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3 Biotech Jul 2017Fipronil is a phenylpryazole insecticide which is extensively used for the protection of agricultural yields. However, this insecticide poses various threats to...
Fipronil is a phenylpryazole insecticide which is extensively used for the protection of agricultural yields. However, this insecticide poses various threats to the environment. Therefore it is essential to develop an effective method to degrade or eliminate this pollutant from the environment. In this present study, a fungal strain AJAG1 capable of degrading fipronil and its metabolite, fipronil sulfone, was isolated through enrichment technique. Isolated fungal strain was identified as Aspergillus glaucus based upon its morphological, and 18S rRNA sequence analysis. Strain AJAG1 could degrade 900 mg L of fipronil efficiently in both aqueous medium and soil. In addition, fipronil degradation was tested with various kinetic models and the results revealed that biodegradation in aqueous medium and soil was ascertained by pseudo-first order and zero order rate kinetics, respectively. The infrared spectrum of fipronil degraded sample confirmed the formation of esters, nitro, and alkanes groups. A tentative degradation pathway of fipronil by strain AJAG1 has been proposed on the basis of gas chromatography-mass spectrometry (GC-MS) analysis. The lignolytic enzymes activities were studied during fipronil degradation by strain AJAG1. Further, scanning electron microscopy (SEM) was used to examine the surface morphology of strain AJAG1 after fipronil degradation. In the present investigation, bioformulation of strain AJAG1 was developed using low cost materials such as groundnut shell powder, molasses, and fly ash to remediate the fipronil from agricultural field. These results highlight A. glaucus strain AJAG1 may have potential for use in bioremediation of fipronil-contaminated environment.
PubMed: 28667652
DOI: 10.1007/s13205-017-0820-8 -
Fungal Biology May 2016The Antarctic fungal strain Aspergillus glaucus 363 produces cold-active (CA) Cu/Zn-superoxide dismutase (SOD). The strain contains at least one gene encoding Cu/Zn-SOD...
The Antarctic fungal strain Aspergillus glaucus 363 produces cold-active (CA) Cu/Zn-superoxide dismutase (SOD). The strain contains at least one gene encoding Cu/Zn-SOD that exhibited high homology with the corresponding gene of other Aspergillus species. To our knowledge, this is the first nucleotide sequence of a CA Cu/Zn-SOD gene in fungi. An effective laboratory technology for A. glaucus SOD production in 3 L bioreactors was developed on the basis of transient cold-shock treatment. The temperature downshift to 10 °C caused 1.4-fold increase of specific SOD activity compared to unstressed culture. Maximum enzyme productivity was 64 × 10(3) U kg(-1) h(-1). Two SOD isoenzymes (Cu/Zn-SODI and Cu/Zn-SODII) were purified to electrophoretic homogeneity. The specific activity of the major isoenzyme, Cu/Zn-SODII, after Q-Sepharose chromatography was 4000 U mg(-1). The molecular mass of SODI (38 159 Da) and of SODII (15 835 Da) was determined by electrospray quadropole time-of-flight (ESI-Q-TOF) mass spectrometry and dynamic light scattering (DLS). The presence of Cu and Zn were confirmed by inductively coupled plasma mass spectrometry (ICP-MS). The N-terminal amino acid sequence of Cu/Zn-SODII revealed a high degree of structural homology with Cu/Zn-SOD from other fungi, including Aspergillus species.
Topics: Antarctic Regions; Aspergillus; Cold Temperature; Conserved Sequence; Copper; Mass Spectrometry; Molecular Weight; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Superoxide Dismutase; Zinc
PubMed: 27109365
DOI: 10.1016/j.funbio.2016.03.002 -
Applied and Environmental Microbiology Oct 2015Aquaglyceroporins (GlpFs) that transport glycerol along with water and other uncharged solutes are involved in osmoregulation in myriad species. Fungal species form a...
