Frequent Microalgae in the Fountains of the Alhambra and Generalife: Identification and Creation of a Culture Collection

Abstract

Cyanobacteria, green algae and diatoms are significant factors in the biodeterioration of stone cultural heritage sites, and specifically fountain monuments, due to the constant presence of water. In this study, samples were taken from different fountains in the Alhambra and Generalife, which are among the Spanish monuments of greatest historical and artistic value and which together were declared a World Heritage Site by UNESCO in 1984. The aim was to identify which species of colonising microalgae are most frequent and to obtain monoalgal cultures from them. From a conservation point of view, it is interesting to identify which algae are growing in these fountains and how they behave in order to develop new methods to control their growth. The most abundant groups of algae in our samples were green algae and cyanobacteria. The most common genera in the former group were Bracteacoccus, Chlorosarcina, Chlorosarcinopsis, Apatococcus and Klebsormidium. As for cyanobacteria, the most abundant genera were Phormidium, Calothrix, Leptolyngbya, Chamaesiphon, Pleurocapsa and Chlorogloea. Using our collected samples, 10 genera of green algae and 13 genera of cyanobacteria were isolated, thereby constituting the base samples for the creation of a reference collection of living algae from the Alhambra and Generalife contexts, which can be used in subsequent studies to develop new types of treatment against biodeterioration.