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improved production of trichoderma harzianum endochitinase by expression in trichoderma reesei.the chromosomal endochitinase gene (then-42) of the mycoparasite fungus trichoderma harzianum p1 was isolated and overexpressed in the filamentous fungus trichoderma reesei under the promoter of the major cellulase gene cbhl1. the host strain rutc-30 did not produce any endogenous endochitinase activity. the prepro region of the t harzianum endochitinase was correctly processed in t. reesei. no differences in expression were observed when the prepro region was replaced with the cbhi signal seque ...19968787411
inhibition of cellulose saccharification and glycolignin-attacking enzymes of five lignocellulose-degrading fungi by ferulic acid.at 5 g/l, ferulic acid, a plant cell-wall phenolic, severely repressed growth of the lignocellulose-degrading fungi trichoderma harzianum, chaetomium cellulolyticum, phanaerochaete chrysosporium, trametes versicolor and pleurotus sajor-caju. at 0.5 g/l, howerver, it slightly stimulated growth of the latter two organisms. two classes of extracellular enzymes involved in cellulose and glycolignin breakdown were assayed: cellulases; and phenol oxidases as laccases. all of the strains depolymerized ...199624415080
effect of cassavar cultivar, age and pretreatment processes of cellulase and xylanase production from cassava waste by trichoderma harzianum.cassava wastes--the peel and the root fibre were taken through various pretreatment procedures before being subjected to solid state fermentation with trichoderma harzianum. most of the pretreatment processes increased the cellulose and hemicellulose content of the cassava peel and fibre by as high as 155% while sulfuric acid treatment resulted in 25.3% loss in the peel hemicellulose. the best pretreatment found to be 1% naoh at 120 degrees c gave the highest production of the cx, the cl and xyl ...19968956490
trichoderma harzianum peritonitis in peritoneal dialysis. 19968893195
secretion of an enzymatically active trichoderma harzianum endochitinase by saccharomyces cerevisiae.a novel endochitinase agar-plate assay has been developed and used to identify 11 full-length cdnas encoding endochitinase i (enci) from a trichoderma harzianum cdna library by expression in yeast. the 1473-bp chi1 cdna encodes a 424-residue precursor protein including both a signal sequence and a propeptide. the deduced enci amino-acid sequence is homologous to other fungal and bacterial chitinases, and the enzyme cross-reacts with a polyclonal antiserum raised against chitinase a1 from bacillu ...19968598062
production of beta-xylosidase activity by trichoderma harzianum strains.nine trichoderma harzianum strains were screened for beta-xylosidase activity when grown in solid-state cultures on media containing wheat bran as the carbon source. all strains produced beta-xylosidase activity, the most active being in extracts of cultures of t. harzianum strain 4. a beta-xylosidase was purified by ammonium sulfate precipitation, ultrafiltration, gel filtration, and ion exchange chromatography from solid-state cultures of t. harzianum strain c. enzyme preparations yielded a si ...19968662186
isolation and characterization of a cdna from trichoderma harzianum p1 encoding a 14-3-3 protein homolog.a full-length cdna close, th1433, (genbank accession no. u24158), was isolated and characterized from the filamentous fungus, trichoderma harzianum. the deduced amino acid (aa) sequence showed an acidic 30-kda protein homologous to the 14-3-3 proteins, a family of putative kinase regulators originally characterized in mammalian brain tissue. the greatest homology, 71% identical aa, was found to bmh1, the corresponding protein from saccharomyces cerevisiae and to the epsilon isoform from sheep br ...19968675020
mycoparasitic species of trichoderma produce lectins.culture filtrates and mycelial extracts of two mycoparasitic trichoderma species were tested for the presence of lectins, by haemagglutination with human and marsupial erythrocytes. in trichoderma viride, haemagglutinating activity was present in both mycelial extracts and culture filtrate. while secreted lectins were only detected after 6 days of growth, the presence of mycelium-associated lectins was first noted in 3-day-old cultures. agglutinating activity was also demonstrated in the myceliu ...19968742357
molecular cloning and expression of the nag1 gene (n-acetyl-beta-d-glucosaminidase-encoding gene) from trichoderma harzianum p1.a 72-kda n-acetyl-beta-d-glucosaminidase was purified from the mycoparasitic fungus trichoderma harzianum p1; antibodies were raised against it, and aa-sequences were obtained. the antibody reacted with a single 72-kda protein band in culture filtrates of t. harzianum grown on chitin, and was subsequently used to clone the corresponding nag1 gene from a lambdagt11 cdna expression library. it was interrupted by two short introns and encoded a protein of 580 amino acids. the deduced protein sequen ...19968781176
cell wall synthesis is a major target of mycoparasitic antagonism by trichoderma harzianum.we have investigated the molecular basis for the reported synergism between peptaibols and cell wall hydrolytic enzymes in the antagonism of phytopathogenic fungi by trichoderma harzianum. beta-glucan synthase activity on isolated plasma membranes of botrytis cinerea was inhibited in vitro by the peptaibols trichorzianin ta and tb, and this inhibition was reversed by the addition of phosphatidylcholine. beta-glucan synthesis in vivo, assayed by the incorporation of [2-(3)h]glucose into cell wall ...19968892847
mycoparasitic interaction relieves binding of the cre1 carbon catabolite repressor protein to promoter sequences of the ech42 (endochitinase-encoding) gene in trichoderma harzianum.the fungus trichoderma harzianum is a potent mycoparasite of various plant pathogenic fungi. we have studied the molecular regulation of mycoparasitism in the host/mycoparasite system botrytis cinerea/t. harzianum. protein extracts, prepared from various stages of mycoparasitism, were used in electrophoretic mobility-shift assays (em-sas) with two promoter fragments of the ech-42 (42-kda endochitinase-encoding) gene of t. harzianum. this gene was chosen as a model because its expression is trigg ...19968962147
harziphilone and fleephilone, two new hiv rev/rre binding inhibitors produced by trichoderma harzianum.during the screening of the natural products for their ability to inhibit the binding of rev (regulation of virion expression) protein to [33p] labeled rre (rev responsive element) rna, two novel fungal metabolites, harziphilone and fleephilone, were isolated from the butanol-methanol (1:1) extract of the fermentation broth of trichoderma harzianum by bioassay guided fractionation. the structures of these two new compounds were established by spectroscopic methods. harziphilone and fleephilone s ...19968968392
[influence of bacillus intermedius rnase on growth-stimulating and antagonistic characteristics of trichoderma harzianum].bacillus intermedius rnaase (with specific activity of 1,000,000 units per one mg of protein) at concentration of 1 x 10(-3) mg/ml was shown to increase antagonistic and growth-stimulating properties of trichoderma harzianum. an application of trichodermin which was treated with an enzyme enhanced cucumber crop capacity by 15-18% in industrial conditions.19969011860
