Active Hydrocarbon Biosynthesis and Accumulation in a Green Alga, Botryococcus braunii (Race A)
Active Hydrocarbon Biosynthesis and Accumulation in a Green Alga, Botryococcus braunii (Race A)
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DOI：
10.1128/ec.00088-13
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发表时间：
2013-08-01
期刊：
影响因子：
--
通讯作者：
Noguchi, Tetsuko
中科院分区：
文献类型：
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作者：
Hirose, Mana;Mukaida, Fukiko;Noguchi, Tetsuko
在产油微藻中，群体绿色藻布氏葡萄球菌（Botryococcus braunii）积累特别大量的烃。这种积累可以通过在细胞外空间而不是在细胞质中储存脂质来实现，就像所有其他检查的含油微藻的情况一样。细胞周期中烃类合成的阶段由放射自显影确定。B的细胞周期。通过氨基尿嘧啶处理使Braunii小种A同步化，在细胞周期的各个阶段取细胞，并在含有[C-14]乙酸盐的培养基中培养。检测到C-14掺入碳氢化合物中。最高的标记发生在隔膜形成后，约为间期的2.6倍。荧光和电子显微镜显示，新的脂质积累在细胞表面发生在至少两个不同的生长阶段和网站的细胞。间期细胞胞质中的脂质体不明显。然后，这些脂质体的数量，大小和夹杂物增加，达到最大值之前的第一个脂质积累在细胞表面上的细胞顶点。其中大多数从细胞质中消失，伴随着第二个新的积累在基底外侧区，细胞外脂质不断积累。B细胞膜附近的粗面内质网明显。braunii，并且在脂体数量增加的细胞中，内质网经常与叶绿体和脂体接触。讨论了A小种胞外烃类前体物质的运输途径。
Among oleaginous microalgae, the colonial green alga Botryococcus braunii accumulates especially large quantities of hydrocarbons. This accumulation may be achieved more by storage of lipids in the extracellular space rather than in the cytoplasm, as is the case for all other examined oleaginous microalgae. The stage of hydrocarbon synthesis during the cell cycle was determined by autoradiography. The cell cycle of B. braunii race A was synchronized by aminouracil treatment, and cells were taken at various stages in the cell cycle and cultured in a medium containing [C-14] acetate. Incorporation of C-14 into hydrocarbons was detected. The highest labeling occurred just after septum formation, when it was about 2.6 times the rate during interphase. Fluorescent and electron microscopy revealed that new lipid accumulation on the cell surface occurred during at least two different growth stages and sites of cells. Lipid bodies in the cytoplasm were not prominent in interphase cells. These lipid bodies then increased in number, size, and inclusions, reaching maximum values just before the first lipid accumulation on the cell surface at the cell apex. Most of them disappeared from the cytoplasm concomitant with the second new accumulation at the basolateral region, where extracellular lipids continuously accumulated. The rough endoplasmic reticulum near the plasma membrane is prominent in B. braunii, and the endoplasmic reticulum was often in contact with both a chloroplast and lipid bodies in cells with increasing numbers of lipid bodies. We discuss the transport pathway of precursors of extracellular hydrocarbons in race A.