Iron availability enhances the cellular energetics of aerobic Escherichia coli cultures while upregulating anaerobic respiratory chains.

Aerobic Escherichia coli growth at restricted iron concentrations (≤ 1.75 ± 0.04 μM) is characterized by lower biomass yield, higher acetate accumulation and higher activation of the siderophore iron-acquisition systems.

Emerging Applications of Bacteriocins as Antimicrobials, Anticancer Drugs, and Modulators of The Gastrointestinal Microbiota.

The use of bacteriocins holds great promise in different areas such as health, food, nutrition, veterinary, nanotechnology, among others. Many research groups worldwide continue to advance the knowledge to unravel a novel range of therapeutic agents and food preservatives. This review addresses the advances of bacteriocins and their producer organisms as biocontrol agents for applications in the medical industry and agriculture.

Bacillus cereus MH778713 elicits tomato plant protection against Fusarium oxysporum.

Aim: The genus Fusarium comprises plant pathogenic species with agricultural relevance. Fusarium oxysporum causes tomato wilt disease with significant production losses. The use of agrochemicals to control the Fusarium wilt of tomato is not environmentally friendly.

Growth inhibition of pathogenic microorganisms by Pseudomonas protegens EMM-1 and partial characterization of inhibitory substances.

The bacterial strain, EMM-1, was isolated from the rhizosphere of red maize ("Rojo Criollo") and identified as Pseudomonas protegens EMM-1 based on phylogenetic analysis of 16S rDNA, rpoB, rpoD, and gyrB gene sequences. We uncovered genes involved in the production of antimicrobial compounds like 2,4-diacetylphloroglucinol (2,4-DAPG), pyoluteorin, and lectin-like bacteriocins. These antimicrobial compounds are also produced by other fluorescent pseudomonads alike P.

Long-Chain Hydrocarbons (C21, C24, and C31) Released by sp. MH778713 Break Dormancy of Mesquite Seeds Subjected to Chromium Stress.

Volatile organic compounds (VOCs) produced by rhizobacteria have been proven to stimulate plant growth during germination and seedling stages. However, the modulating effect of bacterial volatiles on the germination of seeds subjected to heavy metal stress is scarcely studied. In this work, the ability of volatiles released by sp.

Structural characterization of scorpion peptides and their bactericidal activity against clinical isolates of multidrug-resistant bacteria.

Scorpion venom peptides represent a novel source of antimicrobial peptides (AMPs) with broad-spectrum activity. In this study, we determined the minimum bactericidal concentration (MBC) of three scorpion AMPs, Uy234, Uy17, and Uy192, which are found in the venomous glands of the Urodacus yaschenkoi scorpion, against the clinical isolates of multidrug-resistant (MDR) bacteria. In addition, we tested the activity of a consensus AMP designed in our laboratory based on some previously reported IsCT-type (cytotoxic linear peptide) AMPs with the aim of obtaining higher antimicrobial activity.

Chromium Hyper-Tolerant sp. MH778713 Assists Phytoremediation of Heavy Metals by Mesquite Trees ().

Heavy metal accumulation in mesquite trees () growing in aluminum, titanium, chromium and zirconium-polluted soils of a semi-arid region in Mexico was investigated using wavelength dispersive X-ray fluorescence analysis. The results showed that trees can hyper accumulate up to 4100 mg/kg of Al, 14000 mg/kg of Fe, 1600 mg/kg of Ti, 2500 mg/kg of Zn, but not chromium, regarding high chromium concentrations found in soils (435 mg/kg). Since plant-associated microorganism can modulate phytoremediation efficiency, the biodiversity of associated bacteria was studied.

Desiccation-induced viable but nonculturable state in Pseudomonas putida KT2440, a survival strategy.

The potential of Pseudomonas putida KT2440 to act as a plant-growth promoter or as a bioremediator of toxic compounds can be affected by desiccation. In the present work, the bacterial survival ratio (BSR) in response to air desiccation was evaluated for P. putida KT2440 in the presence of different protectors.

