Symbiotic Growth of a Thermophilic Sulfide-Oxidizing Photoautotroph and an Elemental Sulfur-Disproportionating Chemolithoautotroph and Cooperative Dissimilatory Oxidation of Sulfide to Sulfate
This study shows a novel symbiotic relationship between a sulfide-oxidizing photoautotroph and an elemental sulfur-disproportionating chemolithoautotroph via cooperative dissimilatory sulfide oxidation to sulfate. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Managing Agroecosystems for Soil Microbial Carbon Use Efficiency: Ecological Unknowns, Potential Outcomes, and a Path Forward
Agricultural systems are increasingly managed for improving soil carbon (C) accumulation. However, there are limits to C returns in agricultural systems that constrain soil C accumulation capacity. Increasing the efficiency of how soil microbes process C is gaining interest as an important management strategy for increasing soil C and is a key feature of soil C dynamics in many new microbial-explicit models. A higher microbial C use efficiency (CUE) may increase C storage while reducing C system losses and is a fundamental trait affecting community assembly dynamics and nutrient cycling. However, the numerous ecological un...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Switching the Post-translational Modification of Translation Elongation Factor EF-P
Tripeptides with two consecutive prolines are the shortest and most frequent sequences causing ribosome stalling. The bacterial translation elongation factor P (EF-P) relieves this arrest, allowing protein biosynthesis to continue. A seven amino acids long loop between beta-strands β3/β4 is crucial for EF-P function and modified at its tip by lysylation of lysine or rhamnosylation of arginine. Phylogenetic analyses unveiled an invariant proline in the -2 position of the modification site in EF Ps that utilize lysine modifications such as Escherichia coli. Bacteria with the arginine modification like Pseudomonas p...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

The Design of FluxML: A Universal Modeling Language for 13C Metabolic Flux Analysis
13C metabolic flux analysis (MFA) is the method of choice when a detailed inference of intracellular metabolic fluxes in living organisms under metabolic quasi-steady state conditions is desired. Being continuously developed since two decades, the technology made major contributions to the quantitative characterization of organisms in all fields of biotechnology and health-related research. 13C MFA, however, stands out from other “-omics sciences”, in that it requires not only experimental-analytical data, but also mathematical models and a computational toolset to infer the quantities of interest, i.e., the me...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

The Effect of Previous Life Cycle Phase on the Growth Kinetics, Morphology, and Antibiotic Resistance of Salmonella Typhimurium DT104 in Brain Heart Infusion and Ground Chicken Extract
Growth models are predominately used in the food industry to estimate the potential growth of select microorganisms under environmental conditions. The growth kinetics, cellular morphology and antibiotic resistance were studied throughout the life cycle of Salmonella Typhimurium. The effect of the previous life cycle phase (late log phase [LLP], early stationary phase [ESP], late stationary phase [LSP] and early death phase [EDP]) of Salmonella after reinoculation in brain heart infusion broth (BHI), ground chicken extract (GCE) and BHI at pH 5, 7 and 9 and salt concentrations 2, 3 and 4% was investigated. The growth media...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

IgA-Targeted Lactobacillus jensenii Modulated Gut Barrier and Microbiota in High-Fat Diet-Fed Mice
IgA-coated Lactobacillus live in the mucous layer of the human or mammalian intestine in close proximity to epithelial cells. They act as potential probiotics for functional food development, but their physiological regulation has not yet been studied. We isolated IgA-targeted (Lactobacillus jensenii IgA21) and lumen lactic acid bacterial strains (Pediococcus acidilactici FS1) from the fecal microbiota of a healthy woman. C57BL/6 mice were fed a normal (CON) or high fat diet (HFD) for 6 weeks and then treated with IgA21 or FS1 for 4 weeks. HFD caused dyslipidemia, mucosal barrier damage, and intestinal microbiota abnormali...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Fifteen Marseilleviruses Newly Isolated From Three Water Samples in Japan Reveal Local Diversity of Marseilleviridae
In this study, we isolated 12 or 15 new members of the family Marseilleviridae from three sampling locations in Japan. Molecular phylogenetic analysis of the MCP genes showed that the new viruses could be further classified into three groups, hokutoviruses, kashiwazakiviruses, and kyotoviruses. Hokutoviruses were closely related to lineage B, kyotoviruses were related to lineage A, and kashiwazakiviruses were also classified into lineage B but a new putative subgroup of lineage B, revealing the diversity of this lineage. Interestingly, more than two viruses with slightly different MCP genes were isolated from a single wate...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

