Highlights
- Maximum lipid content and productivity were 62 % and 85.9 mg L−1d−1, respectively.
- Controlled acidification altered gene expression during nitrogen depletion.
- Up-regulation of genes in energy metabolism was observed in the conditions studied.
- Down-regulation of lipid degradation and carbohydrate synthesis was observed.
- ANIm analysis confirmed the identity of Scenedesmus obtusiusculus AT-UAM.
Abstract
Scenedesmus obtusiusculus AT-UAM was able to accumulate up to 62 % of lipids when controlled acidification was applied to a nitrogen-deplete culture. Under these conditions, up-regulation of genes related to lipid synthesis and central carbon metabolism (glycolysis, the tricarboxylic acid cycle, and the pentose phosphate pathway) was recorded. Additionally, genes related to photosynthesis were up-regulated in the nitrogen depletion and nitrogen depletion with controlled acidification conditions with respect to the control samples analyzed under nutritional sufficiency. The Pyani program was used to establish pairwise ANI values between reported and annotated NCBI genomes to uphold genomics similarity. ANI analysis confirms the previously observed identity of S. obtusiusculus AT-UAM with the 18S rRNA and ITS2 regions, and also provides a solid framework for understanding the genetic stability and lineage of the strain. Results obtained are encouraging for integrating biofuel production processes and carbon capture technologies. Specifically, the up-regulation of genes related to both lipid synthesis and photosynthesis under controlled conditions indicates the potential of S. obtusiusculus AT-UAM for efficient biofuel production while simultaneously sequestering carbon. These biochemical properties make this strain a promising candidate for sustainable energy solutions and environmental mitigation strategies.
Estrada-Graf A. A., Sigala J.-C., Sánchez-Pérez M. & Morales-Ibarría M., 2024. Induction of lipid production through controlled acidification: a transcriptional insight into the metabolism of Scenedesmus obtusiusculus AT-UAM. Process Biochemistry 147: 175-185. Article (subscription required).