Effect of amino acids on transcription and translation of key genes in E. coli K and B grown at a steady state in minimal medium.

Growing E. coli to high densities is a common strategy for biologicals production. The process is implemented by using complex or minimal media with different feeding strategies.

Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

Plant growth-promoting rhizobacteria (PGPR) increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium) apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR.

Increasing dissolved-oxygen disrupts iron homeostasis in production cultures of Escherichia coli.

The damaging effect of high oxygen concentration on growth of Escherichia coli is well established. Over-oxygenation increases the intracellular concentration of reactive oxygen species (ROS), causing the destruction of the [4Fe-4S] cluster of dehydratases and limiting the biosynthesis of both branched-chain amino acids and nicotinamide adenine dinucleotide. A key enzyme that reduces the damaging effect of superoxide is superoxide dismutase (SOD).

Effect of elevated oxygen concentration on bacteria, yeasts, and cells propagated for production of biological compounds.

The response of bacteria, yeast, and mammalian and insects cells to oxidative stress is a topic that has been studied for many years. However, in most the reported studies, the oxidative stress was caused by challenging the organisms with H2O2 and redox-cycling drugs, but not by subjecting the cells to high concentrations of molecular oxygen. In this review we summarize available information about the effect of elevated oxygen concentrations on the physiology of microorganisms and cells at various culture conditions.

Production of recombinant protein by a novel oxygen-induced system in Escherichia coli.

Background: The SoxRS regulon of E. coli is activated in response to elevated dissolved oxygen concentration likely to protect the bacteria from possible oxygen damage. The soxS expression can be increased up to 16 fold, making it a possible candidate for recombinant protein expression.

Escherichia coli avoids high dissolved oxygen stress by activation of SoxRS and manganese-superoxide dismutase.

Background: High concentrations of reactive oxygen species (ROS) were reported to cause oxidative stress to E. coli cells associated with reduced or inhibited growth. The high ROS concentrations described in these reports were generated by exposing the bacteria to H2O2 and superoxide-generating chemicals which are non-physiological growth conditions.

Simulation of dissolved CO(2) gradients in a scale-down system: a metabolic and transcriptional study of recombinant Escherichia coli.

Deficient mixing in industrial-scale bioreactors is an important concern as it results in a heterogeneous environment that may affect microbial cell physiology. Dissolved carbon dioxide (dCO(2) ) fluctuations, which can occur in large-scale bioreactors, were simulated for the first time and their effects were evaluated on Escherichia coli expressing recombinant green fluorescent protein (GFP). The dCO(2) gradients were simulated by continuously circulating the medium between two vessels of a scale-down system to mimic mean circulation times (t(c) ) of 50, 170, and 375 s.

High-flux isobutanol production using engineered Escherichia coli: a bioreactor study with in situ product removal.

Promising approaches to produce higher alcohols, e.g., isobutanol, using Escherichia coli have been developed with successful results.

Driving forces enable high-titer anaerobic 1-butanol synthesis in Escherichia coli.

1-Butanol, an important chemical feedstock and advanced biofuel, is produced by Clostridium species. Various efforts have been made to transfer the clostridial 1-butanol pathway into other microorganisms. However, in contrast to similar compounds, only limited titers of 1-butanol were attained.

Metabolic and transcriptional response of recombinant Escherichia coli to elevated dissolved carbon dioxide concentrations.

The effect of dissolved carbon dioxide (dCO(2)) concentration on the stoichiometric and kinetic constants and by-product accumulation was determined for Escherichia coli cells producing recombinant green fluorescent protein (GFP). Constant dCO(2), in the range of 20-300 mbar, was maintained during batch cultures by manipulating the inlet gas composition. As dCO(2) increased, specific growth rate (micro) decreased, and acetate accumulation and the time for onset of GFP production increased.