Aquaglyceroporins (GlpFs) that transport glycerol along with water and other uncharged solutes are involved in osmoregulation in myriad species. Fungal species form a large group of eukaryotic organisms, and their GlpFs may be diverse, exhibiting various activities. However, few filamentous fungal GlpFs have been biologically investigated. Here, a glpF gene from the halophilic fungus Aspergillus glaucus (AgglpF) was verified to be a channel of water or glycerol in Xenopus laevis oocytes and was further functionally analyzed in three heterologous systems. In Saccharomyces cerevisiae, cells overexpressing AgglpF possessed significant tolerance of drought, salt, and certain metal ions. AgglpF was then characterized in the filamentous fungus of Neurospora crassa. Based on the N. crassa aquaporin gene (NcAQP) disruption mutant (the Δaqp mutant), a series of complementary strains carrying NcAQP and AgglpF and three asparagine-proline-alanine-gene (NPA)-deleted AgglpF fragments were created. As revealed by salt resistance analysis, the AgglpF complementary strain possessed the highest salt resistance among the tested strains. In addition, the intracellular glycerol content in the AgglpF complementary strain was markedly higher than that in the other strains. The AgGlpF-green fluorescent protein (GFP) fusion protein was subcellularly localized in the plasma membrane of onion epidermal cells, suggesting that AgglpF functions in plants. Indeed, when AgglpF was expressed in Arabidopsis thaliana, transgenic lines survived under conditions of high osmotic stress and under conditions of drought stress in particular. Overall, our results revealed that AgGlpF as a water/glycerol transporter is required for survival of both fungi and plants under conditions of high osmotic stress and may have value in applications in genetic engineering for generating high salt and drought resistance.
Topics: Animals; Aquaglyceroporins; Arabidopsis; Aspergillus; Droughts; Fungal Proteins; Gene Expression; Glycerol; Oocytes; Osmosis; Plants, Genetically Modified; Saccharomyces cerevisiae; Water; Xenopus laevis
PubMed: 26209670
DOI: 10.1128/AEM.02127-15 -
[Inhibition of aflatoxin production and fungal growth on stored corn by allyl isothiocyanate vapor].Shokuhin Eiseigaku Zasshi. Journal of... 2015Studies were conducted to determine the effectiveness of allyl isothiocyanate (AIT) vapor treatment with a commercial mustard seed extract (Wasaouro(®)) in controlling...
Studies were conducted to determine the effectiveness of allyl isothiocyanate (AIT) vapor treatment with a commercial mustard seed extract (Wasaouro(®)) in controlling aflatoxin-producing fungi on stored corn. The concentration of AIT in the closed container peaked at 54.6 ng/mL on the 14th day and remained at 21.8 ng/mL on the 42nd day. AIT inhibited visible growth of aflatoxigenic molds in unsterilized corn and in sterilized corn inoculated with various aflatoxigenic fungi. However, fungi such as Aspergillus glaucus group, A. penicillioides and A. restrictus were detected by means of culture methods.
Topics: Aflatoxins; Aspergillus; Depression, Chemical; Dose-Response Relationship, Drug; Food Microbiology; Food Storage; Fungi; Isothiocyanates; Penicillium; Time Factors; Volatilization; Zea mays
PubMed: 25748979
DOI: 10.3358/shokueishi.56.1 -
International Journal of Molecular... Jan 2015High salt in soils is one of the abiotic stresses that significantly reduces crop yield, although saline lands are considered potential resources arable for agriculture....
High salt in soils is one of the abiotic stresses that significantly reduces crop yield, although saline lands are considered potential resources arable for agriculture. Currently, genetic engineering for enhancing salt tolerance is being tested as an efficient and viable strategy for crop improvement. We previously characterized a large subunit of the ribosomal protein RPL44, which is involved in osmotic stress in the extremely halophilic fungus Aspergillus glaucus. Here, we screened another ribosomal protein (AgRPS3aE) that also produced high-salt tolerance in yeast. Bioinformatics analysis indicated that AgRPS3aE encodes a 29.2 kDa small subunit of a ribosomal protein belonging to the RPS3Ae family in eukaryotes. To further confirm its protective function against salinity, we expressed AgRPS3aE in three heterologous systems, the filamentous fungus Magnaporthe oryzae and two model plants Arabidopsis and tobacco. Overexpression of AgRPS3aE in all tested transformants significantly alleviated stress symptoms compared with controls, suggesting that AgRPS3aE functions not only in fungi but also in plants. Considering that ribosomal proteins are housekeeping components in organisms from prokaryotes to eukaryotes, we propose that AgRPS3aE is one of the optimal genes for improving high-salt tolerance in crops.
