MicrobiologyOpen

The term “open” has two meanings: first, MicrobiologyOpen is an open access journal, but, more importantly, it also means that it is open to all aspects of microbiology. Together we aim at reaching a level of excellence for MicrobiologyOpen, which means that only manuscripts of high scientific interest and value will be accepted.

A new Saccharophagus species Myt-1 was isolated from Toyama Bay, Toyama Prefecture, Japan. Myt-1 produces a variety of enzymes capable of effectively decomposing different kinds of seaweed and their component polysaccharides.

We characterized 12 RND-type multidrug efflux transporters in Vibrio parahaemolyticus. Deletion mutants of all twelve transporter genes showed higher sensitivity for several antibiotics and bile, and lower pathogenicity.

Two types of diets with low and normal protein levels were fed to genetically improved farmed tilapia. The results suggest that insufficient dietary proteins are likely to restrict growth and weaken disease resistance. The pellet feed diets with low protein level strongly affected the gut microbial composition and significantly decreased intestinal microbial diversity.

A rapid, efficient approach for the expression of active recombinant extracellular polyhydroxybutyrate (PHB) depolymerases originating from various bacterial strains. It enables the characterization of new PHB depolymerases and the direct comparison of activity between enzymes and conditions; as an example, the activity of five PHB depolymerases is evaluated and compared at different pH and temperatures. This approach can accelerate the investigation and development of applications based on the degradation of biopolymers.

We present the result of national survey during which microbiologists from 204 Italian hospitals have been interviewed on the application of guidelines concerning the proper use of blood cultures. Although the study showed some positive aspects, a full compliance with the guidelines is still far away, and more surveys will be needed to monitor the situation in the future.

Roxarsone (ROX) is an organoarsenic animal drug used in production as a feed additive to increase weight gain and improve feed efficiency. This study revealed the close relationship between ROX and microbial growth. A stable anaerobic bacterial consortium that effectively degraded ROX was identified. The bacterial community, growth curve, and degradation ability at different ROX concentrations were assessed.

Altitude has a potential effect on the animal symbiotic microbiome. Here, we provided an example of this effect in the wild amphibians. High relative abundance of Caulobacteraceae and Sphingomonadaceae was found in skin samples from both Bufo gargarizans and the other high-altitude amphibians (nine species combined). High relative abundance of Coxiellaceae and Mycoplasmataceae was found in gut samples from both B. gargarizans and the other high-altitude amphibians.

Pathogenic bacteria often carry large plasmids that contain multiple resistance genes; individually, these elements coselect for additional resistance genes that are genetically linked by the plasmid. In this short communication, we demonstrate increased triclosan resistance can be conjugatively transferred in Staphylococcus aureus. Furthermore, in a competition assay, we show subinhibitory concentrations of antiseptics abrogate the fitness cost of a large multidrug resistance plasmid in S. aureus, thus coselecting for the numerous antimicrobial resistance genes present on the plasmid.

The aim of this study was to identify the source of β-alanine in Rhizobium etli. We show that Rhizobium etli CFN42 synthesizes β-alanine de novo using β-alanine synthase instead of aspartate decarboxylase enzyme.

By using the polymerase chain reaction coupled with electrospray ionization-mass spectrometry (PCR/ESIMS) technology, we detected pathogenic agents in 29.4% (47 of 160) more samples than by using 16S rRNA PCR and/or blood culture. Thus, the PCR/ESI-MS represented an opportunity to make the bloodstream infection diagnostics highly sensitive and accurate.

We engineered the mesophilic prokaryote Clostridium cellulolyticum, which can degrade cellulosic biomass, to utilize the resulting glucose monomers as a feedstock for the production of isoprene. We have shown for the first time that engineered C. cellulolyticum can be used as a metabolic chassis for the sustainable production of isoprene.

This work was carried out to determine the microbial biodiversity of spontaneous sourdoughs that are made from wheat, spelt, and rye wholemeal flour on an industrial scale. The culture-independent approach demonstrated how the microbial ecology changed during 72 hr of fermentation. The Weissella was the most abundant genus after a 24 hr of fermentation of the rye sourdough, but as the process progressed, its abundance decreased in favor of the Lactobacillus genus similarly as in wheat and spelt sourdoughs.

Over-expression of the cytoplasmic membrane protein TolQ resulted in a division phenotype similar to that seen in cells depleted for FtsN. Two hybrid analysis suggested that TolQ and FtsN physically interact through domains that localize in the periplasmic space; while the concurrent over-expression of FtsN alleviated the TolQ over-expression phenotype. Together these results suggest a model wherein over-expressed TolQ sequesters FtsN, disrupting normal cell division.

Targeting protein cargo to bacterial microcompartments (BMCs) is reliant on the presence and effectiveness of N-terminal encapsulation peptides. Three distinct tags were investigated for their ability to target cargo to a recombinant BMC. The three tags resulted in variations in the amount of aggregation and/or colocalization. The level of aggregation was found to influence enzymatic activity, packing, and the size and shape of the structure.

Ammonia-oxidizing microbes (AOM) residing in the beach sands of Myrtle Beach, South Carolina, are abundant, representing 3%–6% of the total diversity present. Ammonia-oxidizing archaea (AOA) are numerically dominant and more diverse than the ammonia-oxidizing Bacteria (AOB). Results from microcosm experiments suggest that the AOA are more active than the AOB with regard to ammonia oxidation in this ecosystem, differentiating this system from other intertidal systems.

We explored the intracellular proteome profile of Aspergillus niger 3.316 in group T (50°C stress) and group C (30°C control) using isobaric tags for relative and absolute quantitation proteomic approach, and the observations were further verified using a parallel reaction monitoring approach. The label-free proteomic analysis provided an additional explanation of the differences between groups T and C. Bioinformatic analysis, combined with the proteomics data, significantly enhances our understanding of the heat stress response mechanism of A. niger.

By combining DNA stable-isotope probing and Illumina Miseq high-throughput sequencing, we identified 14 bacterial taxonomic groups actively involved in the decomposition of particulate organic matter (POM) at different pressures. Both particle-attached and free-living microorganisms were able to decompose POM and assimilate the released dissolved organic matter, suggesting the decoupling between microbial lifestyles and ecological functions. Our results provide direct evidence linking the specific microbial lineages to decomposition and degradation of POM and identified the potential mediators of POM fluxes in the ocean.

Marine sulfur cycling depends to a large extent on the transformation of the dominant algal osmolyte dimethylsulfoniopropionate (DMSP). We show that other low molecular weight zwitterionic dimethylsulfonio (DMS)-compounds, including dimethylsulfonioacetate (DMSA) and gonyol can serve as alternative substrates fueling the pool of volatile sulfur species from the oceans. We demonstrate that these prevalent zwitterions from algae are metabolized by marine bacteria and that gonyol acts as an inhibitor of bacterial metabolism of the abundant oceanic dimethylsulfoniopropionate. We thus argue that the prevalence of DMSA and gonyol and their inhibitory properties of DMSP-metabolism modulates the planktonic sulfur cycle and the flux of climate-active DMS to the atmosphere.

This study revealed mechanisms underlying EPS synthesis for biofilm development of Listeria monocytogenes. Especially, it elaborated on the cooperation of signal molecules in metabolic pathways and the quorum sensing (QS) network. These findings pave a way for systematically targeting key regulators in L. monocytogenes metabolism and QS to prevent biofilm development.