterotrophic bacteria to phytoplankton bloom development at different pCO<sub>2</sub> levels: a mesocosm study

2008 ◽  
Vol 5 (1) ◽  
pp. 317-359 ◽  
Author(s):  
M. Allgaier ◽  
U. Riebesell ◽  
M. Vogt ◽  
R. Thyrhaug ◽  
H.-P. Grossart
Keyword(s):  
Community Structure ◽  
Heterotrophic Bacteria ◽  
Phytoplankton Bloom ◽  
C:N Ratio ◽  
Life Forms ◽  
Bacterial Activity ◽  
Free Living ◽  
Seawater Chemistry ◽  
Attached Bacteria ◽  
Living Bacteria

Abstract. The predicted rise in anthropogenic CO2 emissions will increase CO2 concentrations and decrease seawater pH in the upper ocean. Recent studies have revealed effects of pCO2 induced changes in seawater chemistry on a variety of marine life forms, in particular calcifying organisms. To test whether the predicted increase in pCO2 will directly or indirectly (via changes in phytoplankton dynamics) affect abundance, activities, and community composition of heterotrophic bacteria during phytoplankton bloom development, we have aerated mesocosms with CO2 to obtain triplicates with three different partial pressures of CO2 (pCO2): 350 µatm (1×CO2), 700 µatm (2×CO2) and 1050 µatm (3×CO2). The development of a phytoplankton bloom was initiated by the addition of nitrate and phosphate. In accordance to an elevated carbon to nitrogen drawdown at increasing pCO2, bacterial production (BPP) of free-living and attached bacteria as well as cell-specific BPP (csBPP) of attached bacteria were related to the C:N ratio of suspended matter. These relationships significantly differed among treatments. However, bacterial abundance and activities were not statistically different among treatments. Solely community structure of free-living bacteria changed with pCO2 whereas that of attached bacteria seemed to be independent of pCO2 but tightly coupled to phytoplankton bloom development. Our findings imply that changes in pCO2, although reflected by changes in community structure of free-living bacteria, do not directly affect bacterial activity. Furthermore, bacterial activity and dynamics of heterotrophic bacteria, especially of attached bacteria, were tightly linked to phytoplankton development and, hence, may also potentially depend on changes in pCO2.

scholarly journals Opening a next-generation black box: ecological trends for hundreds of species-like taxa uncovered within a single bacterial >99% 16S rRNA operational taxonomic unit

2021 ◽  
Author(s):  
Martin Hahn ◽  
Andrea Huemer ◽  
Alexandra Pitt ◽  
Matthias Hoetzinger
Keyword(s):  
16S Rrna ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Taxon Richness ◽  
Large Set ◽  
Free Living ◽  
Environmental Distribution ◽  
Living Bacteria

Current knowledge on environmental distribution and taxon richness of free-living bacteria is mainly based on cultivation-independent investigations employing 16S rRNA gene sequencing methods. Yet, 16S rRNA genes are evolutionarily rather conserved, resulting in limited taxonomic and ecological resolutions provided by this marker. We used a faster evolving protein-encoding marker to reveal ecological patterns hidden within a single OTU defined by >99% 16S rRNA sequence similarity. The studied taxon, subcluster PnecC of the genus Polynucleobacter, represents a ubiquitous group of planktonic freshwater bacteria with cosmopolitan distribution, which is very frequently detected by diversity surveys of freshwater systems. Based on genome taxonomy and a large set of genome sequences, a sequence similarity threshold for delineation of species-like taxa could be established. In total, 600 species-like taxa were detected in 99 freshwater habitats scattered across three regions representing a latitudinal range of 3400 km (42°N to 71°N) and a pH gradient of 4.2 to 8.6. Besides the unexpectedly high richness, the increased taxonomic resolution revealed structuring of Polynucleobacter communities by a couple of macroecological trends, which was previously only demonstrated for phylogenetically much broader groups of bacteria. A unexpected pattern was the almost complete compositional separation of Polynucleobacter communities of Ca-rich and Ca-poor habitats, which strongly resembled the vicariance of plant species on silicate and limestone soils. The presented new cultivation-independent approach opened a window to an incredible, previously unseen diversity, and enables investigations aiming on deeper understanding of how environmental conditions shape bacterial communities and drive evolution of free-living bacteria.

scholarly journals Designer endosymbionts: Converting free-living bacteria into organelles

2020 ◽  
Vol 24 ◽  
pp. 41-50
Author(s):  
Rebecca S. Meaney ◽  
Samir Hamadache ◽  
Maximillian P.M. Soltysiak ◽  
Bogumil J. Karas
Keyword(s):  
Free Living ◽  
Living Bacteria
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