POLY-EXTREMOPHILIC BACTERIA FROM HIGH ALTITUDE ANDEAN LAKES: ARSENIC RESISTANCE PROFILES AND BIOFILM PRODUCTION

OMAR F. ORDOÑEZ; VIRGINIA H. ALBARRACIN; PORTERO LUCIANO; FARIAS, ME,; ZANNIER FEDERICO; LUCIANO JOSÉ MARTINEZ

BioMed Research International

Hindawi Publishing Corporation

Año: 2019

2314-6133

The high levels of arsenic present in HAAL ecosystems have selected 23arsenic-resistant microbial communities which are of novel interest to study 24adaptations mechanisms which can be applied in bioremediation processes. 25We herein performed a detailed characterization of the arsenic tolerance 26profiles and the biofilm production of two HAAL poly-extremophiles, 27Acinetobacter sp. Ver3 (Ver3) and Exiguobacterium sp. S17 (S17). Cellular 28adherence over glass and polypropylene surfaces were evaluated together with 29the effect of increasing doses and oxidative states of arsenic over the quality 30and quantity of their biofilm production. 31The arsenic tolerance outcomes showed that HAAL strains could 32tolerate higher arsenic concentrations than phylogenetic related DSMZ str ains, 33which suggest adaptations of HAAL strains to their original environment. On the 34other hand, the crystal violet method (CV) and SEM analysis showed that Ver3 35and S17 were able to attach to solid surfaces and to form the biofilm. The 36quantification of biofilms production in 48 hours cultures through CV shows that 37Ver3 yielded higher production in the treatment without arsenic cultured on a 38glass support, while S17 yield higher biofilm production under intermediate 39arsenic concentration on glass supports. Polypropylene supports had negative 40effects on the biofilm production of Ver3 and S17. SEM analysis shows that the 41highest biofilm yields could be associated with a larger number of attached cells 42as well as the development of more complex 3D multicellular structures.