Project description:In this study, we characterized the fatty acid production in Neochloris aquatica at transcriptomics and biochemical levels under limiting, normal, and excess nitrate concentrations in different growth phases. At the stationary phase, N. aquatica mainly produced saturated fatty acids such as stearic acid under the limiting nitrate concentration, which is suitable for biodiesel production. However, it produced polyunsaturated fatty acids such as α-linolenic acid under the excess nitrate concentration, which has nutritional values as food supplements. In addition, RNA-seq was employed to identify genes and pathways that were being affected in N. aquatica for three growth phases in the presence of the different nitrate amounts. Genes that are responsible for the production of saturated fatty acids were upregulated in the cells grown under a limiting nitrogen amount while genes that are responsible for the production of polyunsaturated fatty acid were upregulated in the cells grown under excess nitrogen amount. Further analysis showed more genes differentially expressed (DEGs) at the loga- rithmic phase in all conditions while a relatively steady trend was observed during the transition from the logarithmic phase to the stationary phase under limiting and excess nitrogen. Our results provide a foundation for identifying developmentally important genes and understanding the biological processes in the different growth phases of the N. aquatica in terms of biomass and lipid production.
Project description:Investigation of whole genome gene expression level changes in Pichia stipitis CBS 6054 grown aerobically in xylose, compared to the same strain grown aerobically in glucose. A six array study using total RNA recovered from three separate cultures of Pichia stipitis CBS 6054 grown in glucose and three separate cultures of Pichia stipitis CBS 6054 grown in xylose. Each array measures the expression level of 374,100 probes (average probe length 53.6 +/- 4.1 nt) tiled across the Pichia stipitis CBS 6054 genome with a median spacing distance of 33 nt. During data processing, probes are filtered to include only those probes corresponding to annotated protein-coding genes.