Biotechnology Alberto Scoma, Paloma Garrido-Amador, Søren Dollerup Nielsen, Hans Røy, Kasper Urup Kjeldsen DOI: 10.1128/AEM.00802-19 ABSTRACT In polyextremophiles, i.e., microorganisms growing preferentially under multiple extremes, synergistic effects may allow growth when application of the same extremes alone would not. High hydrostatic pressure (HP) is rarely considered in studies of polyextremophiles, and its role in potentially enhancing tolerance to other extremes remains unclear.