Finkel Zoe V, Follows Mick J, Liefer Justin D, Brown Chris M, Benner Ina, Irwin Andrew J
Environmental Science Program, Mount Allison University, Sackville, New Brunswick, Canada.
Department of Earth, Atmosphere and Planetary Sciences, MIT, Cambridge, MA, United States of America.
PLoS One. 2016 May 26;11(5):e0155977. doi: 10.1371/journal.pone.0155977. eCollection 2016.
The elemental stoichiometry of microalgae reflects their underlying macromolecular composition and influences competitive interactions among species and their role in the food web and biogeochemistry. Here we provide a new estimate of the macromolecular composition of microalgae using a hierarchical Bayesian analysis of data compiled from the literature. The median macromolecular composition of nutrient-sufficient exponentially growing microalgae is 32.2% protein, 17.3% lipid, 15.0% carbohydrate, 17.3% ash, 5.7% RNA, 1.1% chlorophyll-a and 1.0% DNA as percent dry weight. Our analysis identifies significant phylogenetic differences in macromolecular composition undetected by previous studies due to small sample sizes and the large inherent variability in macromolecular pools. The phylogenetic differences in macromolecular composition lead to variations in carbon-to-nitrogen ratios that are consistent with independent observations. These phylogenetic differences in macromolecular and elemental composition reflect adaptations in cellular architecture and biochemistry; specifically in the cell wall, the light harvesting apparatus, and storage pools.
微藻的元素化学计量反映了其潜在的大分子组成，并影响物种间的竞争相互作用及其在食物网和生物地球化学中的作用。在此，我们利用对文献汇编数据进行的分层贝叶斯分析，对微藻的大分子组成进行了新的估算。营养充足、呈指数生长的微藻的大分子组成中位数为：蛋白质占干重的32.2%、脂质占17.3%、碳水化合物占15.0%、灰分占17.3%、RNA占5.7%、叶绿素a占1.1%、DNA占1.0%。我们的分析发现，由于样本量小以及大分子库中固有的巨大变异性，先前研究未检测到大分子组成存在显著的系统发育差异。大分子组成的系统发育差异导致碳氮比的变化，这与独立观察结果一致。大分子和元素组成的这些系统发育差异反映了细胞结构和生物化学方面的适应性；特别是在细胞壁、光捕获装置和储存库方面。
