Testing the salinity tolerance levels of similar invasive species found in the San Francisco Bay

Testing the salinity tolerance levels of similar invasive species found in the San Francisco Bay Julia Smith1,2, Elizabeth Sheets2, and C. Sarah Cohen2 1Department of Teacher Education, California State University, Sacramento 2Department of Biology and Romberg Tiburon Center, San Francisco State University Three non-indigenous colonial ascidian species, Botrylloides violaceus, Botrylloides diegensis, and Botryllus schlosseri, have become well established in San Francisco Bay. Two species, B. violaceous and B. schlosseri, are globally distributed, and understanding the salinity ranges and tolerances of these successful invaders in their introduced habitats is important for predicting their spread. We tested the tolerance of these three morphologically similar species to salinity ranges that they may encounter locally in San Francisco Bay, and globally, in their broad distributions, including a freshwater transit experiment designed to simulate conditions for ships transiting through the Panama Canal. Botrylloides violaceus, B. diegensis, and Botryllus schlosseri were exposed to various salinities (10, 15, 18, and 20 ppt) for a period of 14 hours, and then assessed for two signs of vitality immediately after each treatment, and were monitored for survival after a week. Our preliminary results showed survival of Botrylloides diegensis, and B. violaceus at the lowest (10 ppt) salinity treatment after 1 week, but no colonies of Botryllus schlosseri survived this salinity treatment in a preliminary trial. The three species all showed survival at our higher (15, 18, and 20 ppt) salinity treatments. In a separate trial, the three target species were also exposed to a drastic salinity decrease to 0 ppt for 7 hours, related to conditions in the Panama Canal. There were no signs of immediate survival in colonies that experienced very low salinity conditions. However, small vascular fragments appear to remain in many colonies three weeks later, and are currently being monitored in the event that they may regenerate, as local colonies of each of these speceis have successfully carried out whole body regeneration from vascular fragments as small as 3.9 mm (Benson Chow, unpub. data)

Phase I/II Trial of Dose-Escalated Busulfan Delivered by Prolonged Continuous Infusion in Allogeneic Transplant Patients

Intensive chemotherapy or chemotherapy plus irradiation and allogeneic stem cell transplantation can be curative for patients with hematologic diseases. Reduced intensity transplants can also achieve cure, and result in less treatment related mortality but higher relapse rates. Thus, optimizing the conditioning regimens used in allogeneic transplantation remains an important goal. We conducted a Phase I/II trial to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLT) of a continuous infusion of busulfan over 90 hours in conjunction with fludarabine followed by allogeneic related or unrelated donor transplant. Fifty-four patients with advanced hematologic malignancies were enrolled on this study. The MTD was identified as a 24 hour area under the curve (AUC) of approximately 7095 uMmin which represents a 43% increase over the standard total daily AUC dose of 4800 uMmin given by intermittent schedules. DLTs at doses over 8000 uMmin were identified as a desquamative skin rash and mucositis. No dose-related increase in hepatic, pulmonary or other organ toxicies were seen while efficacy appeared to be improved at higher dose levels. Continuous infusion busulfan with intermittent fludarabine provides an alternative treatment strategy that is generally well tolerated and permits an increase in total busulfan dose with encouraging efficacy

Members of Marinobacter and Arcobacter Influence System Biogeochemistry During Early Production of Hydraulically Fractured Natural Gas Wells in the Appalachian Basin

Hydraulic fracturing is the prevailing method for enhancing recovery of hydrocarbon resources from unconventional shale formations, yet little is understood regarding the microbial impact on biogeochemical cycling in natural-gas wells. Although the metabolisms of certain fermentative bacteria and methanogenic archaea that dominate in later produced fluids have been well studied, few details have been reported on microorganisms prevelant during the early flowback period, when oxygen and other surface-derived oxyanions and nutrients become depleted. Here, we report the isolation, genomic and phenotypic characterization of Marinobacter and Arcobacter bacterial species from natural-gas wells in the Utica-Point Pleasant and Marcellus Formations coupled to supporting geochemical and metagenomic analyses of produced fluid samples. These unconventional hydrocarbon system-derived Marinobacter sp. are capable of utilizing a diversity of organic carbon sources including aliphatic and aromatic hydrocarbons, amino acids, and carboxylic acids. Marinobacter and Arcobacter can metabolize organic nitrogen sources and have the capacity for denitrification and dissimilatory nitrate reduction to ammonia (DNRA) respectively; with DNRA and ammonification processes partially explaining high concentrations of ammonia measured in produced fluids. Arcobacter is capable of chemosynthetic sulfur oxidation, which could fuel metabolic processes for other heterotrophic, fermentative, or sulfate-reducing community members. Our analysis revealed mechanisms for growth of these taxa across a broad range of salinities (up to 15% salt), which explains their enrichment during early natural-gas production. These results demonstrate the prevalence of Marinobacter and Arcobacter during a key maturation phase of hydraulically fractured natural-gas wells, and highlight the significant role these genera play in biogeochemical cycling for this economically important energy system

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

Patterns and Processes of Salt Efflorescences in the McMurdo region, Antarctica

Evaporite salts are abundant around the McMurdo region, Antarctica (~78°S) due to very low precipitation, low relative humidity, and limited overland flow. Hygroscopic salts in the McMurdo Dry Valleys (MDVs) are preferentially formed in locations where liquid water is present in the austral summer, including along ephemeral streams, ice-covered lake boundaries, or shallow groundwater tracks. In this study, we collected salts from the Miers, Garwood, and Taylor Valleys on the Antarctic continent, as well as around McMurdo Station on Ross Island in close proximity to water sources with the goal of understanding salt geochemistry in relationship to the hydrology of the area. Halite is ubiquitous; sodium is the major cation (ranging from 70%–90% of cations by meq kg-1 sediment) and chloride is the major anion (\u3e50%) in nearly all samples. However, a wide variety of salt phases and morphologies are tentatively identified through scanning electron microscopy (SEM) and X-ray diffraction (XRD) work. We present new data that identifies trona (Na3(CO3)(HCO3)·2H2O), tentative gaylussite (Na2Ca(CO3)2·5H2O), and tentative glauberite (Na2Ca(SO4)2) in the MDV, of which the later one has not been documented previously. Our work allows for the evaluation of processes that influence brine evolution on a local scale, consequently informing assumptions underlying large-scale processes (such as paleoclimate) in the MDV. Hydrological modeling conducted in FREZCHEM and PHREEQC suggests that a model based on aerosol deposition alone in low elevations on the valley floor inadequately characterizes salt distributions found on the surfaces of the soil because it does not account for other hydrologic inputs/outputs. Implications for the salt distributions include their use as tracers for paleolake levels, geochemical tracers of ephemeral water tracks or “wet patches” in the soil, indicators of chemical weathering products, and potential delineators of ecological communities