Differential timing for glucose assimilation in Prochlorococcus and coexistent microbial populations at the North Pacific Subtropical Gyre
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ABSTRACT:
ORGANISM(S): Prochlorococcus
PROVIDER: GSE154594 | GEO | 2022/08/23
REPOSITORIES: GEO
Similar Datasets
Project description:The marine cyanobacterium Prochlorococcus can utilize glucose as a source of carbon. However, the relative importance of inorganic and organic carbon assimilation and the timing of glucose assimilation are still poorly understood in these numerically dominant cyanobacteria. Here, we investigated whole microbial community and group-specific primary production and glucose assimilation using incubations with radioisotopes combined with flow cytometry cell sorting. We also studied changes in the microbial community structure in response to glucose enrichments and analyzed the transcription of Prochlorocccus genes involved in carbon metabolism and photosynthesis. Our results showed a diel variation for glucose assimilation in Prochlorococcus, with maximum assimilation at midday and minimum at midnight (~2-fold change), which was different from that of the total microbial community. This suggests that the timing in glucose assimilation in Prochlorococcus is coupled to photosynthetic light reactions producing energy, it being more convenient for Prochlorococcus to show maximum glucose uptake precisely when the rest of microbial populations have their minimum glucose uptake. Many transcriptional responses to glucose enrichment occurred after 12- and 24-h periods, but community composition did not change. High-light Prochlorococcus strains were the most impacted by glucose addition, with transcript-level increases observed for genes in pathways for glucose metabolism, such as the pentose phosphate pathway, the Entner-Doudoroff pathway, glycolysis, respiration, and glucose transport. While Prochlorococcus C assimilation from glucose represented less than 0.1% of the bacterium's photosynthetic C fixation, increased assimilation during the day and glcH gene upregulation upon glucose enrichment indicate an important role of mixotrophic C assimilation by natural populations of Prochlorococcus. IMPORTANCE Several studies have demonstrated that Prochlorococcus, the most abundant photosynthetic organism on Earth, can assimilate organic molecules, such as amino acids, amino sugars, ATP, phosphonates, and dimethylsulfoniopropionate. This autotroph can also assimilate small amounts of glucose, supporting the hypothesis that Prochlorococcus is mixotrophic. Our results show, for the first time, a diel variability in glucose assimilation by natural populations of Prochlorococcus with maximum assimilation during midday. Based on our previous results, this indicates that Prochlorococcus could maximize glucose uptake by using ATP made during the light reactions of photosynthesis. Furthermore, Prochlorococcus showed a different timing of glucose assimilation from the total population, which may offer considerable fitness advantages over competitors "temporal niches." Finally, we observed transcriptional changes in some of the genes involved in carbon metabolism, suggesting that Prochlorococcus can use both pathways previously proposed in cyanobacteria to metabolize glucose.
| S-EPMC9602893 | biostudies-literature
Project description:Differential timing for glucose assimilation in Prochlorococcus and coexistent microbial populations at the North Pacific Subtropical Gyre
| PRJNA646748 | ENA
Project description:Prochlorococcus is found throughout the euphotic zone in the oligotrophic open ocean. Deep mixing and sinking in aggregates or while attached to particles can, however, transport cells below this sunlit zone, depriving them of light for extended periods of time and influencing their circulation via ocean currents. Viability of these cells over extended periods of darkness could shape the ecology and evolution of the Prochlorococcus collective. We have shown that when co-cultured with a heterotrophic microbe and subjected to repeated periods of extended darkness, Prochlorococcus cells develop a heritable dark-tolerant phenotype – through an apparent epigenetic mechanism – such that they survive longer periods of darkness. Here we examine this adaptation at the level of physiology and metabolism in co-cultures of dark-tolerant and parent strains of Prochlorococcus, each grown with the heterotroph Alteromonas under diel light:dark conditions. The relative abundance of Alteromonas is higher in dark-tolerant than parental co-cultures, while dark tolerant Prochlorococcus cells are also larger, contain less chlorophyll, and are less synchronized to the light:dark cycle. Meta-transcriptome analysis of the cultures further suggests that dark-tolerant co-cultures undergo a coupled shift in which Prochlorococcus uses more organic carbon and less photosynthesis, and Alteromonas uses more organic acids and fewer sugars. Collectively, the data suggest that dark adaptation involves a loosening of the coupling between Prochlorococcus metabolism and the light:dark cycle and a strengthening of the coupling between the carbon metabolism of Prochlorococcus and Alteromonas.
2024-04-23 | GSE264347 | GEO
Project description:For this manuscript, the Prochlorococcus MED4 strain shotgun proteome dataset was used for benchmarking a de novo-directed sequencing approach. De novo peptide sequencing, where the sequence of amino acids is determined directly from mass spectra rather than by comparison (or peptide spectrum matching) to a selected database. We perform a benchmarking experiment using Prochlorococcus culture data, demonstrating de novo peptides are sufficiently accurate and taxonomically specific to be useful in environmental studies. The MED4 dataset herein represents the output from peptide spectrum matching using COMET within the transproteomic pipeline (TPP). Additional MED4 data outside this manuscript are included for both trypsin and Glu-C protease digestions as well as TPP output for post-translational modification searches. De novo output data derived from Peaks Studio can be found by referencing the manuscript publication.
