TY  - JOUR
AB  - Background

Oleaginous microalgae are promising production hosts for the sustainable generation of lipid-based bioproducts and as bioenergy carriers such as biodiesel. Transcriptomics of the lipid accumulation phase, triggered efficiently by nitrogen starvation, is a valuable approach for the identification of gene targets for metabolic engineering.
Results

An explorative analysis of the detailed transcriptional response to different stages of nitrogen availability was performed in the oleaginous green alga Monoraphidium neglectum. Transcript data were correlated with metabolic data for cellular contents of starch and of different lipid fractions. A pronounced transcriptional down-regulation of photosynthesis became apparent in response to nitrogen starvation, whereas glucose catabolism was found to be up-regulated. An in-depth reconstruction and analysis of the pathways for glycerolipid, central carbon, and starch metabolism revealed that distinct transcriptional changes were generally found only for specific steps within a metabolic pathway. In addition to pathway analyses, the transcript data were also used to refine the current genome annotation. The transcriptome data were integrated into a database and complemented with data for other microalgae which were also subjected to nitrogen starvation. It is available at https://tdbmn.cebitec.uni-bielefeld.de.
Conclusions

Based on the transcriptional responses to different stages of nitrogen availability, a model for triacylglycerol and lipid hyperaccumulation is proposed, which involves transcriptional induction of thioesterases, differential regulation of lipases, and a re-routing of the central carbon metabolism. Over-expression of distinct thioesterases was identified to be a potential strategy to increase the oleaginous phenotype of M. neglectum, and furthermore specific lipases were identified as potential targets for future metabolic engineering approaches.
DA  - 2017
DO  - 10.1186/s13068-017-0882-1
KW  - Monoraphidium neglectum
KW  - mRNA-seq
KW  - Biodiesel
KW  - Lipid metabolism
KW  - Nitrogen starvation
KW  - TAG accumulation
KW  - Pathway analysis
KW  - Fatty acid
KW  - Lipase
KW  - Central carbon metabolism
LA  - eng
IS  - 1
PY  - 2017
SN  - 1754-6834
T2  - Biotechnology for Biofuels
TI  - Time-resolved transcriptome analysis and lipid pathway reconstruction of the oleaginous green microalga Monoraphidium neglectum reveal a model for triacylglycerol and lipid hyperaccumulation
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-29133863
Y2  - 2024-11-22T07:35:10
ER  -