Table of Contents
Spotlight
Minireview
MinireviewMicrobial Dynamics in Traditional and Modern Sour Beer ProductionTraditional sour beers are produced by spontaneous fermentations involving numerous yeast and bacterial species. One of the traits that separates sour beers from ales and lagers is the high concentration of organic acids such as lactic acid and acetic acid, which results in reduced pH and increased acidic taste. Several challenges complicate the production of sour beers through traditional methods. These include poor process control,...
Biodegradation
BiodegradationInsights into the Function and Horizontal Transfer of Isoproturon Degradation Genes (pdmAB) in a Biobed SystemOur study provides novel insights into the interactions of IPU with the bacterial community of biobed systems, reinforces the assumption of a transposable nature of IPU-degrading genes, and verifies that on-farm biobed systems are hot spots for the evolution of pesticide catabolic traits.
BiodegradationDeglycosylation of the Isoflavone C-Glucoside Puerarin by a Combination of Two Recombinant Bacterial Enzymes and 3-Oxo-GlucoseOne important role of the gut microbiota is to metabolize dietary nutrients and supplements such as flavonoid glycosides. Ingested glycosides are metabolized by intestinal bacteria to more-absorbable aglycones and further degradation products that show beneficial effects in humans. Although numerous glycoside hydrolases that catalyze O-deglycosylation have been reported, enzymes responsible for C-deglycosylation are...
Biotechnology
BiotechnologyChanges in the Microbiome of Mariculture Feed Organisms after Treatment with a Potentially Probiotic Strain of Phaeobacter inhibensThis work is an essential part of the risk assessment of the application of roseobacters as probiotics in mariculture. It provides insights into the impact of TDA-producing Phaeobacter inhibens on the commensal bacteria related to mariculture live feed and fish larvae. Also, the study provides a sequencing-based characterization of the microbiomes related to...
BiotechnologyChromosome Engineering To Generate Plasmid-Free Phenylalanine- and Tyrosine-Overproducing Escherichia coli Strains That Can Be Applied in the Generation of Aromatic-Compound-Producing BacteriaPlasmid-free strains for aromatic compound production are desired in the aspect of industrial application. However, the yields of phenylalanine and tyrosine have been considerably lower in plasmid-free strains than in plasmid-based strains. The significance of this research is that we succeeded in generating superior plasmid-free phenylalanine- and tyrosine-producing strains by engineering the...
BiotechnologyEthanol Metabolism Dynamics in Clostridium ljungdahlii Grown on Carbon MonoxideEthanol production from carbon monoxide (CO) as a carbon and energy source by Clostridium ljungdahlii and “Clostridium autoethanogenum” is currently being commercialized. During gas fermentation, ethanol synthesis is NADH-dependent. However, ethanol oxidation and its regulatory mechanism remain...
Biotechnology | SpotlightAncestral Resurrection and Directed Evolution of Fungal Mesozoic LaccasesThe broad variety of biotechnological uses of fungal laccases is beyond doubt (food, textiles, pulp and paper, pharma, biofuels, cosmetics, and bioremediation), and protein engineering (in particular, directed evolution) has become the key driver for adaptation of these enzymes to harsh industrial conditions. Usually, the first requirement for directed laccase evolution is heterologous expression, which presents an important hurdle and...
BiotechnologyA Sensitive Magnetic Arsenite-Specific Biosensor Hosted in Magnetotactic BacteriaWhole-cell biosensors based on reporter genes can be designed for heavy metal detection but often require the optimization of their sensitivity and specific adaptations for practical use in the field. Magnetotactic bacteria as cellular hosts for biosensors are interesting models, as their intrinsic magnetism permits them to be easily concentrated and entrapped to increase the arsenic-response signal. This paves the way for the...
Environmental Microbiology
Environmental MicrobiologyImmobilization of Phosphatidylserine by Ethanol and Lysozyme on the Cell Surface for Evaluation of Apoptosis-Like Decay in Activated-Sludge BacteriaSince the externalization of phosphatidylserine (PS) is considered a crucial characteristic of apoptosis, we sought to identify apoptosis-like decay in bacterial cells by PS staining using AVF. We show that this is possible, provided the bacteria are pretreated with ethanol plus lysozyme to remove a physical staining barrier and preserve the original, decay-related externalization of PS. Our work suggests that PS externalization occurs...
Environmental Microbiology | SpotlightSeveral Metarhizium Species Produce Ergot Alkaloids in a Condition-Specific MannerOur discovery of ergot alkaloids in fungi of the genus Metarhizium has agricultural and pharmaceutical implications. Ergot alkaloids produced by other fungi in the family Clavicipitaceae accumulate in forage grasses or grain crops; in this context they are considered toxins, though their presence also may deter or kill insect pests. Our data report ergot alkaloids in...
Environmental MicrobiologyCan Pathogenic and Nonpathogenic Bacteria Be Distinguished by Sensory Protein Abundance?Sensory proteins (SPs) act as sensors and actuators for a cell and participate in important mechanisms pertaining to bacterial survival, adaptation, and virulence. Therefore, bacterial species residing in similar ecological niches or those sharing common pathotypes are expected to exhibit similar SP signatures. We have investigated profiles of SPs in different species of ...
Environmental Microbiology | SpotlightShort- and Long-Term Transcriptomic Responses of Escherichia coli to Biocides: a Systems AnalysisAntiseptics and disinfectant products are of great importance to control and eliminate pathogens, especially in settings such as hospitals and the food industry. Such products are widely distributed and frequently poorly regulated. Occasional outbreaks have been associated with microbes resistant to such compounds, and researchers have indicated potential cross-resistance with antibiotics. Despite that, there are many gaps in knowledge...
