Bradley Scott Stevenson

Bradley Scott Stevenson
University of Oklahoma | ou · Department of Microbiology and Plant Biology

Ph.D. in Microbiology

About

149
Publications
12,408
Reads
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2,219
Citations
Citations since 2017
53 Research Items
1149 Citations
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Introduction
My research group studies the ecological roles and metabolic activities of novel microorganisms and microbial assemblages. We are specifically interested in their role in the decomposition of complex organic matter, biocorrosion of metal surfaces, production of biofuels, and synthesis of bioactive metabolites. Our work involves cultivation, molecular, and genomic approaches.
Additional affiliations
September 2008 - present
University of Oklahoma
Position
  • Enhancing the production of liquid biofuels from synthesis gas
Description
  • We are investigating and enhancing the production of liquid biofuels from synthesis gas by microbial catalysts (Clostridium spp.) through genomics and genetic manipulation.

Publications

Publications (149)
Preprint
Full-text available
Microbiological contamination in diesel storage tanks is widespread and under-reported. The contaminating microorganisms can degrade components of the fuel, which contributes to fouling and corrosion. To better understand the connection between the microorganisms that are responsible for this contamination, the composition of affected fuels, and th...
Article
Full-text available
Determining the drivers of microbial community assembly is a central theme of microbial ecology, and chemical ecologists seek to characterize how secondary metabolites mediate these assembly patterns. Environmental structure affects how communities assemble and what metabolic pathways aid in that assembly. Here, we bridged these two perspectives by...
Article
SARS-CoV-2 was discovered among humans in late 2019 and rapidly spread across the world. Although the virus is transmitted by respiratory droplets, most infected persons also excrete viral particles in their feces. This fact prompted a range of studies assessing the usefulness of wastewater surveillance to determine levels of infection and transmis...
Article
Full-text available
Fungi that degrade B20 biodiesel in storage tanks have also been linked to microbiologically influenced corrosion (MIC). A member of the filamentous fungal genus Byssochlamys , and a yeast from the genus Wickerhamomyces were isolated from heavily contaminated B20 storage tanks from multiple Air Force bases. Although these taxa were linked to microb...
Article
Full-text available
Molecular techniques continue to reveal a growing disparity between the immense diversity of microbial life and the small proportion that is in pure culture. The disparity, originally dubbed “the great plate count anomaly” by Staley and Konopka, has become even more vexing given our increased understanding of the importance of microbiomes to a host...
Preprint
Full-text available
Fungi that degrade B20 biodiesel in storage tanks have also been linked to microbiologically influenced corrosion (MIC). A member of the filamentous fungal genus Byssochlamys, and a yeast from the genus Wickerhamomyces were isolated from heavily contaminated B20 storage tanks from multiple Air Force bases. Although these taxa were linked to microbi...
Article
Full-text available
Micro-organisms have long been implicated in the construction of stromatolites. Yet, establishing a microbial role in modern stromatolite growth via molecular analysis is not always straightforward because DNA in stromatolites can have multiple origins. For example, the genomic material could represent the microbes responsible for the construction...
Preprint
Full-text available
Molecular techniques continue to reveal a growing disparity between the immense diversity of microbial life and the small proportion that is in pure culture. The disparity, originally dubbed “the great plate count anomaly” by Staley and Konopka, has become even more vexing given our increased understanding of the importance of microbiomes to a host...
Article
Microbially influenced corrosion (MIC) is a common problem in biodiesel storage tanks. Here, thick microbial growths develop at and span aqueous/non-aqueous fluid interfaces. MIC in this setting was investigated in experiments using zero-resistance ammetry (ZRA) measurements. To mimic the water-fuel interface, one carbon steel coupon was deployed i...
Article