In-Depth Genomic and Phenotypic Characterization of the Antarctic Psychrotolerant Strain Pseudomonas sp. MPC6 Reveals Unique Metabolic Features, Plasticity, and Biotechnological Potential
We obtained the complete genome sequence of the psychrotolerant extremophile Pseudomonas sp. MPC6, a natural Polyhydroxyalkanoates (PHAs) producing bacterium able to rapidly grow at low temperatures. Genomic and phenotypic analyses allowed us to situate this isolate inside the Pseudomonas fluorescens phylogroup of pseudomonads as well as reveal its metabolic versatility and plasticity. The isolate possesses the gene machinery for metabolizing a variety of toxic aromatic compounds such as toluene, phenol, chloroaromatics, and TNT. In addition, it can use both C6- and C5-carbon sugars like xylose and arabinose as carbon subs...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Fast Repetition Rate Fluorometry (FRRF) Derived Phytoplankton Primary Productivity in the Bay of Bengal
The approach of fast repetition rate fluorometry (FRRF) requires a conversion factor (Φe:C/nPSII) to derive ecologically-relevant carbon uptake rates (PPz,t). However, the required Φe:C/nPSII is commonly measured by 14C assimilation and varies greatly across phytoplankton taxonomy and environmental conditions. Consequently, the use of FRRF to estimate gross primary productivity (GPz,t), alone or in combination with other approaches, has been restricted by both inherent conversion and procedural inconsistencies. Within this study, based on a hypothesis that the non-photochemical quenching (NPQNSV) can be used as a p...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Exploring First Interactions Between Ostreid Herpesvirus 1 (OsHV-1) and Its Host, Crassostrea gigas: Effects of Specific Antiviral Antibodies and Dextran Sulfate
Viral entry mechanisms of herpesviruses constitute a highly complex process which implicates several viral glycoproteins and different receptors on the host cell surfaces. This initial infection stage was curently undescribed for Ostreid herpes virus 1 (OsHV-1), a herpesvirus infecting bivalves including the Pacific oyster, Crassostrea gigas. To identify OsHV-1 glyproteins implicated in the attachement of the virus to oyster cells, three viral putative membrane proteins, encoded by ORF 25, 41, and 72, were selected and polyclonal antibodies against these targets were used to explore first interactions between the virus and...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Essential Role of σ Factor RpoF in Flagellar Biosynthesis and Flagella-Mediated Motility of Acidithiobacillus caldus
In this study, we analyzed the flagellar gene clusters in Acidithiobacillus strains and uncovered the close relationship between flagella and the sulfur-oxidizing systems (Sox system). The σ28 gene (rpoF) knockout and overexpression strains of Acidithiobacillus caldus were constructed. Scanning electron microscopy shows that A. caldus ΔrpoF cells lacked flagella, indicating the essential role of RpoF in regulating flagella synthesis in these chemoautotrophic bacteria. Motility analysis suggests that the deletion of rpoF resulted in the reduction of swarming capability, while this capability was enhanced in the ...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Assessing Cofactor Usage in Pseudoclostridium thermosuccinogenes via Heterologous Expression of Central Metabolic Enzymes
Pseudoclostridium thermosuccinogenes and Hungateiclostridium thermocellum are being studied for their potential to contribute to a more sustainable bio-based economy. Both species were shown previously to rely on GTP or pyrophosphate instead of ATP as cofactors in specific reactions of central energy metabolism for reasons that are not well understood yet. Since it is often impossible to predict cofactor specificity from the primary protein structure, thirteen enzymes from P. thermosuccinogenes were cloned and heterologous expressed in Escherichia coli to assess the cofactor usage in vitro and paint a more complete picture...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

