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Microbial associations arise as useful tools in several biotechnological processes. Among them, bioremediation of contaminated environments usually takes advantage of these microbial associations. Despite being frequently used, these associations are indicated using a variety of expressions, showing a lack of consensus by specialists in the field. The main idea of this work is to analyze the variety of microbial associations referred to as "microbial consortia" (MC) in the context of pollutants biodegradation and bioremediation. To do that, we summarize the origin of the term pointing out the features that an MC is expected to meet, according to the opinion of several authors. An analysis of related bibliography was done seeking criteria to rationalize and classify MC in the context of bioremediation. We identify that the microbe's origin and the level of human intervention are usually considered as a category to classify them as natural microbial consortia (NMC), artificial microbial consortia (AMC), and synthetic microbial consortia (SMC). In this sense, NMC are those associations composed by microorganisms obtained from a single source while AMC members come from different sources. SMC are a class of AMC in which microbial composition is defined to accomplish a certain specific task. We propose that the effective or potential existence of the interaction among MC members in the source material should be considered as a category in the classification as well, in combination with the origin of the source and level of intervention. Cross-kingdom MC and new developments were also considered. Finally, the existence of grey zones in the limits between each proposed microbial consortia category is addressed. KEY POINTS: • Microbial consortia for bioremediation can be obtained through different methods. • The use of the term "microbial consortia" is unclear in the specialized literature. • We propose a simplified classification for microbial consortia for bioremediation., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.) more...

The large-scale use of the herbicide glyphosate leads to growing ecotoxicological and human health concerns. Microbe-assisted phytoremediation arises as a good option to remove, contain, or degrade glyphosate from soils and waterbodies, and thus avoid further spreading to non-target areas. To achieve this, availability of plant-colonizing, glyphosate-tolerant and -degrading strains is required and at the same time, it must be linked to plant-microorganism interaction studies focusing on a substantive ability to colonize the roots and degrade or transform the herbicide. In this work, we isolated bacteria from a chronically glyphosate-exposed site in Argentina, evaluated their glyphosate tolerance using the minimum inhibitory concentration assay, their in vitro degradation potential, their plant growth-promotion traits, and performed whole genome sequencing to gain insight into the application of a phytoremediation strategy to remediate glyphosate contaminated agronomic soils. Twenty-four soil and root-associated bacterial strains were isolated. Sixteen could grow using glyphosate as the sole source of phosphorous. As shown in MIC assay, some strains tolerated up to 10000 mg kg -1 of glyphosate. Most of them also demonstrated a diverse spectrum of in vitro plant growth-promotion traits, confirmed in their genome sequences. Two representative isolates were studied for their root colonization. An isolate of Ochrobactrum haematophilum exhibited different colonization patterns in the rhizoplane compared to an isolate of Rhizobium sp. Both strains were able to metabolize almost 50% of the original glyphosate concentration of 50 mg l -1 in 9 days. In a microcosms experiment with Lotus corniculatus L, O. haematophilum performed better than Rhizobium , with 97% of glyphosate transformed after 20 days. The results suggest that L. corniculatus in combination with to O. haematophilum can be adopted for phytoremediation of glyphosate on agricultural soils. An effective strategy is presented of linking the experimental data from the isolation of tolerant bacteria with performing plant-bacteria interaction tests to demonstrate positive effects on the removal of glyphosate from soils., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Massot, Gkorezis, Van Hamme, Marino, Trifunovic, Vukovic, d’Haen, Pintelon, Giulietti, Merini, Vangronsveld and Thijs.) more...

We report here on a high-quality draft genome sequence of Ochrobactrum haematophilum strain P6BS-III (DSM 106071), a Gram negative, non-sporulating bacterium isolated from a pastureland (Buenos Aires province, Argentina) which had been chronically exposed to the herbicide glyphosate. The genome of 5.25 Mb with a DNA G+C content of 56.63% size was estimated to contain 5,291 protein coding genes and 57 RNA genes. Genome analysis revealed the presence of the phn operon, which is involved in the phosphonate degradation pathway, and a class II 5-enolpyruvylshikimate-3-phosphate synthase (EPSP) that confers tolerance to glyphosate. Genes related to plant growth promotion traits are also present, and include genes for phosphorus metabolism, calcium phosphate and phytate solubilization, siderophore production, organic acid biosynthesis and indole acetic acid (IAA) production. more...

