Limits...
Metabolomic Profiling of 13 Diatom Cultures and Their Adaptation to Nitrate-Limited Growth Conditions.

Bromke MA, Sabir JS, Alfassi FA, Hajarah NH, Kabli SA, Al-Malki AL, Ashworth MP, Méret M, Jansen RK, Willmitzer L - PLoS ONE (2015)

Bottom Line: In order to explore the diversity of lipophilic compounds produced by diatoms, we describe the results from an analysis of 13 diatom strains.Furthermore, an increase of triacylglycerol (TAG) accumulation was observed in low nitrogen samples, although this trend was not consistent across all 13 diatom strains.Overall, our results expand the current understanding of metabolomics diversity in diatoms and confirm their potential value for producing lipids for either bioenergy or as feed stock.

View Article: PubMed Central - PubMed

Affiliation: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany.

ABSTRACT
Diatoms are very efficient in their use of available nutrients. Changes in nutrient availability influence the metabolism and the composition of the cell constituents. Since diatoms are valuable candidates to search for oil producing algae, measurements of diatom-produced compounds can be very useful for biotechnology. In order to explore the diversity of lipophilic compounds produced by diatoms, we describe the results from an analysis of 13 diatom strains. With the help of a lipidomics platform, which combines an UPLC separation with a high resolution/high mass accuracy mass spectrometer, we were able to measure and annotate 142 lipid species. Out of these, 32 were present in all 13 cultures. The annotated lipid features belong to six classes of glycerolipids. The data obtained from the measurements were used to create lipidomic profiles. The metabolomic overview of analysed cultures is amended by the measurement of 96 polar compounds. To further increase the lipid diversity and gain insight into metabolomic adaptation to nitrogen limitation, diatoms were cultured in media with high and low concentrations of nitrate. The growth in nitrogen-deplete or nitrogen-replete conditions affects metabolite accumulation but has no major influence on the species-specific metabolomic profile. Thus, the genetic component is stronger in determining metabolic patterns than nitrogen levels. Therefore, lipid profiling is powerful enough to be used as a molecular fingerprint for diatom cultures. Furthermore, an increase of triacylglycerol (TAG) accumulation was observed in low nitrogen samples, although this trend was not consistent across all 13 diatom strains. Overall, our results expand the current understanding of metabolomics diversity in diatoms and confirm their potential value for producing lipids for either bioenergy or as feed stock.

No MeSH data available.


Related in: MedlinePlus

Principal Component Analysis of the lipid profiles of 13 analysed cultures grown in nitrogen-replete conditions based on 142 annotated lipid analytes (32 analytes common for all samples).Each replicate is represented by a coloured abbreviation of the culture name: Ampant, Amphitetras antediluviana; Bidbid, Biddulphia biddulphiana; Cerdea, Cerataulina daemon; Chasim, Chaetoceros simplex; Eunlae, Eunotogramma sp.; Hemsin, Hemiaulus sinensis; Lepdan, Leptocylindrus danicus; Rhiset, Rhizosolenia setigera; Thafra, Thalassionema frauenfeldii; Tp1007, Thalassiosira pseudonana CCMP1007; Tp1335, Thalassiosira pseudonana CCMP 1335; Tw1587, Thalassiosira weissflogii CCMP 1587; Tweiss1336, Thalassiosira weissflogii.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4595471&req=5

pone.0138965.g003: Principal Component Analysis of the lipid profiles of 13 analysed cultures grown in nitrogen-replete conditions based on 142 annotated lipid analytes (32 analytes common for all samples).Each replicate is represented by a coloured abbreviation of the culture name: Ampant, Amphitetras antediluviana; Bidbid, Biddulphia biddulphiana; Cerdea, Cerataulina daemon; Chasim, Chaetoceros simplex; Eunlae, Eunotogramma sp.; Hemsin, Hemiaulus sinensis; Lepdan, Leptocylindrus danicus; Rhiset, Rhizosolenia setigera; Thafra, Thalassionema frauenfeldii; Tp1007, Thalassiosira pseudonana CCMP1007; Tp1335, Thalassiosira pseudonana CCMP 1335; Tw1587, Thalassiosira weissflogii CCMP 1587; Tweiss1336, Thalassiosira weissflogii.

Mentions: In order to obtain further insight into the diversity of the diatom lipids, the data were subjected to a principal component analysis (PCA, Fig 3). Two main conclusions were apparent: first, all 13 diatom strains could be separated from each other in a non-supervised fashion, clearly proving the diversity and species specificity of the lipid profiles; second, all five biological replicates of each species clustered together supporting the statistical relevance of our findings and the reproducibility of the culture conditions. The analysed data set contained profiles of 142 annotated analytes. The first two principal components accounted for more than 83% of the variance (Fig 3). The compound with the strongest influence on resolution was PC 40:6, being on extremes of principal component 1 and 2. This lipid compound was detected only in extracts of T. pseudonana CCMP1007, T. weissflogii CCMP1336, T. weissflogii CCMP1587, and Leptocylindrus danicus. All T. pseudonana profiles clustered very closely, and the two isolates CCMP1335 and CCMP1007 of T. pseudonana were not well discriminated. This was also evident in the heatmap (Fig 1), where we used a colour scale for visualization of individual data points in lipid profiles. The hierarchical clustering analysis applied to profiles of the other pair of related isolates of T. weissflogii showed a surprising difference. In consequence, the isolate T. weissflogii CCMP1336 seemed to be more similar to T. pseudonana profiles than to the T. weissflogii CCMP1587, which clustered together with C. daemon.