characterization and ultrastructural localization of chitinases from metarhizium anisopliae, m. flavoviride, and beauveria bassiana during fungal invasion of host (manduca sexta) cuticle.extracellular chitinases have been suggested to be virulence factors in fungal entomopathogenicity. we employed isoelectric focusing and a set of three fluorescent substrates to investigate the numbers and types of chitinolytic enzymes produced by the entomopathogenic fungi metarhizium anisopliae, metarhizium flavoviride, and beauveria bassiana. each species produced a variety of n-acetyl-(beta)-d-glucosaminidases and endochitinases during growth in media containing insect cuticle. m. flavovirid ...199616535278
incorporation of weather forecasting in integrated, biological-chemical management of botrytis cinerea.abstract a strategy for integrated biological and chemical control of botrytis cinerea in nonheated greenhouse vegetables was developed. the biocontrol agent used was a commercial preparation developed from an isolate of trichoderma harzianum, t39 (trichodex). decisions concerning whether to spray the biocontrol agent or a fungicide were made based on a weather-based disease warning system. the integrated strategy (botman [short for botrytis manager]) was implemented as follows: when slow or no ...199718945177
physiological and biochemical characterization of trichoderma harzianum, a biological control agent against soilborne fungal plant pathogens.monoconidial cultures of 15 isolates of trichoderma harzianum were characterized on the basis of 82 morphological, physiological, and biochemical features and 99 isoenzyme bands from seven enzyme systems. the results were subjected to numerical analysis which revealed four distinct groups. representative sequences of the internal transcribed spacer 1 (its 1)-its 2 region in the ribosomal dna gene cluster were compared between groups confirming this distribution. the utility of the groupings gene ...19979251205
mr566a and mr566b, new melanin synthesis inhibitors produced by trichoderma harzianum. i. taxonomy, fermentation, isolation and biological activities.new melanin synthesis inhibitors (mr566a and b) and six related known isocyanocyclopentenes were isolated from the fermentation broth of trichoderma harzianum. the ic50 values of mr566a and b against mushroom tyrosinase were 1.72 and 47 microm, respectively. they inhibited melanin biosynthesis in b16 melanoma cells with mic values of 0.1 and 2.2 microm, respectively. also isolated from the same culture extract of t. harzianum was a new oxazole (mr93b), which showed no inhibitory activity against ...19979268001
a model for the combined effects of temperature and salt concentration on growth rate of food spoilage molds.we modeled mold growth on a solid culture medium at various temperatures and nacl concentrations by using five common food spoilage molds (penicillium roqueforti, trichoderma harzianum, paecilomyces variotii, aspergillus niger, and emericella nidulans). for the description of the growth rate (expressed as the increase in colony diameter per unit of time) as a function of temperature and nacl concentration, a six-parameter model has been developed. the model combines either the rosso-type or the ...19979327540
structural and functional properties of low molecular weight endo-1,4-beta-xylanases.there are currently four crystal structures of low molecular weight endo-1,4-beta-xylanases (e.c.3.2.1.8), i.e. family g/11 xylanases, available at the brookhaven data bank: 2 xylanases from trichoderma reesei (törrönen et al., 1994; törrönen and rouvinen, 1995) and one from bacillus circulans and another from trichoderma harzianum (campbell et al., 1993). they consist of two beta-sheets and one alpha-helix and have been described to resemble a partly-closed right hand. the catalytic residues ar ...19979335170
hydrophobin gene srh1, expressed during sporulation of the biocontrol agent trichoderma harzianum.a cdna clone encoding a spore-related hydrophobin, srhi, was isolated from a cdna bank prepared from mrna induced in sporulating cultures of trichoderma harzianum by heterologous hybridization using the hfb2 gene encoding a spore-bound hydrophobin of trichoderma reesei as a probe. based on sequence similarity the predicted protein was identified as a new member of the class-ii hydrophobin family. including the signal sequences, srhi has 65% and 56% amino-acid similarity with the t. reesei hydrop ...19979339348
the ability of soil-borne fungi to degrade organophosphonate carbon-to-phosphorus bonds.the ability of a wide variety of soil-borne fungal strains to degrade four structurally different compounds containing p-c bonds, namely the naturally occurring amino acid ciliatine, the popular herbicide glyphosate, phosphonoacetic acid and 2-amino-3-phosphonopropionic acid, was studied in order to show that soil fungi may play an important role in the biodegradation of organophosphonates. most of the strains appeared to utilize ciliatine as the sole source of phosphorus for growth. only a limi ...19979390463
purification of a chitinase from trichoderma sp. and its action on sclerotium rolfsii and rhizoctonia solani cell walls.trichoderma harzianum is an effective biocontrol agent of several important plant pathogenic fungi. this trichoderma species attacks other fungi by secreting lytic enzymes, including beta-1,3-glucanase and chitinolytic enzymes. superior biocontrol potential may then be found in strains having a high capacity to produce these enzymes. we have therefore evaluated the capacity of six unidentified trichoderma spp. isolates to produce chitinolytic enzymes and beta-1,3-glucanases in comparison with t. ...199712501351
in vitro studies on the potential for biological control of aspergillus flavus and fusarium moniliforme by trichoderma species. a study of the production of extracellular metabolites by trichoderma species.culture filtrates of trichoderma viride and trichoderma harzianum were inhibitory of fusarium moniliforme and, to a lesser extent, aspergillus flavus. the degree of inhibition was, however, dependent on the carbon or nitrogen source incorporated into the medium. scanning electron microscopy revealed the development of abnormal fruiting structures on exposure to some trichoderma culture filtrate, while macroscopically, growth restriction and, in the case of a. flavus, altered colony colouration w ...199716284721
identification of genes induced in alkaloid-producing cultures of claviceps sp.in order to identify genes which are expressed during alkaloid synthesis in an axenic culture of claviceps sp. (strain atcc 26245), a cdna library from a producing culture was differentially screened with cdna from producing (cdna+) and non-producing (cdna-) cultures, respectively. altogether, ten cdna clones were obtained, the alkaloid-synthesis-correlated expression of which was confirmed by northern analyses. evaluation of their nucleotide and derived amino-acid sequences identified one gene ...19979108144
glyceraldehyde-3-phosphate dehydrogenase expression in trichoderma harzianum is repressed during conidiation and mycoparasitism.a glyceraldehyde-3-phosphate dehydrogenase (gpd) cdna was isolated from the filamentous fungus trichoderma harzianum in the course of a search for light-regulated genes in this organism. there is apparently only one copy of gpd in the t. harzianum genome, and its sequence is most similar to that of other filamentous ascomycetes. trichoderma grows in the soil as a saprophyte or mycoparasite. a brief pulse of blue light, or nutrient depletion, induces sporulation, which is accompanied by altered p ...19979353920
mr566a and mr566b, new melanin synthesis inhibitors produced by trichoderma harzianum. ii. physico-chemical properties and structural elucidation.new melanin synthesis inhibitors (mr566a and b) and six related known isocyanocyclopentenes were isolated from the fermentation broth of trichoderma harzianum, and their structures were elucidated by spectroscopic methods. the structures of novel isocyanides, mr566a (1) and b (2), were elucidated as 1-(3-chloro-1,2-dihydroxy-4-isocyano-4-cyclopenten-1-yl)etha nol, 1-(1,2,3-trihydroxy-3-isocyano-4-cyclopenten-1-yl)ethanol, respectively. the structure of novel oxazole, mr93b (9), was elucidated as ...19979268002
