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Biochemical Characterization of the Housekeeping 3-deoxy-D-arabino-heptulosonate-7-phosphate Synthases of \u3cem\u3ePseudomonas aeruginosa\u3c/em\u3e PAO1
No full textAbstract removed at faculty mentor reques
Bridging Prairie Restoration and Regenerative Agriculture with Compost Tea
Full text linkInland Pacific Northwest prairie is an endangered ecosystem that has been reduced by conversion to agriculture. There is growing interest in the role of soil microorganisms in prairie ecosystems, which may be crucial for restoration of the plant community through interspecies interactions within the soil near plant roots. One method for improving soil microorganism community composition is compost tea: enriched liquid compost extract. Compost tea is used in regenerative agriculture to improve crop yields and protect against pathogens, ostensibly through the activity of the added compost microbes. While research has supported compost tea application in regenerative agriculture, it has not been widely studied in the context of ecosystem restoration. To investigate whether compost tea improves native plant establishment, I conducted a greenhouse experiment in pots seeded with a native prairie seed mixture. Pots were divided into three groups, each receiving weekly treatments of either compost tea, boiled compost tea, or water as a control. A comparison between the compost tea and boiled compost tea groups will determine the degree to which the effects of compost tea on native plant growth are due to the nutrients versus the microorganisms in the solution. Overall, my study will inform how compost tea affects native plant biomass, post-treatment abundance, species richness, and community composition. If compost tea application has a positive impact on these metrics, it may be an inexpensive and scalable method to support ecosystem restoration
The effects of salinity on the cutaneous microbiome and pathogen infection on the Pacific Tree frog (Pseudacris regilla) in Monterey Bay, California, USA
No full textGlobal climate change and infectious diseases are considered a leading cause of amphibian population declines worldwide. Changes in precipitation and salinity have altered watershed systems and microbial communities, reducing habitat availability and physiological performances for amphibian survival. The salt refuge hypothesis, however, is a proposed explanation that higher saline environments may reduce susceptibility to pathogens such as Batrachochytrium dendrobatidis (Bd). The Moro Cojo Slough State Marine Reserve (MCSSMR) (California, USA) is known as an abundant breeding ground for endangered/threatened amphibian species. To test and expand the salt refuge hypothesis, I evaluated Bd prevalence and intensity and the cutaneous microbiome of the common Pacific Tree Frog (Pseudacris regilla) across a salinity gradient (0.05-30 ppt) at 10 sites within the reserve. I hypothesized that amphibians in higher saline environments would have lower Bd infection rates and different microbial communities compared to freshwater sites and their environment. Fifteen skin swab samples were collected per site and DNA was extracted for the molecular quantification of Bd via qPCR and bacterial community analysis using 16s rRNA gene (V4-V5 region) sequencing. Bd prevalence decreased across our salinity gradient, from 93% in freshwater to 0% in saltwater sites. Infection intensity was significantly lower in low and medium salt groups compared to freshwater. Salinity as a categorical variable was a significant driver of bacterial composition and diversity in both frog and environmental samples. Salinity as a continuous variable was negatively correlated with bacterial alpha diversity in frogs, while the environmental microbial communities remained consistent across the salinity gradient. Lastly, Bd presence and intensity were correlated with skin microbiome structure, although salinity was a stronger driver. These results support the salt refuge hypothesis and indicate the potential for increased habitat restoration projects where changing environmental conditions, like increasing salinity, could limit pathogen infection and improve amphibian conservation efforts