Background Environmental contamination of patient rooms and adjacent areas with C. difficile spores is a recognized transmission risk. Previous studies have shown that spores are aerosolized during patient care. These spores can remain airborne for extended periods and may contaminate distant surfaces. High volume air sampling equipment allows for...
Article
Full-text available
Renewable fuels hold great promise for the future yet their susceptibility to biodegradation and subsequent corrosion represents a challenge that needs to be directly assessed. Biodiesel is a renewable fuel that is widely used as a substitute or extender for petroleum diesel and is composed of a mixture of fatty acid methyl esters derived from plan...
Article
Full-text available
The airborne dissemination of Clostridium difficile (C. difficile) endospores (spores) in healthcare environments is documented in multiple studies. Once airborne, spores have the potential for transport on air currents to other areas. This study compared the methods in the collection of C. difficile spore aerosol. This study determined the relativ...
Article
Full-text available
Phialemoniopsis curvata D216 is a filamentous fungus isolated from contaminated diesel fuel. The genome size is 40.3 Mbp with a G+C content of 54.81%. Its genome encodes enzymes and pathways likely involved in the degradation of and survival in fuel, including lipases, fatty acid transporters, and beta oxidation.
Article
Full-text available
The microscopic alga Picocystis sp. strain ML is responsible for recurrent algal blooms in Mono Lake, CA. This organism was characterized by only very little molecular data, despite its prominence as a primary producer in saline environments. Here, we report the draft genome sequence for Picocystis sp. strain ML based on long-read sequencing.
Preprint
Full-text available
Biodiesel is a renewable substitute, or extender, for petroleum diesel that is composed of a mixture of fatty acid methyl esters (FAME) derived from plant and animal fats. Ultra-low sulfur diesel (ULSD) blended with up to 20% FAME can be used interchangeably with ULSD, is compatible with existing infrastructure, but is also more susceptible to biod...
Article
Algal blooms in lakes are often associated with anthropogenic eutrophication; however, they can occur without the human introduction of nutrients to a lake. A rare bloom of the alga Picocystis sp. strain ML occurred in the spring of 2016 at Mono Lake, a hyperalkaline lake in California, which was also at the apex of a multiyear-long drought. These...
Article
Full-text available
Microbial mats are found in a variety of modern environments, with evidence for their presence as old as the Archean. There is much debate about the rates and conditions of processes that eventually lithify and preserve mats as microbialites. Here, we apply novel tracer experiments to quantify both mat biomass addition and the formation of CaCO3. M...
Preprint
Full-text available
Algal blooms in lakes are often associated with anthropogenic eutrophication; however, they can occur naturally. In Spring of 2016 Mono Lake, a hyperalkaline lake in California, was near the height of a rare bloom of the algae Picocystis strain ML and at the apex of a multi-year long drought. These conditions presented a unique sampling opportunity...
Article
Full-text available
Hot spring environments can create physical and chemical gradients favorable for unique microbial life. They can also include authigenic mineral precipitates that may preserve signs of biological activity on Earth and possibly other planets. The abiogenic or biogenic origins of such precipitates can be difficult to discern, therefore a better under...
Article
Full-text available
Byssochlamys sp. strain AF001 is a filamentous fungus isolated from fouled B20 biodiesel. Its growth on B20 biodiesel results in the degradation and fouling of the fuel and higher rates of corrosion in affected storage tanks. The genome ofByssochlamyssp. AF001 is 35.9 Mbp and is composed of 10 scaffolds, with a G+C content of 45.89%.
Article
Full-text available
Pseudomonas sp. strain WP001 is a laboratory isolate capable of polyurethane polymer degradation and harbors a predicted lipase precursor gene. The genome of strain WP001 is 6.15 Mb in size and is composed of seven scaffolds with a G+C content of 60.54%. Strain WP001 is closely related toPseudomonas fluorescensbased on ribosomal DNA comparisons.
Article
Full-text available
Ancient putative microbial structures that appear in the rock record commonly serve as evidence of early life on Earth, but thedetails of their formation remain unclear. The study of modern microbial mat structures can help inform the properties of theirancient counterparts, but modern mineralizing mat systems with morphological similarity to ancie...
