Transcriptomic analysis of a moderately growing subisolate Botryococcus braunii 779 (Chlorophyta) in response to nitrogen deprivation
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ABSTRACT:
ORGANISM(S): Botryococcus braunii
PROVIDER: GSE71296 | GEO | 2015/08/03
REPOSITORIES: GEO
Similar Datasets
Project description:We report the transcriptomic response of a moderately growing subisolate from the culture of Botryococcus sp. CCALA-779 upon nitrogen deprivation (ND). Examination of transcriptomes upon nitrogen deprivation (ND). B.braunii_non_redundant_transcriptome_assembly_61220.fasta: non-redundant assembly (with 61220 in number) of B.braunii 779 transcriptome in this study B.braunii_annotated_12292.fasta: investigated ESTs (with 12292 in number, which perfectly matches with our processed RNA expression profiling) in this study
2015-08-03 | E-GEOD-71296 | biostudies-arrayexpress
Project description:Oleaginous microalgae Nannochloropsis spp. are considered to be promissing species for production of biofuels and biomaterials. Nevertheless, its biofuel production remains to be economically unviable. Hence, further improvement of cultivation conditions and genetic traits for high-lipid contents without affecting growth is required. To understand genes involved in neutral lipid accumulation upon nitrogen deprivation (ND) in a novel isolate of Nannochloropsis sp. PJ12, we performed comparative transcriptomic and lipidomic analyses of cells under ND and NR (nitrogen replete) conditions. Transcriptomic profiling indicated that, while enzymes involved in TCA cycle in PJ12 under ND condition were upregulated compared to that under NR condition, those involved in Calvin cycle and glycolysis under ND condition were downregulated, consistent with the observation that quantum yield was reduced under ND condition. Furthermore, we showed that enzymes involved in fatty acid synthesis and glycerolipid synthesis were downregulated but not b-oxidation. Lipidomic profiling indicated that, while the level of neutral lipids in ND cells was increased compared to that of NR cells, level of photosynthetic membrane-lipids DGDG and MGDG was decreased. Taken together, our analysis indicated that TAG accumulation is attributed to the modification of membrane lipids derived primarily from “prokaryotic” pathway and secondarily from “eukaryotic” pathway based on the 16:X or 18:X fatty acid at the sn2 position of the glycerol backbone. We propose that two-phase (NR-ND) growth is ideal for biomass and biofuel production because ND reduces cell growth rate due to the loss of photosynthetic membrane and decreased quantum yield.
2019-03-20 | GSE118760 | GEO
Project description:As global temperatures climb to historic highs, the far-reaching effects of climate change have impacted agricultural nutrient availability. This has extended to low latitude oceans, where a deficit in both nitrogen and phosphorus stores has led to dramatic decreases in carbon sequestration in oceanic phytoplankton. Although Chlamydomonas reinhardtii, a freshwater model green alga, has shown drastic systems-level alterations following nitrogen deprivation, the mechanism(s) through which these alterations are triggered and regulated are unclear. This study examined the role of reversible oxidative signaling in the nitrogen stress response of C. reinhardtii. Using oxidized cysteine resin-assisted capture enrichment coupled with label-free quantitative proteomics, 7,889 unique oxidized cysteine thiol identifiers were quantified, with 231 significantly changing peptides from 184 proteins following 2 h of nitrogen deprivation. These results demonstrate proteins affected by oxidation involved in nitrogen assimilation, amino acid metabolism, photosynthesis, and other metabolic processes. An enhanced role of non-damaging oxidative pathways is observed throughout the photosynthetic apparatus that provides a framework for further analysis in phototrophs.
2020-06-28 | PXD019491 | Pride
Project description:Here, we report the transcriptome of Anabaena sp. strain 7120, a cyanobacterium that forms specialized nitrogen-fixing cells called heterocysts. Our data suggests that cyanobacteria frequently have more complex transcripts than thought, with large 5' UTRs, numerous antisense transcripts, and multiple transcriptional start sites or processing sites.
