Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, PR China.
Bioresour Technol. 2017 Dec;245(Pt B):1484-1490. doi: 10.1016/j.biortech.2017.06.035. Epub 2017 Jun 9.
The aim of this study was to improve biomass production of the green microalga Chlamydomonas sp. JSC4 under high salinity conditions. For this purpose, heavy ion beam-coupled mutagenesis and evolutionary engineering were performed using JSC4 as the parent strain. After long-term and continuous cultivation with high salinity, salt-resistant strains that grow well even in the presence of 7% sea salt were successfully obtained. Transcriptional analysis revealed inactivation of starch-to-lipid biosynthesis switching, which resulted in delayed starch degradation and decreased lipid content in the salt-resistant strains. Cellular aggregation and hypertrophy during high salinity were relieved in these strains, indicating strong resistance to salt stress. These results suggest that high salinity stress, not the salinity condition itself, is important for activating lipid accumulation mechanisms in microalgae.
本研究旨在提高绿藻 Chlamydomonas sp. JSC4 在高盐条件下的生物质产量。为此，使用 JSC4 作为亲本菌株进行了重离子束诱变和进化工程。经过长期连续的高盐培养，成功获得了即使在 7%海水盐存在下也能良好生长的耐盐菌株。转录分析表明，淀粉到脂质生物合成转换的失活导致耐盐菌株中淀粉降解延迟和脂质含量降低。在这些菌株中，高盐时的细胞聚集和肥大得到缓解，表明对盐胁迫有很强的抗性。这些结果表明，高盐胁迫而不是盐度条件本身对于激活微藻中的脂质积累机制很重要。
