A method for the experimental determination of light absorption by aquatic heterotrophic bacteria
A method for the experimental determination of light absorption by aquatic heterotrophic bacteria
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DOI：
10.1093/plankt/20.4.757
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发表时间：
1998-04-01
影响因子：
2.1
通讯作者：
Tassan, S
中科院分区：
文献类型：
--
作者：
Ferrari, GM;Tassan, S
建立了一种测定水生异养菌体内吸光体积系数的实验方法。这里描述的应用是对细菌部分的吸收测量，这些细菌部分通过常用的GF/F过滤器并且仍然未被解释。实验样品通过GF/F和0.22 μ m Millipore膜进行连续水过滤。使用配备积分球附件的双光束分光光度计进行滤光片保留样品的透光和光反射测量。样品吸收是通过一种程序从数据中得出的，该程序纠正了由于细菌高度光散射而导致的结果污染。用K2S2O8溶液漂白细菌呼吸色素，区分细菌吸收与细碎屑吸收。通过实验得到的表达式对滤光片中多次散射引起的吸收放大进行了修正。对在海洋和内陆水域收集的样本进行了包括误差分析在内的方法测试。以典型情况为例，测定了异养菌和不同类型颗粒物对光吸收的相对贡献。将测量的体积吸收系数与Mie理论计算的后向散射系数相结合，可以产生一组多组分光学模型的输入数据，用于评估这些异养细菌对辐射传输过程的贡献。
A method has been set up for the experimental determination of the volume coefficient for light absorption in vivo by aquatic heterotrophic bacteria. The application described here is the absorption measurement of the bacterial fraction that passes through the commonly used GF/F filter and remains unaccounted for. The experimental samples were prepared by successive water filtrations through GF/F and 0.22 mu m Millipore membranes. Light-transmission and light-reflection measurements of the filter-retained samples were performed using a dual-beam spectrophotometer equipped with an integrating sphere attachment. Sample absorption was derived from the data by a procedure that corrects for the contamination of the results due to the high degree of light scattering by the bacteria. The bacterial absorption was discriminated from fine detritus absorption by bleaching the bacterial respiratory pigments using a K2S2O8 solution. The absorption amplification caused by multiple scattering in the filter was corrected for by an expression that was obtained experimentally. A test of the method, including error analysis, was performed on samples collected in both marine and inland waters. The relative contributions to light absorption by heterotrophic bacteria and various types of particulate matter were also measured for a typical situation. Combining the measured volume absorption coefficients with backscattering coefficients computed by Mie theory yields a set of input data to multicomponent optical models that is needed to assess the contribution of these heterotrophic bacteria to the radiative transfer process.