PNA Length Restriction of Antibacterial Activity of Peptide-PNA Conjugates in Escherichia coli Through Effects of the Inner Membrane
Peptide Nucleic Acid (PNA)-peptide conjugates targeting essential bacterial genes are showing promise as antisense antimicrobials in drug discovery. Optimization has focused on selection of target genes and exact localization around the ribosome binding site, but surprisingly a length optimum around 10-12 nucleobases has been found. Addressing this observation, we have investigated the relationship between PNA-length, PNA-RNA duplex stability and antimicrobial activity in E. coli in more detail. For PNAs of identical length of ten nucleobases the expected reverse correlation between the thermal stability (Tm) of the PNA-RN...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Sub-inhibitory Effects of Antimicrobial Peptides
We describe how AMP action is non-linear and unpredictable, also showing that exposure to AMP can lead to antimicrobial resistance via triggering various regulatory systems. Being one of the most known types of antimicrobials, bacteriocins have dual action and can also be utilised by microorganisms as signaling molecules at naturally achievable sub-inhibitory concentrations. Unpredictable nature of AMP action and the pathogenic response triggered by them remains an area of knowledge that requires further investigation. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

SGI-4 in Monophasic Salmonella Typhimurium ST34 Is a Novel ICE That Enhances Resistance to Copper
A multi drug resistant Salmonella enterica 4,[5],12:i- of sequence type 34 (monophasic S. Typhimurium ST34) is a current pandemic clone associated with livestock, particularly pigs, and numerous outbreaks in the human population. A large genomic island, termed SGI-4, is present in the monophasic Typhimurium ST34 clade and absent from other S. Typhimurium strains. SGI-4 consists of 87 open reading frames including sil and pco genes previously implicated in resistance to copper (Cu) and silver, and multiple genes predicted to be involved in mobilisation and transfer by conjugation. SGI-4 was excised from the chromosome, circ...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Maternal-Fetal Conflict During Infection: Lessons From a Mouse Model of Placental Malaria
Infections that reach the placenta via maternal blood target the fetal-placental barrier and are associated with reduced birth weight, increased stillbirth, miscarriage and perinatal mortality. Malaria during pregnancy can lead to infection of the placental tissue with adverse effects on the unborn child even if the parasite is successfully cleared, indicating that placental sufficiency is significantly compromised. Human samples and animal models of placental malaria have been used to unravel mechanisms contributing to this insufficiency and have implicated molecular pathways related to inflammation, innate immunity and n...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Vancomycin-Loaded Nanoparticles Enhance Sporicidal and Antibacterial Efficacy for Clostridium difficile Infection
Current antibiotic treatments fail to eliminate the Clostridium difficile (C. difficile) spores and induce dysbiosis and intestinal inflammation via off-target effect, which causes refractory C. difficile infection raise an unmet need for a spore-specific antimicrobial treatment. We developed a sporicidal and antimicrobial vancomycin-loaded spore-targeting iron oxide nanoparticle (van-IONP) that selectively binds to C. difficile spores. Cryo-electron microscopy showed that vancomycin-loaded nanoparticles can target and completely cover spore surfaces. They not only successfully delayed the germination of the spores but als...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

