-
Journal of Fungi (Basel, Switzerland) May 2021Two novel xylanolytic enzymes, a xylanase and a β-xylosidase, were simultaneously isolated and characterized from the extracellular medium of ATHUM 8891 (anamorph...
Two novel xylanolytic enzymes, a xylanase and a β-xylosidase, were simultaneously isolated and characterized from the extracellular medium of ATHUM 8891 (anamorph ATHUM 8891), grown on Brewer's Spent Grain as a sole carbon source. They represent the first pair of characterized xylanolytic enzymes of the genus and the first extensively characterized xylanolytic enzymes of the family . In contrast to other xylanolytic enzymes isolated from the same family, both enzymes are characterized by exceptional thermostability and stability at low pH values, in addition to activity optima at temperatures around 65 °C and acidic pH values. Applying nano-LC-ESI-MS/MS analysis of the purified SDS-PAGE bands, we sequenced fragments of both proteins. Based on sequence-comparison methods, both proteins appeared conserved within the genus . Xylanase was classified within Glycoside Hydrolase family 11 (GH 11), while β-xylosidase in Glycoside Hydrolase family 3 (GH 3). The two enzymes showed a synergistic action against xylan by rapidly transforming almost 40% of birchwood xylan to xylose. The biochemical profile of both enzymes renders them an efficient set of biocatalysts for the hydrolysis of xylan in demanding biorefinery applications.
PubMed: 34072339
DOI: 10.3390/jof7060430 -
Plants (Basel, Switzerland) Apr 2021Hydroponic systems have gained interest and are increasingly used in hot and dry desert areas. Numbers of benefits are offered by hydroponic systems such as the ability...
Hydroponic systems have gained interest and are increasingly used in hot and dry desert areas. Numbers of benefits are offered by hydroponic systems such as the ability to save water, enhance nutrients use efficiency, easy environmental control, and prevention of soil-borne diseases. However, the high consumption of chemical fertilizers for nutrient solution and the sensitivity of closed hydroponic systems to salinity are issues that need solutions. Thus, the main goal of our research activities is to isolate plant growth promoting fungi in order to develop sustainable hydroponic systems. We are working on isolating and testing the possibility to incorporate the cell-free filtrate (CFF) of plant growth promoting fungi (PGPF) in the composition of the nutrient solution. In this work, we isolated six strains of PGPF from the rhizosphere of the halophyte grass . Phylogenetic analyses of DNA sequences amplified by ITS1 and ITS4 primers identified the isolated fungi as: , , , , , and . The promoting of vigor in tobacco seedlings was used as criteria to evaluate the biostimulant activity of these fungi by adding either their mycelia (DE: direct effect) or their cell-free filtrates (CFF: indirect effect) to the plant-growth media. The best significant growth stimulation was obtained with plants treated by . However, only the CFFs of (A5.1) and (A8) when added at a dilution factor of 1/50 to half-strength nutritive solution (0.5NS) resulted in significant improvement of all assessed growth parameters. Indeed, the A5.1CFF and A8CFF in 0.5NS induced a significant better increase in the biomass production when compared to NS or 0.5NS alone. All fungi produced indole acetic acid in the CFFs, which could be one of the key factors explaining their biostimulant activities. Furthermore, six genes involved in nitrogen-metabolism ( and ), auxin biosynthesis ( and ), and brassinosteroid biosynthesis ( and ) were shown to be induced in roots or leaves following treatment of plants with the all CFFs. This work opens up a prospect to study in deep the biostimulant activity of PGPFs and their applications to decrease the requirement of chemical fertilizers in the hydroponic growing systems.
