Abstract
The Antarctic continent is known for its harsh conditions, but it can sustain well-adapted microorganisms that are able to survive in these extreme conditions. Different bacterial phyla are found predominating the soils of Antarctic Peninsula including those of King George Island, which is part of the South Shetlands archipelago. It has been previously demonstrated that Firmicutes make up a substantial proportion of the bacterial communities in rhizosphere soils of the region. However, far less is known about the presence of this group of bacteria in different soils of this island. Eleven soil samples of Admiralty Bay, King George Island (Yellow soil, Copacabana, Demay Point, Domeyko Glacier, Hennequin, Ipanema, Machu Picchu, Arctowski, Smok Beach, Punta Plaza and Vale Ulman) were obtained and analysed using culture-independent methods (clone libraries based on the 16S rRNA encoding gene). In total, 582 clones were obtained and those related to Firmicutes were found in all samples varying from 3% (Vale Ulman) to 62.2% (Machu Picchu). The genus Sporosarcina (61.4%) followed by the genus Bacillus (29.1%) predominated among the Firmicutes-related clones. Non-metric multidimensional scaling analysis (NMDS) showed that potassium and phosphorous concentrations influenced the diversity and relative abundance of the different genera belonging to Firmicutes in Copacabana and Arctowski soils, while soil texture was the main driver in Punta Plaza, Machu Picchu, Yellow soil and Demay Point. This study contributes to our current knowledge of the diversity of Firmicutes in different soils across King George Island, Antarctic Peninsula.