A revised mineral nutrient supplement increases biomass and growth rate in Chlamydomonas reinhardtii.
A revised mineral nutrient supplement increases biomass and growth rate in Chlamydomonas reinhardtii.
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DOI：
10.1111/j.1365-313x.2011.04537.x
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发表时间：
2011-06
期刊：
影响因子：
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通讯作者：
Malasarn D
中科院分区：
文献类型：
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作者：
Kropat J;Hong-Hermesdorf A;Casero D;Ent P;Castruita M;Pellegrini M;Merchant SS;Malasarn D
利用藻类作为生物燃料的兴趣，以及无机营养缺乏在诱导细胞中甘油三酯（TAG）积累中的作用，需要一种有效配制易于操作的物种特异性培养基的策略。利用参考生物莱茵衣藻，我们验证了一个假设，即在细胞离子素之后模拟微量元素补充会导致优化的细胞生长。我们测定了几种常用的衣藻菌株在不同培养条件下的痕量金属含量，并开发了一种修订的微量元素溶液来平行这些测量。与传统的微量元素溶液相比，在修改后的补品中生长的细胞显示出更快的生长速度和更高的最大细胞密度。在传统培养基和改良培养基中培养的RNA-seq分析表明，转录组的差异小于在传统Hutner培养基中生长的不同野生型菌株之间的差异。目视观察未发现新补品在细胞运动或交配效率方面的缺陷。CYC6启动子的Ni2+诱导表达仍然是一个有用的工具，尽管由于在修订的培养基中引入了EDTA缓冲系统，对Ni2+的要求增加了。其他优点包括更容易制备微量元素原液，减少化学品的总使用量，更一致的批对批配方和长期稳定性（测试长达5年）。在新的生长机制下，我们分析了在不同宏量和微量营养素缺乏下生长的细胞。氮缺乏条件下TAG积累量与新培养基相当。尼罗红染色显示，缺铁和缺锌也能诱导TAG积累。这种方法可以有效地优化其他藻类物种的培养条件，以提高生长和测定细胞生理。
Interest in exploiting algae as a biofuel source and the role of inorganic nutrient deficiency in inducing triacylglyceride (TAG) accumulation in cells necessitates a strategy to efficiently formulate species-specific culture media that can easily be manipulated. Using the reference organism Chlamydomonas reinhardtii, we tested the hypothesis that modeling trace element supplements after the cellular ionome would result in optimized cell growth. We determined the trace metal content of several commonly used Chlamydomonas strains in various culture conditions and developed a revised trace element solution to parallel these measurements. Comparison of cells growing in the revised supplement versus a traditional trace element solution revealed faster growth rates and higher maximum cell densities with the revised recipe. RNA-seq analysis of cultures growing in the traditional versus revised medium suggest that the variation in transcriptomes was smaller than that found between different wild-type strains grown in traditional Hutner’s supplement. Visual observation did not reveal defects in cell motility or mating efficiency in the new supplement. Ni2+-inducible expression from the CYC6 promoter remained a useful tool, albeit with an increased requirement for Ni2+ because of the introduction of an EDTA buffer system in the revised medium. Other advantages include more facile preparation of trace element stock solutions, a reduction in total chemical use, a more consistent batch-to-batch formulation, and long-term stability (tested up to 5 years). Under the new growth regime, we analyzed cells growing under different macro- and micronutrient-deficiencies. TAG accumulation in N deficiency is comparable in the new medium. Fe and Zn deficiency also induced TAG accumulation, as suggested by Nile Red staining. This approach can be used to efficiently optimize culture conditions for other algal species to improve growth and to assay cell physiology.