2022-01-06 | PXD027589 | Pride
Project description:Theoretical studies predict that competition for limited resources reduces biodiversity to the point of ecological instability, whereas strong predator/prey interactions enhance the number of coexisting species and limit fluctuations in abundances. In open ocean ecosystems, competition for low availability of essential nutrients results in relatively few abundant microbial species. The remarkable stability in overall cell abundance of the dominant photosynthetic cyanobacterium Prochlorococcus is assumed to reflect a simple food web structure strongly controlled by grazers and/or viruses. This hypothesized link between stability and ecological interactions, however, has been difficult to test with open ocean microbes because sampling methods commonly have poor temporal and spatial resolution. Here we use continuous techniques on two different winter-time cruises to show that Prochlorococcus cell production and mortality rates are tightly synchronized to the day/night cycle across the subtropical Pacific Ocean. In warmer waters, we observed harmonic oscillations in cell production and mortality rates, with a peak in mortality rate consistently occurring ∼6 h after the peak in cell production. Essentially no cell mortality was observed during daylight. Our results are best explained as a synchronized two-component trophic interaction with the per-capita rates of Prochlorococcus consumption driven either directly by the day/night cycle or indirectly by Prochlorococcus cell production. Light-driven synchrony of food web dynamics in which most of the newly produced Prochlorococcus cells are consumed each night likely enforces ecosystem stability across vast expanses of the open ocean.
| S-EPMC4491802 | biostudies-literature
Project description:We report the full transcriptome of T4-like cyanophage P-HM2 infecting Prochlorococcus in light and dark
2016-03-18 | GSE79359 | GEO
Project description:Dimethylsulfoniopropionate (DMSP) is an organic sulfur compound that is rapidly metabolized by marine bacteria either by cleavage to dimethylsulfide (DMS) or demethylation to 3-methiolpropionate. The abundance and diversity of genes encoding bacterial DMS production (dddP) and demethylation (dmdA) were measured in the North Pacific subtropical gyre (NPSG) between May 2008 and February 2009 at Station ALOHA (22°45'N, 158°00'W) at two depths: 25 m and the deep chlorophyll maximum (DCM; ?100 m). The highest abundance of dmdA genes was in May 2008 at 25 m, with ?16.5% of cells harboring a gene in one of the eight subclades surveyed, while the highest abundance of dddP genes was in July 2008 at 25 m, with ?2% of cells harboring a gene. The dmdA gene pool was consistently dominated by homologs from SAR11 subclades, which was supported by findings in metagenomic data sets derived from Station ALOHA. Expression of the SAR11 dmdA genes was low, with typical transcript:gene ratios between 1:350 and 1:1,400. The abundance of DMSP genes was statistically different between 25 m and the DCM and correlated with a number of environmental variables, including primary production, photosynthetically active radiation, particulate DMSP, and DMS concentrations. At 25 m, dddP abundance was positively correlated with pigments that are diagnostic of diatoms; at the DCM, dmdA abundance was positively correlated with temperature. Based on gene abundance, we hypothesize that SAR11 bacterioplankton dominate DMSP cycling in the oligotrophic NPSG, with lesser but consistent involvement of other members of the bacterioplankton community.
| S-EPMC3318810 | biostudies-other
Project description:Examining the impact of short term exposure to HDPE and PVC plastic leachates on gene transcription in Prochlorococcus cultures in vitro
2018-12-01 | GSE118155 | GEO
Project description:Diverse organisms within the marine microbial communities show 24-hour cycles of gene expression, likely driven by the need to harness energy from sunlight and to cope with dramatic fluctuations in solar radiation over the course of the day. Metabolites are the direct product of metabolic activity; they are therefore expected to both reflect and influence the daily cycle of the microbial community. Here we measure the intracellular metabolome of the microbial community of the North Pacific Subtropical Gyre, sampled at 4-hour intervals for 8 days. Concentrations of some metabolites common to many organisms exhibit diel periodicity, revealing synchrony of community-level metabolism. Comparing these data to gene expression data reveals temporal offsets between gene transcription and cellular activity, and ties some metabolites to the activities of specific organisms. For example, the dramatic fluctuations of the disaccharide trehalose likely reflect the daily cycles of {Crocosphaera}, a photosynthesizing cyanobacteria that needs to store energy during the day to fuel nighttime nitrogen-fixation. This study illustrates how pairing multiple types of 'omics and environmental data can provide insight into how the activities of individual organisms lead to community functions such as net primary productivity and nitrogen fixation.
2020-03-23 | ST001356 | MetabolomicsWorkbench
Project description:Prochlorococcus is an obligate marine microorganism which are dominant autotroph in tropical and subtropical central oceans. However, what is the low salinity boundary and how Prochlorococcus would response to low salinity exposure is still unknown. In this study, we first tested the growing salinity range of two Prochlorococcus strains, NATL1A and MED4, and then compared the global transcriptome of their low salinity acclimated cells and cells growing in normal seawater salinity. We found that MED4 could be acclimated in the lowest salinity of 25% and NATL1A could be acclimated in the lowest salinity of 28%. Measurement of the effective quantum yield of PSII photochemistry (Fv/Fm) indicated that both strains were stressed when growing in salinity lower than 34%. The transcriptomic response of NATL1A and MED4 were approximately different, with much more genes having changed transcript abundance in NATL1A than in MED4. To cope with low salinity, NATL1A downregulated the transcript of most genes involved in translation, ribosomal structure and biogenesis, while MED4 upregulated those genes. Moreover, low salinity acclimated NATL1A cells suppressed ATP-producing genes and induced the expression of photosynthesis related genes, while low salinity acclimated MED4 upregulated ATP-producing genes and downregulated photosynthesis related genes. These results indicate that the response to low salinity stress of different Prochlorococcus strains could be distinct. The study provided the first glimpse into the growing salinity range of Prochlorococcus cells and their global gene expression changes due to low salinity stress.
2022-02-02 | GSE195946 | GEO