The effect of irradiance and specific inhibitors on protein and nucleic acid synthesis in the marine cyanobacterium Synechococcus sp. WH 7803

Kramer, Jonathan G.

doi:10.1007/bf00248968

Cited by 10 publications

(8 citation statements)

References 29 publications

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“…Synechococcus sp. strain WH7803 grew only on inorganic nitrogen sources despite evidence for its capacity to assimilate organic compounds such as leucine, methionine, uracil, and adenine into proteins and nucleic acids (30,8,48; personal observations). In addition, cells supplied with leucine as the sole nitrogen source retained their pigmentation for several days (personal observations).…”

Section: Discussionmentioning

confidence: 99%

Ecological Aspects of ntcA Gene Expression and Its Use as an Indicator of the Nitrogen Status of Marine Synechococcus spp

Lindell

Post

2001

Appl Environ Microbiol

106

136

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Nitrogen nutrition in cyanobacteria is regulated by NtcA, a transcriptional activator that is subject to negative control by ammonium. Using Synechococcus sp. strain WH7803 as a model organism, we show that ntcA expression was induced when cells were exposed to nitrogen stress but not when they were subjected to phosphorus or iron deprivation. Transcript levels accumulated in cells grown on a variety of inorganic and organic nitrogen sources, with the sole exception of ammonium. ntcA transcription was induced when ammonium levels dropped below 1 M and reached maximal levels within 2 h. Furthermore, the addition of more than 1 M ammonium led to a rapid decline in ntcA mRNA. The negative effect of ammonium was prevented by the addition of Lmethionine-D,L-sulfoximine (MSX) and azaserine, inhibitors of ammonium assimilation. Thus, basal ntcA transcript levels are indicative of ammonium utilization. Conversely, the highest ntcA transcript levels were found in cells lacking a nitrogen source capable of supporting growth. Therefore, maximal ntcA expression would indicate nitrogen deprivation. This state of nitrogen deprivation was induced by a 1-h incubation with MSX. The rapid response of ntcA gene expression to the addition of ammonium and MSX was used to design a protocol for assessing relative ntcA transcript levels in field populations of cyanobacteria, from which their nitrogen status can be inferred. ntcA was basally expressed in Synechococcus at a nutrient-enriched site at the northern tip of the Gulf of Aqaba, Red Sea. Therefore, these cyanobacteria were not nitrogen stressed, and their nitrogen requirements were met by regenerated nitrogen in the form of ammonium.

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Section: Discussionmentioning

confidence: 99%

Ecological Aspects of ntcA Gene Expression and Its Use as an Indicator of the Nitrogen Status of Marine Synechococcus spp

Lindell

Post

2001

Appl Environ Microbiol

106

136

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“…In contrast, Paerl (1991) showed light-dependent uptake of mixed amino acids at subnanomolar levels by autofluorescent picoplankton in mixed bacterioplankton assemblages. Leucine incorporation was used by others to measure protein synthesis by synechococcus strain WH7803, albeit at micromolar additions (Kramer 1990). The apparently discrepancy between the results of Kirchman and colleagues and the uptake of mixed amino acids reported by Paerl might be explained by a lower ability of Synechococcus to uptake leucine at nanomolar and subnanomolar concentrations in comparison with other amino acids.…”

Section: Uptake Of Nucleosides and Amino Acidsmentioning

confidence: 95%

Photoheterotrophic Marine Prokaryotes

Béjà

Suzuki

2008

Microbial Ecology of the Oceans

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“…Several Synechococcus strains have ectoproteolytic activity (Martinez & Azam 1993); however, these rates are greatly reduced in the dark (Kramer 1990, Martinez & Azam 1993, Mary et al 2008. Lochte & Turley (1988) incubated phytodetritus taken from the sediment surface (water depth 4500 m) with deep sea (450 atm, 2°C) or surface water (1 atm, 15°C) conditions in the dark and detected a 4-fold increase in Synechococcus abundance on Day 1 under both conditions.…”