cellular and molecular mechanisms involved in the interaction between trichoderma harzianum and pythium ultimum.the interaction between trichoderma harzianum and the soilborne plant pathogen pythium ultimum was studied by electron microscopy and further investigated by gold cytochemistry. early contact between the two fungi was accompanied by the abnormal deposition of a cellulose-enriched material at sites of potential antagonist penetration. the antagonist displayed the ability to penetrate this barrier, indicating that cellulolytic enzymes were produced. however, the presence of cellulose in the walls ...199716535619
improved biocontrol activity of trichoderma harzianum by over-expression of the proteinase-encoding gene prb1.transformation systems developed for trichoderma spp. were utilized to improve the biocontrol efficiency of the mycoparasitic fungus trichoderma harzianum by increasing the copy number of the basic proteinase gene prb1. the transformants were stable and carried from two to ten copies of prb1. high levels of expression of prb1 during fungus-fungus interaction were detected when t. harzianum and rhizoctonia solani were confronted in vitro. in liquid cultures the proteinase was induced by cell wall ...19979000378
genetic diversity and vegetative compatibility among trichoderma harzianum isolates.trichoderma harzianum is the collective name of a set of asexual fungal strains which exhibit heterogeneity in genome structure, dna sequence and behavior. contour-clamped homogeneous field (chef) electrophoresis of the chromosomes of ten isolates of t. harzianum revealed six clearly distinct electrophoretic karyotypes. of the ten isolates analyzed, four (gh12, g109, y and yf) could be classified in a single group with identical karyotypes, while the strains t35 and 315 formed a second group. th ...19979349704
morphological and molecular identification of trichoderma isolates on north american mushroom farms.green mold disease (causal agent, trichoderma) has resulted in severe crop losses on mushroom farms worldwide in recent years. we analyzed 160 isolates of trichoderma from mushroom farms for morphological, cultural, and molecular characteristics and classified these isolates into phenotypic groups. the most common group comprised approximately 40% of the isolates and was identified as a strain of trichoderma harzianum. this group was consistently recovered from farms with severe green mold disea ...19989435070
the expression of genes involved in parasitism by trichoderma harzianum is triggered by a diffusible factor.the mycoparasite trichoderma harzianum has been extensively used in the biocontrol of a wide range of phytopathogenic fungi. hydrolytic enzymes secreted by the parasite have been directly implicated in the lysis of the host. dual cultures of trichoderma and a host, with and without contact, were used as means to study the mycoparasitic response in trichoderma. northern analysis showed high-level expression of genes encoding a proteinase (prb1) and an endochitinase (ech42) in dual cultures even i ...19989862475
exg1p, a novel exo-beta1,3-glucanase from the fungus cochliobolus carbonum, contains a repeated motif present in other proteins that interact with polysaccharides.genomic and cdna copies of exg1, a gene encoding an exo-beta1, 3-glucanase from the plant pathogenic fungus cochliobolus carbonum, were isolated. the gene contains two introns of 50 and 53 bp, and the mrna has a 5'-untranslated region of 90 nt and a 3'-untranslated region of 159 nt. the deduced protein product, exg1p, has a predicted signal peptide of 17 amino acids, but based on the known n-terminus of the mature protein is further processed to remove an additional 25 amino acids. the sequence ...19989838227
a new tool for studying the molecular architecture of the fungal cell wall: one-step purification of recombinant trichoderma beta-(1-6)-glucanase expressed in pichia pastoris.the fungal cell wall is a supramolecular network of glycoproteins and polysaccharides. its analysis is seriously hampered by the lack of easily available hydrolytic enzymes in a pure form. here we describe a simple and efficient purification procedure of a recombinant beta-(1-6)-glucanase from trichoderma harzianum expressed in pichia pastoris. transformed cells efficiently secreted the enzyme into the induction medium. we purified the enzyme using a one-step method based on hydrophobic interact ...19989795258
intracellular chitinase gene from rhizopus oligosporus: molecular cloning and characterization.multiple chitinases have been found in hyphae of filamentous fungi, which are presumed to have various functions during hyphal growth. here it is reported, for the first time, the primary structure of one such intracellular chitinase, named chitinase iii, from rhizopus oligosporus, a zygomycete filamentous fungus. chitinase iii was purified to homogeneity from actively growing mycelia of r. oligosporus using three steps of column chromatography. its molecular mass was 43.5 kda and the ph optimum ...19989782514
ionophoric activity of the antibiotic peptaibol trichorzin pa vi: a 23na- and 35cl-nmr study.trichorzin pa vi (ac aib1 ser ala aib iva gln aib val aib gly10 leu aib pro leu aib aib gln pheol18) is one of the seven main peptaibols forming the natural antibiotic 18-residue peptide mixture biosynthesised by a trichoderma harzianum strain. trichorzins exhibit antimycoplasmic activity resulting from membrane permeability perturbations. the membrane permeabilisation process by trichorzin pa vi has been examined in egg yolk phosphatidylcholine large unilamellar vesicles (luv) and under conditi ...19989675337
the purification and characterization of a trichoderma harzianum exochitinase.a chitinolytic enzyme was purified from the culture filtrate of t. harzianum (t198) by precipitation with ammonium sulphate followed by affinity binding to swollen chitin and release with 10% (v/v) acetic acid. the molecular weight of the enzyme was calculated to be 28 and 27.5 kd by gel filtration chromatography and sds-page, respectively. the isoelectric point of the enzyme was 7.4. the ph optimum for activity was 3.5 and maximum activity was obtained at 50 degrees c. the enzyme displayed acti ...19989546051
cytotoxic substances produced by a fungal strain from a sponge: physico-chemical properties and structures.five novel metabolites, trichodenones a-c (1-3), harzialactone a (4) and b (5), have been isolated together with known r-mevalonolactone (6) from the culture broth of a strain of trichoderma harzianum oups-n115 originally separated from the sponge halichondria okadai. their structures have been elucidated by spectral evidence. among them, 1-3 exhibited significant cytotoxicity against cultured p388 cells.19989531985
analysis of the beta-1,3-glucanolytic system of the biocontrol agent trichoderma harzianum.the biocontrol agent trichoderma harzianum imi206040 secretes beta-1,3-glucanases in the presence of different glucose polymers and fungal cell walls. the level of beta-1,3-glucanase activity secreted was found to be proportional to the amount of glucan present in the inducer. the fungus produces at least seven extracellular beta-1,3-glucanases upon induction with laminarin, a soluble beta-1,3-glucan. the molecular weights of five of these enzymes fall in the range from 60,000 to 80,000, and the ...199816349547
