Fungal Alcohol Dehydrogenases: Physiological Function, Molecular Properties, Regulation of Their Production, and Biotechnological Potential.

Fungal alcohol dehydrogenases (ADHs) participate in growth under aerobic or anaerobic conditions, morphogenetic processes, and pathogenesis of diverse fungal genera. These processes are associated with metabolic operation routes related to alcohol, aldehyde, and acid production. The number of ADH enzymes, their metabolic roles, and their functions vary within fungal species.

Secretion of the siderophore rhizoferrin is regulated by the cAMP-PKA pathway and is involved in the virulence of Mucor lusitanicus.

Mucormycosis is a fungal infection caused by Mucorales, with a high mortality rate. However, only a few virulence factors have been described in these organisms. This study showed that deletion of rfs, which encodes the enzyme for the biosynthesis of rhizoferrin, a siderophore, in Mucor lusitanicus, led to a lower virulence in diabetic mice and nematodes.

Chromogenic Escherichia coli reporter strain for screening DNA damaging agents.

The presence of pollutants in soil and water has given rise to diverse analytical and biological approaches to detect and measure contaminants in the environment. Using bacterial cells as reporter strains represents an advantage for detecting pollutants present in soil or water samples. Here, an Escherichia coli reporter strain expressing a chromoprotein capable of interacting with soil or water samples and responding to DNA damaging compounds is validated.

Alteration of Fermentative Metabolism Enhances Mucor circinelloides Virulence.

The fungus undergoes yeast-mold dimorphism, a developmental process associated with its capability as a human opportunistic pathogen. Dimorphism is strongly influenced by carbon metabolism, and hence the type of metabolism likely affects fungus virulence. We investigated the role of ethanol metabolism in virulence.

Alcohol dehydrogenase 1 participates in the Crabtree effect and connects fermentative and oxidative metabolism in the Zygomycete Mucor circinelloides.

Mucor circinelloides is a dimorphic Zygomycete fungus that produces ethanol under aerobic conditions in the presence of glucose, which indicates that it is a Crabtree-positive fungus. To determine the physiological role of the alcohol dehydrogenase (ADH) activity elicited under these conditions, we obtained and characterized an allyl alcohol-resistant mutant that was defective in ADH activity, and examined the effect of adh mutation on physiological parameters related to carbon and energy metabolism. Compared to the Adh strain R7B, the ADH-defective (Adh) strain M5 was unable to grow under anaerobic conditions, exhibited a considerable reduction in ethanol production in aerobic cultures when incubated with glucose, had markedly reduced growth capacity in the presence of oxygen when ethanol was the sole carbon source, and exhibited very low levels of NAD-dependent alcohol de-hydrogenase activity in the cytosolic fraction.

Impact of Cr(VI) on the oxidation of polyunsaturated fatty acids in Helianthus annuus roots studied by metabolomic tools.

The impact of Cr(VI) in sunflower roots has been studied, focusing on the oxidation of polyunsaturated fatty acids. Plants were grown hydroponically in the presence of 0, 1.0, 5.

CrpP Is a Novel Ciprofloxacin-Modifying Enzyme Encoded by the Pseudomonas aeruginosa pUM505 Plasmid.

The pUM505 plasmid, isolated from a clinical isolate, confers resistance to ciprofloxacin (CIP) when transferred into the standard strain PAO1. CIP is an antibiotic of the quinolone family that is used to treat infections. analysis, performed to identify CIP resistance genes, revealed that the 65-amino-acid product encoded by the gene in pUM505 displays 40% amino acid identity to the aminoglycoside phosphotransferase (an enzyme that phosphorylates and inactivates aminoglycoside antibiotics).

Changes of Metabolomic Profile in under Exposure to Chromium(VI) Studied by capHPLC-ESI-QTOF-MS and MS/MS.

The application of capHPLC-ESI-QTOF-MS and MS/MS to study the impact of Cr(VI) on metabolites profile in is reported. Germinated seeds were grown hydroponically in the presence of Cr(VI) (25 mgCr/L) and root extracts of the exposed and control plants were analyzed by untargeted metabolomic approach. The main goal was to detect which metabolite groups were mostly affected by Cr(VI) stress; two data analysis tools (ProfileAnalysis, Bruker, and online XCMS) were used under criteria of intensity threshold 5 · 10 cps, fold change ≥ 5, and ≤ 0.

Nitrate assimilation pathway (NAP): role of structural (nit) and transporter (ntr1) genes in Fusarium oxysporum f.sp. lycopersici growth and pathogenicity.