K21 Compound, a Potent Antifungal Agent: Implications for the Treatment of Fluconazole-Resistant HIV-Associated Candida Species
Conclusion: The study established the efficacy of K21 as an antifungal agent and with fluconazole-resistant candidiasis on the increase, the development of K21 can provide a promising alternative to combat acquired drug resistance. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Distinct YFV Lineages Co-circulated in the Central-Western and Southeastern Brazilian Regions From 2015 to 2018
The current outbreak of yellow fever virus (YFV) that is afflicting Brazil since the end of 2016 probably originated from a re-introduction of YFV from endemic areas into the non-endemic Southeastern Brazil. However, the lack of genomic sequences from endemic regions hinders the tracking of YFV’s dissemination routes. We assessed the origin and spread of the ongoing YFV Brazilian outbreak analyzing a new set of YFV strains infecting humans, non-human primates (NHP) and mosquitoes sampled across five Brazilian states from endemic and non-endemic regions between 2015 and 2018. We found two YFV sub-clade 1E lineages cir...
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Fermented dairy foods: Impact on intestinal microbiota and health-linked biomarkers
The intake of fermented foods is gaining increasing interest due to their health-promoting benefits. Among them, fermented dairy foods have been associated with obesity prevention, and reduction on the risk of metabolic disorders and immune-related pathologies. Fermented foods could lead to these health benefits by providing the consumer both easily metabolizable nutrients and beneficial microorganisms. Our aim was to evaluate the possible relationship between the consumption of fermented dairy products and the intestinal microbiota, serum lipid profile and the pro-oxidant / inflammatory status. 130 healthy adults (age 58....
Source: Frontiers in Microbiology - May 24, 2019 Category: Microbiology Source Type: research