biological control of sclerotinia sclerotiorum attacking soybean plants. degradation of the cell walls of this pathogen by trichoderma harzianum (bafc 742). biological control of sclerotinia sclerotiorum by trichoderma harzianum.two experiments of biological control of sclerotinia sclerotiorum, one in the greenhouse and the other in the field, were carried out with soybean and trichoderma harzianum as host and antagonist, respectively. significant control of disease was achieved in both experiments, but there were no significant differences in plant growths. in the greenhouse, the application of t. harzianum as alginate capsules, increased the survival of soybean plants more than 100% with respect to the disease treatme ...199816284851
ecological studies of transformed trichoderma harzianum strain 1295-22 in the rhizosphere and on the phylloplane of creeping bentgrass.abstract a beta-glucuronidase (gus) reporter gene and a hygromycin b (hygb) phosphotransferase gene were integrated separately into the trichoderma harzianum strain 1295-22 genome, using biolistic transformation. the mycelial growth and biocontrol ability of the transformed strains did not differ from that of the original strain. the transformed gus(+)-kanamycin-resistant (gus(+)kan(r)) strains were used to monitor growth and interactions with rhizoctonia solani on creeping bentgrass plants. the ...199818944981
unexpected homology between inducible cell wall protein qid74 of filamentous fungi and br3 salivary protein of the insect chironomus.a gene, qid74, of mycoparasitic filamentous fungus trichoderma harzianum and its allies encodes a cell wall protein that is induced by replacing glucose in the culture medium with chitin (simulated mycoparasitism conditions). because no trace of this gene can be detected in related species such as gibberella fujikuroi and saccharomyces cerevisiae, the qid74 gene appears to have arisen de novo within the genus trichoderma. qid74 protein, 687 residues long, is now seen as highly conserved tandem r ...19989600944
fungitoxicity of chemical analogs with heartwood toxins.trans-stilbene and tropolone as chemical analogs with naturally occurring fungitoxic heartwood compounds were studied with respect to their fungitoxic potency. while stilbene showed no fungitoxic activity towards the fungi aureobasidium pullulans var. melanogenum, penicillium glabrum, and trichoderma harzianum in the concentrations tested, the minimal inhibiting concentration of tropolone was 10(-3) m for penicillium glabrum and trichoderma harzianum, and 10(-5) m for aureobasidium pullulans var ...19989625794
genes from mycoparasitic fungi as a source for improving plant resistance to fungal pathogens.disease resistance in transgenic plants has been improved, for the first time, by the insertion of a gene from a biocontrol fungus. the gene encoding a strongly antifungal endochitinase from the mycoparasitic fungus trichoderma harzianum was transferred to tobacco and potato. high expression levels of the fungal gene were obtained in different plant tissues, which had no visible effect on plant growth and development. substantial differences in endochitinase activity were detected among transfor ...19989653105
chitinolytic activity at low temperature of an antarctic strain (a3) of verticillium lecanii.the chitinolytic activity of verticillium cfr. lecanii a3, a strain isolated from continental antarctica, was compared to those of two selected strains of trichoderma harzianum. after 72 h of incubation at 25 degrees c in media containing chitin as the sole carbon source, all strains showed the same enzyme activity (ca. 230 mu/ml); at 15 degrees c, the levels of enzyme activity of the three strains were similar to those obtained at 25 degrees c. at 5 degrees c, in contrast, the activity of v. le ...19989766230
effect of metabolites produced by trichoderma harzianum biotypes and agaricus bisporus on their respective growth radii in culturetrichoderma harzianum biotypes th1, th2, and th3 produced volatile metabolites in vitro which had similar fungistatic effects on the growth of agaricus bisporus. metabolites present in agar colonized by these strains also inhibited mycelial growth of a. bisporus, although the reduction in growth was less in the presence of metabolites produced by biotype th2 than that in the presence of metabolites produced by th1 or th3. a. bisporus produced metabolites in liquid culture that inhibited the grow ...19989835609
availability of phosphorus and sulfur of insecticide origin by fungi.thirteen fungal species isolated from soil treated with pesticides were tested for their ability to mineralize and degrade three organophosphate insecticides currently used in egypt (cyolan, malathion and dursban) in liquid media free from phosphorus (p) and sulfur (s). all fungal species grew successfully on the culture media treated with the three used doses of insecticides (10, 50 and 100 ppm active ingredient) but the growth rate varied with the species, the insecticide and the doses. at 10 ...199810192894
[filamentous fungi preservation in distilled water.].some methods for keeping the fungal culture collection have been used. however, the choice of either one on the basis that must ensure the cultural genetic stability and its phenotipic characteristics. in this work the preservation method in distilled water recognized in the literature as a single, economic and certain method that guarantie the survival of fungus cultures for long periods was used. 26 strains of generus and species: aspergillus niger, aspergillus candidus, fusarium sp., fusarium ...199818473541
[mycoparasites effect on reproductive ability of sclerotinia sclerotiorum sclerotia.].the ability to parasitise sclerotinia sclerotiorum and the effect on apothecia production was evaluated for the following antagonists: trichoderma harzianum; trichoderma koningii; gliocladium roseum and chaetomium globosum. plastic trays were filled with of steam-sterilized soil. each one of them was infested with sclerotia of s. sclerotiorum and the culture of the antagonists. the trays were kept in a greenhouse and after 30, 60 and 90 days, evaluations were made. the rates of carpogenic germin ...199817655415
the mycoparasite ampelomyces quisqualis expresses exga encoding an exo-beta-1,3-glucanase in culture and during mycoparasitism.abstract ampelomyces quisqualis, a mycoparasite of fungi causing powdery mildews, exhibited high levels of extracellular exo-beta-1,3-glucanase activity in culture compared with neurospora crassa and gliocladium roseum. a. quisqualis culture filtrates affected powdery mildew caused by sphaerotheca fusca in a manner indicative of cell wall degradation, as determined by microscopic examination. a gene encoding an exo-beta-1,3-glucanase in a. quisqualis, designated exga, was isolated and sequenced. ...199918944674
characterization of two novel type i ribosome-inactivating proteins from the storage roots of the andean crop mirabilis expansa.two novel type i ribosome-inactivating proteins (rips) were found in the storage roots of mirabilis expansa, an underutilized andean root crop. the two rips, named me1 and me2, were purified to homogeneity by ammonium sulfate precipitation, cation-exchange perfusion chromatography, and c4 reverse-phase chromatography. the two proteins were found to be similar in size (27 and 27.5 kd) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their isoelectric points were determined to be ...199910198104
expression of two major chitinase genes of trichoderma atroviride (t. harzianum p1) is triggered by different regulatory signals.regulation of the expression of the two major chitinase genes, ech42 (encoding the chit42 endochitinase) and nag1 (encoding the chit73 n-acetyl-beta-d-glucosaminidase), of the chitinolytic system of the mycoparasitic biocontrol fungus trichoderma atroviride (= trichoderma harzianum p1) was investigated by using a reporter system based on the aspergillus niger glucose oxidase. strains harboring fusions of the ech42 or nag1 5' upstream noncoding sequences with the a. niger goxa gene displayed a gl ...199910223970
