O Instituto de Investigação e Tecnologia da Agronomia e Meio Ambiente (IITAA) desenvolve trabalho de investigação com o objetivo de perseguir estudos em diversas áreas, como a caracterização / previsão do clima insular e os efeitos das mudanças globais em comunidades do oceano para os to... Ler mais »
Lava caves are common on Earth, but despite their frequency, relatively little is known of their microbial communities. The Archipelago of the Azores, composed of nine volcanic islands, is located between 37° and 40°N latitude and 25° and 31°W longitude at the triple junction of the Eurasian, African and North American plates, an area with active volcanoes and high seismicity. Recent work has documented 69 lava caves on Terceira and 129 on Pico islands, mostly lava tubes. In order to identify the diversity of microorganisms associated with the microbial mats in these caves and discover novel biodiversity, basaltic lava caves from Terceira and Pico Island in Azores were sampled. A colorful and diverse array of microbial mats that vary in color from white to yellow to pink covering walls of caves were studied by using culture-dependent and culture-independent methods. Microbial mats showed a similar composition at the phylum level. The most ubiquitously found phyla include the Actinobacteria, Proteobacteria, Acidobacteria, Chloroflexia and Nitrospirae. Found frequently are the additional phyla of Gemmatimonadetes, Bacteroidetes, Firmicutes, Planctomycetes, Verrucomicrobia, Chlamydiae, Ktedonobacteria, OP10 and TM7. The phylum Actinobacteria is of particular interest because of the widespread ability to produce bioactive secondary metabolites. The acquired resistance of pathogens to commonly used antibiotics is an increasing problem in society, highlighting the need of finding novel antibiotics. Extreme environments are considered a promising target for survey of bioactive compounds. Cave bacteria isolates were tested for antibiotic activity against antibiotic-resistant pathogens and isolates displaying a wide-spectrum of inhibition were sequenced and identified. What actually controls the microbial diversity and distribution found in these lava caves is currently under investigation. Factors that might influence microbial mat community composition include surface precipitation, surface land use and/or vegetation, geography, geological age of the lava flows or chemical composition of the basalt substrate and the microenvironment within lava caves. Conservation of local biodiversity is needed to preserve potential economical and social benefits of bioactive secondary metabolites from extreme environments such as lava tubes.
Sexta, 02 Dezembro, 2011