Effect of pH on growth and carbon metabolism of maltose-releasing Chlorella (Chlorophyta)
Effect of pH on growth and carbon metabolism of maltose-releasing Chlorella (Chlorophyta)
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pH 对释放麦芽糖小球藻 (Chlorophyta) 生长和碳代谢的影响
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
H. Hodge
中科院分区：
文献类型：
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作者：
M. Dorling;P. McAuley;H. Hodge
比较了低pH对与法氏草履虫共生分离的两株小球藻生长和光合作用的影响。一种是3N813A，在低pH下释放大量麦芽糖；另一种是NC64A，在培养中不释放麦芽糖。低pH下的麦芽糖合成似乎比pH本身对细胞生长的影响更大。释放麦芽糖的3N813A的生长与pH有直接关系；不释放麦芽糖的NC64A仅在pH从7.0降至5.5时生长减慢。在pH 5.0时，3N813A细胞的净光合能力下降到pH 7.0时的76%，但特定生长常数(k)下降到22%，在pH 4.0时，细胞的生长和硝酸盐吸收受到抑制。在pH为5.0的3N813A细胞中，碳(C)从细胞生长、净叶绿素合成、氮(N)同化、蛋白质和淀粉合成转向麦芽糖释放，但C:N比值不变。在NC54A细胞中，pH 5.0抑制淀粉合成，但不抑制蛋白质合成。
The effect of low pH on growth and photosynthesis was compared in two strains of Chlorella isolated from symbiosis with Paramecium bursaria. One, 3N813A, releases large amounts of maltose at low pH; the other, NC64A, does not release maltose in culture. Maltose synthesis at low pH appeared to have a greater effect on cell growth than pH by itself. Growth of maltose-releasing 3N813A showed a direct relationship with pH; growth of non-maltose-releasing NC64A was reduced only as pH fell from 7.0 to 5.5. At pH 5.0, net photosynthetic capacity of 3N813A cells was reduced to 76% of controls at pH 7.0, but the specific growth constant (k) was reduced to 22%, and at pH 4.0 growth and nitrate uptake were inhibited. In 3N813A cells at pH 5.0, carbon (C) was diverted from cell growth, net chlorophyll synthesis, assimilation of nitrogen (N), and synthesis of protein and starch to maltose release, but C:N ratios were unchanged. In NC54A cells, starch but not protein synthesis was inhibited at pH 5.0, and a reduction i...