Showing papers on "Trichoderma longibrachiatum published in 2001"

Salicylic Acid and Ethylene Pathways Are Differentially Activated in Melon Cotyledons by Active or Heat-Denatured Cellulase from Trichoderma longibrachiatum

Abstract: Infiltration of cellulase (EC 3.2.1.4) from Trichoderma longibrachiatum into melon (Cucumis melo) cotyledons induced several key defense mechanisms and hypersensitive reaction-like symptoms. An oxidative burst was observed 3 hours after treatment and was followed by activation of ethylene and salicylic acid (SA) signaling pathways leading to marked induction of peroxidase and chitinase activities. The treatment of cotyledons by heat-denatured cellulase also led to some induction of peroxidase and chitinase activities, but the oxidative burst and SA production were not observed. Co-infiltration of aminoethoxyvinil-glycine (an ethylene inhibitor) with the active cellulase did not affect the high increase of peroxidase and chitinase activities. In contrast, co-infiltration of aminoethoxyvinil-glycine with the denatured enzyme blocked peroxidase and chitinase activities. Our data suggest that the SA pathway (induced by the cellulase activity) and ethylene pathway (induced by heat-denatured and active protein) together coordinate the activation of defense mechanisms. We found a partial interaction between both signaling pathways since SA caused an inhibition of the ethylene production and a decrease in peroxidase activity when co-infiltrated with denatured cellulase. Treatments with active or denatured cellulase caused a reduction in powdery mildew (Sphaerotheca fuliginea) disease.

Antimicrobial activity of ergokonin A from Trichoderma longibrachiatum.

Abstract: Aims: Natural fungal products were screened for antifungal compounds. The mode of action of one of the hits found and the taxonomy of the producing organism were analysed. Methods and Results: An extract from a Trichoderma species showed a more potent activity in an agar-based assay against the null mutant fks1::HIS strain than against the wild-type strain, suggesting that it could contain a glucan synthesis inhibitor. The active component was identified as the known compound ergokonin A. The compound exhibited activity against Candida and Aspergillus species, but was inactive against Cryptococcus species. It induced alterations in the hyphal morphology of Aspergillus fumigatus. The identification of the producing isolate was confirmed by sequencing of the rDNA internal transcribed spacers and comparison with the sequences of other Trichoderma species. The analysis showed that the producing fungus had a high homology with other strains classified as Trichoderma longibrachiatum and its teleomorph Hypocrea schweinitzii. Conclusions: The antifungal activity spectrum of ergokonin A and the morphology alterations induced on A. fumigatus are consistent with glucan synthesis as the target for ergokonin A. The production of ergokonin A is not uncommon, but is probably restricted to Trichoderma species. Significance and Impact of the Study: The discovery that ergokonin A could be an inhibitor of glucan synthesis, having a structure very different to other inhibitors, increases the likelihood that orally active agents with this fungal-specific mode of action may be developed.

Identification of Trichoderma strains by image analysis of HPLC chromatograms

Abstract: Forty-four Trichoderma strains from water-damaged building materials or indoor dust were classified with chromatographic image analysis on full chromatographic matrices obtained by high performance liquid chromatography with UV detection of culture extracts. The classes were compared with morphological identification and rDNA sequence data, and for each class all strains were of the same identity. With all three techniques each strain – except one – was identified as the same species. These strains belonged to Trichoderma atroviride (nine strains), Trichoderma viride (three strains), Trichoderma harzianum (10 strains), Trichoderma citrinoviride (12 strains), and Trichoderma longibrachiatum (nine strains). The odd strain was identified as Trichoderma hamatum by morphology and rDNA sequencing, but not by image analysis as no reference strains of this species were included. It is concluded that the secondary metabolite profile contains sufficient information for classification and species identification.

Sequences and antimycoplasmic properties of longibrachins LGB II and LGB III, two novel 20-residue peptaibols from Trichoderma longibrachiatum

Abstract: Longibrachins are members of the class of natural Aib-containing peptides designated as peptaibols. Six longibrachins, LGA I-IV and LGB II and III, were purified from a Trichoderma longibrachiatum strain by a procedure employing several chromatography steps including reversed-phase HPLC. The amino acid sequence determination was based on a combination of liquid secondary ion mass spectrometry (LSIMS) and two-dimensional 1H and 13C NMR spectroscopy. Longibrachins are 20-residue peptaibols with a C-terminal phenylalaninol and either neutral (LGA; Gln18) or acidic (LGB; Glu18) character. Longibrachins LGB II and III have novel sequences. Both longibrachins LGA and LGB show significant bactericidal activity against mycoplasmas (Acholeplasma, Mycoplasma, and Spiroplasma), with minimal inhibitory concentrations in the range 1.56-12.5 microM (3-25 micrograms/mL), and also perturb the permeability of membrane bilayers. Longibrachin LGA IV is the most potent of the presently known 18-20-residue peptaibols. The antimicrobial and membrane-perturbing properties of longibrachins, which are described here for the first time, were shown to be correlated.

