Chlorophyceae from Biofilms on Monuments of a Mexican Archaeological Area

Abstract

The microbial community interacts in different ways with the environment. Regarding mineral materials particularly, the microbial community may be present either on the surface, the divisions or in the fissures. This microbial interaction with the materials and their environment can lead to biodeterioration, a common problem in monuments and archaeological sites. Microorganisms form biofilms, which are communities structured by bacteria, algae, cyanobacteria, fungi and protozoa that are embedded in a polymeric matrix. The aim of this work was the morphological identification of Chlorophyceae microorganisms from biofilm mounds of the Yohualichan, an archaeological zone in Puebla, Mexico. Biofilm samples were collected from archaeological monuments in the area known as "Juego de Pelota" (Ballgame), as well as in the East Building, the West Building and "Las Grecas" (Fretworks). The strains were isolated by using BG-11 medium, solidified with 1.3% bacteriological agar, until obtaining monoalgal cultures and the propagation of isolates in liquid BG-11. Twenty one monoalgal cultures were obtained, grouped into five different orders and nine genera: Chlorella, Chlorococcum, Chlorokybus, Desmodesmus, Elakatothrix, Fernandinella, Fottea, Klebsormidium and Oocystis. To conclude it can be said that microalgae primarily make biofilms present in this archaeological site.