PubMed: 33923476
DOI: 10.3390/plants10040784 -
The Journal of General Virology Nov 2023is a thermo-tolerant, ubiquitous fungus commonly found in food products, indoor environments, soil and clinical samples. It is a well-known biocontrol agent used...
is a thermo-tolerant, ubiquitous fungus commonly found in food products, indoor environments, soil and clinical samples. It is a well-known biocontrol agent used against phytopathogenic fungi and its metabolites have many industrial applications. Rare reports of related human infections have been found in the medical literature. In this study, we report for the first time the infection of isolated from a soil sample collected in a rice field with a double-stranded RNA virus, Paeciliomyces variotii partitivirus 1 (PvPV-1) in the family harboured icosahedral virus particles 30 nm in diameter with two dsRNA segments 1758 and 1356 bp long. Both dsRNA1 and dsRNA2 have a single open reading frame encoding proteins of 63 and 40 kDa, respectively. These proteins have significant similarity to the RNA-dependent RNA polymerase and capsid protein encoded by the genomic segments of several viruses from the family . Phylogenetic analysis revealed that PvPV-1 belongs to the family but in an unclassified group/genus, tentatively nominated Zetapartitivirus. PvPV-1 was found to increase the growth rate of the host fungus, as indicated by time course experiments performed on a range of different media for virus-infected and virus-free isogenic lines. Further, dual-culture assays performed for both isogenic lines confirmed the antagonistic potential of against other phytopathogenic fungi. The findings of this study assist us in understanding as a potential biocontrol agent, together with plant-fungus-virus interactions.
Topics: Humans; Phylogeny; Byssochlamys; Capsid Proteins; Soil
PubMed: 38015047
DOI: 10.1099/jgv.0.001925 -
Mycology Apr 2020Ten specimens of coral reefs were collected from the Red Sea in the Ein El-Sukhna region. Fungal isolation was done using two media, Dextrose Yeast Extract Agar (DYA)...
Ten specimens of coral reefs were collected from the Red Sea in the Ein El-Sukhna region. Fungal isolation was done using two media, Dextrose Yeast Extract Agar (DYA) and Rose Bengal Agar (RBA). The morphological traits identified 18 fungal isolates belonging to the phyla Ascomycota, Mucoromycota and Deuteromycota. Five genera in three orders have been isolated: Eutrotiales ( and ), Mucorales () and Moniliales (). The heat mapping clustering of the isolated fungi declared that and were the most frequently isolate fungi in coral reefs. It was found that colonised eight coral samples with 80% colonisation rate. Moreover, about 50% of the isolated fungal species were specific to one coral reef only such as and isolated from only, and from from and from from and and from . Biological activities (antimicrobial, antioxidant antiradical and cytotoxicity) of the most predominant fungal species were investigated. The antimicrobial activity of coral fungal filtrates were investigated against six pathogenic bacteria including ATCC11775, ATCC19424, ATCC10145, ATCC19433, subsp. ATCC25923, subsp. ATCC6633 and two pathogenic yeast including ATCC7102 and ATCC22019. Most of these fungal filtrates exhibited moderate to high antibacterial activities against both gram positive and gram negative bacteria, however it showed relatively low bioactivity towards the pathogenic species. Investigating the free radical scavenging activity using DPPH reagent showed low to moderate bioactivities. The highest cytotoxic activity against liver cancer cell line Hep-G2 with an IC values of 18.8 µg/ml was exhibited by MN083316 and a metabolomics study was done on the ethyl acetate extract of this strain using LC-ESI-MS fingerprints leading to the isolation and purification of compound . Using 1D and 2D NMR techniques compound was identified as ditryptophenaline. Compound exhibited a strong antimicrobial, antioxidant activities as well as cytotoxic activities against MCF-7 and HEPG2 with IC values of 5.8 and 7.6 mmole, respectively. The objective of this study, isolation of Coral-reef associated fungi and studying their biological activities to produce the most active secondary metabolite which might possess a novel biological activity.
PubMed: 33062385
DOI: 10.1080/21501203.2020.1741470 -
Archives of Microbiology Jan 2023Fungal deterioration is one of the major factors that significantly contribute to mummy cartonnage damage. Isolation and molecular identification of thirteen fungal...
Fungal deterioration is one of the major factors that significantly contribute to mummy cartonnage damage. Isolation and molecular identification of thirteen fungal species contributing to the deterioration of ancient Egyptian mummy cartonnage located in El-Lahun regions, Fayoum government, Egypt was performed. The most dominant deteriorated fungal species are Aspergillus flavus (25.70%), Aspergillus terreus (16.76%), followed by A. niger (13.97%). A newly synthesized series of tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline chalcone derivatives were synthesized and evaluated for their antifungal activities in vitro against the isolated deteriorated fungal species (Aspergillus flavus, A. niger, A. terreus, Athelia bombacina, Aureobasidium iranianum, Byssochlamys spectabilis, Cladosporium cladosporioides, C. ramotenellum, Penicillium crustosum, P. polonicum, Talaromyces atroroseus, T. minioluteus and T. purpureogenus). The most efficient chalcone derivatives are new chalcone derivative numbers 9 with minimum inhibitory concentration (MIC) ranging from 1 to 3 mg/mL followed by chalcone derivatives number 5 with MIC ranging from 1 to 4 mg/mL.
