Isolation and Identification of Phototrophic Microorganisms from Rudkhan Castle as a Biodeteriorating Agent

Abstract

Introduction: Phototrophic microorganisms are the first residents of different surfaces of ancient buildings’ walls. These organisms can expand to provide the colonization of other microorganisms and to form microbial biofilms. During biofilm growth, acids and metabolites production bore the substratum and cause surfaces damages. Rudkan Castle, the historic monument located in Gilan province, an area with a humid climate has an appropriate surfaces to grow these microorganisms. Materials and methods: In this study, morphological identification of algae and cyanobacteria which was isolated from different areas of the brick walls of Castle has been investigated. Samples were taken from 24 different areas of Castle walls and were aseptically cultured into Blue Green Medium (BGM) and Bolds Basal Medium (BBM), and colonies were observed using light microscopy. Results: The dominant organisms which were isolated and identified, were Cladophora, Trentepohlia, Klebsormidium, Trebouxia, Pleurastrum, Chlorococcum as chlorophyta order and Scytonema, Tolypothrix, Leptolyngbya, Plectolyngbya, Phormidium, Gloeocapsa, Microcoleus, Nostoc as a cyanobacteria order. Discussion and conclusion: As expected, diversity of a large number of cyanobacteria and algae phototrophs was isolated. Diversity of organisms on the surface of monuments depends on many factors, including the weather condition such as moisture, the amount of radiation absorbed by the surface, temperature of area, the materials used in the monuments, the biological acceptance of surface and presence of variety of organisms in the soil surface and the air on. Study of destructive factors is the first step toward the protection and restoration of ancient monuments.

Keywords

• Biodeterioration
• Rudkhan Castle
• Phototroph