Applied and Environmental Science
Research Article | Applied and Environmental ScienceArginine Exposure Decreases Acidogenesis in Long-Term Oral Biofilm MicrocosmsArginine is used in dental health formulations to help prevent dental cavities. This study assessed the effects of the long-term dosing of laboratory dental plaques with an arginine dentifrice. Data indicate that the addition of arginine dentifrice during sucrose challenge significantly increased plaque pH, thus potentially mitigating cariogenesis. Several functional groups of bacteria associated with tooth decay were significantly...
Editor's Pick Research Article | Applied and Environmental ScienceMonodeuterated Methane, an Isotopic Tool To Assess Biological Methane Metabolism RatesMicrobial methane consumption is a critical component of the global carbon cycle, with wide-ranging implications for climate regulation and hydrocarbon exploitation. Nonetheless, quantifying methane metabolism typically involves logistically challenging methods and/or specialized equipment; these impediments have limited our understanding of methane fluxes and reservoirs in natural systems, making effective management difficult. Here,...
Research Article | Applied and Environmental ScienceCharacterization of Legionella Species from Watersheds in British Columbia, CanadaMany species of Legionella can cause Legionnaires’ disease, a significant cause of bacterial pneumonia. Legionella in human-made water systems such as cooling towers and building plumbing systems are the primary sources of Legionnaires’ disease outbreaks. In this temporal study of natural aquatic environments, Legionella relative abundance was shown to vary in watersheds associated with different land uses....
Research Article | Applied and Environmental ScienceLignocellulose-Degrading Microbial Communities in Landfill Sites Represent a Repository of Unexplored Biomass-Degrading DiversityThe microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored...
Research Article | Applied and Environmental ScienceVisualizing Antimicrobials in Bacterial Biofilms: Three-Dimensional Biochemical Imaging Using TOF-SIMSModern analytical techniques are becoming increasingly important in the life sciences; imaging mass spectrometry offers the opportunity to gain unprecedented amounts of information on the distribution of chemicals in samples—both xenobiotics and endogenous compounds. In particular, simultaneous imaging of antibiotics (and other antimicrobial compounds) and bacterium-derived metabolites in complex biological samples could be very...
Research Article | Applied and Environmental ScienceSulfide Generation by Dominant Halanaerobium Microorganisms in Hydraulically Fractured ShalesAlthough thousands of wells in deep shale formations across the United States have been hydraulically fractured for oil and gas recovery, the impact of microbial metabolism within these environments is poorly understood. Our research demonstrates that dominant microbial populations in these subsurface ecosystems contain the conserved capacity for the reduction of thiosulfate to sulfide and that this process is likely occurring in the...
Research Article | Applied and Environmental ScienceRetrospective Surveillance of Wastewater To Examine Seasonal Dynamics of Enterovirus InfectionsEnterovirus infections are often not tracked or reported to health officials. This makes it hard to know how many people in a community are infected with these viruses at any given time. Here, we explored enterovirus in municipal wastewater to look at this issue. We show that enteroviruses are present year-round in municipal wastewater at levels of up to 800,000 genomic copies per liter. We estimate that, on average, 2.8% of the people...
Research Article | Applied and Environmental ScienceUnique Features of Aeromonas Plasmid pAC3 and Expression of the Plasmid-Mediated Quinolone Resistance GenesIn the present study, plasmid pAC3 isolated from a highly fluoroquinolone-resistant isolate of Aeromonas species was sequenced and found to contain two fluoroquinolone resistance genes, aac(6′)-Ib-cr and qnrS2. Comparative analyses of plasmid pAC3 and other Aeromonas sp. IncU-type plasmids revealed a mobile insertion cassette element with a unique structure containing a qnrS2...
Editor's Pick Research Article | Applied and Environmental ScienceAnalysis of Light- and Carbon-Specific Transcriptomes Implicates a Class of G-Protein-Coupled Receptors in Cellulose SensingIn fungi, most metabolic processes are subject to regulation by light. For Trichoderma reesei, light-dependent regulation of cellulase gene expression is specifically shown. Therefore, we intended to unravel the relationship between regulation of enzymes by the carbon source and regulation of enzymes by light. Our two-dimensional analysis included inducing and repressing carbon sources which we used to compare light-specific...
Observation | Applied and Environmental ScienceNovel β-Lactamase blaARL in Staphylococcus arlettaePenicillins are an important group of antibiotics used to treat various types of infections caused by Gram-positive bacteria. So far, the blaZ gene was the only known β-lactamase gene in staphylococci. However, other putative β-lactamases were identified, and one of them was shown to be a novel functional β-lactamase encoded by blaARL in ...