The Assimilation of Ammonia and Nitrate by Nitrogen-Starved Cells of Chlorella vulgaris. III. Differences of Metabolism Dependent on the Nature of the Nitrogen Source
The Assimilation of Ammonia and Nitrate by Nitrogen-Starved Cells of Chlorella vulgaris. III. Differences of Metabolism Dependent on the Nature of the Nitrogen Source
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普通小球藻的氮饥饿细胞对氨和硝酸盐的同化。
DOI：
10.1111/j.1399-3054.1956.tb08989.x
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发表时间：
1956
影响因子：
6.4
通讯作者：
P. J. Syrett
中科院分区：
文献类型：
--
作者：
P. J. Syrett
在pH值为6.1的条件下，氮饥饿细胞吸收氨氮的速度是硝态氮的4倍左右。两种形态的氮的同化伴随着较高的呼吸速率和细胞内碳水化合物的减少。碳水化合物从氨处理的细胞中消失得更快。当硝态氮被吸收时，可溶性有机氮化合物几乎没有增加，但在氨态氮细胞中，它们的数量增加了两倍。在铵电池中合成不溶性氮的速度是前者的两倍。伴随着两种形态氮的同化而产生的二氧化碳的速率是相同的，比对照的速率高5倍。氨氮同化伴随着较高的耗氧速率，RQ约为0.8，而伴随硝酸盐同化的吸氧速率较低，RQ约为2.5。大部分可用于合成和呼吸的碳是碳水化合物碳。在氮素同化过程中，乙醚可溶物略有增加。这两种形态的氮在同一时间后停止同化，当这种情况发生时，培养物仍含有无机氮。当同化停止时，经铵处理的细胞含有的碳水化合物比硝酸盐细胞少得多。
Nitrogen-starved cells of C. vulgaris assimilate ammonium-N about 4 times as quickly as nitrate-N at pH 6.1. The assimilation of both forms of nitrogen is accompanied by a high respiration rate and a decrease of intracellular carbohydrate. Carbohydrate disappears more rapidly from the ammonium-treated cells. When nitrate-N is assimilated soluble organic nitrogen compounds increase little but in the ammonium cells they treble in amount. Insoluble-N is synthesised twice as quickly in the ammonium cells. The rate of carbon dioxide production accompanying the assimilation of both forms of nitrogen is the same and 5 times higher than the control rate. The assimilation of ammonium-N is accompanied by a high rate of oxygen uptake and the RQ is about 0.8; the rate of oxygen uptake accompanying nitrate assimilation is lower and the RQ about 2.5. Most of the carbon available for synthesis and respiration is carbohydrate carbon. Ether soluble material increases slightly during the period of nitrogen assimilation. The assimilation of both forms of nitrogen ceases after the same period of time and, when this happens, the cultures still contain inorganic nitrogen. When assimilation ceases the ammonium treated cells contain considerably less carbohydrate than the nitrate cells.