Environmental MicrobiologyABC Transporter DerAB of Lactobacillus casei Mediates Resistance against Insect-Derived DefensinsAntimicrobial peptides (AMPs) play an important role in suppressing the growth of microorganisms. They can be produced by bacteria themselves—to inhibit competitors—but are also widely distributed in higher eukaryotes, including insects and mammals, where they form an important component of innate immunity. In low-GC-content Gram-positive bacteria, BceAB-like transporters play a crucial role in AMP resistance but have so far been...
Food Microbiology
Food MicrobiologyIn-Depth Longitudinal Study of Listeria monocytogenes ST9 Isolates from the Meat Processing Industry: Resolving Diversity and Transmission Patterns Using Whole-Genome SequencingListeria monocytogenes is a deadly foodborne pathogen that is widespread in the environment, and certain types can be established in food factories. The sequence type ST9 dominates in meat processing environments, and this work was undertaken to obtain data needed for the tracking of this subtype. By using whole-genome sequencing (WGS), we revealed the presence of...
Food MicrobiologyInactivation Kinetics and Membrane Potential of Pathogens in Soybean Curd Subjected to Pulsed Ohmic Heating Depending on Applied Voltage and Duty RatioHigh-water-activity food products, such as soybean curd, are vulnerable to microbial contamination, which causes fatal foodborne diseases and food spoilage. Inactivating microorganisms inside food is difficult because the transfer of thermal energy is slower inside than it is outside the food. POH is an adequate sterilization technique because of its rapid and uniform heating without causing electrode corrosion. To elucidate the...
Genetics and Molecular Biology
Genetics and Molecular Biology | SpotlightInteractions of GMP with Human Glrx3 and with Saccharomyces cerevisiae Grx3 and Grx4 Converge in the Regulation of the Gcn2 PathwaySaccharomyces cerevisiae is an optimal eukaryotic microbial model to study biological processes in higher organisms despite the divergence in evolution. The molecular function of yeast glutaredoxins Grx3 and Grx4 is enormously interesting, since both proteins are required to maintain correct iron homeostasis and an efficient response to oxidative stress. The human...
Genetics and Molecular BiologyHistone-like Nucleoid-Structuring Protein (H-NS) Paralogue StpA Activates the Type I-E CRISPR-Cas System against Natural Transformation in Escherichia coliStpA is normally considered a molecular backup of the nucleoid-structuring protein H-NS, which was reported as a transcriptional repressor of the type I-E CRISPR-Cas system in Escherichia coli. However, the role of StpA in regulating the type I-E CRISPR-Cas system remains elusive. Our previous work uncovered a new route for double-stranded DNA (dsDNA) entry during...
Genetics and Molecular BiologyTransformation of the Drosophila Sex-Manipulative Endosymbiont Spiroplasma poulsonii and Persisting Hurdles for Functional Genetic StudiesDozens of bacterial endosymbiont species have been described and estimated to infect about half of all insect species. However, only a few them are tractable in vitro, which hampers our understanding of the bacterial determinants of the host-symbiont interaction. Developing a transformation method for S. poulsonii is a major step toward genomic engineering of this symbiont, which will foster basic research on...
Invertebrate Microbiology
Invertebrate Microbiology | SpotlightSea Cucumber Intestinal Regeneration Reveals Deterministic Assembly of the Gut MicrobiomeThe gut microbiome is pertinent to many aspects of animal health, and there is a great need for natural but tractable experimental systems to examine the processes shaping gut microbiome assembly. Here, the holothurian (sea cucumber) Sclerodactyla briareus was explored as an experimental system to study microbial colonization in the gut, as S. briareus individuals have the ability to completely eviscerate and rapidly...
Methods
MethodsXylose-Inducible Promoter Tools for Pseudomonas Species and Their Use in Implicating a Role for the Type II Secretion System Protein XcpQ in the Inhibition of Corneal Epithelial Wound ClosurePseudomonas species are enormously important in human infections, in biotechnology, and as model systems for investigating basic science questions. In this study, we have developed a xylose-inducible promoter system, evaluated it in P. aeruginosa and P. fluorescens, and found it to be...
Microbial Ecology
Microbial EcologyContrasting Patterns in Diversity and Community Assembly of Phragmites australis Root-Associated Bacterial Communities from Different SeasonsUnderstanding the composition and assembly mechanisms of root-associated microbial communities of plants is crucial for understanding the interactions between plants and soil. Most previous studies of the plant root-associated microbiome focused on model and economic plants, with fewer temporal or seasonal investigations. The assembly mechanisms of root-associated bacterial communities in different seasons remain poorly known,...
Microbial EcologyAntimicrobial Peptide GH12 Prevents Dental Caries by Regulating Dental Plaque MicrobiotaThe anticaries effects and microecological regulation effects of the antimicrobial peptide GH12 were evaluated systematically in vitro and in vivo. GH12 inhibited the cariogenic virulence of dental plaque without overintervening in the microbial ecology of healthy individuals in vitro. GH12 regulated the microbial ecology of dental plaque to a certain extent in vivo under cariogenic conditions,...
Plant Microbiology
Plant MicrobiologyA Framework for the Selection of Plant Growth-Promoting Rhizobacteria Based on Bacterial Competence MechanismsNumerous plant growth-promoting rhizobacteria (PGPR) have been inoculated into the soil with the aim of improving the supply of nutrients to crop plants and decreasing the requirement of chemical fertilizers. However, sometimes these microbes fail to competitively colonize the plant roots and rhizosphere. Hence, the plant growth promotion effect is not observed. Here, we describe a new screening strategy aiming at the selection of more...
Masthead
