A5018049723- Microbial Community Ecology and Physiology
- Polar Research and Ecology
- Enzyme Structure and Function
- Spaceflight effects on biology
- Methane Hydrates and Related Phenomena
- Planetary Science and Exploration
- Mercury impact and mitigation studies
- Molecular Sensors and Ion Detection
- Chemical Analysis and Environmental Impact
- Biocrusts and Microbial Ecology
- Space Science and Extraterrestrial Life
- Enzyme Production and Characterization
- Genomics and Phylogenetic Studies
- Porphyrin Metabolism and Disorders
- Protein Structure and Dynamics
University of Maryland, Baltimore
2016-2022
University System of Maryland
2021-2022
Effects of perchlorate salts prevalent on the surface Mars are significant interest to astrobiology from perspective potential life Red Planet. Halorubrum lacusprofundi, a cold-adapted halophilic Antarctic archaeon, was able grow anaerobically 0.04 M concentration perchlorate. With increasing concentrations perchlorate, growth inhibited, with half-maximal rate in ca. 0.3 NaClO4 and 0.1 Mg(ClO4)2 under aerobic conditions. Magnesium ions were also inhibitory for growth, but at considerably...
Abstract Halophilic Archaea are known to tolerate multiple extreme conditions on Earth and have been proposed as models for astrobiology. In order assess the importance of cold-adaptation these microorganisms in surviving stratospheric conditions, we launched live, liquid cultures two species, mesophilic model Halobacterium sp. NRC-1 cold-adapted Antarctic isolate Halorubrum lacusprofundi ATCC 49239, helium balloons. After return Earth, species showed nearly complete survival while exhibited...
Significance Combining comparative genomics, mutagenesis, kinetic analysis, and molecular modeling provides a powerful way to explore understand the structure function of proteins under extreme potentially astrobiological conditions. Alignment closely related cold-active mesophilic β-galactosidase enzymes from halophilic Archaea, followed by mutagenesis demonstrates importance specific amino acid residues in temperature-dependent catalytic activity, while structural framework for their...
Halorubrum sp. strain BOL3-1 was isolated from Salar de Uyuni, Bolivia, and sequenced using single-molecule real-time sequencing. Its 3.7-Mbp genome analyzed for gene content methylation patterns incorporated into the Haloarchaeal Genomes Database (http://halo.umbc.edu). The polyextremophilic character high-elevation environment make microbe of interest astrobiology.
The polyextremophilic β-galactosidase enzyme of the haloarchaeon Halorubrum lacusprofundi functions in extremely cold and hypersaline conditions. To better understand basis activity, was studied using steady-state kinetics molecular dynamics at temperatures ranging from 10 °C to 50 salt concentrations 1 M 4 KCl. Kinetic analysis showed that while catalytic efficiency (kcat/Km) improves with increasing temperature salinity, Km is reduced decreasing consistent improved substrate binding low...
The Antarctic haloarchaeon, Halorubrum lacusprofundi, contains a polyextremophilic family 42 β-galactosidase, which we are using as model for cold-active enzymes. Divergent amino acid residues in this 78 kDa protein were identified through comparative genomics and hypothesized to be important cold activity. Six previously mutated five shown by steady-state kinetic analysis have altered temperature-dependent catalytic activity profiles via effects on Km and/or kcat compared the wild-type...