ABSTRACT: Transcriptome analysis of Oleaginous microalgae from the Peruvian Amazon of the genus Ankistrodesmus, Chlorella, and Scenedesmus Transcriptome
Project description:We demonstrate that low-dose ionizing radiation from X-rays drives metabolic activation in microalgae. We exploited this phenomenon to develop a method for increased lipid yield in stationary phase Chlorella sorokiniana cultures by 25% in just 24 hours, caused by a reproducible metabolic response that includes up-regulation of >30 lipid metabolism genes. This approach avoids the need to modify the strain or cultivation conditions, and does not affect cell viability or biomass.
Project description:The microalga Coccomyxa subellipsoidea C-169 possesses some features that may be valuable for lipid production, and, as demonstrated in this study, can be greatly induced to produce a high amount of fatty acid by CO2 supplementation. Here we have compared the transcriptome of air group (AG, cells cultured under 0.04% CO2) and CO2-supplemented group (CG, cells cultured under 2% CO2), and found that dramatic and collaborative regulation in central metabolic pathways as well as biochemical processes occured in response to CO2 supplementation. This study gains a broad understanding of how CO2 stress regulates gene expression and eventually reveals a fine-tuned strategy adopted by C-169 to sustain rapid cell growth and lipid production, which will be helpful for the implementation of biofuels production from oleaginous microalgae. Transcriptomic profiles of Coccomyxa subellipsoidea C-169 cultured for 4 days under two CO2 levels (0.04% and 2%, v/v) were generated by digital gene expression (DGE) analysis, in triplicate, using Illumina Hiseq2000.
Project description:The microalga Coccomyxa subellipsoidea C-169 possesses some features that may be valuable for lipid production, and, as demonstrated in this study, can be greatly induced to produce a high amount of fatty acid by CO2 supplementation. Here we have compared the transcriptome of air group (AG, cells cultured under 0.04% CO2) and CO2-supplemented group (CG, cells cultured under 2% CO2), and found that dramatic and collaborative regulation in central metabolic pathways as well as biochemical processes occured in response to CO2 supplementation. This study gains a broad understanding of how CO2 stress regulates gene expression and eventually reveals a fine-tuned strategy adopted by C-169 to sustain rapid cell growth and lipid production, which will be helpful for the implementation of biofuels production from oleaginous microalgae.
Project description:Microalgae and cyanobacteria represent an emerging and sustainable source of bioactive compounds for the food, cosmeceutical, and pharmaceutical sectors. In this study, the potential of two microalgae-cyanobacteria consortia, consortium 1 (C1) consisting of Chlorella vulgaris and Arthrospira platensis, and consortium 2 (C2) consisting of Kamptonema sp., Nannochloropsis oculata, Tetraselmis suecica, and Chlorella vulgaris, as a source of bioactive peptides was evaluated. Firstly, protein extraction from both biomasses was optimized by testing different protein solubilization and precipitation pHs, with pH 10 and pH 5 providing the best results in terms of protein recovery in both cases. Selected protein extracts, with protein contents of 28.50 ± 2.69 % (C1) and 8.46 ± 0.45 % (C2), were further hydrolyzed with Alcalase, evaluating the impact of the incubation time on peptide release and the antioxidant capacity of hydrolysates. 1 h of hydrolysis proved to be enough for antioxidant capacity increase. In addition, in silico hydrolysis with Alcalase of the proteins identified in C1 and C2 was evaluated, assessing the potential bioactivity of the peptides produced, more specifically their antioxidant capacity. Our findings demonstrate that both microalgae-cyanobacteria consortia are valuable sources of bioactive compounds with antioxidant capacity, with potential interest as functional ingredients for the food, cosmeceutical, and pharmaceutical industries.