Abstract

The impact of concrete composition and roughness on the formation of microalgal biofilms and their photobiology were studied on marine infrastructures presenting four different compositions combined with two degrees of roughness (rough and smooth). The structures were first inoculated with a natural microphytobenthic biofilm and immersed in sterilised seawater with a controlled photoperiod for six days. Photosynthetic activity was assessed with an imaging PAM-(Pulse Amplitude Modulated) fluorometer and microtopography was monitored in parallel with a 3-D camera. The results indicated that roughness had an impact on the biofilm biomass, its physiological status and its photosynthetic efficiency and capacity. The assessment of surface roughness indicated that negative reliefs were preferably colonised by MPB (microphytobenthic) cells with better photosynthetic performances. Moreover, MPB biofilms showed better photoacclimation in these microhabitats than on the positive and smooth reliefs. This study confirms the importance of microhabitat for biofilm formation and their photobiology.

摘要

在海洋基础设施上研究了混凝土成分和粗糙度对微藻生物膜形成及其光生物学的影响，这些基础设施呈现四种不同的成分，结合两种粗糙度（粗糙和光滑）。这些结构首先用天然微底栖生物膜接种，然后在经过控制的光周期的灭菌海水中浸泡六天。用成像 PAM-（脉冲幅度调制）荧光计评估光合作用活动，并与 3-D 相机并行监测微地形。结果表明，粗糙度对生物膜生物量、其生理状态及其光合效率和能力有影响。表面粗糙度的评估表明负浮雕优选由具有更好光合性能的 MPB（微​​型底栖）细胞定植。此外，MPB 生物膜在这些微生境中比在正面和光滑的浮雕上表现出更好的光驯化。这项研究证实了微生境对生物膜形成及其光生物学的重要性。