Spotlight
Environmental Microbiology
Environmental MicrobiologyThe Interactive Effects of Crude Oil and Corexit 9500 on Their Biodegradation in Arctic SeawaterChemical dispersants such as Corexit 9500 are commonly used in oil spill response and are currently under consideration for use in the Arctic, where their fate and effects have not been well studied. This research was performed to determine the interactive effects of the copresence of crude oil and Corexit 9500 on the degradation of components from each mixture and the associated microbial community structure over time in Arctic...
Environmental MicrobiologyFungal-Associated Molecules Induce Key Genes Involved in the Biosynthesis of the Antifungal Secondary Metabolites Nunamycin and Nunapeptin in the Biocontrol Strain Pseudomonas fluorescens In5Cyclic lipopeptide (CLP) synthesis gene clusters in pseudomonads display a high degree of synteny, and the structures of the peptides synthesized are very similar. Accordingly, the genomic island encoding the synthesis of syringomycin and syringopeptin in P. syringae pv. syringae closely resembles that of...
Environmental MicrobiologyStructural and Functional Insights into Iturin W, a Novel Lipopeptide Produced by the Deep-Sea Bacterium Bacillus sp. Strain wsm-1Plant disease caused by pathogenic fungi is one of the most devastating diseases, which affects the food safety of the whole world to a great extent. Biological control of plant diseases by microbial natural products is more desirable than traditional chemical control. In this study, we discovered a novel lipopeptide, iturin W, with promising prospects in biological control of plant diseases. Moreover, the effects of different carbon...
Food Microbiology
Food Microbiology | SpotlightProcessing Has Differential Effects on Microbiota-Accessible Carbohydrates in Whole Grains during In Vitro FermentationDietary nondigestible carbohydrates, or dietary fiber, have long been recognized for their beneficial health effects. However, recent studies have revealed that fermentation of nondigestible carbohydrates by gut bacteria is critical in mediating many of the health-promoting properties of dietary fibers. Whole grains are excellent candidates to supply the microbiome with a plentiful source of nondigestible carbohydrates, although...
Genetics and Molecular Biology
Genetics and Molecular BiologyFerric Uptake Regulator Fur Coordinates Siderophore Production and Defense against Iron Toxicity and Oxidative Stress and Contributes to Virulence in Chromobacterium violaceumMaintenance of iron homeostasis, i.e., avoiding both deficiency and toxicity of this metal, is vital to bacteria and their hosts. Iron sequestration by host proteins is a crucial strategy to combat bacterial infections. In bacteria, the ferric uptake regulator Fur coordinates the expression of several iron-related genes. Sometimes, Fur can also regulate several other processes. In this work, we performed an in-depth phenotypic...
Genetics and Molecular Biology | SpotlightFatty Acid and Alcohol Metabolism in Pseudomonas putida: Functional Analysis Using Random Barcode Transposon SequencingTo engineer novel metabolic pathways into P. putida, a comprehensive understanding of the genetic basis of its versatile metabolism is essential. Here, we provide functional evidence for the putative roles of hundreds of genes involved in the fatty acid and alcohol metabolism of the bacterium. These data provide a framework facilitating precise genetic changes to...
Genetics and Molecular BiologyAntibacterial Activity of Bacillus inaquosorum Strain T1 against pirABVp-Bearing Vibrio parahaemolyticus: Genetic and Physiological CharacterizationThe shrimp aquaculture industry has been significantly impacted by acute hepatopancreatic necrosis disease (AHPND), resulting in significant financial losses annually. AHPND is caused by strains of the bacterial pathogen Vibrio parahaemolyticus, and treatment of AHPND involves the use of antibiotics, which leads to a rise in the number of antibiotic-resistant strains...
Invertebrate Microbiology
Invertebrate MicrobiologyEndosymbionts of Metazoans Dwelling in the PACManus Hydrothermal Vent: Diversity and Potential Adaptive Features Revealed by Genome AnalysisDeep-sea hydrothermal vents are dominated by several invertebrate species. The establishment of symbiosis has long been thought to be the key to successful colonization by these sedentary species in such harsh environments. However, the relationships between symbiotic bacteria and their hosts and their role in environmental adaptations generally remain unclear. In this paper, we show that the distribution of three host species showed...