Zika Virus Induced More Severe Inflammatory Response Than Dengue Virus in Chicken Embryonic Livers
Dengue (DENV) and Zika virus (ZIKV) are important flaviviruses in tropical and subtropical regions, causing severe Dengue Hemorrhagic Fever (DHF)/Dengue Shock Syndrome (DSS) and microcephaly, respectively. The infection of both viruses during pregnancy were reported with adverse fetal outcomes. To investigate the effects of ZIKV and DENV infections on fetal development, we established an infection model in chicken embryos. Compared with DENV-2, the infection of ZIKV significantly retarded the development of chicken embryos. High viral loads of both DENV-2 and ZIKV was detected in brain, eye and heart 7 and 11 days post inf...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Regulation of Gram-Positive Conjugation
Type IV Secretion Systems (T4SS) are membrane-spanning multiprotein complexes dedicated to protein secretion or conjugative DNA transport (conjugation systems) in bacteria. The prototype and best-characterized T4SS is that of the Gram-negative soil bacterium Agrobacterium tumefaciens. For Gram-positive bacteria, only conjugative T4SSs have been characterized in some biochemical, structural and mechanistic detail. These conjugation systems are predominantly encoded by self-transmissible plasmids but are also increasingly detected on integrative conjugative elements (ICE) and transposons. Here, we report regulatory details o...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Gut Microbiome Alterations During HIV/SIV Infection: Implications for HIV Cure
Gut mucosal damage associated with Human Immunodeficiency Virus-1 (HIV) infection is characterized by depletion in CD4+ T cells and persistent immune activation as a result of early epithelial barrier disruption and systemic translocation of microbial products. Unique approaches in studying both HIV infection in human patients and Simian Immunodeficiency Virus (SIV) infection in rhesus macaques have provided critical evidence for pathogenesis and treatment of HIV/AIDS. While there is vast resemblance between SIV and HIV infection, the development of gut dysbiosis attributed to HIV infection in chronically infected patients...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Assessing the Diversity of Endogenous Viruses Throughout Ant Genomes
Endogenous viral elements (EVEs) can play a significant role in the evolution of their hosts and have been identified in animals, plants, and fungi. Additionally, EVEs potentially provide an important snapshot of the evolutionary frequency of viral infection. The purpose of this study is to take a comparative host-centered approach to EVE discovery in ant genomes to better understand the relationship of EVEs to their ant hosts. Using a comprehensive bioinformatic pipeline, we screened all nineteen published ant genomes for EVEs. Once these EVEs were identified, we assessed their phylogenetic relationships to other closely ...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Nucleoside Analogues as Antibacterial Agents
The rapid increase in antibiotic-resistant bacteria has emphasised the urgent need to identify new treatments for bacterial infections. One attractive approach, avoiding the need for expensive and time-consuming clinical trials, is to re-purpose existing clinically-approved compounds for use as antibacterial agents. Nucleoside analogues are commonly used for treating viral and fungal infections, as well as for treating cancers, but have received relatively little attention as treatments for bacterial infections. However a significant number of clinically-approved derivatives of both pyrimidines and purines including haloge...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Dynamic Alterations in Yak Rumen Bacteria Community and Metabolome Characteristics in Response to Feed Type
Current knowledge about the relationships between ruminal bacterial communities and metabolite profiles in the yak rumen is limited. This is due to differences in the nutritional and metabolic features between yak and other ordinary cattle combined with difficulties associated with farm-based research and a lack of technical guidance. A comprehensive analysis of the composition and alterations in ruminal metabolites is required to advance the development of modern yak husbandry. In the current study, we characterized the effect of feed type on the ruminal fluid microbiota and metabolites in yak using 16S rRNA gene sequenci...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Characterization of New Recombinant Forms of HIV-1 From the Comunitat Valenciana (Spain) by Phylogenetic Incongruence
Recombination is one of the main processes shaping the evolution of HIV-1, with relevant consequences for its epidemiology and, possibly, the efficacy of treatments. Up to date, more than 80 circulating recombinant forms (CRFs) have been described which add to the 9 “pure” subtypes recognized for the M group of this virus. The characterization of recombination events and variants can be very laborious, especially in light of the increasing amount of partially or completely sequenced viral samples. Besides, there is no standard methodological procedure for describing and accepting new recombination events. Here,...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Microevolution and Adaptive Strategy of Psychrophilic Species Flavobacterium bomense sp. nov. Isolated From Glaciers
In this study, we used a polyphasic approach to determine the taxonomic status of 11 psychrophilic Flavobacterium strains isolated from glaciers on the Tibetan Plateau and performed a comparative genomic analysis. The phylogenetic tree based on the concatenated single copy gene sequences showed the 11 strains clustered together, forming a distinct and novel clade in the genus Flavobacterium. The average nucleotide identity (ANI) values among these strains were higher than 96%. However, the values much lower than 90% between them and related species, indicated that they represent a novel species and the name Flavobacterium ...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Role of the R349 Gene and Its Repeats in the MIMIVIRE Defense System
In this study, a recently isolated Mimivirus of lineage A with R349 gene lacking 3 of 4 repeats was demonstrated to be susceptible to Zamilon. To reinforce the importance of the R349 gene in MIMIVIRE system, we developed and presented, for the 1st time to our knowledge, a protocol for Mimivirus genomic editing. By knocking out R349 gene in a Mimivirus lineage A, we observed the replication of Zamilon, indicating that this gene is critical for the resistance against this specific group of virophages. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Elucidation of Akkermansia muciniphila Probiotic Traits Driven by Mucin Depletion
In conclusion, mucin content in the growth medium plays a critical role in the improvement by A. muciniphila of high-fat diet-induced obesity, intestinal inflammation, and compromised intestinal barrier integrity related to a decrease in goblet cell density. Our findings suggest the depletion of animal-derived mucin in growth medium as a novel principle for the development of A. muciniphila for human therapeutics. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

