Influence of light and anoxia on chemiosmotic energy conservation in <i>Dinoroseobacter shibae</i>

Holert, Johannes; Hahnke, Sarah; Cypionka, Heribert

doi:10.1111/j.1758-2229.2010.00199.x

Cited by 17 publications

(29 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The importance of light controlling AAP bacterial activity has been shown by several pure culture studies (Shiba, 1984;Okamura et al, 1986;Holert et al, 2011;Tomasch et al, 2011;Hauruseu and Koblížek, 2012). However, we did not see a significant effect of light in short term incubations.…”

Section: Discussioncontrasting

confidence: 58%

“…This presumed advantage led to the hypothesis that one type of photoheterotroph, aerobic anoxygenic phototrophic (AAP) bacteria, would be most abundant in oligotrophic systems (Kolber et al, 2000), but subsequent work demonstrated that AAP bacteria are abundant in eutrophic estuaries and coastal waters when compared with the open oceans Jiao et al, 2007;Lami et al, 2007;Waidner and Kirchman, 2007;Ritchie and Johnson, 2012). Light has been shown to positively affect the growth rate and other aspects of AAP bacterial activity in laboratory experiments (Shiba, 1984;Okamura et al, 1986;Holert et al, 2011;Tomasch et al, 2011;Hauruseu and Koblížek, 2012), but it has complex effects on natural microbial communities which include photoheterotrophic microbes Straza and Kirchman, 2011;Ruiz-González et al, 2012a;Ruiz-González et al, 2012b). Data on growth-related activity in natural communities would help elucidate the advantages of photoheterotrophy and whether photoheterotrophic microbes change models of carbon cycling (Karl, 2002).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary

2014

View full text Add to dashboard Cite

Aerobic anoxygenic phototrophic (AAP) bacteria are well known to be abundant in estuaries, coastal regions and in the open ocean, but little is known about their activity in any aquatic ecosystem. To explore the activity of AAP bacteria in the Delaware estuary and coastal waters, single-cell 3 H-leucine incorporation by these bacteria was examined with a new approach that combines infrared epifluorescence microscopy and microautoradiography. The approach was used on samples from the Delaware coast from August through December and on transects through the Delaware estuary in August and November 2011. The percent of active AAP bacteria was up to twofold higher than the percentage of active cells in the rest of the bacterial community in the estuary. Likewise, the silver grain area around active AAP bacteria in microautoradiography preparations was larger than the area around cells in the rest of the bacterial community, indicating higher rates of leucine consumption by AAP bacteria. The cell size of AAP bacteria was 50% bigger than the size of other bacteria, about the same difference on average as measured for activity. The abundance of AAP bacteria was negatively correlated and their activity positively correlated with light availability in the water column, although light did not affect 3 H-leucine incorporation in light-dark experiments. Our results suggest that AAP bacteria are bigger and more active than other bacteria, and likely contribute more to organic carbon fluxes than indicated by their abundance.

show abstract

Section: Discussioncontrasting

confidence: 58%

Section: Introductionmentioning

confidence: 99%

Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary

2014

View full text Add to dashboard Cite

show abstract

“…The effects of a change from anoxic to oxic conditions have been investigated in detail for D. shibae, and it was concluded that the energy charge of the cell was back to normal oxic values within less than a minute (27). We assume that the same also held true for the other three organisms and that our measurements of energy metabolism, expressed by the rates of O 2 consumption during about 10-min periods of oxic conditions, represent short-term steady-state values (not taking the O 2 concentration dependence into account).…”

Section: Discussionmentioning

confidence: 99%

Respiratory Kinetics of Marine Bacteria Exposed to Decreasing Oxygen Concentrations