Section: Physiological State Of Synechococcus In the Dark Oceanmentioning

confidence: 99%

“…Synechococcus sp. WH7803 can uptake leucine and uracil in the dark for at least 24 h, though incorporation is suppressed (Kramer 1990). Further study would be required to determine whether exogenous organic compounds meet the energy demands of Synechococcus in deep seawater or whether the rates of metabolism of deep Synechococcus cells fall to lower levels, as is seen in some strains of chlorophytes and prymnesiophytes (Jochem 1999).…”

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confidence: 99%

Distribution of Synechococcus in the dark ocean

Sohrin

Isaji²,

Agostini³

et al. 2011

Aquat. Microb. Ecol.

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Synechococcus is widely distributed in the world's ocean surfaces, and is often found in sediment traps. However, its distribution and ecological importance have not been well studied in meso-and bathypelagic waters. We measured Synechococcus abundance in the Suruga Bay (central Japan) and the subtropical NW Pacific. Synechococcus abundance at depths of 200 m and below varied from 2.4 to 190 cells ml -1 , but was in proportion to the surface abundance, suggesting transport of epipelagic populations to greater depths. Surprisingly, Synechococcus was evenly distributed from 200 m down to 1420 m (Suruga Bay) or to 2000 m (subtropical NW Pacific), regardless of season. The contribution of deep Synechococcus to the total population was highest in spring in the Suruga Bay (36 to 77%), and lowest in summer in the Suruga Bay (1 to 9%) and in the subtropical NW Pacific (4 and 10%). These results suggest effective transport of Synechococcus cells down the water column during productive seasons by attachment to large particles and limited transport under oligotrophic and stratified conditions. Deep Synechococcus abundance decreased from fall to winter in the Suruga Bay, though in filtered deep seawater it did not significantly decrease for 30 d in the dark, and it increased in a light/dark cycle. Our investigations show that the standing stock of Synechococcus has been significantly underestimated in previous studies of epipelagic waters conducted during productive seasons and that Synechococcus seems to be grazed and to contribute to biogeochemical cycles in the dark ocean. KEY WORDS: Synechococcus · Dark ocean · Vertical distribution · Vertical exportResale or republication not permitted without written consent of the publisher ability to utilize organic substrates (Zubkov et al. 2003, Zubkov & Tarran 2005, suggesting that Synechococcus can survive in darkness (Cottrell & Kirchman 2009).These earlier studies led us to examine how Synechococcus is dispersed throughout the dark ocean. The purpose of the present study is to clarify the abundance and distribution of Synechococcus in the dark ocean and to make inferences about the ecological and biogeochemical roles of the organism. Surprisingly, at depths of 200 m and below, Synechococcus was evenly distributed regardless of the season or area studied. These deep populations accounted for up to 77% of total Synechococcus population in the entire water column. MATERIALS AND METHODSSampling. Seawater was collected in Niskin bottles mounted on a CTD-carousel sampler at Station (Stn) 2 (34°51' N, 138°37' E, Suruga Bay) and Stn C2700 (27°00' N, 138°00' E, subtropical NW Pacific), during cruises on board the RV 'Suruga-maru' (Shizuoka Prefectural Research Institute of Fisheries) and RV 'Soyomaru' (National Research Institute of Fisheries Science, Fisheries Research Agency). The sampling location and hydrological conditions are shown in Table 1. Stn 2 is located near the Suruga Trough, at the center of the Suruga Bay, and Stn C2700 is a time-series station on O-Line (S...

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The effect of irradiance and specific inhibitors on protein and nucleic acid synthesis in the marine cyanobacterium Synechococcus sp. WH 7803

Cited by 10 publications

References 29 publications

Ecological Aspects of ntcA Gene Expression and Its Use as an Indicator of the Nitrogen Status of Marine Synechococcus spp

Ecological Aspects of ntcA Gene Expression and Its Use as an Indicator of the Nitrogen Status of Marine Synechococcus spp

Photoheterotrophic Marine Prokaryotes

Distribution of Synechococcus in the dark ocean

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