Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production
Open Access
- 28 December 2013
- journal article
- Published by Springer Science and Business Media LLC in BMC Genomics
- Vol. 14 (1), 926
- https://doi.org/10.1186/1471-2164-14-926
Abstract
Microalgae are gaining importance as sustainable production hosts in the fields of biotechnology and bioenergy. A robust biomass accumulating strain of the genus Monoraphidium (SAG 48.87) was investigated in this work as a potential feedstock for biofuel production. The genome was sequenced, annotated, and key enzymes for triacylglycerol formation were elucidated. Monoraphidium neglectum was identified as an oleaginous species with favourable growth characteristics as well as a high potential for crude oil production, based on neutral lipid contents of approximately 21% (dry weight) under nitrogen starvation, composed of predominantly C18:1 and C16:0 fatty acids. Further characterization revealed growth in a relatively wide pH range and salt concentrations of up to 1.0% NaCl, in which the cells exhibited larger structures. This first full genome sequencing of a member of the Selenastraceae revealed a diploid, approximately 68 Mbp genome with a G + C content of 64.7%. The circular chloroplast genome was assembled to a 135,362 bp single contig, containing 67 protein-coding genes. The assembly of the mitochondrial genome resulted in two contigs with an approximate total size of 94 kb, the largest known mitochondrial genome within algae. 16,761 protein-coding genes were assigned to the nuclear genome. Comparison of gene sets with respect to functional categories revealed a higher gene number assigned to the category “carbohydrate metabolic process” and in “fatty acid biosynthetic process” in M. neglectum when compared to Chlamydomonas reinhardtii and Nannochloropsis gaditana, indicating a higher metabolic diversity for applications in carbohydrate conversions of biotechnological relevance. The genome of M. neglectum, as well as the metabolic reconstruction of crucial lipid pathways, provides new insights into the diversity of the lipid metabolism in microalgae. The results of this work provide a platform to encourage the development of this strain for biotechnological applications and production concepts.This publication has 71 references indexed in Scilit:
- Three Acyltransferases and Nitrogen-responsive Regulator Are Implicated in Nitrogen Starvation-induced Triacylglycerol Accumulation in ChlamydomonasJournal of Biological Chemistry, 2012
- Draft genome sequence and genetic transformation of the oleaginous alga Nannochloropsis gaditanaNature Communications, 2012
- Triacylglycerol profiling of microalgae strains for biofuel feedstock by liquid chromatography–high-resolution mass spectrometryAnalytical and Bioanalytical Chemistry, 2011
- Eukaryotic Gene Prediction Using GeneMark.hmm‐E and GeneMark‐ESCurrent Protocols in Bioinformatics, 2011
- MEGA5: Molecular Evolutionary Genetics Analysis Using Maximum Likelihood, Evolutionary Distance, and Maximum Parsimony MethodsMolecular Biology and Evolution, 2011
- Microalgae for biodiesel production and other applications: A reviewRenewable and Sustainable Energy Reviews, 2010
- Lipid productivity as a key characteristic for choosing algal species for biodiesel productionJournal of Applied Phycology, 2009
- Microalgae for oil: Strain selection, induction of lipid synthesis and outdoor mass cultivation in a low‐cost photobioreactorBiotechnology & Bioengineering, 2008
- RNAmmer: consistent and rapid annotation of ribosomal RNA genesNucleic Acids Research, 2007
- tRNAscan-SE: A Program for Improved Detection of Transfer RNA Genes in Genomic SequenceNucleic Acids Research, 1997