A5004001320- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Hydrocarbon exploration and reservoir analysis
- Microbial Community Ecology and Physiology
- Marine Biology and Ecology Research
- Marine and coastal ecosystems
- Marine and coastal plant biology
- Microbial metabolism and enzyme function
- Bacteriophages and microbial interactions
- Geology and Paleoclimatology Research
- Genomics and Phylogenetic Studies
- Coal Properties and Utilization
- Gut microbiota and health
- Geochemistry and Elemental Analysis
University of California, Santa Barbara
2023-2024
University of California, Los Angeles
2021-2023
Planetary Science Institute
2021-2023
Abstract Many microbes in nature reside dense, metabolically interdependent communities. We investigated the and extent of microbe-virus interactions relation to microbial density syntrophy by examining a biomass deep-sea hydrothermal mat. Using metagenomic sequencing, we find numerous instances where phylogenetically distant (up domain level) encode CRISPR-based immunity against same viruses Evidence viral with hosts cross-cutting domains is particularly striking between known syntrophic...
A fourth of the global seabed sediment volume is buried at depths where temperatures exceed 80 °C, a previously proposed thermal barrier for life in subsurface. Here, we demonstrate, utilizing an extensive suite radiotracer experiments, prevalence active methanogenic and sulfate-reducing populations deeply marine from Nankai Trough subduction zone, heated to extreme temperature (up ~120 °C). The small microbial community subsisted with high potential cell-specific rates energy metabolism,...
Microbial anaerobic oxidation of methane (AOM) substantially mitigates atmospheric emissions on Earth and is a process to consider for astrobiological targets where has been detected. The measurement doubly substituted, or "clumped", isotopes proven useful in tracing processes formation oxidation. Both near-equilibrium extreme disequilibrium clumped isotope signatures can be attributed AOM, but, date, understanding the mechanistic environmental controls those lacking. We report measurements...
Methanogenesis has recently been shown to fuel anaerobic oxidation of methane (AOM) within the sulfate-reducing zone marine sediments, coining term "cryptic cycle". Here we present research on relationship between methanogenesis and AOM in a shallow hypersaline pool (∼130 PSU) southern California coastal wetland. Sediment (top 20 cm) was subjected geochemical analyses, in-vitro slurry experiments, radiotracer incubations using 35S-SO42−, 14C-mono-methylamine, 14C-CH4, study sulfate...
Abstract. The Santa Barbara Basin naturally experiences transient deoxygenation due to its unique geological setting in the southern California Borderland and seasonal changes ocean currents. Long-term measurements of basin showed that anoxic events subsequent nitrate exhaustion bottom waters have been occurring more frequently lasting longer over past decade. One characteristic is development extensive mats benthic nitrate-reducing sulfur-oxidizing bacteria, which are found at...
Abstract. The recently discovered cryptic methane cycle in the sulfate-reducing zone of marine and wetland sediment couples methylotrophic methanogenesis to anaerobic oxidation (AOM). Here we present evidence cycling activity within upper regions zone, along a depth transect Santa Barbara Basin, off coast California, USA. top 0–20 cm from each station was subjected geochemical analyses radiotracer incubations using 35S–SO42-, 14C–mono-methylamine, 14C–CH4 find cycling. Methane concentrations...
Abstract Methylotrophic methanogenesis in the sulfate reduction zone of wetland and marine sediment has recently been coupled to anaerobic oxidation methane (AOM), now referred as cryptic cycle. In this study we present evidence cycling activity within sulfate-reducing zone, along a land-ocean transect Carpinteria Salt Marsh Reserve (CSMR), Carpinteria, CA, USA consisting four stations; two brackish, one marine, hypersaline. The top 20 cm collected was subjected geochemical molecular...
Abstract. The recently discovered cryptic methane cycle in the sulfate-reducing zone of marine and wetland sediments couples methylotrophic methanogenesis to anaerobic oxidation (AOM). Here we present evidence cycling activity within upper regions zone, along a depth transect Santa Barbara Basin, off coast California, USA. top 0–20 cm sediment from each station was subjected geochemical analyses radiotracer incubations using 35S-SO42-, 14C-mono-methylamine, 14C- CH4 find cycling. Methane...
Wetland methane emissions are the primary natural contributor to global budget, accounting for approximately one-third of total from and anthropogenic sources. Anaerobic oxidation (AOM) serves as major sink in anoxic wetland sediments, where electron acceptors present, thereby effectively mitigating its emissions. Nevertheless, environmental controls on acceptors, particular, ubiquitous iron oxides, involved AOM poorly understood. Here, we explored sinks within a hypersaline pool situated...
Abstract. The Santa Barbara Basin naturally experiences transient deoxygenation due to its unique geological setting in the Southern California Borderland and seasonal changes ocean currents. Long-term measurements of basin showed that anoxic events subsequent nitrate exhaustion bottom waters have been occurring more frequently lasting longer over past decade. One characteristic is development extensive mats benthic nitrate-reducing sulfur-oxidizing bacteria, which are found at...
Sequestration of carbon dioxide via sinking farmed seaweed into the ocean is a promising strategy to ever-growing need achieve negative emissions dioxide. A key component durability method which biomass conveyed seafloor. The purpose this white paper introduce four different conveyance techniques, plans for how each technique will be implemented at smaller scales, and describe modeled. development guided by balance between overcoming positively buoyant kelp biomass, overall feasibility given...
One promising carbon dioxide removal (CDR) strategy to achieve negative emissions of is the sinking farmed seaweed into ocean where it may be sequestered. Methods quantify rates, degradation rates and release products from kelp fundamental understanding durability if applied scale. The aim this white paper describe methods we plan use determine such as particulate dissolved organic carbon, well inorganic carbon. design guided by previously published considers type packaging conveyance...
<p>Sulfate reduction, a crucial metabolic pathway for organic matter remineralization in marine sediments, produces hydrogen sulfide that can be subsequently utilized by chemoautotrophic organisms. When the water column above sediments becomes anoxic, microbial metabolisms at sediment-water interface shift to take advantage of electron donors and acceptors available new redox conditions. These processes were examined In November 2019 during AT42-19 expedition aboard RV...
<p>Microbial anaerobic oxidation of methane (AOM) significantly mitigates atmospheric emissions on Earth and represents a thermodynamically favorable metabolic strategy for astrobiological targets where has been detected. The bulk carbon hydrogen isotope ratios produced by AOM have used to probe the thermodynamic drive intracellular reactions that involve bi-directional enzymes methanogenesis pathway. Recently, measurements abundance doubly-substituted isotopologues provide...
<p>     Methane in anoxic marine sediments comes primarily from microbial methanogenesis. Methanogenesis is facilitated by groups of obligate anaerobic archaea and the last step carbon remineralization according to redox cascade. Before methane emitted into water column ultimately atmosphere, where acts as a potent greenhouse gas, large portion (~90%) consumed oxidation (AOM). In AOM typically mediated consortium methanotrophic...
<p>A fourth of the global seabed sediment volume is buried at depths where temperatures exceed 80 °C, a previously proposed thermal barrier for life in subsurface. Here, we demonstrate, utilizing an extensive suite radiotracer experiments, prevalence active methanogenic and sulfate-reducing populations deeply marine from Nankai Trough subduction zone, heated to extreme temperature (up ~120 °C). Sediment cores were recovered during International Ocean...