Arctic microbial and next-generation sequencing approach for bacteria in snow and frost flowers: selected identification, abundance and freezing nucleation

Abstract

Abstract. During the spring of 2009, as part of the OceanAtmosphere-Sea Ice-Snowpack (OASIS) campaign in Barrow, Alaska, USA, we examined the identity, population diversity, freezing nucleation ability of the microbial communities of five different snow types and frost flowers. In addition to the culturing and gene-sequence-based identification approach, we utilized a state-of-the-art genomic next-generation sequencing (NGS) technique to examine the diversity of bacterial communities in Arctic samples. Known phyla or candidate divisions were detected (11-18) with the majority of sequences (12.3-83.1 %) belonging to one of the five major phyla: Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Cyanobacteria. The number of genera detected ranged from, 101-245. The highest number of cultivable bacteria was observed in frost flowers (FFs) and accumulated snow (AS) with 325 ± 35 and 314 ± 142 CFU m L −1 , respectively; and for cultivable fungi 5 ± 1 CFU m L −1 in windpack (WP) and blowing snow (BS). Morphology/elemental composition and ice-nucleating abilities of the identified taxa were obtained using high resolution electron microscopy with energy-dispersive X-ray spectroscopy and ice nucleation cold-plate, respectively. Freezing point temperatures for bacterial isolates ranged from −20.3 ± 1.5 to −15.7 ± 5.6 • C, and for melted snow samples from −9.5 ± 1.0 to −18.4 ± 0.1 • C. An isolate belonging to the genus Bacillus (96 % similarity) had ice nucleation activity of −6.8 ± 0.2 • C. Comparison with Montreal urban snow, revealed that a seemingly diverse community of bacteria exists in the Arctic with some taxa possibly originating from distinct ecological environments. We discuss the potential impact of snow microorganisms in the freezing and melting process of the snowpack in the Arctic.

Snow‐borne nanosized particles: Abundance, distribution, composition, and significance in ice nucleation processes

“…Since bacterial species are considered to be among the most efficient identified IN, in a parallel study, we focused our research on the identity, population, and ice nucleation ability of the bacterial and fungal communities in the different types of snow examined [ Mortazavi et al , ]. Complementary morphology of the identified taxa was obtained using TEM (Figure ).…”

Bacterial microbiota associated with flower pollen is influenced by pollination type, and shows a high degree of diversity and species‐specificity

“…2). Floral nectar-related major bacterial phyla from different plant species were Proteobacteria, Actinobacteria and Firmicutes ( Alvarez-P erez et al, 2012; Mortazavi et al, 2015). The extreme low overlap of bacterial species between the investigated pollens (Fig.…”

Characteristics of bacterial community in cloud water at Mt Tai: similarity and disparity under polluted and non-polluted cloud episodes

“…Combined with field investigations and laboratory experiments, diverse bacterial communities have been retrieved, and the bacterial metabolism active in cloud water has been further demonstrated. In the atmospheric aqueous phase, microorganisms can act as cloud condensation nuclei (CCN) and ice nuclei (IN), which have a potential impact on cloud formation and precipitation processes (Amato et al, 2015;Bauer et al, 2003;Mortazavi et al, 2015). Moreover, microorganisms in cloud water are available to metabolize organic carbon compounds (degrading organic acids, formate, acetate, lactate, and succinate) and are associated with carbon and nitrogen recycling (Amato et al, 2007a;Hill et al, 2007;Vaïtilingom et al, 2010).…”

“…Accumulation literature indicates that bacteria in cloud/fog water droplets have a potential effect on the diversity and function of atmospheric and terrestrial ecosystems (Delort et al, 2010;Vaïtilingom et al, 2013), even inducing health risks through microbial pathogen dispersion (Vaïtilingom et al, 2012). Previous studies have examined the bacterial community in rain or snow (Cho and Jang, 2014;Mortazavi et al, 2015). They also focus on the bacteria associated with CNN/IN, potential pathogens, and biochemical reactions.…”