Photoinhibition of marine nitrifying bacteria .1. Wavelength-dependent response
Photoinhibition of marine nitrifying bacteria .1. Wavelength-dependent response
复制标题
DOI：
10.3354/meps141183
复制
发表时间：
1996-10-01
影响因子：
2.5
通讯作者：
Jones, RD
中科院分区：
文献类型：
--
作者：
Guerrero, MA;Jones, RD
趋化石营养硝化细菌（NH4+和NO2-氧化剂）的无菌培养物以不同的方式对光作出反应。经过短期（2至4小时）单色照射后，两种类型的硝化细菌在近紫外区域（300至375 nm）表现出广泛的光敏性，在光谱的蓝色区域（400至475 nm）表现出不同的光敏性。总的来说，亚硝酸盐氧化剂对蓝光抑制的敏感性低于铵态氧化剂。典型地，光抑制的程度是物种特异性的，光响应是剂量和波长依赖的。较高底物浓度的光保护作用仅在铵氧化剂中观察到。增加的细胞密度改变了亚硝酸盐氧化剂的光耐受性，使这些生物对光敏感。同样，当使用高细胞密度时，长时间的低光剂量治疗对亚硝酸盐氧化剂更具破坏性。多色照射证实了单色结果。冷白荧光灯对NH4+氧化活性有抑制作用，对NO2-氧化活性无抑制作用。暴露在阳光下会抑制两种类型的硝化菌的活性。这些数据表明，光对自养硝化的影响不仅取决于硝化物的类型（NH4+或NO2-氧化剂），还取决于其环境条件。
Axenic cultures of chemolithotrophic nitrifying bacteria (NH4+ and NO2- oxidizers) respond to light in distinct manners. After short-term (2 to 4 h) monochromatic irradiations both types of nitrifying bacteria demonstrated a widespread photosensitivity in the near-UV region (300 to 375 nm) and a differential photosensitivity in the blue region of the spectrum (400 to 475 nm). Nitrite oxidizers were less sensitive overall to blue Light inhibition than were ammonium oxidizers. Characteristically, the extent of the photoinhibition was species-specific and Light response was dose- and wavelength-dependent. Photoprotection by higher substrate concentrations was only observed with ammonium oxidizers. Increased cell densities altered the phototolerance of nitrite oxidizers and made these organisms light-susceptible. Similarly, treatment with a low light dose for extended periods was more damaging to nitrite oxidizers, when high cell densities were used. polychromatic irradiations served to confirm the monochromatic results. Cool-white fluorescent light inhibited NH4+ oxidizing activity but not NO2- oxidizing activity. Exposure to sunlight resulted in inhibition of activity in both types of nitrifiers. These data demonstrate that the effect of Light on autotrophic nitrification depends not only on the type of nitrifier (NH4+ or NO2- oxidizer), but also on the conditions of their environment.