Article
Full-text available
Significance Using a combined approach relying on mass spectrometric analysis and molecular phylogeny, a fungus was identified that produced the gichigamins, which are peptaibols that contain a remarkable combination of structural features. The gichigamins possess a repeating α-residue/α-residue/β-residue motif creating a 3 11 - P -helix secondary...
Article
Full-text available
Offshore oil-producing platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three o...
Article
Full-text available
Few secondary metabolites have been reported from mammalian microbiome bacteria despite the large numbers of diverse taxa that inhabit warm-blooded higher vertebrates. As a means to investigate natural products from these microorganisms, an opportunistic sampling protocol was developed, which focused on exploring bacteria isolated from roadkill mam...
Article
Full-text available
Microbial life is ubiquitous, yet we are just beginning to understand how microbial communities are assembled. We test whether relationships between ant microbiomes and their environments resemble patterns identified in the human home microbiome. We examine the microbial communities and chemical composition of ants, their waste, their nest, and the...
Article
Full-text available
Microorganisms found in terrestrial subsurface environments make up a large proportion of the Earth’s biomass. Biogeochemical cycles catalyzed by subsurface microbes have the potential to influence the speciation and transport of radionuclides managed in geological repositories. To gain insight on factors that constrain microbial processes within a...
Poster
Mono Lake is a closed-basin stratified soda lake (pH = 9.8; salinity = 60 g/L) that supports high rates of primary productivity (annual average of 100 mmol C m-2 d-1), and is dominated by a eukaryotic alga, Picocystis strain ML. To further investigate the unique biology of the lake, we sampled the water column during an algal bloom when productivit...
Article
Few secondary metabolites have been reported from mammalian microbiome bacteria despite the large numbers of diverse taxa that inhabit warm-blooded higher vertebrates. As a means to investigate natural products from these microorganisms, an opportunistic sampling protocol was developed, which focused on exploring bacteria isolated from roadkill mam...
Article
Full-text available
Microbial activity associated with produced water from hydraulic fracturing operations can lead to gas souring and corrosion of carbon-steel equipment. We examined the microbial ecology of produced water and the prospective role of the prevalent microorganisms in corrosion in a gas production facility in the Barnett Shale. The microbial community w...
Article
Full-text available
Landfills are the final repository for most of the discarded material from human society and its "built environments." Microorganisms subsequently degrade this discarded material in the landfill, releasing gases (largely CH4 and CO2) and a complex mixture of soluble chemical compounds in leachate. Characterization of "landfill microbiomes" and thei...
Data
QIIME-compatible mapping file used for meta-analyses of microbial communities.
Data
Results from PERMANOVA analyses of allapost-hoc tests of environmental variables and CEC concentrations.
Data
Relative abundance of OTUs detected in each landfill leachate sample.
Data
Concentrations of CECs (ng/mL) for leachates used in PERMANOVA analyses.
Data
QIIME-compatible mapping file used for comparison of landfill leachates.
Data
Diversity indices for sampled leachate microbiomes.
Data
Taxonomy of OTUs found in the landfill leachate core microbiome.
Data
Phylogenetic tree based on the non-redundant tree (SILVA r123 NR99) within the phylogenetic software package ARB, which is composed of all unclassified OTUs from landfill leachates and closely related sequences. Taxonomic groupings are labeled and delineated with brackets. Scale bar represents a nucleotide dissimilarity of 0.10.
Data
Volume (mL) filtered and concentration (ng/μL) of DNA recovered from each leachate sample.
Data
Environmental variables for leachates used in PERMANOVA analyses.
Data
Absolute abundance of OTUs detected in each landfill leachate sample.
Poster
Ancient conical stromatolite formation is poorly understood and modern analogues are uncommon (and typically not CaCO3). However, a team from the 2015 International GeoBiology Course investigated carbonate-rich microbial cones found in a hot spring pool near Little Hot Creek (LHC), Long Valley Caldera, California, in order to improve the understand...