The tomato pathogen Fusarium oxysporum f.sp. lycopersici possesses the capability to use nitrate as the only nitrogen source under aerobic and anaerobic conditions and to activate virulence-related functions when cultivated in the presence of nitrate, but not in ammonium.

Bacterial diversity in fumarole environments of the Paricutín volcano, Michoacán (Mexico).

Active volcanoes are among the most extreme environments on Earth. The extreme temperatures, presence of toxic heavy metals and low nutrient bioavailability favor the development of extremophiles. We characterized the physical-chemical parameters of and bacterial communities (T-RFLP and 16S rRNA gene libraries) inhabiting fumarole niches of the Paricutín volcano located in Michoacán (Mexico).

Cr(VI) reduction by gluconolactone and hydrogen peroxide, the reaction products of fungal glucose oxidase: Cooperative interaction with organic acids in the biotransformation of Cr(VI).

The Cr(VI) reducing capability of growing cells of the environmental A. tubingensis Ed8 strain is remarkably efficient compared to reference strains A. niger FGSC322 and A.

The Adh1 gene of the fungus Metarhizium anisopliae is expressed during insect colonization and required for full virulence.

Zymography of alcohol dehydrogenase (ADH) activity in the entomopathogenic fungus Metarhizium anisopliae grown under various conditions revealed that micro-aerobic growth was associated with increased ADH activity. The major ADH protein, AdhIp, was purified to homogeneity by affinity chromatography and has an estimated molecular weight of 41kDa and an isoelectric point (pI) of 6.4.

Selection of reference genes for quantitative real time RT-PCR during dimorphism in the zygomycete Mucor circinelloides.

Mucor circinelloides is a dimorphic fungal model for studying several biological processes including cell differentiation (yeast-mold transitions) as well as biodiesel and carotene production. The recent release of the first draft sequence of the M. circinelloides genome, combined with the availability of analytical methods to determine patterns of gene expression, such as quantitative Reverse transcription-Polymerase chain reaction (qRT-PCR), and the development of molecular genetic tools for the manipulation of the fungus, may help identify M.

Role of Bacillus subtilis error prevention oxidized guanine system in counteracting hexavalent chromium-promoted oxidative DNA damage.

Chromium pollution is potentially detrimental to bacterial soil communities, compromising carbon and nitrogen cycles that are essential for life on earth. It has been proposed that intracellular reduction of hexavalent chromium [Cr(VI)] to trivalent chromium [Cr(III)] may cause bacterial death by a mechanism that involves reactive oxygen species (ROS)-induced DNA damage; the molecular basis of the phenomenon was investigated in this work. Here, we report that Bacillus subtilis cells lacking a functional error prevention oxidized guanine (GO) system were significantly more sensitive to Cr(VI) treatment than cells of the wild-type (WT) strain, suggesting that oxidative damage to DNA is involved in the deleterious effects of the oxyanion.

Microbial diversity in Los Azufres geothermal field (Michoacán, Mexico) and isolation of representative sulfate and sulfur reducers.

Los Azufres spa consists of a hydrothermal spring system in the Mexican Volcanic Axis. Five samples (two microbial mats, two mud pools and one cenote water), characterized by high acidity (pH between 1 and 3) and temperatures varying from 27 to 87 °C, were investigated for their microbial diversity by Terminal-Restriction Fragment Length Polymorphism (T-RFLP) and 16S rRNA gene library analyses. These data are the first to describe microbial diversity from Los Azufres geothermal belt.

Application of reversed-phase high-performance liquid chromatography with fluorimetric detection for simultaneous assessment of global DNA and total RNA methylation in Lepidium sativum: effect of plant exposure to Cd(II) and Se(IV).

In the present work, application of the previously established reversed-phase liquid chromatography procedure based on fluorescent labeling of cytosine and methylcytosine moieties with 2-bromoacetophenone (HPLC-FLD) is presented for simultaneous evaluation of global DNA and total RNA methylation at cytosine carbon 5. The need for such analysis was comprehended from the recent advances in the field of epigenetics that highlight the importance of non-coding RNAs in DNA methylation and suggest that RNA methylation might play a similar role in the modulation of genetic information, as previously demonstrated for DNA. In order to adopt HPLC-FLD procedure for DNA and RNA methylation analysis in a single biomass extract, two extraction procedures with different selectivity toward nucleic acids were examined, and a simplified calibration was designed allowing for evaluation of methylation percentage based on the ratio of chromatographic peak areas: cytidine/5-methylcytidine for RNA and 2'-deoxycytidine/5-methyl-2'-deoxycytidine for DNA.

The Neurospora crassa chr-1 gene is up-regulated by chromate and its encoded CHR-1 protein causes chromate sensitivity and chromium accumulation.

