Improvement of Nannochloropsis oceanica growth performance through chemical mutation and characterization of fast growth physiology by transcriptome profiling

• Published in: Chinese journal of oceanology and limnology Vol. 35; no. 4; pp. 792 - 802
• Main Author: 梁思杰 郭栗 林根妹 张忠义 丁海燕 王亚梅 杨官品
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.07.2017; Springer Nature B.V
• Subjects: Amino acids; Anatomy & physiology; Asexual reproduction; biochemical pathways; Biology; Cell culture; Cell cycle; Cell density; Construction; Construction equipment; Construction industry; Density; developmental stages; Division; Earth and Environmental Science; Earth Sciences; Fatty acids; Gene expression; Genes; genetic improvement; Growth; growth performance; Machinery; Machinery and equipment; Metabolic networks; Metabolism; microalgae; monoploidy; mutants; Mutation; N-Methyl-N'-nitro-N-nitrosoguanidine; Nannochloropsis; Networks; Nuclei; Nucleus; Oceanography; Photosynthesis; Physiology; Polyunsaturated fatty acids; Profiling; Reproduction (biology); Ribosomes; Sugar; sugars; Transcription; transcriptomics; Well construction; 化学诱变; 基因表达谱; 多不饱和脂肪酸; 微绿球藻; 快速生长; 氨基酸代谢; 生理特性; 生长性能; mutation; cell cycle; transcriptome
• ISSN: 0254-4059; 2096-5508; 1993-5005; 2523-3521
• DOI: 10.1007/s00343-017-6023-7

Nannochloropsis oceanica promises to be an industrial-level producer of polyunsaturated fatty acids. In this study, the fastest and slowest growing N. oceanica mutants were selected through N-methyl-N＇-nitro-N-nitrosoguanidine mutation, and two mutant strains and the wild type （WT） subjected to transcriptome profiling. It was found that the 0D680 reads at stationary growth phase of both WT and its mutants were proportional to their cell density, thus indicating their division rate and growth speed during culture. This chemical mutation was effective for improving growth performance, and the fast strain divided faster by upregulating the expression of genes functioning in the cell cycle and downregulating genes involved in synthesis of amino acids, fatty acids, and sugars as well as the construction of ribosome and photosynthetic machinery. However, the relationship among the effected genes responsible for cell cycle, metabolism of fatty and amino acids, and construction of ribosome and photosynthetic machinery remained unclear. Further genetic studies are required for clarifying the genetic/metabolic networks underpinning the growth performance ofN. oceanica. These findings demonstrated that this mutation strategy was effective for improving the growth performance of this species and explored a means ofmicroalgal genetic improvement, particularly in species possessing a monoploid nucleus and asexual reproduction.