Microbial Endoliths on East Adriatic Limestone Coast: Morphological vs. Molecular Diversity

ABSTRACTFor the first time, a combined genotype-phenotype diversity analysis of endolithic microorganisms by pyrosequencing and microscopy was carried out across the intertidal and supratidal ranges of the Adriatic limestone coast. The coastal profiles represent ecotones between the sea and land, which express gradients of water supply, solar illumination, and salinity. The use of scanning electron microscopy imagery of resin casts showed that euendolith penetration remained shallow in the uppermost zones and was progressively deeper in the lower ranges where the water supply was more frequent. Microbial genotypes and phenotypes along the coastal profile showed large differences in dominance of taxa, but less in their diversity. The linkage between morphotypes observed along the profile and sequences was achieved by sequencing single cells/filaments, which were morphologically identified prior to their amplification. Molecular signatures of Hormathonema spp., Hyella caespitosa, Scytonema endolithicum, Sol...