Topics: Amino Acid Sequence; Animals; Arabidopsis; Aspergillus; Cloning, Molecular; Evolution, Molecular; Fungal Proteins; Humans; Molecular Sequence Data; Osmotic Pressure; Phylogeny; Plants, Genetically Modified; Ribosomal Proteins; Salt Tolerance; Seedlings; Sequence Alignment; Nicotiana
PubMed: 25642759
DOI: 10.3390/ijms16023058 -
TheScientificWorldJournal 2014The halotolerant fungus Aspergillus glaucus CCHA was isolated from the surface of wild vegetation around a saltern with the salinity range being 0-31%. Here, a...
The halotolerant fungus Aspergillus glaucus CCHA was isolated from the surface of wild vegetation around a saltern with the salinity range being 0-31%. Here, a full-length cDNA library of A. glaucus under salt stress was constructed to identify genes related to salt tolerance, and one hundred clones were randomly selected for sequencing and bioinformatics analysis. Among these, 82 putative sequences were functionally annotated as being involved in signal transduction, osmolyte synthesis and transport, or regulation of transcription. Subsequently, the cDNA library was transformed into E. coli cells to screen for putative salt stress-related clones. Five putative positive clones were obtained from E. coli cells grown on LB agar containing 1 M NaCl, on which they showed rapid growth compared to the empty vector control line. Analysis of transgenic Arabidopsis thaliana lines overexpressing CCHA-2142 demonstrated that the gene conferred increased salt tolerance to plants as well by protecting the cellular membranes, suppressing the inhibition of chlorophyll biosynthesis. These results highlight the utility of this A. glaucus cDNA library as a tool for isolating and characterizing genes related to salt tolerance. Furthermore, the identified genes can be used for the study of the underlying biology of halotolerance.
Topics: Arabidopsis; Aspergillus; Carbohydrates; Caseins; Escherichia coli; Gene Expression Regulation, Fungal; Gene Library; Lipids; Plant Proteins, Dietary; Plants, Genetically Modified; Salinity; Salt Tolerance; Signal Transduction; Sodium Chloride; Stress, Physiological
PubMed: 25383373
DOI: 10.1155/2014/620959 -
Microbial Cell Factories May 2014For filamentous fungi, the basic growth unit of hyphae usually makes it sensitive to shear stress which is generated from mechanical force and dynamic fluid in...
BACKGROUND
For filamentous fungi, the basic growth unit of hyphae usually makes it sensitive to shear stress which is generated from mechanical force and dynamic fluid in bioreactor, and it severely decreases microbial productions. The conventional strategies against shear-sensitive conundrum in fungal fermentation usually focus on adapting agitation, impeller type and bioreactor configuration, which brings high cost and tough work in industry. This study aims to genetically shape shear resistant morphology of shear-sensitive filamentous fungus Aspergillus glaucus to make it adapt to bioreactor so as to establish an efficient fermentation process.
RESULTS
Hyphal morphology shaping by modifying polarized growth genes of A. glaucus was applied to reduce its shear-sensitivity and enhance aspergiolide A production. Degenerate PCR and genome walking were used to obtain polarized growth genes AgkipA and AgteaR, followed by construction of gene-deficient mutants by homologous integration of double crossover. Deletion of both genes caused meandering hyphae, for which, ΔAgkipA led to small but intense curves comparing with ΔAgteaR by morphology analysis. The germination of a second germ tube from conidiospore of the mutants became random while colony growth and development almost maintained the same. Morphology of ΔAgkipA and ΔAgteaR mutants turned to be compact pellet and loose clump in liquid culture, respectively. The curved hyphae of both mutants showed no remarkably resistant to glass bead grinding comparing with the wild type strain. However, they generated greatly different broth rheology which further caused growth and metabolism variations in bioreactor fermentations. By forming pellets, the ΔAgkipA mutant created a tank environment with low-viscosity, low shear stress and high dissolved oxygen tension, leading to high production of aspergiolide A (121.7 ± 2.3 mg/L), which was 82.2% higher than the wild type.
CONCLUSIONS
A new strategy for shaping fungal morphology by modifying polarized growth genes was applied in submerged fermentation in bioreactor. This work provides useful information of shaping fungal morphology for submerged fermentation by genetically modification, which could be valuable for morphology improvement of industrial filamentous fungi.
Topics: Anthraquinones; Antineoplastic Agents; Aspergillus; Batch Cell Culture Techniques; Fungal Proteins; Mutation; Open Reading Frames; Polyketides
PubMed: 24886193
DOI: 10.1186/1475-2859-13-73 -
Applied and Environmental Microbiology Jul 2014Ribosomal proteins are highly conserved components of basal cellular organelles, primarily involved in the translation of mRNA leading to protein synthesis. However,...
