scholarly journals Diel Protein Regulation of Marine Picoplanktonic Communities Assessed by Metaproteomics

2021 ◽  
Vol 9 (12) ◽  
pp. 2621
Author(s):  
Augustin Géron ◽  
Johannes Werner ◽  
Philippe Lebaron ◽  
Ruddy Wattiez ◽  
Sabine Matallana-Surget
Keyword(s):  
Heterotrophic Bacteria ◽  
Temporal Structure ◽  
Sea Surface ◽  
Diel Cycle ◽  
Diel Variation ◽  
Protein Regulation ◽  
Free Living ◽  
Bacterial Populations ◽  
Form Complex ◽  
Attached Bacteria

The diel cycle is of enormous biological importance in that it imposes temporal structure on ecosystem productivity. In the world’s oceans, microorganisms form complex communities that carry out about half of photosynthesis and the bulk of life-sustaining nutrient cycling. How the functioning of microbial communities is impacted by day and night periods in surface seawater remains to be elucidated. In this study, we compared the day and night metaproteomes of the free-living and the particle-attached bacterial fractions from picoplanktonic communities sampled from the northwest Mediterranean Sea surface. Our results showed similar taxonomic distribution of free-living and particle-attached bacterial populations, with Alphaproteobacteria, Gammaproteobacteria and Cyanobacteria being the most active members. Comparison of the day and night metaproteomes revealed that free-living and particle-attached bacteria were more active during the day and the night, respectively. Interestingly, protein diel variations were observed in the photoautotroph Synechococcales and in (photo)-heterotrophic bacteria such as Flavobacteriales, Pelagibacterales and Rhodobacterales. Moreover, our data demonstrated that diel cycle impacts light-dependent processes such as photosynthesis and UV-stress response in Synechococcales and Rhodobacterales, respectively, while the protein regulation from the ubiquitous Pelagibacterales remained stable over time. This study unravels, for the first time, the diel variation in the protein expression of major free-living and particle-attached microbial players at the sea surface, totaling an analysis of eight metaproteomes.

scholarly journals Diel Rhythms of Marine Picoplanktonic Communities Assessed by Comparative Metaproteomics

2020 ◽  
Author(s):  
Augustin Geron ◽  
Johannes Werner ◽  
Philippe Lebaron ◽  
Ruddy Wattiez ◽  
Sabine Matallana-Surget
Keyword(s):  
Temporal Structure ◽  
Diel Cycle ◽  
Taxonomic Structure ◽  
Specific Response ◽  
Free Living ◽  
Form Complex ◽  
North West ◽  
Attached Bacteria ◽  
First Time ◽  
Dependent Processes

Abstract Background Diel cycle is of enormous biological importance in that it imposes temporal structure on ecosystem productivity. In the world oceans, microorganisms form complex communities that carry out about half of photosynthesis and the bulk of life-sustaining nutrient cycling. Within these natural microbial assemblages, photoautotrophs, such as Cyanobacteria , display diel rhythmicity in gene expression. To what extent autotrophs and heterotrophs are impacted by light and dark oscillations and how this collectively influences community structure and functionality remains poorly documented. In this study, we compared eight day/night metaproteome profiles of Cyanobacteria and both free-living and attached bacterial fractions from picoplanktonic communities sampled over two consecutive days from the surface north-west Mediterranean Sea. Results Our results showed similar taxonomic structure in both free-living and particle-attached bacteria, dominated by Alphaproteobacteria and Gammaproteobacteria . Temporal rhythmicity in protein expression was observed in both Synechococcales and Rhodobacterales in light-dependent processes such as photosynthesis or UV-stress response. Other biological processes, such as phosphorus or amino acid metabolisms, were also found to cycle in phototrophs. In contrast, proteins from the ubiquitous Pelagibacterales remained stable independently of the day/night oscillations. Conclusion This work integrated for the first time diel comparative metaproteomics on both free-living and particle attached bacterial fractions in coastal oligotrophic environment. Our findings demonstrated a taxa-specific response to diel cycle with a more controlled protein regulation for phototrophs. This study provided additional evidences that timekeeping mechanisms might be widespread among bacteria, broadening our knowledge on diel microbial assemblage dynamics.

Distribution of heterotrophic bacteria in relation to the concentration of particulate organic matter in seawater

1983 ◽  
Vol 29 (5) ◽  
pp. 570-575 ◽  
Author(s):  
Kimio Fukami ◽  
Usio Simidu ◽  
Nobuo Taga
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Heterotrophic Bacteria ◽  
Viable Count ◽  
Plate Count ◽  
Free Living ◽  
Count Method ◽  
Attached Bacteria ◽  
Geographical Scale ◽  
Living Bacteria

The relationship between the number of bacteria and the concentration of particulate organic carbon (POC) in seawater was investigated. In coastal seawater in summer, the POC concentration showed better correlation to the density of bacteria obtained by the viable plate count method (viable count, V.C.) than by the total direct count method (total count, T.C.). The number of attached bacteria (A) showed significant fluctuation, both laterally on a geographical scale and vertically in the water column; on the other hand, the number of free-living bacteria (F) was relatively constant. The POC concentration had a much higher correlation with A (r = 0.8795) than with T.C. (r = 0.7339), and had a low correlation with F (r = 0.6935). Moreover, a very good correlation was observed between the density of bacteria obtained by V.C. and A (r = 0.9153). These results indicate that when the concentration of particulate organic matter (POM) increases, some free-living bacteria become attached to POM, and grow on the surface of POM. These communities of attached bacteria have the ability to make colonies on plate media and can be counted as the "viable plate count."

