NITROGEN LIMITATION IN ISOCHRYSIS-GALBANA (HAPTOPHYCEAE) .1. PHOTOSYNTHETIC ENERGY-CONVERSION AND GROWTH EFFICIENCIES
NITROGEN LIMITATION IN ISOCHRYSIS-GALBANA (HAPTOPHYCEAE) .1. PHOTOSYNTHETIC ENERGY-CONVERSION AND GROWTH EFFICIENCIES
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DOI：
10.1111/j.1529-8817.1989.tb00251.x
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发表时间：
1989-09-01
影响因子：
2.9
通讯作者：
FALKOWSKI, PG
中科院分区：
文献类型：
--
作者：
HERZIG, R;FALKOWSKI, PG
研究了稳态氮素限制对海洋等鞭金藻的光合作用特性和生长效率的影响。硝酸盐限制性化学药物维持在9种稀释率，范围从0.18-0.96d-1，在175µm o l量子点的连续照射水平下。M-2.cntdo.S-1，在所有生长速率下都能使光合作用饱和的照度水平。氮素限制导致色素沉着总体减少，反应中心的细胞浓度降低；然而，归一化为Chla的光吸收截面增加。此外，在氮素限制的细胞中Chl c/a比值较高，Chl c/a比值的变化与光系统II功能尺寸的增加相关，归一化的光饱和光合作用速率和比呼吸损失与生长速率呈线性正相关。归一化为Chla的光饱和光合作用速率对氮素供应速率相对不敏感。总光合放氧量的最低需氧量由12.4量子/O2提高到17.0量子/O2。在生长照度下，量子需求增加了88%，从19.9量子/O2增加到37.5量子/O2。当稀释率大于最大相对生长率的35%时，光合作用/呼吸比率保持相对恒定。因此，净生长效率，定义为比生长速率MU与比总光合作用P的比率，在平均85+-的增长速率范围内也保持相对恒定。3%。
The effect of steady-state nitrogen limitation on photosynthetic characteristics and growth efficiency was examined in the marine haptophyte Isochrysis galbana Green. Nitrate limited chemostats were maintained at nine dilution rates, ranging from 0.18-0.96 d-1, under continuous irradiance levels of 175 .mu.mol quanta .cntdot. m-2 .cntdot. s-1, an irradiance level which saturated photosynthesis at all growth rates. Nitrogen limitation led to an overall reduction in pigmentation and a decrease in the cellular concentration of reaction centers; however, the optical absorption cross section, normalized to Chl a, increased. Moreover, Chl c/a ratios were higher in nitrogen-limited cells; the change in Chl c/a ratios were correlated with an increase in the functional size of Photosystem II. Both light saturated photosynthetic rates normalized per cell and specific respiratory losses were positively linearly correlated with growth rate. Light saturated photosynthetic rates normalized to Chl a remained relatively insensitive to the rate of nitrogen supply. The minimum quantum requirement for gross photosynthetic oxygen evolution increased from 12.4 to 17.0 quanta/O2. At the growth irradiance, the quantum requirement increased 88%, from 19.9 to 37.5 quanta/O2. Photosynthesis/respiration ratios remained relatively constant at dilution rates greater than 35% of the maximum relative growth rate. Consequently, net growth efficiency, defined as the ratio of the specific growth rate, .mu., to specific gross photosynthesis, P, also remained relatively constant over this range of growth rates averaging 85 .+-. 3%.