Topics: Egypt; Chalcones; Mummies; Antifungal Agents; Aspergillus flavus; Isoquinolines
PubMed: 36609727
DOI: 10.1007/s00203-022-03395-7 -
Frontiers in Microbiology 2018Species in the genus , a member of the fungal order Eurotiales, are ubiquitous in nature and impact a variety of human endeavors. Here, the biology of one common...
Species in the genus , a member of the fungal order Eurotiales, are ubiquitous in nature and impact a variety of human endeavors. Here, the biology of one common species, , was explored using genomics and functional genetics. Sequencing the genome of two isolates revealed key genome and gene features in this species. A striking feature of the genome was the two-part nature, featuring large stretches of DNA with normal GC content separated by AT-rich regions, a hallmark of many plant-pathogenic fungal genomes. These AT-rich regions appeared to have been mutated by repeat-induced point (RIP) mutations. We developed methods for genetic transformation of , including forward and reverse genetics as well as crossing techniques. Using transformation and crossing, RIP activity was identified, demonstrating for the first time that RIP is an active process within the order Eurotiales. A consequence of RIP is likely reflected by a reduction in numbers of genes within gene families, such as in cell wall degradation, and reflected by growth limitations on on diverse carbon sources. Furthermore, using these transformation tools we characterized a conserved protein containing a domain of unknown function (DUF1212) and discovered it is involved in pigmentation.
PubMed: 30619145
DOI: 10.3389/fmicb.2018.03058 -
Scientific Reports Jul 2022Melanin-containing fungi (black molds) have the capacity to thrive under extreme environmental conditions such as the elevated radiation levels inside the former...
Melanin-containing fungi (black molds) have the capacity to thrive under extreme environmental conditions such as the elevated radiation levels inside the former Chernobyl reactors. These fungi have been hypothesized to grow toward and use gamma radiation as an energy source, but the literature does not clearly address which energies of the electromagnetic spectrum, if any, positively affect fungal growth. The goal of this work was to characterize the response of non-melanized and melanized fungi to two distinct electromagnetic wavelengths, i.e., ultraviolet (UV) and gamma ray, keeping absorption and other potentially confounding variables constant. Exposure to UV or gamma radiation induced significant changes in fungi pigmentation, but not growth rate of Cladosporium cladosporioides and Paecilomyces variotii. Specifically, increased pigmentation of both fungi was observed in samples exposed to UV, while decreased pigmentation was observed for gamma-irradiated samples. These results provide new insights into the role of electromagnetic energies on growth of fungi and provide an impetus to examine additional energies and types of radiation to develop a fundamental understanding of this phenomenon.
Topics: Byssochlamys; Cladosporium; Gamma Rays; Melanins; Pigmentation; Ultraviolet Rays
PubMed: 35840596
DOI: 10.1038/s41598-022-16063-z -
Scientific Reports Aug 2021Paecilomyces variotii xylanase was, produced in stirred tank bioreactor with yield of 760 U/mL and purified using 70% ammonium sulfate precipitation and ultra-filtration...
