Nitrification, a key process in the nitrogen cycle, involves the oxidation of ammonia to nitrite and nitrate by a diverse group of chemolithoautotrophic microorganisms. The order Nitrospirales (referred to in literature as the genus Nitrospira), which includes both nitrite-oxidizing and complete ammonia-oxidizing bacteria, plays a central role in this process. We sequenced the genomes of nine Nitrospirales members, incorporating genomes from previously unsequenced taxonomic Nitrospirales lineages.
View Article and Find Full Text PDFDespite their large environmental impact and multiple independent emergences, the processes leading to the evolution of anaerobic methanotrophic archaea (ANME) remain unclear. This work uses comparative metagenomics of a recently evolved but understudied ANME group, " Methanovorans" (ANME-3), to identify evolutionary processes and innovations at work in ANME, which may be obscured in earlier evolved lineages. We identified horizontal transfer of homologs and convergent evolution in carbon and energy metabolic genes as potential early steps in evolution.
View Article and Find Full Text PDFPaddy fields are major contributors to agricultural greenhouse gas emissions. Applying ~1% biochar by topsoil weight (high single, HS) effectively reduces greenhouse gas emissions from paddy fields, but long-term impacts are unclear. Here we present 8-year field experiments showing HS reduces CO equivalent per hectare by 59% and yields a net benefit of US$1,810 per hectare.
View Article and Find Full Text PDFDiscovering new deep hydrothermal vent systems is one of the biggest challenges in ocean exploration. They are a unique window to elucidate the physical, geochemical, and biological processes that occur on the seafloor and are involved in the evolution of life on Earth. In this study, we present a molecular analysis of the microbial composition within the newly discovered hydrothermal vent field, , situated in the Southern Pescadero Basin within the Gulf of California.
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