Closed environments such as the International Space Station (ISS) and spacecraft for other planned interplanetary destinations require sustainable environmental control systems for manned spaceflight and habitation. These systems require monitoring for microbial contaminants and potential pathogens that could foul equipment or affect the health of the crew. Technological advances may help to facilitate this environmental monitoring, but many of the current advances do not function as expected in reduced gravity conditions.
View Article and Find Full Text PDFAppl Environ Microbiol
February 2013
Microorganisms are abundant in the upper atmosphere, particularly downwind of arid regions, where winds can mobilize large amounts of topsoil and dust. However, the challenge of collecting samples from the upper atmosphere and reliance upon culture-based characterization methods have prevented a comprehensive understanding of globally dispersed airborne microbes. In spring 2011 at the Mt.
View Article and Find Full Text PDFMicroorganisms are abundant in the troposphere and can be transported vast distances on prevailing winds. This study measures the abundance and diversity of airborne bacteria and fungi sampled at the Mt. Bachelor Observatory (located 2.
View Article and Find Full Text PDFA two-component bacteriophage-based bioluminescent reporter system was developed for the detection of Escherichia coli in environmental samples. The bioreporter system consists of a luxI integrated lambda bacteriophage and a lux-based bioluminescent reporter cell that responds to the infection event through acyl-homoserine lactone (AHL) mediated quorum sensing and bioluminescent signal stimulation. This work addresses the ability of the bioreporter system to detect and quantify the target pathogen in response to two analytical challenges: (1) detection of target cells in the presence of lactonase-producing non-target organisms that could interrupt AHL signal transduction, and (2) detection of sub-lethally injured or physiologically stressed target cells.
View Article and Find Full Text PDFThe redox control bioreactor (RCB) is a new hollow fiber membrane bioreactor (HFMBR) design in which oxygen and hydrogen gases are provided simultaneously through separate arrays of juxtaposed hollow fiber (HF) membranes. This study applied the RCB for completely autotrophic conversion of ammonia to N(2) through nitrification with O(2) and denitrification using hydrogen as an electron donor (i.e.
View Article and Find Full Text PDFHigh-throughput screening (HTS) assays based upon fluorometric detection of oxygen consumption in microtiter plates were primarily developed for applications in drug discovery and ecotoxicology but have recently been adopted for use in microbial community-level physiological profiling assays (CLPP). The widespread use of oxygen biosensor systems for CLPP applications has, however, been hindered by the relatively high cost of oxygen biosensor reagent systems and limited access to microplate fluorometer instrumentation platforms. The ability to recycle and reuse oxygen biosensor system plates would expand their utilization for CLPP assays and other research applications in microbial ecology.
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