2011-06-22 | GSE26633 | GEO
Project description:BackgroundThe colonial microalga Botryococcus braunii has been brought to people's attention for its conspicuous ability to accumulate a variety of lipids including hydrocarbons. B. braunii strains are classified into 3 races based on the types of hydrocarbons. A and B races are known to accumulate high level of lipids. However, their extreme slow growth rate has impeded its application for renewable biofuel production.ResultsIn this study, we report the transcriptomic response of a moderately growing subisolate from the culture of Botryococcus sp. CCALA-779 upon nitrogen deprivation (ND). We show that the subisolate has an average growth rate of 0.52 g l(-1) day(-1) under photoautotrophic growth conditions and lipid content is enhanced to 75 % of CDW upon ND. Both rDNA sequence and hydrocarbon composition analyses indicate that the subisolate belongs to A race B. braunii. Hence, it is designated as B. braunii 779. We show that B. braunii 779 transcriptome shares homology to majority of the A race but not B race B. braunii ESTs, suggesting that transcriptomes of A race differ from that of B race. We found that many homologous ESTs between A races 779 and Bot-88 are unknown sequences, implying that A race contains many unknown genes. Pathway-based transcriptomic analysis indicates that energy metabolisms are among the top expressed functions in log-phase cells, indicating that the slow growth rate is a result that energy flow is directed to lipid biosynthesis but not population growth. Upon ND, reconfiguration of metabolisms for reducing power is apparent, suggesting that B. braunii 779 is rapidly adapting under ND condition by transcriptomic reprogramming.ConclusionsTaken together, our result shows that the subisolate B. braunii 779, similar to the Gottingen strain, is useful for biofuel production. Difference between transcriptomes of A and B races implies that different races of B. braunii strains belong to different sub-species. Furthermore, there are many novel genes that are unique to A race, suggesting that sequences of many enzymes involved in hydrocarbon biosynthesis are not currently known. We propose that B. braunii transcriptomes provide a rich source for discovery of novel genes involved in hydrocarbon biosynthesis.
| S-EPMC4552190 | biostudies-literature
Project description:Varying levels of nitrogen deprivation can improve lipid accumulation differently in microalgae, whose underlying regulations are unknown. To investigate the related mechanisms, Auxenochlorella pyrenoidosa was exposed to 1.5, 1, 0.5 and 0 g/L sodium nitrate (NaNO3) for 5 days and RNA-seq were detected.
2023-06-06 | GSE233967 | GEO
Project description:To examine the mechanisms during oil production and integrate analysis of lactylation in N. oceanica, protein expression profiles were tracked after nitrogen deprivation for three days using 4D label-free proteome method. Under nitrogen deprivation (ND) and nitrogen repletion (NR) cultivation conditions, we mapped proteome of proliferating microalgal cells.
2024-07-03 | PXD038833 | Pride
Project description:Drastic alteration in macronutrients causes large changes in gene expression in the photosynthetic unicellular alga Chlamydomonas reinhardtii. Preliminary data suggested that cells follow a biphasic response to this change hinging on the initiation of lipid accumulation, and we hypothesized that drastic repatterning of metabolism also followed this biphasic modality. To test this hypothesis, transcriptomic, proteomic, and metabolite changes that occur under nitrogen (N) deprivation were analyzed. Eight sampling times were selected covering the progressive slowing of growth and induction of oil synthesis between 4 and 6 h after N deprivation. Results of the combined, systems-level investigation indicated that C. reinhardtii cells sense and respond on a large scale within 30 min to a switch to N-deprived conditions turning on a largely gluconeogenic metabolic state, which then transitions to a glycolytic stage between 4 and 6 h after N depletion. This nitrogen-sensing system is transduced to carbon- and nitrogen-responsive pathways, leading to down-regulation of carbon assimilation and chlorophyll biosynthesis, and an increase in nitrogen metabolism and lipid biosynthesis. For example, the expression of nearly all the enzymes for assimilating nitrogen from ammonium, nitrate, nitrite, urea, formamide/acetamide, purines, pyrimidines, polyamines, amino acids and proteins increased significantly. Although arginine biosynthesis enzymes were also rapidly up-regulated, arginine pool size changes and isotopic labeling results indicated no increased flux through this pathway.
2015-06-17 | PXD002377 | Pride
Project description:Here, we report the transcriptome of Anabaena sp. strain 7120, a cyanobacterium that forms specialized nitrogen-fixing cells called heterocysts. Our data suggests that cyanobacteria frequently have more complex transcripts than thought, with large 5' UTRs, numerous antisense transcripts, and multiple transcriptional start sites or processing sites. Four samples of total filament RNA were sequenced with Illumina 40bp reads using directional RNA sequencing (see the Illumina small RNA prep protocol). The samples are 0hr (vegetative cells grown in the presence of ammonia) and 6hr, 12hr, and 21hr cells (after nitrogen step down).
2011-06-22 | E-GEOD-26633 | biostudies-arrayexpress
Project description:Transcriptome reprogramming of Nannochloropsis oceanica in response to Nitrogen deprivation
| PRJNA933693 | ENA