The Cost of Toxicity in Microalgae: Direct Evidence From the Dinoflagellate Alexandrium
Empirical evidence of the cost of producing toxic compounds in harmful microalgae is completely lacking. Yet costs are often assumed to be high, implying substantial ecological benefits with adaptive significance exist. To study potential fitness costs of toxin production, sixteen strains including three species of the former Alexandrium tamarense species complex were grown under both carbon limitation and unlimited conditions. Growth rates, levels of intracellular paralytic shellfish poisoning toxins (PSTs) and effects of lytic compounds were measured to provide tradeoff curves of toxicity for both PST and lytic toxicity ...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Characterization of 3-Oxacyl-Acyl Carrier Protein Reductase Homolog Genes in Pseudomonas aeruginosa PAO1
In this study, we characterized the functions of these genes with biochemical and genetic techniques. With the exception of PA2697, which encodes FabG, an essential protein in fatty acid synthesis, only the PA4389 and PA4786 gene products had OAR activity, and the single deletion of these two genes reduced the ability of P. aeruginosa to produce several specific quorum-sensing (QS) signals. However, PA4389 and PA4786 do not play key roles in fatty acid synthesis. An analysis of carbon source utilization suggested that both OAR homologues predominantly function in sugar metabolism. Moreover, although most OAR homologues had...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Transcriptional Comparison Investigating the Influence of the Addition of Unsaturated Fatty Acids on Aroma Compounds During Alcoholic Fermentation
The levels of unsaturated fatty acids (UFAs) in grape must significantly influence yeast metabolism and the production of aroma compounds. In this work, cDNA microarray technology was applied to analyze the transcriptional discrepancies of wine yeast (commercial wine yeast Lalvin EC1118) fermenting in synthetic grape must supplemented with different concentrations of a mixture of UFAs (including linoleic acid, oleic acid and α-linolenic acid). The results showed that the initial addition of a high level of UFAs can significantly enrich the intracellular UFAs compared to the low addition of UFAs and further increase t...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Deletion of FgHOG1 Is Suppressive to the mgv1 Mutant by Stimulating Gpmk1 Activation and Avoiding Intracellular Turgor Elevation in Fusarium graminearum
Fusarium head blight caused by Fusarium graminearum is an important disease of wheat and barley. Previous studies have showed that all three MAP kinase genes, MGV1, FgHOG1, and GPMK1, are involved in regulating hyphal growth, sexual reproduction, plant infection, and stress responses in this pathogen. To determine the relationship between the Mgv1 and FgHog1 pathways, in this study we generated and characterized the mgv1 Fghog1 double mutant. Deletion of FgHOG1 partially rescued the defects of mgv1 mutant in vegetative growth and cell wall integrity but had no effects on its defects in plant infection and DON production. T...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

The Fungal and Bacterial Rhizosphere Microbiome Associated With Grapevine Rootstock Genotypes in Mature and Young Vineyards
In conclusion, grapevine rootstock genotypes in the mature vineyard were associated with different rhizosphere microbiomes. The latter could also have been affected by age of the vineyard, soil properties or field management practices. A more comprehensive study is needed to decipher the cause of the rootstock microbiome selection and the mechanisms by which grapevines are able to shape their associated microbial community. Understanding the vast diversity of bacteria and fungi in the rhizosphere and the interactions between microbiota and grapevine will facilitate the development of future strategies for grapevine protect...
Source: Frontiers in Microbiology - May 22, 2019 Category: Microbiology Source Type: research

Bacillus subtilis Inhibits Vibrio natriegens-Induced Corrosion via Biomineralization in Seawater
The marine bacterium, Vibrio natriegens, grows quickly in a marine environment and can significantly accelerate the corrosion of steel materials. Here, we present an approach to inhibit Vibrio natriegens-induced corrosion by biomineralization. The corrosion of steel is mitigated in seawater via the formation of a biomineralization induced by Bacillus subtilis. The film is composed of extracellular polymeric substances and calcite, exhibiting stable anti-corrosion activity. The microbial diversity and medium chemistry tests demonstrated that the inhibition of V. natriegens growth by B. subtilis was essential for the formati...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Use of Rhizobacteria and Mycorrhizae Consortium in the Open Field as a Strategy for Improving Crop Nutrition, Productivity and Soil Fertility
Plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) are known for their beneficial effects. In recent years, more attention has been paid to their use as biofertilizers to reduce the use of chemical fertilizers causing significant damage to the environment. To have high plant yields, biofertilizers may not be able to sustain plant demands and could be used in combination with chemical fertilizers. However, the application of biofertilizers in the field such as rhizobacteria and AMF are understudied and powerfully needed. In this context, this study aims to evaluate the effect of inoculation w...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Emerging Health Concepts in the Probiotics Field: Streamlining the Definitions
(Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Getting to Know the Gut Microbial Diversity of Metropolitan Buenos Aires Inhabitants
In recent years, the field of immunology has been revolutionized by the growing understanding of the fundamental role of microbiota in the immune system function​. The immune system has evolved to maintain a symbiotic relationship with these microbes. The aim of our study was to know in depth the uncharacterized metagenome of Buenos Aires (BA) city population and its metropolitan area, being the second most populated agglomeration in the southern hemisphere. For this purpose, we evaluated 30 individuals (age: 35,23 ± 8,26 years and BMI: 23,91 ± 3,4 kg/m2), from the general population of BA. The hypervariabl...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

