Biofilm formation and interspecies interactions in mixed cultures of thermo-acidophilic archaea Acidianus spp. and Sulfolobus metallicus

CAMILA CASTRO; RUIYONG ZHANG; JIN LIU; SÖREN BELLENBERG; THOMAS NEU; EDGARDO DONATI; WOLFGANG SAND; MARIO VERA

RESEARCH IN MICROBIOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016

0923-2508

The understanding of biofilm formation by metal-oxidizing microorganisms is of great importance for influencing mineral dissolution ratesand to prevent acid mine drainage (AMD). Thermo-acidophilic archaea such as Acidianus, Sulfolobus and Metallosphaera are of special interestdue to their ability to perform leaching processes at high temperatures, thereby enhancing leaching rates. In this work, leaching experiments andvisualization by microscopy of cell attachment and biofilm formation patterns of the crenarchaeotes Sulfolobus metallicus DSM 6482T and theAcidianus isolates DSM 29038 and DSM 29099 in pure and mixed cultures on sulfur or pyrite were studied. Confocal laser scanning microscopy(CLSM) combined with cell fluorescent dyes as well as fluorescently labeled lectins were used to visualize different components (e.g. DNA,proteins or glycoconjugates) of the aforementioned species. The data indicate that cell attachment and the subsequently formed biofilms werespecies- and substrate-dependent. Pyrite leaching experiments coupled with pre-colonization and further inoculation with a second speciessuggest that both species may negatively influence each other during pyrite leaching with respect to initial attachment and pyrite dissolutionrates. In addition, the investigation of binary biofilms on pyrite showed that both species were heterogeneously distributed on pyrite surfaces inthe form of individual cells or microcolonies. Physical contact between the two species seems to occur, as revealed by specific lectins able tospecifically bind single species within mixed cultures