rapid blue light regulation of a trichoderma harzianum photolyase gene.photolyases and blue light receptors belong to a superfamily of flavoproteins that make use of blue and uva light either to catalyze dna repair or to control development. we have isolated a dna photolyase gene (phr1) from trichoderma harzianum, a common soil fungus that is of interest as a biocontrol agent against soil-borne plant pathogens and as a model for the study of light-dependent development. the sequence of phr1 is similar to other class i type i eukaryotic photolyase genes. low fluence ...199910318850
pcr-based genotyping of epidemic and preepidemic trichoderma isolates associated with green mold of agaricus bisporus.we used randomly amplified polymorphic dna (rapd)-pcr to estimate genetic variation among isolates of trichoderma associated with green mold on the cultivated mushroom agaricus bisporus. of 83 isolates examined, 66 were sampled during the recent green mold epidemic, while the remaining 17 isolates were collected just prior to the epidemic and date back to the 1950s. trichoderma harzianum biotype 4 was identified by rapd analysis as the cause of almost 90% of the epidemic-related episodes of gree ...199910347059
solubilization of phosphates and micronutrients by the plant-growth-promoting and biocontrol fungus trichoderma harzianum rifai 1295-22we investigated the capability of the plant-growth-promoting and biocontrol fungus trichoderma harzianum rifai 1295-22 (t-22) to solubilize in vitro some insoluble or sparingly soluble minerals via three possible mechanisms: acidification of the medium, production of chelating metabolites, and redox activity. t-22 was able to solubilize mno2, metallic zinc, and rock phosphate (mostly calcium phosphate) in a liquid sucrose-yeast extract medium, as determined by inductively coupled plasma emission ...199910388685
purification and properties of a basic endo-beta-1,6-glucanase (bgn16.1) from the antagonistic fungus trichoderma harzianum.the antagonistic fungus trichoderma harzianum cect 2413 produces at least two extracellular beta-1,6-glucanases, among other hydrolases acting on polysaccharides from fungal cell walls, when grown in chitin as the sole carbon source. we have previously reported on the purification and biochemical characterization of the major activity, which corresponds to an acidic enzyme named bgn16.2 [de la cruz, j., pintor-toro, j.a., benítez, t. & llobell, a. (1995) j. bacteriol. 177, 1864-1871]. in this pa ...199910491168
nitrogen availability to pseudomonas fluorescens df57 is limited during decomposition of barley straw in bulk soil and in the barley rhizosphere.the availability of nitrogen to pseudomonas fluorescens df57 during straw degradation in bulk soil and in barley rhizosphere was studied by introducing a bioluminescent reporter strain (df57-n3), responding to nitrogen limitation, to model systems of varying complexity. df57-n3 was apparently not nitrogen limited in the natural and sterilized bulk soil used for these experiments. the soil was subsequently amended with barley straw, representing a plant residue with a high carbon-to-nitrogen rati ...199910508054
fatal case of trichoderma harzianum infection in a renal transplant recipient.we describe the second known case of human infection by trichoderma harzianum. a disseminated fungal infection was detected in the postmortem examination of a renal transplant recipient and confirmed in culture. the only other reported infection by this fungus caused peritonitis in a diabetic patient. the in vitro antifungal susceptibilities of the clinical strain and three other strains of trichoderma species to six antifungal drugs are provided. this case illustrates the widening spectrum of o ...199910523593
role of the trichoderma harzianum endochitinase gene, ech42, in mycoparasitism.the role of the trichoderma harzianum endochitinase (ech42) in mycoparasitism was studied by genetically manipulating the gene that encodes ech42, ech42. we constructed several transgenic t. harzianum strains carrying multiple copies of ech42 and the corresponding gene disruptants. the level of extracellular endochitinase activity when t. harzianum was grown under inducing conditions increased up to 42-fold in multicopy strains as compared with the wild type, whereas gene disruptants exhibited p ...199910049844
purification of active cysteine proteases by affinity chromatography with attached e-64 inhibitor.cysteine proteases are implicated in many regulatory and degradative processes in animal and plant cells. many of the proteases are strongly inhibited by an irreversible inhibitor, trans-(epoxysuccinyl)-l-leucylamino-4-guanidinobutane (e-64) from aspergillus japonicus. here we report a method for purification of cysteine proteases by affinity chromatography on e-64. attachment of the inhibitor to thiopropyl sepharose through its epoxy group resulted in the loss of its irreversible activity but d ...199910092483
transformation with green fluorescent protein of trichoderma harzianum 1051, a strain with biocontrol activity against crinipellis perniciosa, the agent of witches'-broom disease of cocoa.a plasmid vector for fungal expression of an enhanced, red-shifted variant of the aequoria victoriae green fluorescent protein was constructed by fusion of the egfp gene to the highly expressed aspergillus nidulans gpd promoter and the a. nidulans trpc terminator. this construction was introduced by cotransformation, using benomyl selection, into trichoderma harzianum strain 1051, a strain being evaluated for the biological control of witches'-broom disease of cocoa caused by crinipellis pernici ...199912501389
fungal degradation of aflatoxin b1.a number of fungal cultures were screened to select an organism suitable to be used in the detoxification of aflatoxin b1. they were co-cultured in czapek-dox-casamino acid medium with aflatoxin b1 producing aspergillus flavus. several fungal cultures were found to prevent synthesis of aflatoxin b1 in liquid culture medium. among these phoma sp., mucor sp., trichoderma harzianum, trichoderma sp. 639, rhizopus sp. 663, rhizopus sp. 710, rhizopus sp. 668, alternaria sp. and some strains belonging ...199910945479
molecular phylogenetic analyses of biological control strains of trichoderma harzianum and other biotypes of trichoderma spp. associated with mushroom green mold.abstract a polymerase chain reaction-amplified dna containing the internal transcribed spacer (its)-1, 5.8s, and its-2 regions of the nuclear ribosomal dna transcriptional unit was sequenced for 81 isolates of trichoderma spp. associated with mushroom culture or used for biological control of plant pathogens. phylogenetic analyses revealed that the biocontrol isolates were more closely related to an isolate of t. harzianum biotype 1 (th1) than to the aggressive biotypes 2 and 4. th1 has been iso ...199918944776
increased antifungal activity of trichoderma harzianum transformants that overexpress a 33-kda chitinase.abstract transformants of the biocontrol agent trichoderma harzianum strain cect 2413 that overexpressed a 33-kda chitinase (chit33) were obtained and characterized. strain cect 2413 was cotransformed with the amds gene and its own chit33 gene under the control of the pki constitutive promoter from t. reesei. southern blotting indicated that the chit33 gene was integrated ectopically, mostly in tandem. some transformants showed the same restriction pattern, indicating preferable sites of integra ...199918944767
