Terrestrial cyanobacteria are phototrophic microorganisms, which grow embedded in a matrix of extracellular polymeric substances (EPS) as biofilms. To perform photosynthesis, cyanobacteria have developed, additionally to chlorophyll-a and carotenoids, the so-called phycobilisomes, which consist of differently pigmented phycobiliproteins (PBPs). The production of natural dyes, pharmaceutical substances and their nutrient rich biomass makes cyanobacterial biofilms interesting research targets for industrial development. However, characterization of biofilms during cultivation implies several difficulties, since standard sampling applied in suspended cultures is not possible. The aim of this study was to find new possibilities for documenting biofilm growth. Therefore, two methods for non-invasive examination of phototrophic biofilms were combined. The terrestrial cyanobacteria Trichocoleus sociatus und Coleofasciculus chthonoplastes were cultivated surface-associated in an aerosol. Every three to four days biofilm thickness was measured using optical coherence tomography (OCT) and biofilm area using PAM fluorometry. Additionally, three replicates were harvested to determine biomass formation and pigment composition. According to our results, an increase of biomass, biofilm thickness and biofilm area was detected. The non-linear correlation between these parameters indicates an increase of biofilm area and thickness in the early phase of cultivation with a time-delayed biomass production. Hereby, possibly the proportion of EPS and biomass changed in the beginning in combination with biofilm spreading to increase the utilization of available light and aerosol components. Afterwards, biomass production was increased. Concerning pigment composition in the course of cultivation, for T. sociatus all PBPs were degraded, whereas in C. chthonoplastes an increase of all PBPs was measured. This can be explained with the role of PBPs for photosynthesis but as well as nitrogen storage, which is adjusted strain dependent. Summarizing, the shown methods are suitable for phototrophic biofilm characterization in a small scale. This allows the examination of cyanobacteria and a valuation of their suitability for possible production processes.

陆地蓝细菌是光养微生物，它们以生物膜的形式嵌入细胞外聚合物质（EPS）的基质中生长。为了进行光合作用，除叶绿素-a和类胡萝卜素（所谓的藻胆体）外，蓝细菌已经发展起来，它们由色素不同的藻胆蛋白（PBP）组成。天然染料，药物及其营养丰富的生物质的生产使蓝细菌生物膜成为工业发展的有趣研究目标。但是，在培养过程中生物膜的表征存在许多困难，因为无法在悬浮培养物中进行标准采样。这项研究的目的是发现记录生物膜生长的新可能性。因此，结合了两种非侵入性检查光养性生物膜的方法。毛滴虫和破囊藻被培养成与气溶胶表面相关。每三至四天使用光学相干断层扫描（OCT）测量生物膜厚度，并使用PAM荧光测定法测量生物膜面积。另外，收获三个重复样品以确定生物质形成和颜料组成。根据我们的结果，检测到生物量，生物膜厚度和生物膜面积增加。这些参数之间的非线性相关性表明，随着时间推移生物量的产生，培养初期的生物膜面积和厚度增加。由此，EPS和生物质的比例可能在开始时与生物膜扩散结合而改变，以增加对可用光和气溶胶组分的利用。之后，增加了生物量的生产。关于栽培过程中的色素成分，社交锥虫所有PBPs均被降解，而在华支睾吸虫中，所有PBPs均增加。这可以用PBPs在光合作用中的作用以及氮的存储来解释，氮的存储取决于应变。总之，所示的方法适用于小规模的光养生物膜表征。这样可以检查蓝细菌并评估其对可能的生产工艺的适用性。