The transition metals iron (Fe) and copper (Cu) are needed at low levels for normal health and at higher levels they become toxic for humans and animals. The acute liver toxicity of Fe and Cu was studied in Sprague Dawley male rats (200 g) that received ip 0-60 mg/kg FeCl(2) or 0-30 mg/kg CuSO(4). Dose and time-responses were determined for spontaneous in situ liver chemiluminescence, phospholipid lipoperoxidation, protein oxidation and lipid soluble antioxidants. The doses linearly defined the tissue content of both metals. Liver chemiluminescence increased 4 times and 2 times after Fe and Cu overloads, with half maximal responses at contents (C(50%)) of 110 μgFe/g and 42 μgCu/g liver, and with half maximal time responses (t(1/2)) of 4h for both metals. Phospholipid peroxidation increased 4 and 1.8 times with C(50%) of 118 μg Fe/g and 45 μg Cu/g and with t(1/2) of 7h and 8h. Protein oxidation increased 1.6 times for Fe with C(50%) at 113 μg Fe/g and 1.2 times for Cu with 50 μg Cu/g and t(1/2) of 4h and 5h respectively. The accumulation of Fe and Cu in liver enhanced the rate of free radical reactions and produced oxidative damage. A similar free radical-mediated process, through the formation HO(•) and RO(•) by a Fenton-like homolytic scission of H(2)O(2) and ROOH, seems to operate as the chemical mechanism for the liver toxicity of both metals., (Copyright © 2012 Elsevier Inc. All rights reserved.) more...

Introduction: Duchenne/Becker muscular dystrophies (DMD/BMD) are X-linked recessive diseases caused by mutations in the dystrophin gene., Methods: We used multiplex polymerase chain reaction (PCR) and short tandem repeat (STR) segregation analysis for DMD/BMD-carrier detection and prenatal diagnosis., Results: Twenty-four at-risk pregnancies were evaluated: 17 were excluded from carrying dystrophin gene mutations with 95-100% certainty. Of the remaining cases, 2 were determined to carry a dystrophin gene mutation with 95-100% certainty. Three cases had a 67% probability of carrying the mutation, and 2 others were not informative. The certainty of the test increased to ~100% in some cases due to the identification of several genetic events: 4 recombinations; 4 de novo mutations; and 8 deletions encompassing some of the STRs evaluated., Discussion: Overall, 19 of 24 (79%) molecular prenatal diagnoses were informative, indicating that multiplex PCR/STR segregation analysis is a reliable method for carrier detection and prenatal diagnosis when other more sophisticated techniques are unavailable., (Copyright © 2011 Wiley Periodicals, Inc.) more...

Fusarium Ear Blight is a destructive fungal disease of cereals including wheat and can contaminate the crop with various trichothecene mycotoxins. This investigation has produced a new β-glucuronidase (GUS) reporter strain that facilitates the quick and easy assessment of plant infection. The constitutively expressed gpdA:GUS strain of Fusarium graminearum was used to quantify the overall colonisation pattern. Histochemical and biochemical approaches confirmed, in susceptible wheat ear infections, the presence of a substantial phase of symptomless fungal growth. Separate analyses demonstrated that there was a reduction in the quantity of physiologically active hyphae as the wheat ear infection proceeded. A simplified linear system of rachis infection was then utilised to evaluate the expression of several TRI genes by RT-qPCR. Fungal gene expression at the advancing front of symptomless infection was compared with the origin of infection in the rachis. This revealed that TRI gene expression was maximal at the advancing front and supports the hypothesis that the mycotoxin deoxynivalenol plays a role in inhibiting plant defences in advance of the invading intercellular hyphae. This study has also demonstrated that there are transcriptional differences between the various phases of fungal infection and that these differences are maintained as the infection proceeds. more...