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HighlightsEMS and UV mutagenesis of Nannochloropsis salina combined with FACS for mutant enrichment.Productivity of EMS mutants increased by 76% and showed range of FA profile changes.Dual EMS and UV mutants accumulated 3 fold more lipid than the wild type.Elevation in lipid content comes with a cost to growth rate impacting productivity.Mutants suitable for divergent industries generated (biofuel, high value PUFA production).

The Coccolithoviridae are a group of viruses which infect the marine coccolithophorid microalga Emiliania huxleyi. The Emiliania huxleyi viruses (known as EhVs) described herein have 160-to 180-nm diameter icosahedral structures, have genomes of approximately 400 kbp, and consist of more than 450 predicted coding sequences (CDSs). Here, we describe the genomic features of four newly sequenced coccolithoviruses (EhV-88, EhV-201, EhV-207, and EhV-208) together with their draft genome sequences and their annotations, highlighting the homology and heterogeneity of these genomes to the EhV-86 model reference genome.T he coccolithoviruses infect Emiliania huxleyi, a globally distributed bloom-forming marine microalga. The abundance of Emiliania huxleyi viruses (EhVs) in natural seawater can typically reach 10 7 ml Ϫ1 in bloom conditions and 10 8 to 10 9 ml Ϫ1 under laboratory culture (6). Following the full sequencing of the model virus EhV-86 (isolated in 1999 from the English Channel) and the partial sequencing of EhV-163 (isolated from a Norwegian fjord the following year), we have recently undertaken to sequence the remaining English Channel isolates currently contained within the Plymouth Virus Collection (PVC) (1). The draft genomes of EhV-84, EhV-203, and EhV-202 have been described previously (4, 5). Here, we present the draft genomes of the remaining four coccolithoviruses in the PVC: EhV-88, EhV-201, EhV-207, and EhV-208.EhV-88 was isolated from the English Channel (50°15=N/ 04°13=W) from a depth of 5 m in 1999, while were isolated from the English Channel (49°56=N/ 04°19=W, 50°15=N/04°13=W, and 50°15=N/04°13=W, respectively) from a depth of 2 to 15 m in 2001 (1, 8). Their icosahedral virion structure and morphology are similar to those of other coccolithoviruses and of phycodnaviruses in general (9). Phylogenetic analysis of available major capsid protein (MCP) and DNA pol gene sequences indicates that the closest relatives to EhV-88 are EhV-84 and EhV-86 (4, 7), while EhV-201, EhV-207, and EhV-208 are closely related to 8).Genome sequencing, finishing, and annotation were performed by the Broad Institute. The genomes were sequenced using the 454 FLX pyrosequencing technology platform (Roche/454, Branford, CT). Library construction and sequencing were performed as previously described (2). General protocols for library construction can be found at http://www.broadinstitute.org /annotation/viral/Phage/Protocols.html. De novo genome assembly of resulting reads was performed using the Newbler v2.3 assembly software package (2). A total of 74,782, 78,268, 33,894, and 85,422 reads were produced and assembled into 8,7, 16, and 17 contigs, comprising 396,598 bp, 406,701 bp, 420,391 bp, and 409,403 bp,, respectively. Genes were identified using the Broad Institute's Automated Phage Annotation Protocol (2). Additional gene prediction analysis and functional annotation was performed within the Integrated Microbial Genomes-Expert Review (IMG-ER) platform (3).General features of the genomes include nucleotide compo...

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The Coccolithoviridae is a recently discovered group of viruses that infect the marine coccolithophorid Emiliania huxleyi. Emiliania huxleyi virus 84 (EhV-84) has a 160 -180 nm diameter icosahedral structure and a genome of approximately 400 kbp. Here we describe the structural and genomic features of this virus, together with a near complete draft genome sequence (~99%) and its annotation. This is the fourth genome sequence of a member of the coccolithovirus family.

We evaluate the effects of nutrient limitation on cellular composition of polar lipid classes/species in Chlorella sp. using modern polar lipidomic profiling methods (liquid chromatography–tandem mass spectrometry; LC-MS/MS). Total polar lipid concentration was highest in nutrient-replete (HN) cultures with a significant reduction in monogalactosyldiacylglycerol (MGDG), phosphatidylglycerol (PG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE) class concentrations for nutrient-deplete (LN) cultures. Moreover, reductions in the abundance of MGDG relative to total polar lipids versus an increase in the relative abundance of digalactosyldiacylglycerol (DGDG) were recorded in LN cultures. In HN cultures, polar lipid species composition remained relatively constant throughout culture with high degrees of unsaturation associated with acyl moieties. Conversely, in LN cultures lipid species composition shifted towards greater saturation of acyl moieties. Multivariate analyses revealed that changes in the abundance of a number of species contributed to the dissimilarity between LN and HN cultures but with dominant effects from certain species, e.g., reduction in MGDG 34:7 (18:3/16:4). Results demonstrate that Chlorella sp. significantly alters its polar lipidome in response to nutrient limitation, and this is discussed in terms of physiological significance and polar lipids production for applied microalgal production systems.