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 A circadian clock in a nonphotosynthetic prokaryote

2021 ◽  
Vol 7 (2) ◽  
pp. eabe2086
Author(s):  
Zheng Eelderink-Chen ◽  
Jasper Bosman ◽  
Francesca Sartor ◽  
Antony N. Dodd ◽  
Ákos T. Kovács ◽  
...  
Keyword(s):  
Temperature Compensation ◽  
Temporal Structure ◽  
Bacterial Biofilm ◽  
Circadian Clocks ◽  
Industrial Processes ◽  
Free Living ◽  
Considerable Potential ◽  
Free Running ◽  
Free Running Period ◽  
Constant Dark

Circadian clocks create a 24-hour temporal structure, which allows organisms to occupy a niche formed by time rather than space. They are pervasive throughout nature, yet they remain unexpectedly unexplored and uncharacterized in nonphotosynthetic bacteria. Here, we identify in Bacillus subtilis circadian rhythms sharing the canonical properties of circadian clocks: free-running period, entrainment, and temperature compensation. We show that gene expression in B. subtilis can be synchronized in 24-hour light or temperature cycles and exhibit phase-specific characteristics of entrainment. Upon release to constant dark and temperature conditions, bacterial biofilm populations have temperature-compensated free-running oscillations with a period close to 24 hours. Our work opens the field of circadian clocks in the free-living, nonphotosynthetic prokaryotes, bringing considerable potential for impact upon biomedicine, ecology, and industrial processes.

scholarly journals Diversity of Free-Living and Attached Bacteria in Offshore Western Mediterranean Waters as Depicted by Analysis of Genes Encoding 16S rRNA

1999 ◽  
Vol 65 (2) ◽  
pp. 514-522 ◽  
Author(s):  
Silvia G. Acinas ◽  
Josefa Antón ◽  
Francisco Rodríguez-Valera
Keyword(s):  
16S Rdna ◽  
Restriction Analysis ◽  
Western Mediterranean ◽  
Bacterial Cells ◽  
Free Living ◽  
Attached Bacteria ◽  
Genes Encoding ◽  
Community Fingerprinting ◽  
Close Relatives ◽  
Alteromonas Macleodii

ABSTRACT In a previous study (S. G. Acinas, F. Rodrı́guez-Valera, and C. Pedrós-Alió, FEMS Microbiol. Ecol. 24:27–40, 1997), community fingerprinting by 16S rDNA restriction analysis applied to Mediterranean offshore waters showed that the free-living pelagic bacterial community was very different from the bacterial cells aggregated or attached to particles of more than about 8 μm. Here we have studied both assemblages at three depths (5, 50, and 400 m) by cloning and sequencing the 16S rDNA obtained from the same samples, and we have also studied the samples by scanning electron microscopy to detect morphology patterns. As expected, the sequences retrieved from the assemblages were very different. The subsample of attached bacteria contained very little diversity, with close relatives of a well-known species of marine bacteria, Alteromonas macleodii, representing the vast majority of the clones at every depth. On the other hand, the free-living assemblage was highly diverse and varied with depth. At 400 m, close relatives of cultivated γProteobacteria predominated, but as shown by other authors, near the surface most clones were related to phylotypes described only by sequence, in which the α Proteobacteria of the SAR11 cluster predominated. The new technique of rDNA internal spacer analysis has been utilized, confirming these results. Clones representative of the A. macleodii cluster have been completely sequenced, producing a picture that fits well with the idea that they could represent a genus with at least two species and with a characteristic depth distribution.

Dynamics of free-living nitrogen-fixing bacterial populations in antagonistic conditions

2007 ◽  
Vol 200 (1-2) ◽  
pp. 243-253 ◽  
Author(s):  
A. Kavadia ◽  
D.V. Vayenas ◽  
S. Pavlou ◽  
G. Aggelis
Keyword(s):  
Nitrogen Fixing ◽  
Free Living ◽  
Bacterial Populations

The dynamics of attached and free-living bacterial population in tropical coastal waters

2015 ◽  
Vol 66 (8) ◽  
pp. 701 ◽  
Author(s):  
Siew Wen Lee ◽  
Choon Weng Lee ◽  
Chui Wei Bong ◽  
Kumaran Narayanan ◽  
Edmund Ui-Hang Sim
Keyword(s):  
Coastal Waters ◽  
Bacterial Population ◽  
Bacterial Abundance ◽  
Large Fraction ◽  
Free Living ◽  
Water Port ◽  
Eutrophic Water ◽  
Attached Bacteria ◽  
Student’S T ◽  
Student’S T Test

We investigated the dynamics of attached and free-living bacterial abundance over a period of 18 months in tropical coastal waters of Malaysia. We measured the abundance at both oligotrophic coastal water (Port Dickson) and eutrophic estuary (Klang), and hypothesised that attached bacteria are predominant in eutrophic waters. We found that bacterial abundance was higher at Klang than Port Dickson (Student’s t-test: t=4.87, d.f.=19, P<0.001). Attached bacteria also formed a large fraction of the total bacteria at Klang (75% ±13s.d.) relative to Port Dickson (56% ±22), and showed preference for chlorophyll-a-based particles rather than total suspended solids. The bacterial community structure was clearly different between the two stations but was similar between the attached and free-living bacterial population. Our results showed the importance of attached bacteria in eutrophic water where they could play a major role in carbon and nutrient cycling.

Sign in / Sign up

Export Citation Format

Share Document