Microbial Biofilms on the Sandstone Monuments of the Angkor Wat Complex, Cambodia

摘要: Discoloring biofilms from Cambodian temples Angkor Wat, Preah Khan, and the Bayon West Prasat in Thom contained a microbial community dominated by coccoid cyanobacteria. Molecular analysis identified Chroococcidiopsis as major colonizer, but low similarity values (<95%) suggested similar genus or species not present databases. In only two of six sites sampled were filamentous cyanobacteria, Microcoleus, Leptolyngbya, Scytonema, found; first detected sequencing 16S rRNA gene library clones samples moist green biofilm on internal walls where Lyngbya (possibly synonymous with Microcoleus) was seen direct microscopy colonizer. Scytonema also an wall Bayon. This suggests that cyanobacteria are more prevalent (high moisture) areas. Heterotrophic bacteria found all samples. DNA bands DGGE gels Proteobacteria (Stenotrophomonas maltophilia Methylobacterium radiotolerans) Firmicutes (Bacillus sp., Bacillus niacini, sporothermodurans, Lysinibacillus fusiformis, Paenibacillus panacisoli, zanthoxyli). Some these produce organic acids, potentially degrading stone. Actinobacteria, mainly streptomycetes, most samples; algae fungi rare. A dark-pigmented fungus external Khan samples, while alga Trentepohlia taken external, pink-stained stone at Khan. Results show mature communities whose constituents resistant to dehydration high levels irradiation can be involved deterioration sandstone. Such analyses important prerequisites application control strategies.