Gong

García‐Robledo

Schramm

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

O xygen (O 2 ), the second most abundant gas in the atmosphere on Earth, plays a critical role in nature, including aquatic environments. As the most favorable electron acceptor, O 2 drives the degradation of organic matter and influences the cycling of other elements (e.g., nitrogen, sulfur, phosphorus) (1). For decades, aerobic respiration has been studied by different methods in various environments (2-4). Due to the limit of detection by traditional methods (Winkler methods and methods that use electrochemical sensors and optodes), the measurement of respiratory activity in low-O 2 environments, such as oceanic oxygenminimum zones (OMZs), is rare (5), and even in fully oxygenated waters, the direct measurement of oxygen dynamics is difficult and the more indirect method of measurement of formazan formation has therefore been applied (6). The lack of detailed data on aerobic respiration in low-O 2 environments restricts the understanding of carbon budgets (7) and the prediction of the development of O 2 within such environments (8). Recently, STOX oxygen sensors have been applied to quantify O 2 respiration rates in OMZs (9), and by this technique, it was possible to measure rates down to about 1 nmol Ϫ1 liter Ϫ1 h Ϫ1 , which is a level of resolution that is a factor of 10 higher than that obtained by traditional methods (10). Half-saturation constants (apparent K m values) for microbial communities were estimated from the data obtained with STOX oxygen sensors, but highly variable values ranging from 30 to 200 nmol liter Ϫ1 were obtained. Another study indicated high half-saturation O 2 concentrations of several micromolar, supposedly caused by diffusion limitation around and within aggregates (11).The final step of aerobic respiration is conducted by a terminal cytochrome oxidase, a membrane-associated protein which transfers electrons to O 2 (12). Two main families of terminal oxidases have been classified on the basis of structural and functional differences (13-16): the heme-copper oxidases (HCOs) and the cytochrome bd-type oxidases. Furthermore, three classes have been identified within HCOs according to the combination of different heme subunits (classes A, B, and C). The kinetic parameters maximum respiration rate (V max ) and K m can be used to describe respiratory activity as a function of the O 2 concentration, although it should be kept in mind that the Michaelis-Menten equation strictly applies only to the kinetics of single enzymes. According to the affinity of O 2 , these terminal oxidases can be classified as high-affinity terminal oxidases (with K m values of about 3 to 8 nmol liter Ϫ1 ) (17) and low-affinity terminal oxidases (with K m values of about 200 nmol liter Ϫ1 ) (18). Respiration rates in aquatic environments have been estimated by different methods, and the kinetics have been estimated using several models. Different equations have been proposed to estimate V max and K m values, such as fitting of the data directly to the Michaelis-Menten equation by computer-aided iterative regres...

show abstract

“…Proton gradients and ATP generated by PR can potentially affect the global ocean carbon budgets in two ways: (i) they could decrease carbon respiration rates, if less dissolved organic carbon is respired and preferably used for anabolic processes, as shown for aerobic anoxygenic phototrophs (Holert et al, 2011;Tomasch et al, 2011), or (ii) they could enhance the uptake of solutes that could subsequently be respired via PR-powered ion gradients. Both of these mechanisms have been shown for Ca.…”

Section: Introductionmentioning

confidence: 99%

Proteorhodopsin light-enhanced growth linked to vitamin-B1 acquisition in marine Flavobacteria

et al. 2015

View full text Add to dashboard Cite

Proteorhodopsins (PR) are light-driven proton pumps widely distributed in bacterioplankton. Although they have been thoroughly studied for more than a decade, it is still unclear how the proton motive force (pmf) generated by PR is used in most organisms. Notably, very few PR-containing bacteria show growth enhancement in the light. It has been suggested that the presence of specific functions within a genome may define the different PR-driven light responses. Thus, comparing closely related organisms that respond differently to light is an ideal setup to identify the mechanisms involved in PR light-enhanced growth. Here, we analyzed the transcriptomes of three PR-harboring Flavobacteria strains of the genus Dokdonia: Dokdonia donghaensis DSW-1 T , Dokdonia MED134 and Dokdonia PRO95, grown in identical seawater medium in light and darkness. Although only DSW-1 T and MED134 showed light-enhanced growth, all strains expressed their PR genes at least 10 times more in the light compared with dark. According to their genomes, DSW-1 T and MED134 are vitamin-B 1 auxotrophs, and their vitamin-B 1 TonB-dependent transporters (TBDT), accounted for 10-18% of all pmf-dependent transcripts. In contrast, the expression of vitamin-B 1 TBDT was 10 times lower in the prototroph PRO95, whereas its vitamin-B 1 synthesis genes were among the highest expressed. Our data suggest that light-enhanced growth in DSW-1 T and MED134 derives from the use of PR-generated pmf to power the uptake of vitamin-B 1 , essential for central carbon metabolism, including the TCA cycle. Other pmf-generating mechanisms available in darkness are probably insufficient to power transport of enough vitamin-B 1 to support maximum growth of these organisms.

show abstract

Influence of light and anoxia on chemiosmotic energy conservation in Dinoroseobacter shibae

Cited by 17 publications

References 36 publications

Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary

Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary

Respiratory Kinetics of Marine Bacteria Exposed to Decreasing Oxygen Concentrations

Proteorhodopsin light-enhanced growth linked to vitamin-B1 acquisition in marine Flavobacteria

Contact Info

Product

Resources

About