Biofilm Formation and Interspecies Interactions in Mixed Cultures of Thermoacidophilic Archaea Acidianus spp. and Sulfolobus metallicus

LIU J.; DONATI E.R.; ZHANG R.; NEU T.R.; VERA M.; CASTRO C.; BELLENBERG S.; SAND W.

RESEARCH IN MICROBIOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 167 p. 604 - 612

0923-2508

The understanding of biofilm formation by metal-oxidizingmicroorganisms is of great importance for influencing mineral dissolutionrates and to prevent acid mine drainage (AMD). Thermo-acidophilic archaeasuch 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 formationpatterns of the crenarchaeotes Sulfolobus metallicus DSM 6482T and theAcidianus isolates DSM 29038 and DSM 29099 in pure and mixed cultures onsulfur or pyrite were studied. Confocal laser scanning microscopy (CLSM)combined with cell fluorescent dyes as well as fluorescently labeledlectins were used to visualize different components (e.g. DNA, proteinsor glycoconjugates) of the aforementioned species. The data indicate thatcell attachment and the subsequently formed biofilms were species- andsubstrate dependent. Pyrite leaching experiments coupled to precolonizationand further inoculation with a second species suggest thatboth species may negatively influence each other during pyrite leachingwith respect to initial attachment and pyrite dissolution rates. Inaddition, the investigation of binary biofilms on pyrite showed that bothspecies were heterogeneously distributed on pyrite surfaces in the formof individual cells or microcolonies. Physical contact between bothspecies seem to occur, as revealed by specific lectins able tospecifically bind single species within mixed cultures.