College of Agriculture

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As the foundation of the land grant mission at Montana State University, the College of Agriculture and the Montana Agricultural Experiment Station provide instruction in traditional and innovative degree programs and conduct research on old and new challenges for Montana’s agricultural community. This integration creates opportunities for students and faculty to excel through hands-on learning, to serve through campus and community engagement, to explore unique solutions to distinct and interesting questions and to connect Montanans with the global community through research discoveries and outreach.

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    Culturable bacteria isolated from seven high-altitude ice cores on the Tibetan Plateau
    (2019-02) Liu, Yongqin; Priscu, John C.; Yao, Tandong; Vick-Majors, Trista J.; Michaud, Alexander B.
    Microorganisms are the most abundant organisms on Earth, and microbial abundance records preserved in ice cores have been connected to records of environmental change. As an alternative to high resolution abundance records, which can be difficult to recover, we used culture-dependent and culture-independent methods to examine bacteria in glacier ice from the Tibetan Plateau (TP). We recovered a total of 887 bacterial isolates from ice cores of up to 164 m in depth retrieved from seven glaciers, located across the TP. These isolates were related to 53 genera in the Actinobacteria, Firmicutes, Bacteroidetes, and Proteobacteria, with 13 major genera accounting for 78% of isolates. Most of the genera were common across the geographic region covered by our sampling, but there were differences in the genera recovered from different depths in the ice, with the deepest portions of the ice cores dominated by a single genus (Sporosarcina). Because microorganisms deposited on glaciers must survive atmospheric transport under a range of temperatures, temperature tolerance should be an important survival mechanism. We tested isolate growth across a range of temperatures (0-35 °C), and found psychrotolerance to be common. Together, our results show that ice depth, and by extension age, are characterized by different types of microorganisms, providing new information about microbial records in ice.
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    Salinity drives archaeal distribution patterns in high altitude lake sediments on the Tibetan Plateau
    (2016-03) Liu, Yongqin; Priscu, John C.; Xiong, Jinbo; Conrad, Ralf; Vick-Majors, Trista J.; Chu, Haiyan; Hou, Juzhi
    Archaeal communities and the factors regulating their diversity in high altitude lakes are poorly understood. Here, we provide the first high-throughput sequencing study of Archaea from Tibetan Plateau lake sediments. We analyzed twenty lake sediments from the world\'s highest and largest plateau and found diverse archaeal assemblages that clustered into groups dominated by methanogenic Euryarchaeota, Crenarchaeota and Halobacteria/mixed euryarchaeal phylotypes. Statistical analysis inferred that salinity was the major driver of community composition, and that archaeal diversity increased with salinity. Sediments with the highest salinities were mostly dominated by Halobacteria. Crenarchaeota dominated at intermediate salinities, and methanogens were present in all lake sediments, albeit most abundant at low salinities. The distribution patterns of the three functional types of methanogens (hydrogenotrophic, acetotrophic and methylotrophic) were also related to changes in salinity. Our results show that salinity is a key factor controlling archaeal community diversity and composition in lake sediments on a spatial scale that spans nearly 2000 km on the Tibetan Plateau.
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