Table of Contents
Spotlight
Biodegradation
BiodegradationThe Sterol Carrier Hydroxypropyl-β-Cyclodextrin Enhances the Metabolism of Phytosterols by Mycobacterium neoaurumPhytosterols from soybean are low-cost by-products of soybean oil production and, owing to their good bioavailability in mycobacteria, are preferred as the substrates for steroid drug production via biotransformation by Mycobacterium. However, the low level of production of steroid hormone drugs due to the low aqueous solubility (below 0.1 mmol/liter) of phytosterols limits the commercial use of sterol-transformed strains. To...
Biodegradation | SpotlightMicrobial Degradation of Pyridine: a Complete Pathway in Arthrobacter sp. Strain 68b DecipheredThe biodegradation pathway of pyridine, a notorious toxicant, is relatively unexplored, as no genetic data related to this process have ever been presented. In this paper, we describe the plasmid-borne pyr gene cluster, which includes the complete set of genes responsible for the degradation of pyridine. A key enzyme, the monooxygenase PyrA, which is responsible for the first step of the catabolic pathway, performs an oxidative...
BiodegradationThe 5,6,7,8-Tetrahydro-2-Naphthoyl-Coenzyme A Reductase Reaction in the Anaerobic Degradation of Naphthalene and Identification of Downstream MetabolitesAnaerobic degradation of polycyclic aromatic hydrocarbons is poorly investigated despite its significance in anoxic sediments. Using alternative electron donors for the 5,6,7,8-tetrahydro-2-naphthoyl-CoA reductase reaction, we observed intermediary metabolites of anaerobic naphthalene degradation via in vitro enzyme assays with cell extracts of anaerobic naphthalene degraders. The identified metabolites provide evidence that...
Biotechnology
BiotechnologyQuantitative Proteome Profiling Reveals Cellobiose-Dependent Protein Processing and Export Pathways for the Lignocellulolytic Response in Neurospora crassaLignocellulases are important industrial enzymes for sustainable production of biofuels and bio-products. Insoluble cellulose has been commonly used to induce the production of lignocellulases in filamentous fungi, which causes a difficult fermentation operation and enzyme loss due to adsorption to cellulose. The disadvantages can be overcome by using soluble inducers, such as the disaccharide cellobiose. Quantitative proteome profiling...
Biotechnology | SpotlightNisin M: a Bioengineered Nisin A Variant That Retains Full Induction Capacity but Has Significantly Reduced Antimicrobial ActivityThis study describes the generation of a nisin variant with superior characteristics for use in the NICE protein expression system. The variant, termed nisin M, retains an induction capacity comparable to that of wild-type nisin A but exhibits significantly reduced antimicrobial activity and can therefore be used at concentrations that are normally toxic to the expression host.
Environmental Microbiology
Environmental MicrobiologyA Sulfoglycolytic Entner-Doudoroff Pathway in Rhizobium leguminosarum bv. trifolii SRDI565Sulfonate sulfur is a major form of organic sulfur in soils but requires biomineralization before it can be utilized by plants. Very little is known about the biochemical processes used to mobilize sulfonate sulfur. We show that a rhizobial isolate from soil, Rhizobium leguminosarum SRDI565, possesses the ability to degrade the abundant phototroph-derived carbohydrate...
Environmental MicrobiologyGlobal Regulator of Rubber Degradation in Gordonia polyisoprenivorans VH2: Identification and Involvement in the Regulation NetworkIn order to develop efficient microbial recycling strategies for rubber waste materials, it is required that we understand the degradation pathway of the polymer and how it is regulated. However, only little is known about the transcriptional regulation of the rubber degradation pathway, which seems to be upregulated in the presence of the polymer. We identified a novel key regulator of rubber degradation (CRPVH2) that...
Enzymology and Protein Engineering
Enzymology and Protein EngineeringAn 1,4-α-Glucosyltransferase Defines a New Maltodextrin Catabolism Scheme in Lactobacillus acidophilusThe degradation of starch in the small intestine generates short linear and branched α-glucans. The latter are poorly digestible by humans, rendering them available to the gut microbiota, e.g., lactobacilli adapted to the small intestine and considered beneficial to health. This study unveils a previously unknown scheme of maltooligosaccharide (MOS) catabolism via the concerted activity of an 1,4-α-glucosyltransferase together with a...
Food Microbiology
Food MicrobiologyMicroorganisms Move a Short Distance into an Almond Orchard from an Adjacent Upwind Poultry OperationThe movement of microorganisms, including foodborne pathogens, from animal operations into adjacent plant crop-growing environments is not well characterized. This study provides evidence that dust and bioaerosols moved from a commercial poultry operation a short distance downwind into an almond orchard and altered the microbiome recovered from the leaves. These data provide growers with information they can use to assess food safety...
