Departamento Edafología y Química Agrícola, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain.
Biofouling. 2012;28(3):329-38. doi: 10.1080/08927014.2012.673220.
This paper addresses the detection and monitoring of the development of epilithic phototrophic biofilms on the granite façade of an institutional building in Santiago de Compostela (NW Spain), and reports a case study of preventive conservation. The results provide a basis for establishing criteria for the early detection of phototrophic colonization (greening) and for monitoring its development on granite buildings by the use of color changes recorded with a portable spectrophotometer and represented in the CIELAB color space. The results show that parameter b* (associated with changes of yellowness-blueness) provides the earliest indication of colonization and varies most over time, so that it is most important in determining the total color change. The limit of perception of the greening on a granite surface was also established in a psycho-physical experiment, as Δb*: +0.59 CIELAB units that correspond, in the present study, to 6.3 μg of biomass dry weight cm(-2) and (8.43 ± 0.24) × 10(-3) μg of extracted chlorophyll a cm(-2).
本文针对位于西班牙圣地亚哥-德孔波斯特拉（西班牙西北部）的一座机构建筑的花岗石外墙上附着的石生光养生物膜的检测和监测进行了研究，并报告了一个预防性保护的案例研究。研究结果为建立早期检测光养生物定殖（变绿）的标准以及利用便携式分光光度计记录的颜色变化并在 CIELAB 颜色空间中表示来监测花岗石建筑物上其发展情况提供了依据。结果表明，参数 b*（与黄-蓝变化有关）最早提供了定殖的指示，并且随时间变化最大，因此在确定总颜色变化方面最为重要。在一项心理物理学实验中还确定了在花岗石表面变绿的感知极限，即 Δb*：+0.59 CIELAB 单位，在本研究中，这相当于 6.3 μg 干重生物量 cm(-2)和（8.43 ± 0.24）× 10(-3) μg 提取叶绿素 a cm(-2)。