Methods
MethodsA CRISPRi-dCas9 System for Archaea and Its Use To Examine Gene Function during Nitrogen Fixation by Methanosarcina acetivoransGenetic tools are needed to understand and manipulate the biology of archaea, which serve critical roles in the biosphere. Methanogenic archaea (methanogens) are essential for the biological production of methane, an intermediate in the global carbon cycle, an important greenhouse gas, and a biofuel. The CRISPRi-dCas9 system in the model methanogen Methanosarcina acetivorans...
Microbial Ecology
Microbial EcologyCompetition and Caries on Enamel of a Dual-Species Biofilm Model with Streptococcus mutans and Streptococcus sanguinisThe concept of caries as an ecological disease implies the understanding of the intricate relationships among the populating microorganisms. Under frequent sugar exposure, some bacteria from the dental biofilm develop pathogenic traits that lead to imbalances (dysbiosis). Depending on which microorganism colonizes the dental surface first, different competition strategies may be developed. Studying the interactions in the entire dental...
Microbial EcologySuppression of Rice Planthopper Populations by the Entomopathogenic Fungus Metarhizium anisopliae without Affecting the Rice MicrobiotaEntomopathogenic fungi may be used as crucial biocontrol agents for the control of insect pests, but few effective fungal strains have been reported for the control of the rice planthopper, a major pest of rice. More importantly, the impacts of fungal insecticide application on nontarget microorganisms have not been well evaluated, especially under field conditions. Therefore, in this study, we investigated the effects of the fungal...
Microbial EcologySalmonella enterica Serovar Typhimurium Temporally Modulates the Enteric Microbiota and Host Responses To Overcome Colonization Resistance in SwineLimited information is available on host and enteric microbiota responses incited by Salmonella enterica serovar Typhimurium in swine and on possible mechanisms by which the bacterium overcomes colonization resistance to incite salmonellosis. Temporal characterization of a variety of host metrics in piglets (e.g., physiological, histopathological, and immunological)...
Physiology
Physiology | SpotlightMultiple Drug-Induced Stress Responses Inhibit Formation of Escherichia coli BiofilmsThe prevention of bacterial biofilm formation is one of the major current challenges in microbiology. Here, by systematically screening a large number of approved drugs for their ability to suppress biofilm formation by Escherichia coli, we identified a number of prospective antibiofilm compounds. We further demonstrated different mechanisms of action for individual...
PhysiologyInvolvement of the Cell Wall Integrity Pathway of Saccharomyces cerevisiae in Protection against Cadmium and Arsenate StressesEnvironmental pollution by metal/metalloids such as cadmium and arsenic has become a serious problem in many countries, especially in developing countries. This study shows that in the yeast S. cerevisiae, the CWI pathway plays a protective role against cadmium and arsenate through the upregulation of genes involved in cell wall biosynthesis and cell cycle control,...
Physiology | SpotlightImproving Arsenic Tolerance of Pyrococcus furiosus by Heterologous Expression of a Respiratory Arsenate ReductaseArsenate respiratory reductases (Arr) are much less characterized than the detoxifying arsenate reductase system. The heterologous expression and characterization of an Arr from Pyrobaculum aerophilum in Pyrococcus furiosus provides new insights into the function of this enzyme. From in vivo...
Public and Environmental Health Microbiology
Public and Environmental Health MicrobiologyAssessment of Soil Features on the Growth of Environmental Nontuberculous Mycobacterial Isolates from Hawai'iGlobally and in the United States, the prevalence of NTM pulmonary disease—a potentially life-threatening but underdiagnosed chronic illness—is prominently rising. While NTM are ubiquitous in the environment, including in soil, the specific soil components that promote or inhibit NTM growth have not been elucidated. We hypothesized that NTM culture-positive soil contains minerals that promote NTM growth in vitro. Because Hawai’...
Public and Environmental Health Microbiology | SpotlightThree Candidate Probiotic Strains Impact Gut Microbiota and Induce Anergy in Mice with Cow's Milk AllergyWe showed previously that three probiotic strains, i.e., Lactobacillus rhamnosus LA305, L. salivarius LA307, and Bifidobacterium longum subsp. infantis LA308, exerted different preventive effects in a mouse model of cow’s...
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Applied and Environmental Microbiology® (AEM) publishes study results that make significant contributions to applied microbial research, basic microbial ecology research, and genetic and molecular investigations of microbial topics of practical value.
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