Physical Sciences and Mathematics Commons^™

Biological Effects On Serpentinite Weathering, Mary H. Evert, Julie Baumeister, Elisabeth Hausrath

Undergraduate Research Opportunities Program (UROP)

Serpentinites, perhaps more than any other rock type, control the composition and evolution of the development of the surrounding ecosystems. The bulk chemistry of serpentinite rocks, high in Mg and trace elements, and low in nutrients such as Ca, K, P, and N, causes an extreme and stressful environment for ecosystems. However, the role that those serpentine ecosystems play in development of serpentine soils has not been examined.

Due to the unusual chemistry of serpentine soils, serpentine ecosystems have deeper and better-developed root systems than other ecosystems. The rhizosphere of serpentine systems, documented to produce abundant organic acids and siderophores, …

Long Distance Microbial Transport In Air: Global Change Implications, Bradley J. Davey, J. C. Bruckner, Jenny C. Fisher, Duane P. Moser

Undergraduate Research Opportunities Program (UROP)

The first manifestations of global change will most likelv be observed in the Earth's atmosphere. Changing wind patterns, for example, may effect the long distance dispersal of microor-g anisms. The overall objective of this research is to correlate molecular assessments of microbial community structure from cloud water and snow samples, obtained from DRI's Storm Peak Laboratory atop Mt. Werner in Colorado, with atmospheric data and calculated air mass back trajectories. Our activities for summer of 2009 will be a focused proof-of-concept exercise to determine if intact microbial DNA and viable cells can be recovered from cloud water and alpine snow …

Martian Life Detection With Amino Acid Enantiomers, Ali Jamil, Gaosen Zhang, Henry J. Sun

Undergraduate Research Opportunities Program (UROP)

The Viking mission showed that Martian soil can degrade a heterotrophic medium to carbon dioxide as if live microorganisms were present. The result is considered inconclusive, however, because abiotic oxidants, such as superoxides, may also exist on Mars and would explain the Viking result. One way to resolve this ambiguity is to repeat the Viking experiment with a isomerically pure medium. The consumption of one isomer, either D or L, would indicate biological activity. Indiscriminate destruction of both isomers would indicate abiotic redox processes. This idea was validated for glucose by REU research last summer (Sun et al. 2009). The …

Martian Life Detection With Xylose Enantiomers, Arturo White, Gaosun Zhang, Henry J. Sun

Undergraduate Research Opportunities Program (UROP)

Ability of Martian soil to degrade carbohydrates, shown by the Viking mission, has two interpretations. One possibility is that the soil harbors living microorganisms. Alternatively, the soil is sterile but chemically oxidizing, i.e. it is laden with photochemical oxidants. It was shown by REU research last summer that these two possibilities can be distinguished by the use of glucose enantiomers. Life is selective: Earth organisms use D-glucose, but ignore Lglucose. This stereo selectivity is absent in chemical reactions. The goal of this project is to test if xylose, a five carbon sugar, is also suitable for chiral life detection. Mixed …

Baseline Microbial Characterizations Of An Imperiled Aquatic Diversity Hotspot: Ash Meadows National Wildlife Refuge, Jessica Newburn, Jim Bruckner, Jenny C. Fisher, Duane P. Moser

Undergraduate Research Opportunities Program (UROP)

Located in the discharge zone of the Death Valley Flow System, Ash Meadows National Wildlife Refuge is a spring-fed desert oasis and biodiversity hotspot about 90 miles northwest of Las Vegas. These critical wetlands are potentially threatened by groundwater pumping, exotic species invasions, and climate change. Although a major component of the lower food web, very little is known about the microbial makeup of this ecosystem. As a first step towards understanding the microbial and biogeochemical aspects of this system, a detailed molecular-based characterization of microbial communities, baseline chemistry, and physical characteristics of various springs of Ash Meadows will be …

Diversity Of Estrogen Degrading Microorganisms In Las Vegas Wash And Lake Mead, Nevada, Usa, Susanna Blunt, Jim Bruckner, Jenny C. Fisher, Duane P. Moser

Lake Mead Science Symposium

Endocrine disrupting chemicals (EDCs) are a subject of intense research as more studies reveal their persistence in the environment and detrimental effects on wildlife. Steroid hormones, including the natural and synthetic estrogens estrone (E1), 17-beta-estradiol (E2) and 17- alpha-ethinyl estradiol (EE2), are among the most bioactive and have been detected at low concentrations in waterways downstream from wastewater treatment plants. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater, provides a unique experimental system in which to study the role microorganisms play in the fate and dispersal of these compounds in surface waters.

Potential Antimicrobial Properties Of The Cyanobacterium Microcoleus Vaginatus In Relationship To The Moss Bryum Argenteum, Crystal Erickson, Lloyd Stark

Undergraduate Research Opportunities Program (UROP)

Biological soil crusts play important ecological roles in arid desert regions. These crusts cycle nutrients, prevent wind/water erosion, and form the basis of food chains and soil formation in desert communities. Primary components of these structures include two desert moss species Bryum argenteum and Syntrichia caninervis, and Microcoleus vaginatus, a cyanobacterium. Our Phase I experiment strongly suggests that in an environment of intense light, a condition of stress to Syntrichia caninervis, there is an increase in shoot regeneration when cyanobacteria are present compared to when they are absent. Microcoleus is a highly motile species and our lab observations of fewer …