suppression of the biocontrol agent trichoderma harzianum by mycelium of the arbuscular mycorrhizal fungus glomus intraradices in root-free soiltrichoderma harzianum is an effective biocontrol agent against several fungal soilborne plant pathogens. however, possible adverse effects of this fungus on arbuscular mycorrhizal fungi might be a drawback in its use in plant protection. the objective of the present work was to examine the interaction between glomus intraradices and t. harzianum in soil. the use of a compartmented growth system with root-free soil compartments enabled us to study fungal interactions without the interfering effec ...199910103232
hydrolysis of xylans by enzyme systems from solid cultures of trichoderma harzianum strains.xylanase activity was isolated from crude extracts of trichoderma harzianum strains c and 4 grown at 28 degree c in a solid medium containing wheat bran as the carbon source. enzyme activity was demonstrable in the permeate after ultrafiltration of the crude extracts using an amicon system. the hydrolysis patterns of different xylans and paper pulps by xylanase activity ranged from xylose, xylobiose and xylotriose to higher xylooligosaccharides. a purified ss-xylosidase from the trichoderma harz ...199910454755
a new xylanase from a trichoderma harzianum strain.a new xylanase (xyl2) was purified from solid-state cultures of trichoderma harzianum strain c by ultrafiltration and gel filtration. sds-page of the xylanase showed an apparent homogeneity and molecular weight of 18 kda. it had the highest activity at ph 5.0 and 45 degrees c and was stable at 50 degrees c and ph 5.0 up to 4 h xylanase. xyl2 had a low km with insoluble oat spelt xylan as substrate. compared to the amino acid composition of xylanases from trichoderma spp, xylanase xyl2 presented ...199910455501
chitinase gene expression during mycoparasitic interaction of trichoderma harzianum with its host.for monitoring chitinase expression during mycoparasitism of trichoderma harzianum in situ, we constructed strains containing fusions of green fluorescent protein (gfp) to the 5'-regulatory sequences of the t. harzianum nag1 (n-acetyl-beta-d-glucosaminidase-encoding) and ech42 (42-kda endochitinase-encoding) genes. confronting these strains with rhizoctonia solani led to induction of gene expression before (ech42) or after (nag1) physical contact. a 12-kda cut-off membrane separating the two fun ...199910328983
induction of defense responses in cucumber plants (cucumis sativus l. ) by the biocontrol agent trichoderma harzianumthe potential of the biocontrol agent trichoderma harzianum t-203 to trigger plant defense responses was investigated by inoculating roots of cucumber seedlings with trichoderma in an aseptic, hydroponic system. trichoderma-treated plants were more developed than nontreated plants throughout the experiment. electron microscopy of ultrathin sections from trichoderma-treated roots revealed penetration of trichoderma into the roots, restricted mainly to the epidermis and outer cortex. strengthening ...199910049864
molecular characterization of a novel beta-1,3-exoglucanase related to mycoparasitism of trichoderma harzianum.trichoderma harzianum, a soil-borne filamentous fungus, is capable of parasitizing several plant pathogenic fungi. secretion of lytic enzymes, mainly glucanases and chitinases, is considered the most crucial step of the mycoparasitic process. the lytic enzymes degrade the cell walls of the pathogenic fungi, enabling trichoderma to utilize both their cell walls and cellular contents for nutrition. we have purified a 110kda novel extracellular beta-1,3-exoglucanase from t. harzianum, grown with la ...19999931476
colour pigments of trichoderma harzianum. preliminary investigations with thin-layer chromatography-fourier transform infrared spectroscopy and high-performance liquid chromatography with diode array and mass spectrometric detection.the colour pigments of trichoderma harzianum fermentation broth were separated and the main fractions were tentatively identified by reversed-phase thin-layer chromatography-fourier transform infrared spectroscopy (rp-tlc-ft-ir), rp-hplc-diode array detection and rp-hplc-ms. it was established that the multistep gradient elution developed for rp-tlc separation of pigments can be successfully used as a pilot method for the rational design of gradient elution in rp-hplc for the separation of the s ...200011093640
aroma compounds recovery from mycelial cultures in aqueous two-phase processes.this paper presents the evaluation of the potential use of aqueous two-phase systems (atps) for the recovery of 6-pentyl-alpha-pyrone (6pp) produced by trichoderma harzianum. the partition behaviour of 6pp and trichoderma harzianum mycelium (biomass) in polyethylene glycol (peg)-salt (phosphate and sulphate) and peg-dextran atps was investigated. the influence of defined system parameters (e.g. molecular mass of peg and dextran, volume ratio, etc.) on the partition behaviour of 6pp and trichoder ...200010942311
effect of delivery method and population size of trichoderma harzianum on growth response of unrooted chrysanthemum cuttings.in a previous study, addition of trichoderma harzianum rifai isolate t-12 to a propagative medium resulted in improved performance of chrysanthemum cuttings. however, root and shoot growth of one cultivar, 'dark bronze charm', were more responsive to a lower (5 g t-12/kg medium) than higher (25 g t-12/kg medium) rate of fungal propagules, suggesting potential phytotoxicity at higher concentrations. the objectives of this study were to investigate higher rates of t-12 medium amendment for phytoto ...200010941519
enzymes secreted by filamentous fungi: regulation of secretion and purification of an extracellular protease of trichoderma harzianum.extracellular proteases secreted by the filamentous fungus trichoderma harzianum have been identified. a proteinase active towards z-ala-ala-leu-pna--the substrate of subtilisin-like proteases--dominated in the culture medium. this proteinase is synthesized de novo in response to addition of a protein substrate to the medium. changing the carbohydrate in the culture medium changed the quantitative and qualitative spectrum of secreted enzymes. the most active extracellular proteinase of trichoder ...200010887294
regulation of 36-kda beta-1,3-glucanase synthesis in trichoderma harzianum.the effect of carbon sources on the level of beta-1,3-glucanases in the culture filtrates of trichoderma harzianum (tc) was investigated. enzyme activity was detected in all carbon sources, but highest levels were found when laminarin and purified cell walls were used. three isoforms of beta-1,3-glucanase were produced during growth of the fungus on purified cell walls. two isoforms were produced on chitin, chitosan, n-acetylglucosamine and laminarin, while only one was detected when the fungus ...200010867228
study of drop and bubble sizes in a simulated mycelial fermentation broth of up to four phases.the mean sizes and size distributions of air bubbles and viscous castor oil drops were studied in a salt-rich aqueous solution (medium), first separately, and then simultaneously as a three-phase system. the dispersion was created in a 150-mm-diameter stirred tank equipped with a rushton turbine, and the sizes were measured using an advanced video technique. trichoderma harzianum biomass was added in some experiments to study the effect of a solid phase under unaerated and aerated conditions to ...200010861400