Paecilomyces variotii xylanase was, produced in stirred tank bioreactor with yield of 760 U/mL and purified using 70% ammonium sulfate precipitation and ultra-filtration causing 3.29-fold purification with 34.47% activity recovery. The enzyme purity was analyzed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) confirming its monomeric nature as single band at 32 KDa. Zymography showed xylan hydrolysis activity at the same band. The purified enzyme had optimum activity at 60 °C and pH 5.0. The pH stability range was 5-9 and the temperature stability was up 70 °C. Feand Fe exhibited inhibition of xylanase enzyme while Cu, Ca, Mg and Mn stimulated its activity. Mercaptoethanol stimulated its activity; however, Na-EDTA and SDS inhibited its activity. The purified xylanase could hydrolyze beechwood xylan but not carboxymethyl cellulose (CMC), avicel or soluble starch. Paecilomyces variotii xylanase K and V for beechwood were determined to be 3.33 mg/mL and 5555 U/mg, respectively. The produced xylanase enzyme applied on beech xylan resulted in different types of XOS. The antioxidant activity of xylo-oligosaccharides increased from 15.22 to 70.57% when the extract concentration was increased from 0.1 to 1.5 mg/mL. The enzyme characteristics and kinetic parameters indicated its high efficiency in the hydrolysis of xylan and its potential effectiveness in lignocellulosic hydrolysis and other industrial application. It also suggests the potential of xylanase enzyme for production of XOS from biomass which are useful in food and pharmaceutical industries.
Topics: Antioxidants; Bioreactors; Byssochlamys; Electrophoresis, Polyacrylamide Gel; Endo-1,4-beta Xylanases; Glucuronates; Hydrogen-Ion Concentration; Oligosaccharides
PubMed: 34389757
DOI: 10.1038/s41598-021-95965-w -
Applied and Environmental Microbiology Mar 2008Paecilomyces variotii is a common cosmopolitan species that is able to spoil various food- and feedstuffs and is frequently encountered in heat-treated products.... (Comparative Study)
Comparative Study
Paecilomyces variotii is a common cosmopolitan species that is able to spoil various food- and feedstuffs and is frequently encountered in heat-treated products. However, isolates from heat-treated products rarely form ascospores. In this study we examined by using molecular techniques and mating tests whether this species can undergo a sexual cycle and form ascospores. The population structure of this species was examined by analyzing the nuclear ribosomal internal transcribed spacer 1 (ITS1) and ITS2 and the 5.8S rRNA gene, as well as partial beta-tubulin, actin, and calmodulin gene sequences. Phylogenetic analyses revealed that P. variotii is a highly variable species. Partition homogeneity tests revealed that P. variotii has a recombining population structure. In addition to sequence analyses, mating experiments indicated that P. variotii is able to form ascomata and ascospores in culture in a heterothallic manner. The distribution of MAT1-1 and MAT1-2 genes showed a 1:1 ratio in the progeny of the mating experiments. From the sequence analyses and mating data we conclude that P. variotii is the anamorph of Talaromyces spectabilis and that it has a biallelic heterothallic mating system. Since Paecilomyces sensu stricto anamorphs group within Byssochlamys, a new combination Byssochlamys spectabilis is proposed.
Topics: Actins; Adaptation, Physiological; Base Sequence; Calmodulin; Cluster Analysis; Crosses, Genetic; DNA Primers; DNA, Ribosomal Spacer; Food Microbiology; Genetics, Population; Hot Temperature; Molecular Sequence Data; Paecilomyces; Phylogeny; RNA, Ribosomal, 5.8S; Reproduction; Sequence Analysis, DNA; Spores, Fungal; Tubulin
PubMed: 18192427
DOI: 10.1128/AEM.01761-07 -
Food Science and Biotechnology Jun 2018A total of fourteen roasted coffee samples were collected from different local markets in Nayarit, Mexico. Twenty-two fungi isolates were related to the genera (54.54%)...
A total of fourteen roasted coffee samples were collected from different local markets in Nayarit, Mexico. Twenty-two fungi isolates were related to the genera (54.54%) and (4.5%). The strains R16 (0.33 μg/kg), 6N (1.16 μg/kg) and 11 (0.36 μg/kg) tested positive for OTA (ochratoxin A) production in PDA, the other fungi samples were not toxigenic. According to the sequence analysis of their ITS1-5.8S-ITS2 rDNA region, fungi OTA producers correspond to , and . These three strains were able to produce OTA when inoculated in roasted coffee in concentrations ranging from 75 to 90 μg/kg, after 21 days. Different production stages of roasted coffee (crop management, postharvest practices and storage) along with environmental conditions do not ensure mycotoxigenic fungi free products. This is the first report of OTA natural occurrence in roasted coffee from Nayarit.
PubMed: 30263816
DOI: 10.1007/s10068-017-0288-7