文章基本信息

标题：Contribution of protein synthesis depression to poly-β-hydroxybutyrate accumulation in Synechocystis sp. PCC 6803 under nutrient-starved conditions
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作者：Kazuho Hirai ; Miki Nojo ; Yosuke Sato 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2019
卷号：9
期号：1
页码：1-10
DOI：10.1038/s41598-019-56520-w
出版社：Springer Nature
摘要：Poly-β-hydroxybutyrate (PHB) in cyanobacteria, which accumulates as energy and carbon sources through the action of photosynthesis, is expected to substitute for petroleum-based plastics. This study first demonstrated that PHB accumulation was induced, with the appearance of lipid droplets, in sulfur (S)-starved cells of a cyanobacterium, Synechocystis sp. PCC 6803, however, to a lower level than in nitrogen (N)- or phosphorus (P)-starved cells. Concomitantly found was repression of the accumulation of total cellular proteins in the S-starved cells to a similar level to that in N-starved cells, and a severer level than in P-starved cells. Intriguingly, PHB accumulation was induced in Synechocystis even under nutrient-replete conditions, upon repression of the accumulation of total cellular proteins through treatment of the wild type cells with a protein synthesis inhibitor, chloramphenicol, or through disruption of the argD gene for Arg synthesis. Meanwhile, the expression of the genes for PHB synthesis was hardly induced in S-starved cells, in contrast to their definite up-regulation in N- or P-starved cells. It therefore seemed that PHB accumulation in S-starved cells is achieved through severe repression of protein synthesis, but is smaller than in N- or P-starved cells, owing to little induction of the expression of PHB synthesis genes.