Spotlight
Biodegradation
BiodegradationTranscriptomic and Proteomic Responses of the Organohalide-Respiring Bacterium Desulfoluna spongiiphila to Growth with 2,6-Dibromophenol as the Electron AcceptorRespiratory reductive dehalogenation is an important process in the overall cycling of both anthropogenic and natural organohalide compounds. Marine sponges produce a vast array of bioactive compounds as secondary metabolites, including diverse halogenated compounds that may enrich for dehalogenating bacteria. Desulfoluna spongiiphila strain AA1 was originally...
Biotechnology
Biotechnology | SpotlightMelanin Produced by the Fast-Growing Marine Bacterium Vibrio natriegens through Heterologous Biosynthesis: Characterization and ApplicationMelanins are macromolecules that are ubiquitous in nature and impart a large variety of biological functions, including structure, coloration, radiation resistance, free radical scavenging, and thermoregulation. Currently, in the majority of investigations, melanins are either chemically synthesized or extracted from animals, which presents significant challenges for large-scale production. Bacteria have been used as biocatalysts to...
Environmental Microbiology
Environmental MicrobiologySoil Microbial Communities in Diverse Agroecosystems Exposed to the Herbicide GlyphosateIncreasing the efficiency of food production systems while reducing negative environmental effects remains a key societal challenge to successfully meet the needs of a growing global population. The herbicide glyphosate has become a nearly ubiquitous component of agricultural production across the globe, enabling an increasing adoption of no-till agriculture. Despite this widespread use, there remains considerable debate on the...
Environmental Microbiology | SpotlightSmall Molecules Produced by Commensal Staphylococcus epidermidis Disrupt Formation of Biofilms by Staphylococcus aureusS. aureus is a leading agent of infections worldwide, and its main virulence characteristic is the ability to produce biofilms on surfaces such as medical devices. Biofilms are known to confer increased resistance to antimicrobials and to the host immune responses, requiring aggressive antibiotic treatment and removal of the infected surface. Here, we investigated a...
Enzymology and Protein Engineering
Enzymology and Protein EngineeringA Novel d-Allulose 3-Epimerase Gene from the Metagenome of a Thermal Aquatic Habitat and d-Allulose Production by Bacillus subtilis Whole-Cell Catalysisd-Allulose is a noncaloric sugar substitute with antidiabetes and antiobesity potential. With several characteristics of physiological significance, d-allulose has wide-ranging applications in the food and pharmacology industries. The development of a thermostable biocatalyst is an objective of mainstream research aimed at achieving industrial acceptability of the enzyme. Aquatic habitats...
Food Microbiology
Food Microbiology | SpotlightLaeA Controls Citric Acid Production through Regulation of the Citrate Exporter-Encoding cexA Gene in Aspergillus luchuensis mut. kawachiiA. kawachii has been traditionally used for production of the distilled spirit shochu in Japan. Citric acid produced by A. kawachii plays an important role in preventing microbial contamination during the shochu fermentation process. This study characterized homologous laeA genes; using CAGE, complementation tests, and ChIP-qPCR, it was found that laeA is required for citric acid production through...
Food MicrobiologyAttenuated Lactococcus lactis and Surface Bacteria as Tools for Conditioning the Microbiota and Driving the Ripening of Semisoft Caciotta CheeseThis study provides in-depth knowledge of the effects of attenuated starters and surface bacterial strains on the microbiota and related metabolic activities during cheese ripening. The use of attenuated Lc. lactis strongly impacted the microbiota assembly of caciotta cheese. This led to improved biochemical and sensory features compared to conventional cheese. Among...
Food MicrobiologyNonthermal Plasma Induces the Viable-but-Nonculturable State in Staphylococcus aureus via Metabolic Suppression and the Oxidative Stress ResponseIn recent years, nonthermal plasma (NTP) technology has received a lot of attention as a promising alternative to thermal pasteurization in the food industry. However, little is known about the microbial stress response toward NTP, which could be a potential risk to food safety and impede the development of NTP. A viable but nonculturable (VBNC) state is one of the most common survival strategies employed by microorganisms against...
Food MicrobiologyPerformance and Accuracy of Four Open-Source Tools for In Silico Serotyping of Salmonella spp. Based on Whole-Genome Short-Read Sequencing DataSalmonella spp. are important foodborne pathogens. To reduce the number of infected patients, it is essential to understand which subtypes of the bacteria cause disease outbreaks. Traditionally, characterization of Salmonella requires serological testing, a laboratory method by which Salmonella isolates can be classified into over 2,600 distinct subtypes, called serovars. Due to recent advances in whole-genome...
Food MicrobiologyGenetic Determinants of Hydroxycinnamic Acid Metabolism in Heterofermentative LactobacilliThe metabolism of secondary plant metabolites, including phenolic compounds, by food-fermenting lactobacilli is a significant contributor to the safety, quality, and nutritional quality of fermented foods. The enzymes mediating hydrolysis, reduction, and decarboxylation of phenolic acid esters and phenolic acids in lactobacilli, however, are not fully characterized. The genomic analyses presented here provide evidence for three novel...
