Evaluating the potential for Haloarchaea to serve as ice nucleating particles

Abstract. Aerosols play a crucial role in cloud formation. Biologically derived materials from bacteria, fungi, pollen, lichen, viruses, algae, and diatoms can serve as ice nucleating particles (INPs), some of which initiate glaciation clouds at relatively warm freezing temperatures. However, determining the magnitude interactions between biologically INPs remains significant challenge due to diversity complexity bioaerosols limited observations such aerosols facilitating Additionally, microorganisms domain Archaea have, date, not been evaluated INPs. Here, we present first results reporting nucleation activity four species class Haloarchaea. Intact cells Halococcus morrhuae Haloferax sulfurifontis demonstrated ability induce immersion temperatures up ?18 ?C, while lysed Haloquadratum walsbyi Natronomonas pharaonis were unable Exposure heat peroxide digestion indicated that intact driven by organic (H. H. sulfurifontis) possibly also labile only). While halophiles are prominent hypersaline environments Great Salt Lake Dead Sea, other members Archaea, methanogens thermophiles, prevalent anoxic systems seawater, sea ice, marine sediments, glacial permafrost, cold niches. Archaeal extremophiles both diverse highly abundant. Thus, it is important assess their may lead an improved understanding biological impacts on clouds.