The MAP Kinase CfPMK1 Is a Key Regulator of Pathogenesis, Development, and Stress Tolerance of Colletotrichum fructicola
In this study, a Fus3/Kss1-related MAPK from C. fructicola was functionally characterized via gene deletion. On potato dextrose agar (PDA) and oatmeal agar media, the CfPMK1 gene deletion mutants (∆CfPMK1) were slightly reduced in radial growth rate, severely limited in aerial hyphal differentiation and hyphal melanization, and formed deformed perithecia smaller in size and more compactly organized relative to wild type. When artificially inoculated on plants, conidia of these mutants failed to differentiate appressoria or penetrate cuticle, and their pathogenicity defect could not be rescued by wounding plant tissue pri...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

The MarR-Type Regulator MalR Is Involved in Stress-Responsive Cell Envelope Remodeling in Corynebacterium glutamicum
In conclusion, our results emphasize MalR as a regulator involved in stress-responsive remodeling of the cell envelope of C. glutamicum and suggest a link between cell envelope stress and the control of phage gene expression. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Potential Fossilized Sulfide-Oxidizing Bacteria in the Upper Miocene Sulfur-Bearing Limestones From the Lorca Basin (SE Spain): Paleoenvironmental Implications
The sulfur-bearing limestones interbedded in the upper Miocene diatomaceous sediments (Tripoli Fm.) of the Lorca Basin (SE Spain) are typified, as other Mediterranean coeval carbonate and gypsum deposits, by filamentous, circular and rod-shaped microstructures of controversial origin. These features have been interpreted both as faecal pellets of brine shrimps and/or of copepods, remains of algae or cyanobacteria and fossilized sulfide-oxidizing bacteria. To shed light on their origin, a multidisciplinary study including optical, UV and scanning SEM electron microscopy, Raman microspectroscopy and geochemical (C carbon and...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Detection of Influenza a Virus in Swine Nasal Swab Samples With a Wash-Free Magnetic Bioassay and a Handheld Giant Magnetoresistance Sensing System
The dissemination of Influenza A virus (IAV) throughout the world has become one of the main concerns for the health of both animals and human beings. An efficient and sensitive diagnostic tool is thus needed for the early detection of IAV. Here, we developed a wash-free magnetic bioassay and further integrated it with a handheld platform based on giant-magnetoresistance (GMR) sensors. The wash-free magnetic bioassay significantly accelerates and simplifies the detection process. This brand-new system was successful in detecting both IAV nucleoprotein and IAV-contained nasal swab samples from pigs on the farm. The extrapol...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