study on the production of 6-pentyl-alpha-pyrone using two methods of fermentation.the lactone 6-pentyl-alpha-pyrone has a characteristic coconut aroma and is produced by trichoderma species. a study on the fermentative production of 6-pentyl-alpha-pyrone in both surface and submerged conditions by trichoderma harzianum was carried out. maximum concentrations of 455 mg/l and 167 mg/l after 96 h and 48 h of fermentation in surface and submerged conditions, respectively, were obtained without using any additional recovery operations. the resultant yields are higher than those pr ...200010855724
characterization of blue-light and developmental regulation of the photolyase gene phr1 in trichoderma harzianum.blue light and development regulate the expression of the phr1 gene of the filamentous fungus trichoderma harzianum. the predicted product of phr1, the dna repair enzyme photolyase, is likely to help protect trichoderma, which grows in the soil as a mycoparasite or saprophyte, from damage upon emergence and exposure to ultraviolet-c. phr1 is transiently expressed in mycelium and conidiophores after illumination. phr1 mrna also accumulates in conidiophores during development and spore maturation. ...200010818799
influence of water potential on growth, enzyme secretion and in vitro enzyme activities of trichoderma harzianum at different temperatures.the influence of water potential on linear mycelial growth, secretion, and the in vitro activities of enzymes beta-glucosidase, cellobiohydrolase, beta-xylosidase, exochitinase, and chymotrypsin of trichoderma harzianum strain t66 was studied at different temperatures. nearly linear correlation was found between water potential and colony growth rate at both 25 degrees c and 10 degrees c, with higher growth rates at the higher temperature and higher water potentials. the amounts of enzyme secret ...200010706661
characterization of a 29-kda beta-1,3-glucanase from trichoderma harzianum.a beta-1,3-glucanase, from culture filtrates of trichoderma harzianum, was purified in sequential steps by gel filtration, hydrophobic interaction and ion exchange chromatography. a typical procedure provided 69-fold purification with 0.32% yield. the molecular mass of the protein was found to be approximately 29 kda, as estimated by sds-page on a 10% slab gel. the k(m) and v(max) values for beta-1,3-glucanase, using laminarin as substrate, were 1. 72 mg ml(-1) and 3.10 u ml(-1), respectively. t ...200010650213
[improvement of trichoderma strains for biocontrol].the use of the fungal genus trichoderma to control fungal plant diseases is a promising alternative to the use of chemical compounds. the aim of this work has been to obtain trichoderma strains with improved capacity as biological control agents. to do so, the hydrolytic capacity on fungal cell walls of strains of the fungus trichoderma harzianum has been increased. on one hand, transformation experiments with genes which coded for chitinases and glucanases have been carried out in t. harzianums ...200015762779
elucidation of high micro-heterogeneity of an acidic-neutral trichotoxin mixture from trichoderma harzianum by electrospray ionization quadrupole time-of-flight mass spectrometry.the high micro-heterogeneity of an acidic-neutral trichotoxin mixture from t. harzianum, pc01, was elucidated using a modern tandem mass spectrometer equipped with an electrospray ionization source, a hybrid quadrupole-orthogonal accelerator and a reflectron time-of-flight analyzer. the trichotoxins appeared predominantly in six possible doubly charged pseudo molecular ions with three different adducts (h, na and k) as [m + 2h](2+), [m + h + na](2+), [m + h + k](2+), [m + 2na](2+), [m + na + k]( ...200011180635
fast methods for screening of trichothecenes in fungal cultures using gc-ms/ms.fast methods for screening for production of simple and macrocyclic trichothecenes, produced on solid substrates were developed. crude extracts fromfusarium cultures grown on yeast extract sucrose agar (approx. 0.3 cm(2) culture) were derivatised using pentafluoropropionic anhydride and analysed by gc - tandem mass spectrometry using a finnigan gcq(+) ion trap. the ms was operated in the ei(+) multiscan mode allowing simultaneous full scan and ms/ms of 3-4 parent ions. production of acetyl t-2 t ...200023605545
overproduction of beta-1,6-glucanase in trichoderma harzianum is controlled by extracellular acidic proteases and ph.to produce high amounts of extracellular endo-beta-1,6-glucanase, we overexpressed the gene bgn16.2 from trichoderma harzianum under the control of the pyruvate kinase gene promoter (pki) of t. reesei. transcription of bgn16.2 gene increased under most conditions but not extracellular beta-1,6-glucanase levels. relationship of extracellular bgn16.2 protein and presence of proteases was studied in order to maximize production. after changing the carbon and nitrogen sources and buffering the cultu ...200011018720
combined effects of brassica napus seed meal and trichoderma harzianum on two soilborne plant pathogens.the effects of soil amendment with rapeseed meal from brassica napus cv. 'dwarf essex' (high glucosinolate concentrations) and 'stonewall' (low glucosinolate concentrations) on the biological control activity of trichoderma harzianum towards sclerotinia sclerotiorum and aphanomyces euteiches were evaluated. trichoderma harzianum added to soil reduced myceliogenic germination of s. sclerotiorum by 94%, but did not affect carpogenic germination. in contrast, 100% reduction in carpogenic germinatio ...200011109495
analysis of the dynamics of fungal communities in soil via fungal-specific pcr of soil dna followed by denaturing gradient gel electrophoresis.a molecular method for profiling of fungal communities in soil was applied in experiments in soil microcosms, with two objectives, (1) to assess the persistence of two selected fungal species in soil, and (2) to analyze the response of the natural fungal community to a spill of sulphurous petrol in the same soil. to achieve the aims, two soil dna extraction methods, one originally designed for the direct extraction of bacterial community dna and the other one aimed to obtain fungal dna, were tes ...200011121612
biochemical analysis of recombinant fungal mutanases. a new family of alpha1,3-glucanases with novel carbohydrate-binding domains.nucleotide sequence analysis shows that trichoderma harzianum and penicillium purpurogenum alpha1,3-glucanases (mutanases) have homologous primary structures (53% amino acid sequence identity), and are composed of two distinct domains: a nh(2)-terminal catalytic domain and a putative cooh-terminal polysaccharide-binding domain separated by a o-glycosylated pro-ser-thr-rich linker peptide. each mutanase was expressed in aspergillus oryzae host under the transcriptional control of a strong alpha-a ...200010636904
biodegradation of pyrene by sediment fungi.micromycetes were isolated from pahs-contaminated sediment and identified. they were investigated for pyrene degradation (10 mg l-1) in liquid synthetic medium for two days. among the 41 strains isolated, 10 highly degraded pyrene (> 2.4 mg g-1 dry weight): two zygomycetes (mucor racemosus, m. racemosus var. sphaerosporus), 6 deuteromycetes (gliocladium virens, penicillium simplicissimum, p. janthinellum, phialophora alba, p. hoffmannii, trichoderma harzianum), a dematiaceae (scopulariopsis brum ...200010665394
molecular characterization and identification of biocontrol isolates of trichoderma spp.the most common biological control agents (bcas) of the genus trichoderma have been reported to be strains of trichoderma virens, t. harzianum, and t. viride. since trichoderma bcas use different mechanisms of biocontrol, it is very important to explore the synergistic effects expressed by different genotypes for their practical use in agriculture. characterization of 16 biocontrol strains, previously identified as "trichoderma harzianum" rifai and one biocontrol strain recognized as t. viride, ...200010788356
