Search Results (3)

Artificial (technical) snow production is an increasingly common practice in alpine regions, yet little is known about its role in shaping microbial communities at the molecular level. In this study, we combined culture-based methods with high-throughput 16S rRNA gene sequencing and functional trait prediction (FAPROTAX) to investigate bacterial communities across the full technical snowmaking cycle in one of Polish ski resorts. The molecular profiling revealed that technical snow harbors dominant taxa with known cold-adaptation mechanisms, biofilm-forming abilities, and stress tolerance traits (e.g., Brevundimonas, Lapillicoccus, Massilia, with a relative abundance of 2.95, 2.14, 3.38 and 5.61%, respectively). Functional inference revealed a consistent dominance of chemoheterotrophy (up to 38% in relative abundance) and aerobic chemoheterotrophy (up to 36%), with localized enrichment of fermentation (6.9% in cannon filter and 6.5% in sediment) and aromatic compound degradation (3.7% in source waters, 3.8% in cannon filter and 4.6% in sediment). Opportunistic and potentially pathogenic genera (e.g., Acinetobacter, Flavobacterium, Nocardia) persisted in sediments (7.4%, 21.4% and 3.5%) and meltwater (34.9% and 2.31% for the latter two), raising concerns about their environmental reintroduction. Our findings indicate that technical snowmaking systems act as selective environments not only for microbial survival but also for the persistence of molecular traits relevant to environmental resilience and potential pathogenicity. Our study provides a molecular ecological framework for assessing the impacts of snowmaking on alpine ecosystems and underscores the importance of monitoring microbial functions in addition to taxonomic composition. Full article

Aliphatic nitro compounds cause environmental pollution by being discharged into water with industrial waste. Biodegradation needs to be further explored as a green and pollution-free method of environmental remediation. In this study, we successfully cloned a novel nitronate monooxygenase gene (psnmo) from the genomic DNA library of Psychrobacter sp. ANT206 and investigated its ability to degrade 2-nitropropane (2-NP). Homology modeling demonstrated that PsNMO had a typical I nitronate monooxygenase catalytic site and cold-adapted structural features, such as few hydrogen bonds. The specific activity of purified recombinant PsNMO (rPsNMO) was 97.34 U/mg, rPsNMO exhibited thermal instability and reached maximum catalytic activity at 30 °C. Moreover, rPsNMO was most active in 1.5 M NaCl and remained at 104% of its full activity in 4.0 M NaCl, demonstrating its significant salt tolerance. Based on this finding, a novel bacterial cold-adapted enzyme was obtained in this work. Furthermore, rPsNMO protected E. coli BL21 (DE3)/pET28a(+) from the toxic effects of 2-NP at 30 °C because the 2-NP degradation rate reached 96.1% at 3 h and the final product was acetone. These results provide a reliable theoretical basis for the low-temperature degradation of 2-NP by NMO. Full article

The low-temperature environment of the Tibetan Plateau presents a technical challenge to composting. This study screened cold-adapted microbes with strong degradation ability and selected five strains to experimentally test and evaluate composting cattle manure in a natural environment in the plateau region. The results showed that both the control and the treatment groups had a slow temperature rise at the beginning of the composting. However, after the first turning, the temperature rise in the inoculated group accelerated. The inoculation of cold-adapted bacteria increased the OM loss in the compost by 8.6%, decreased the retention of nitrogen of the compost by 3%, and increased the seed germination index (GI) value from 44.4% to 73.9%. Microbial community structure analysis showed that the relative abundance of Psychrobacter was more than 50% at the beginning of the composting in the two experimental groups. The cold-adapted microbial inoculation increased the diversity of the microbial community, i.e., Truepera and Luteimona, and the abundance of specific microorganisms during the thermophilic and maturation stages. This study demonstrates that inoculation of cold-adapted bacteria improves the maturity and efficiency of cattle manure composting in a natural plateau environment. Full article