Ribosomal proteins are highly conserved components of basal cellular organelles, primarily involved in the translation of mRNA leading to protein synthesis. However, certain ribosomal proteins moonlight in the development and differentiation of organisms. In this study, the ribosomal protein L44 (RPL44), associated with salt resistance, was screened from the halophilic fungus Aspergillus glaucus (AgRPL44), and its activity was investigated in Saccharomyces cerevisiae and Nicotiana tabacum. Sequence alignment revealed that AgRPL44 is one of the proteins of the large ribosomal subunit 60S. Expression of AgRPL44 was upregulated via treatment with salt, sorbitol, or heavy metals to demonstrate its response to osmotic stress. A homologous sequence from the model fungus Magnaporthe oryzae, MoRPL44, was cloned and compared with AgRPL44 in a yeast expression system. The results indicated that yeast cells with overexpressed AgRPL44 were more resistant to salt, drought, and heavy metals than were yeast cells expressing MoRPL44 at a similar level of stress. When AgRPL44 was introduced into M. oryzae, the transformants displayed obviously enhanced tolerance to salt and drought, indicating the potential value of AgRPL44 for genetic applications. To verify the value of its application in plants, tobacco was transformed with AgRPL44, and the results were similar. Taken together, we conclude that AgRPL44 supports abiotic stress resistance and may have value for genetic application.
Topics: Aspergillus; DNA, Fungal; Fungal Proteins; Gene Expression Regulation, Fungal; Gene Library; Osmotic Pressure; Plants, Genetically Modified; Promoter Regions, Genetic; Ribosomal Proteins; Saccharomyces cerevisiae; Sequence Alignment; Sequence Analysis, DNA; Sodium Chloride; Stress, Physiological; Nicotiana; Transcriptome
PubMed: 24814782
DOI: 10.1128/AEM.00292-14 -
Medical Mycology Case Reports 2012Aspergillus are ubiquitous and more than 30 species have been reported to be involved in human infection. Most of the cases occur in immunocompromised patients and are...
Aspergillus are ubiquitous and more than 30 species have been reported to be involved in human infection. Most of the cases occur in immunocompromised patients and are disseminated in the blood. Primary cutaneous aspergillosis in immunocompetent hosts is rare. We report a unique case of primary cutaneous aspergillosis in an immunocompetent patient diagnosed by fine needle aspiration cytology. The characteristic ascocarp and ascospores of Aspergillus species were found in the aspirate and Aspergillus glaucus was isolated in pure culture. The case is presented to increase the awareness of the usefulness of fine needle aspiration cytology for diagnosing fungal infections.
PubMed: 24371752
DOI: 10.1016/j.mmcr.2012.09.004 -
Toxins Mar 2011Thesafety characteristics of feed used in fish and crustacean aquaculture systems are an essential tool to assure the productivity of those animal exploitations. Safety...
Thesafety characteristics of feed used in fish and crustacean aquaculture systems are an essential tool to assure the productivity of those animal exploitations. Safety of feed may be affected by different hazards, including biological and chemical groups. The aim of this preliminary study was to evaluate fungi contamination and the presence of aflatoxins in 87 samples of feed for sea bass, collected in Portugal. Molds were found in 35 samples (40.2%) in levels ranging from 1 to 3.3 log10 CFU∙g(-1). Six genera of molds were found. Aspergillus flavus was the most frequent, found in all positive samples, with a range from 2 to 3.2 log(10) CFU∙g(-1). Aspergillus niger was found in 34 samples (39.1%), ranging from 1 to 2.7 log(10) CFU∙g(-1). Aspergillus glaucus was found in 26 samples (29.9%) with levels between 1 and 2.4 log(10) CFU∙g(-1). Penicillium spp. and Cladosporium spp. were both found in 25 samples (28.7%). Fusarium spp. was found in 22 samples (25.3%), ranging from 1 to 2.3 log(10) CFU∙g(-1). All feed samples were screened for aflatoxins using a HPLC technique, with a detection limit of 1.0 μg∙kg(-1). All samples were aflatoxin negative.
Topics: Aflatoxin B1; Animal Feed; Animals; Aspergillus; Bass; Fisheries; Food Contamination; Portugal
PubMed: 22069703
DOI: 10.3390/toxins3030163