Genetics and Molecular Biology
Genetics and Molecular BiologyCmAim24 Is Essential for Mitochondrial Morphology, Conidiogenesis, and Mycoparasitism in Coniothyrium minitansAim24 proteins are involved in mitochondrial biogenesis and accumulate between the two membranes of a mitochondrion. Their function in prokaryotes and filamentous fungi is as yet unknown. In the present study, we characterized an Aim24 protein, CmAim24, in the mycoparasite Coniothyrium minitans and proved its critical role in mitochondrial morphology and function, conidiogenesis, conidial germination, and mycoparasitism to ...
Genetics and Molecular BiologyNitric Oxide Improves the Tolerance of Pleurotus ostreatus to Heat Stress by Inhibiting Mitochondrial AconitaseHeat stress is one of the abiotic stresses that affect the growth and development of edible fungi. Our previous study found that exogenous NO had a protective effect on mycelia under heat stress. However, its regulatory mechanism had not been elucidated. In this study, we found that NO altered the respiratory pathway of mycelia under heat stress by regulating aco. The results have enhanced our understanding of NO signaling...
Invertebrate Microbiology
Invertebrate MicrobiologyMore Is Not Always Better: Coinfections with Defensive Symbionts Generate Highly Variable OutcomesThe hyperdiverse arthropods often harbor maternally transmitted bacteria that protect against natural enemies. In many species, low-diversity communities of heritable symbionts are common, providing opportunities for cooperation and conflict among symbionts, which can impact the defensive services rendered. Using the pea aphid, a model for defensive symbiosis, we show that coinfections with two common defensive symbionts, the...
Microbial Ecology
Microbial EcologyCore Rhizosphere Microbiomes of Dryland Wheat Are Influenced by Location and Land Use HistoryPlant-associated microbiomes are critical for plant health and other important agroecosystem processes. We assessed the bacterial and fungal microbiomes of wheat grown in soils from across a dryland wheat cropping systems in eastern Washington to identify the core microbiome on wheat roots that is consistent across soils from different locations and land use histories. Moreover, cross-domain co-occurrence network analysis identified...
Microbial EcologyShort-Term Nitrogen Fertilization Affects Microbial Community Composition and Nitrogen Mineralization Functions in an Agricultural SoilAgricultural N management practices influence the enzymatic activities involved in N mineralization. However, specific enzyme activities do not identify the microbial species directly involved in the measured process, leaving the link between the composition of the microbial community and the production of key enzymes poorly understood. In this study, the application of high-throughput sequencing, real-time PCR, and metagenomics shed...
Physiology
PhysiologyPA0335, a Gene Encoding Histidinol Phosphate Phosphatase, Mediates Histidine Auxotrophy in Pseudomonas aeruginosaHistidine is a common amino acid in proteins. Because it plays critical roles in bacterial metabolism, its biosynthetic pathway in many bacteria has been elucidated. However, the pathway remains unclear in Pseudomonas aeruginosa, an important opportunistic pathogen in clinical settings; in particular, there is scant knowledge about histidinol-phosphate phosphatase (...
Public and Environmental Health Microbiology
Public and Environmental Health MicrobiologyShifts in the Molecular Epidemiology of Campylobacter jejuni Infections in a Sentinel Region of New Zealand following Implementation of Food Safety Interventions by the Poultry IndustryThis study provides a unique insight into the effects of food safety interventions implemented in one sector of the food industry on the transmission routes of a major foodborne agent. Following the implementation of food safety interventions by the poultry industry, shifts in the molecular epidemiology of Campylobacter jejuni infections in a sentinel region of New...
Public and Environmental Health MicrobiologyMethicillin-Resistant Staphylococcus aureus Strains in Swiss Pigs and Their Relation to Isolates from Farmers and VeterinariansMRSA is an important human pathogen; thus, its increasing prevalence in livestock over the last decade has a potentially large impact on public health. Farmers and veterinarians are especially at risk due to their close contact with animals. Our work demonstrates a dramatic increase in MRSA prevalence in Swiss pigs, from 2% in 2009 to 44% in 2017. Whole-genome sequencing allowed us to show a close association between farmer and pig...
Public and Environmental Health Microbiology | SpotlightEcological and Technical Mechanisms for Cross-Reaction of Human Fecal Indicators with Animal HostsIdentifying human sources of fecal pollution is critical to remediate sanitation concerns. Large financial investments are required to address these concerns; therefore, a high level of confidence in testing results is needed. Human fecal marker genes validated in this study showed high specificity in both sequencing data and qPCR results. Human marker sequences were rarely found in individual animals, and in most cases, the animals had...
Public and Environmental Health Microbiology | SpotlightHonokiol Restores Polymyxin Susceptibility to MCR-1-Positive Pathogens both In Vitro and In VivoIn the present study, honokiol could effectively inhibit the activity of MCR-1 and showed almost no cytotoxicity to MH-S cells. According to our results, the combination of honokiol and polymyxin had a clear synergistic effect against MCR-1-positive Enterobacteriaceae in vitro. Combination therapy also showed a powerful therapeutic effect in vivo, which can significantly improve mouse livability, reduced the load of...
Public and Environmental Health MicrobiologyTopical Application of Adult Cecal Contents to Eggs Transplants Spore-Forming Microbiota but Not Other Members of the Microbiota to ChicksOver the last 60 years poultry production has intensified in response to increased demand for meat. In modern systems, chicks hatch without contacting chickens and their gut bacteria. Consequently, they are colonized by environmental bacteria that may cause disease. The normal bacteria that live in the gut, or intestinal microbiota, play an important role in the development of the immune system. Therefore, it is essential to find easy...
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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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