The ChrA membrane protein belongs to the CHR superfamily of chromate ion transporters, which includes homologues from bacteria, archaea and eukaryotes. Bacterial ChrA homologues confer chromate resistance by exporting chromate ions from the cell's cytoplasm. The Neurospora crassa strain 74-A chr-1 gene encodes a putative CHR-1 protein of 507 amino acid residues, which belongs to the CHR superfamily.

Bacterial biodiversity from anthropogenic extreme environments: a hyper-alkaline and hyper-saline industrial residue contaminated by chromium and iron.

Anthropogenic extreme environments are among the most interesting sites for the bioprospection of extremophiles since the selection pressures may favor the presence of microorganisms of great interest for taxonomical and astrobiological research as well as for bioremediation technologies and industrial applications. In this work, T-RFLP and 16S rRNA gene library analyses were carried out to describe the autochthonous bacterial populations from an industrial waste characterized as hyper-alkaline (pH between 9 and 14), hyper-saline (around 100 PSU) and highly contaminated with metals, mainly chromium (from 5 to 18 g kg(-1)) and iron (from 2 to 108 g kg(-1)). Due to matrix interference with DNA extraction, a protocol optimization step was required in order to carry out molecular analyses.

Fusarium oxysporum Adh1 has dual fermentative and oxidative functions and is involved in fungal virulence in tomato plants.

An alcohol dehydrogenase gene, adh1, has been identified in the vascular wilt fungus Fusarium oxysporum f. sp. lycopersici.

Isolation, characterization and expression analysis of the ornithine decarboxylase gene (ODC1) of the entomopathogenic fungus, Metarhizium anisopliae.

The gene ODC1, which codes for the ornithine decarboxylase enzyme, was isolated from the entomopathogenic fungus, Metarhizium anisopliae. The deduced amino acid sequence predicted a protein of 447 amino acids with a molecular weight of 49.3 kDa that contained the canonical motifs of ornithine decarboxylases.

Effect of Fusarium oxysporum f. sp. lycopersici on the soil-to-root translocation of heavy metals in tomato plants susceptible and resistant to the fungus.

The purpose of this work was to gain an insight on the potential role of the phytopathogenic fungus Fusarium oxysporum f. sp. lycopersici in the translocation of metals and metalloids from soil to plant roots in tomato (Lycopersicum esculentum).

Effect of Fusarium oxysporum f. sp. lycopersici on the degradation of humic acid associated with Cu, Pb, and Ni: an in vitro study.

The intent of this work was to gain further insight on the fungus-assisted degradation/solubilization of humic acid and the related changes in metal-binding profiles. In the experimental design, Aldrich reagent humic acid (HA) or HA enriched with Cu, Pb, and Ni (HA(Me)) was added to Fusarium oxysporum f. sp.

Cr(VI) reduction by an Aspergillus tubingensis strain: role of carboxylic acids and implications for natural attenuation and biotreatment of Cr(VI) contamination.

Experiments conducted in shake flask cultures, in minimal medium of pH 5.3 containing 50 microg mL(-1)Cr(VI) with glucose as a carbon source, indicated that the biomass of Aspergillus sp. strain Ed8, a chromate-tolerant fungal strain previously isolated from a chromium-polluted soil, responds to the presence of citrate in the medium by increasing the rate of Cr(VI) reduction; this effect required the use of live biomass and was not observed in medium with lactate.

Analytical speciation of chromium in in-vitro cultures of chromate-resistant filamentous fungi.

In this work, different analytical speciation schemes have been used to study the reduction of Cr(VI) by a chromate-resistant strain of filamentous fungi Ed8 (Aspergillus sp), indigenous to contaminated industrial wastes. As demonstrated previously, this strain has the capability to reduce chromate present in the growth medium without its accumulation in the biomass, yet the reduced chromium end-products have not been characterized. Liquid growth medium, initially containing 50 mg L(-1) Cr(VI), was analyzed for Cr(III)/Cr(VI) and for total Cr at different time intervals (0-24 h) after inoculation with fungi.

The protective effect of selenium inorganic forms against cadmium and silver toxicity in mycelia of Pleurotus ostreatus.

The effect of two inorganic selenium forms has been investigated in the mycelia of Pleurotus ostreatus exposed to cadmium and silver salts in the shaken cultures. The degree of toxicity was assessed by the determination of malondialdehyde (MDA; a common biomarker of lipid peroxidation). The mycelia were exposed to one element form (up to 5 mg l(-1)) and also to the following combinations: cadmium(II) + selenium(IV); cadmium(II) + selenium(VI); silver(I) + selenium(IV); silver(I) + selenium(VI).