enzyme diffusion from trichoderma atroviride (= t. harzianum p1) to rhizoctonia solani is a prerequisite for triggering of trichoderma ech42 gene expression before mycoparasitic contact.a plate confrontation experiment is commonly used to study the mechanism by which trichoderma spp. antagonize and parasitize other fungi. previous work with chitinase gene expression (ech42) during the precontact period of this process in which cellophane and dialysis membranes separated trichoderma harzianum and its host rhizoctonia solani resulted in essentially opposite results. here, we show that cellophane membranes are permeable to proteins up to at least 90 kda in size but that dialysis m ...200010788407
hybridization and breeding of the benomyl resistant mutant, trichoderma harziantum antagonized to phytopathogenic fungi by protoplast fusion.a diploid strain obtained from heterokaryons of trichoderma harzianum by protoplast fusion grew on minimal medium containing 100ppm benomyl. this strain inhibited the growth of the phytopathogenic fungus fusarium oxysporum f. sp. raphani on paired cultures and also protected against radish yellows and a drop in germination induced by f. oxysporum f. sp. raphani.200010830500
the production of hemicellulases by aerobic fungi on medium containing residues of banana plant as substrate.trichoderma harzianum strains t4 and t6, acrophialophora nainiana, and humicola grisea var. thermoidea were screened for their ability to produce carbohydrate-degrading enzyme activities in a medium containing banana plant residue as the carbon source. the best balance of enzyme activities was obtained from cultures of h. grisea var. thermoidea. xylanase activity from crude extract of a. nainiana had a maximum activity at ph 5.5-7.0 and a temperature range of 50-55 degrees c. it was stable up to ...200010835259
characterization of an amylase produced by a trichoderma harzianum isolate with antagonistic activity against crinipellis perniciosa, the causal agent of witches' broom of cocoa.an isolate of trichoderma harzianum showing antagonistic activity against crinipellis perniciosa, the causal agent of the witches' broom disease of cocoa, produces substantial amounts of hydrolytic enzymes. an amylase purified from isolate 1051 had a molecular mass of about 68.7 kda. maximal activity against soluble starch was determined at ph 4.0 and 60 degrees c. the k(m) and v(max) values were 3.5 mg ml(-1) and 1.67 mg min(-1) of reducing sugar. the end products were mostly malto-oligosacchar ...200010913701
effect of biological suspensions on the position of the binodal curve in aqueous two-phase systems.this study is concerned with the influence of biological suspension on the position of the binodal curve in aqueous two-phase systems (atpss). three different biological suspensions (i.e., disrupted yeast, e. coli homogenate and fermentation broth from trichoderma harzianum) were selected and their impact upon atps performance was evaluated on the basis of changing volume ratio (vr) and the position of the binodal curve of biological atpss (added with biomass). biological atpss with initial vr g ...200010942267
disease progression by active mycelial growth and biocontrol of pythium ultimum var. ultimum studied using a rhizobox system.abstract this study demonstrates that outward growth of mycelium from primary foci through bulk potting mix to roots of adjoining plants can be an important means of spread of damping-off and root rot caused by pythium ultimum. the use of a rhizobox system, which confines plant roots, enabled us to study the spread of actively growing mycelium between root systems placed at precise distances from each other. in steamed potting mix, hyphae of p. ultimum on average grew 9.6 cm from diseased root t ...200018944533
expression of endochitinase from trichoderma harzianum in transgenic apple increases resistance to apple scab and reduces vigor.abstract the goal of this research was to improve scab resistance of apple by transformation with genes encoding chitinolytic enzymes from the bio-control organism trichoderma harzianum. the endochitinase gene, as cdna and genomic clones, was transferred into apple cv. marshall mcintosh by agrobacterium-transformation. a total of 15 lines were identified as transgenic by nptii enzyme-linked immunosorbent assay and polymerase chain reaction and confirmed by southern analysis. substantial differen ...200018944574
trichoderma harzianum endochitinase does not provide resistance to meloidogyne hapla in transgenic tobacco.eggs of meloidogyne hapla contain chitin, a substrate for chitinase. our goal was to determine if endochitinase from the biocontrol fungus t. harzianum expressed in transgenic tobacco increases resistance to this nematode. endochitinase-transgenic t tobacco seedlings expressing increased endochitinase activity in leaves (11 to 125 times over control) and roots (2 to 15 times over control) were transferred to quartz sand:loam soil mix (4:1 ratio) and inoculated with 5,000 m. hapla eggs/pot. tomat ...200019270979
cotransformation of trichoderma harzianum with beta-glucuronidase and green fluorescent protein genes provides a useful tool for monitoring fungal growth and activity in natural soils.trichoderma harzianum was cotransformed with genes encoding green fluorescent protein (gfp), beta-glucuronidase (gus), and hygromycin b (hygb) resistance, using polyethylene glycol-mediated transformation. one cotransformant (thzid1-m3) was mitotically stable for 6 months despite successive subculturing without selection pressure. thzid1-m3 morphology was similar to that of the wild type; however, the mycelial growth rate on agar was reduced. thzid1-m3 was formed into calcium alginate pellets an ...200010653755
antagonism of nutrient-activated conidia of trichoderma harzianum (atroviride) p1 against botrytis cinerea.abstract the effect of preliminary nutrient activation on the ability of conidia of the antagonist trichoderma harzianum (atroviride) p1 to suppress botrytis cinerea was investigated in laboratory, greenhouse, and field trials. preliminary nutrient activation at 21 degrees c accelerated subsequent germination of the antagonist at temperatures from 9 to 21 degrees c; at >/=18 degrees c, the germination time of preactivated t. harzianum p1 conidia did not differ significantly from that of b. ciner ...200118943332
regulation of chitinase 33 (chit33) gene expression in trichoderma harzianum.we investigated the regulation of chit33 expression in trichoderma harzianum cect 2413. this gene encodes the chit33 endochitinase, which is a major component of the fungus' chitinolytic enzyme system and is important for biocontrol. to this end, both northern analysis and reporter gene fusions of a 1.4-kb fragment of the 5'-upstream sequences of chit33 to the aspergillus niger goxa gene (encoding glucose oxidase) and the aquorea victoria green fluorescent protein were used. northern analysis an ...200111270576
addition of substrate-binding domains increases substrate-binding capacity and specific activity of a chitinase from trichoderma harzianum.chitinase chit42 from trichoderma harzianum cect 2413 is considered to play an important role in the biocontrol activity of this fungus against plant pathogens. chit42 lacks a chitin-binding domain (chbd). we have produced hybrid chitinases with stronger chitin-binding capacity by fusing to chit42 a chbd from nicotiana tabacum chia chitinase and the cellulose-binding domain from cellobiohydrolase ii of trichoderma reesei. the chimeric chitinases had similar activities towards soluble substrate b ...200111325554
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