Metabolomic Profiling of 13 Diatom Cultures and Their Adaptation to Nitrate-Limited Growth Conditions.

Bromke MA, Sabir JS, Alfassi FA, Hajarah NH, Kabli SA, Al-Malki AL, Ashworth MP, Méret M, Jansen RK, Willmitzer L - PLoS ONE (2015)

Principal Component Analysis of the lipid profiles of 13 analysed cultures grown in nitrogen-replete conditions based on 142 annotated lipid analytes (32 analytes common for all samples).Each replicate is represented by a coloured abbreviation of the culture name: Ampant, Amphitetras antediluviana; Bidbid, Biddulphia biddulphiana; Cerdea, Cerataulina daemon; Chasim, Chaetoceros simplex; Eunlae, Eunotogramma sp.; Hemsin, Hemiaulus sinensis; Lepdan, Leptocylindrus danicus; Rhiset, Rhizosolenia setigera; Thafra, Thalassionema frauenfeldii; Tp1007, Thalassiosira pseudonana CCMP1007; Tp1335, Thalassiosira pseudonana CCMP 1335; Tw1587, Thalassiosira weissflogii CCMP 1587; Tweiss1336, Thalassiosira weissflogii.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595471&req=5

pone.0138965.g003: Principal Component Analysis of the lipid profiles of 13 analysed cultures grown in nitrogen-replete conditions based on 142 annotated lipid analytes (32 analytes common for all samples).Each replicate is represented by a coloured abbreviation of the culture name: Ampant, Amphitetras antediluviana; Bidbid, Biddulphia biddulphiana; Cerdea, Cerataulina daemon; Chasim, Chaetoceros simplex; Eunlae, Eunotogramma sp.; Hemsin, Hemiaulus sinensis; Lepdan, Leptocylindrus danicus; Rhiset, Rhizosolenia setigera; Thafra, Thalassionema frauenfeldii; Tp1007, Thalassiosira pseudonana CCMP1007; Tp1335, Thalassiosira pseudonana CCMP 1335; Tw1587, Thalassiosira weissflogii CCMP 1587; Tweiss1336, Thalassiosira weissflogii.
Mentions: In order to obtain further insight into the diversity of the diatom lipids, the data were subjected to a principal component analysis (PCA, Fig 3). Two main conclusions were apparent: first, all 13 diatom strains could be separated from each other in a non-supervised fashion, clearly proving the diversity and species specificity of the lipid profiles; second, all five biological replicates of each species clustered together supporting the statistical relevance of our findings and the reproducibility of the culture conditions. The analysed data set contained profiles of 142 annotated analytes. The first two principal components accounted for more than 83% of the variance (Fig 3). The compound with the strongest influence on resolution was PC 40:6, being on extremes of principal component 1 and 2. This lipid compound was detected only in extracts of T. pseudonana CCMP1007, T. weissflogii CCMP1336, T. weissflogii CCMP1587, and Leptocylindrus danicus. All T. pseudonana profiles clustered very closely, and the two isolates CCMP1335 and CCMP1007 of T. pseudonana were not well discriminated. This was also evident in the heatmap (Fig 1), where we used a colour scale for visualization of individual data points in lipid profiles. The hierarchical clustering analysis applied to profiles of the other pair of related isolates of T. weissflogii showed a surprising difference. In consequence, the isolate T. weissflogii CCMP1336 seemed to be more similar to T. pseudonana profiles than to the T. weissflogii CCMP1587, which clustered together with C. daemon.

Bottom Line: In order to explore the diversity of lipophilic compounds produced by diatoms, we describe the results from an analysis of 13 diatom strains.Furthermore, an increase of triacylglycerol (TAG) accumulation was observed in low nitrogen samples, although this trend was not consistent across all 13 diatom strains.Overall, our results expand the current understanding of metabolomics diversity in diatoms and confirm their potential value for producing lipids for either bioenergy or as feed stock.

View Article: PubMed Central - PubMed

Affiliation: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany.

ABSTRACT
Diatoms are very efficient in their use of available nutrients. Changes in nutrient availability influence the metabolism and the composition of the cell constituents. Since diatoms are valuable candidates to search for oil producing algae, measurements of diatom-produced compounds can be very useful for biotechnology. In order to explore the diversity of lipophilic compounds produced by diatoms, we describe the results from an analysis of 13 diatom strains. With the help of a lipidomics platform, which combines an UPLC separation with a high resolution/high mass accuracy mass spectrometer, we were able to measure and annotate 142 lipid species. Out of these, 32 were present in all 13 cultures. The annotated lipid features belong to six classes of glycerolipids. The data obtained from the measurements were used to create lipidomic profiles. The metabolomic overview of analysed cultures is amended by the measurement of 96 polar compounds. To further increase the lipid diversity and gain insight into metabolomic adaptation to nitrogen limitation, diatoms were cultured in media with high and low concentrations of nitrate. The growth in nitrogen-deplete or nitrogen-replete conditions affects metabolite accumulation but has no major influence on the species-specific metabolomic profile. Thus, the genetic component is stronger in determining metabolic patterns than nitrogen levels. Therefore, lipid profiling is powerful enough to be used as a molecular fingerprint for diatom cultures. Furthermore, an increase of triacylglycerol (TAG) accumulation was observed in low nitrogen samples, although this trend was not consistent across all 13 diatom strains. Overall, our results expand the current understanding of metabolomics diversity in diatoms and confirm their potential value for producing lipids for either bioenergy or as feed stock.

No MeSH data available.


Related in: MedlinePlus