CgGCS, Encoding a Glucosylceramide Synthase, Is Required for Growth, Conidiation and Pathogenicity in Colletotrichum gloeosporioides
In this study, we characterized CgGCS, a protein encoding a glucosylceramide synthase (GCS) in Colleotrichum gloeosporioides. Disruption of CgGCS resulted in a severe reduction of mycelial growth and defects in conidiogenesis. Sphingolipid profile analysis revealed large decreases in glucosylceramide production in the mutant strains. Pathogenicity assays indicated that the ability of the ∆CgGCS mutants to invade both tomato and mango hosts was almost lost. In addition, the expression levels of many genes, especially those related to metabolism, were shown to be affected by the mutation of CgGCS via transcriptome analysis...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Programmed gRNA Removal System for CRISPR-Cas9-Mediated Multi-Round Genome Editing in Bacillus subtilis
CRISPR/Cas9 has become a simple and powerful genome editing tool for many organisms. However, multi-round genome editing should replace single-guide RNA (sgRNA) every round, which is laborious and time-consuming. Here, we have developed a multi-round genome editing system in which genome editing and the programmed removal of the sgRNA have sequentially occurred in a growth-dependent manner in Bacillus subtilis. The system contains two plasmids, one containing a cas9 gene and the other containing two sgRNAs and a donor DNA for homology directed repair. The two sgRNAs are chromosome-targeting (sgRNAct) and self-targeting (sg...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Insights Into the Cultivable Microbial Ecology of “Manna” Ash Products Extracted From Fraxinus angustifolia (Oleaceae) Trees in Sicily, Italy
Microbial communities characterizing a specific food matrix, generally, strongly contribute to both its composition and properties for food applications. To our knowledge, this is the first study to investigate the cultivable microbial ecology of Sicilian “Manna” ash products in order to acquire new information on the hygienic quality, shelf-life and potential application of this traditional food. To this purpose, several manna samples belonging to different commercial categories were collected and subjected to the analysis of bacteria, yeasts and filamentous fungi. Furthermore, an investigation of the sugar co...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Distinct Bacterial Communities in Wet and Dry Seasons During a Seasonal Water Level Fluctuation in the Largest Freshwater Lake (Poyang Lake) in China
This study enriched our knowledge of the impacts of WLFs and seasonal dynamics of lake ecosystems. Given the increasingly pervasive pressure of WLFs on lake ecosystems worldwide, our findings have important implications for conservation and management of lake ecosystems. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Integrating Whole-Genome Sequencing Data Into Quantitative Risk Assessment of Foodborne Antimicrobial Resistance: A Review of Opportunities and Challenges
Whole-genome sequencing (WGS) will soon replace traditional phenotypic methods for routine testing of foodborne antimicrobial resistance (AMR). WGS is expected to improve AMR surveillance by providing a greater understanding of the transmission of resistant bacteria and AMR genes throughout the food chain, and therefore support risk assessment activities. At this stage, it is unclear how WGS data can be integrated into quantitative microbial risk assessment (QMRA) models and whether their integration will impact final risk estimates or the assessment of risk mitigation measures. This review explores opportunities and chall...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Bacteria-Killing Type IV Secretion Systems
Bacteria have been constantly competing for nutrients and space for billions of years. During this time, they have evolved many different molecular mechanisms by which to secrete proteinaceous effectors in order to manipulate and often kill rival bacterial and eukaryotic cells. These processes often employ large multimeric transmembrane nanomachines that have been classified as type I to IX secretion systems. One of the most evolutionarily versatile are the Type IV secretion systems (T4SSs), which have been shown to be able to secrete macromolecules directly into both eukaryotic and prokaryotic cells. Until recently, examp...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research

Diversity and Functional Properties of Lactic Acid Bacteria Isolated From Wild Fruits and Flowers Present in Northern Argentina
Lactic acid bacteria (LAB) are capable of converting carbohydrate substrates into organic acids (mainly lactic acid) and producing a wide range of metabolites. Due to their interesting beneficial properties, LAB are widely used as starter cultures, as probiotics, and as microbial cell factories. Exploring LAB present in unknown niches may lead to the isolation of unique species or strains with relevant technological properties. Autochthonous rather than allochthonous starter cultures are preferred in the current industry of fermented food products, due to better adaptation and performance of autochthonous strains to the ma...
Source: Frontiers in Microbiology - May 21, 2019 Category: Microbiology Source Type: research