Food MicrobiologyAntibiofilm Activity of Lactobacillus plantarum 12 Exopolysaccharides against Shigella flexneriS. flexneri is a widespread foodborne pathogen causing food contamination and responsible for food poisoning outbreaks related to various foods in developing countries. Not only has biofilm formation by S. flexneri been difficult to eliminate, but it has also increased the drug resistance of the...
Geomicrobiology
Geomicrobiology | SpotlightGenome-Resolved Metagenomics and Detailed Geochemical Speciation Analyses Yield New Insights into Microbial Mercury Cycling in Geothermal SpringsLittle is currently known about biogeochemical mercury cycling in geothermal systems. The manuscript presents a new conceptual model, supported by genome-resolved metagenomic analysis and detailed geochemical measurements. The model illustrates environmental factors that influence mercury cycling in acidic springs, including transitions between solid (mineral) and aqueous phases of mercury, as well as the interconnections among mercury...
GeomicrobiologyProtective Role of Bacterial Alkanesulfonate Monooxygenase under Oxidative StressssuD and tauD, which play a role in the degradation of organosulfonate, were expressed during n-hexadecane metabolism and oxidative stress conditions in A. oleivorans DR1. Our study confirmed that hexadecanesulfonate was accidentally generated during bacterial n-hexadecane degradation in sulfate-limited conditions. Removal of this...
Physiology
PhysiologyContribution of Complex I NADH Dehydrogenase to Respiratory Energy Coupling in Glucose-Grown Cultures of Ogataea parapolymorphaSince popular microbial cell factories have typically not been selected for efficient respiratory energy coupling, their ATP yields from sugar catabolism are often suboptimal. In aerobic industrial processes, suboptimal energy coupling results in reduced product yields on sugar, increased process costs for oxygen transfer, and volumetric productivity limitations due to limitations in gas transfer and cooling. This study provides...
Plant Microbiology
Plant MicrobiologyCheY1 and CheY2 of Azorhizobium caulinodans ORS571 Regulate Chemotaxis and Competitive Colonization with the Host PlantAzorhizobium caulinodans ORS571 is a motile soil bacterium that has the dual capacity to fix nitrogen both under free-living conditions and in symbiosis with Sesbania rostrata, forming nitrogen-fixing root and stem nodules. Bacterial chemotaxis to chemoattractants derived from host roots promotes...
Plant Microbiology | SpotlightSpecific Root Exudate Compounds Sensed by Dedicated Chemoreceptors Shape Azospirillum brasilense Chemotaxis in the RhizospherePlant root exudates play critical roles in shaping rhizosphere microbial communities, and the ability of motile bacteria to respond to these gradients mediates competitive colonization of root surfaces. Root exudates are complex chemical mixtures that are spatially and temporally dynamic. Identifying the exact chemical(s) that mediates the recruitment of soil bacteria to specific regions of the roots is thus challenging. Here, we...
Public and Environmental Health Microbiology
Public and Environmental Health MicrobiologySpoVG Modulates Cell Aggregation in Staphylococcus aureus by Regulating sasC Expression and Extracellular DNA ReleaseThis study revealed that SpoVG can modulate cell aggregation by repressing sasC expression and extracellular DNA (eDNA) release. Furthermore, we have demonstrated the potential linkage between cell aggregation and antibiotic resistance. Our findings provide novel insights into the regulatory mechanisms of SpoVG involved in cell aggregation and in biofilm development and formation in...
Public and Environmental Health Microbiology | SpotlightEnvironmental Surveillance Complements Case-Based Surveillance of Acute Flaccid Paralysis in Polio Endgame Strategy 2019–2023Interrupting wild poliovirus transmission and stopping circulating vaccine-derived poliovirus (cVDPV) outbreaks have been proposed as two global goals by the World Health Organization in the Global Polio Eradication Initiative (GPEI). This analysis, based on the 28-year acute flaccid paralysis (AFP) surveillance and 8-year environmental surveillance, provides continued high-quality surveillance performance in achieving the GPEI and...
Public and Environmental Health MicrobiologyPrevalence of Cefotaxime-Resistant Escherichia coli Isolates from Healthy Cattle and Sheep in Northern Spain: Phenotypic and Genome-Based Characterization of Antimicrobial SusceptibilityExtended-spectrum β-lactamase (ESBL)- and AmpC β-lactamase (AmpC)-producing E. coli isolates have emerged in recent years as some of the fastest spreading antimicrobial resistance determinants in humans and food-producing animals, becoming a concern for animal and public health. This study provided insight into the prevalence of cefotaxime-resistant...
Author Correction
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