Effect of macerating enzymes on red wine aroma at laboratory scale: exogenous addition or expression by transgenic wine yeasts.

Abstract: The effects of a Trichoderma longibrachiatum endoglucanase and an Aspergillus nidulans endoxylanase on the concentration of free and bound volatiles, color, and phenolics during maceration in red wine vinification has been studied. Two different approaches have been considered for the utilization of these enzymes: (i) direct addition of the enzymes to must and (ii) inoculation of must with recombinant wine yeasts overexpressing these activities. An experimental design based on a Taguchi orthogonal array was carried out in order to evaluate the effects of the enzymatic treatments. The data show that these fungal activities are able to increase the concentrations of free and glycosidically bound flavor compounds, color, and phenolics to similar or greater extents as compared to a commercial pectolytic enzyme preparation. The effects of the two different ways of addition of the enzymes were not always equivalent. These enzymes could be considered to be of potential application in the red wine maceration process.

Efficacy of Carbohydrases Derived from Trichoderma longibrachiatum in Wheat- and Barley-Based Diets on Performance and Fermentation of Carbohydrates in the Intestine of Broilers

Abstract: Jamroz, D., Orda, J., Wiliczkiewicz, A. and Skorupinska, J. 2001. Efficacy of carbohydrases derived from Trichoderma longibrachiatum in wheat- and barley-based diets on performance and fermentation of carbohydrates in the intestine of broilers. J. Appl. Anim. Res., 19: 61–72. Starbro broiler chickens were fed on diets (starter/grower) differing in the kind of cereals: 49/56% wheat (W), 49/56% barley (B) or 25/28% wheat and 25/28% barley (W+B), with or without supplementation of granulated. enzyme complex derived from Trichoderma longibrachiatum. Performance, carcass characteristics, length of intestinal segments and concentrations of fermentation products in different parts of the intestine were evaluated. The effects of the enzyme supplementation were higher in chickens fed diets containing wheat or wheat and barley. The production of short chain fatty acids as a result of non-starch polysaccharides degradation was not consistently influenced either by the kind of cereal or by the supplementatio...

Aspergillus nidulans as a model organism for the study of the expression of genes encoding enzymes of relevance in the food industry

Abstract: Publisher Summary For optimizing the industrial production of enzymes by molecular means, a logical first step is the study of the regulation of expression of the corresponding genes The principal industrial scale fungal enzyme producers are predominantly members of the genera Aspergillus ( Aspergillus awamori , Aspergillus niger , Aspergillus oryzae ) and Trichoderma ( Trichoderma longibrachiatum , Trichoderma reesei ) Although not employed at the industrial level, Aspergillus nidulans ( A nidulans ) is the organism of choice for carrying out such studies on gene regulation Classical genetic studies have revealed the existence of two principal modes of genetic regulation in A nidulans : (1) pathway-specific regulation and (2) wide-domain regulation Pathway-specific regulation refers to the control of the synthesis of components (permeases and enzymes) of a single metabolic pathway, whereas wide domain regulation refers to control exerted over a number of different pathways The most extensively studied examples of wide domain regulation are nitrogen metabolite repression, carbon catabolite repression, and ambient pH regulation

Use of Wheat, Barley or Triticale in Feed for Laying Hens Supplemented with Carbohydrases Derived from Trichoderma longibrachiatum

Abstract: Jamroz, D., Skorupinska, J., Orda, J., Wiliczkiewicz, A. and Klunter, A.-M. 2001. Use of wheat, barley or triticale in feed for laying hens supplemented with carbohydrases derived from Trichoderma longibrachiatum. J. Appl. Anim. Res., 19: 107–116. The objective of the present experiment was to determine the influence of different cereals (67% wheat, 66% barley or 70% triticale) in feed for laying hens supplemented with and without carbohydrases derived from Trichoderma longibrachiatum on laying performance, egg quality, digestibility and utilization of nutrients. In average of the 386 days of egg production the laying performance was 92.2, 92.0 and 91.2% in the wheat, barley and triticale diet, respectively. Egg production and feed conversion were similar for the diets containing different types of cereals. The addition of the enzyme product to the wheat diet and the barley diet improved the laying performance significantly by 3.2 and 3.0%. With regard to the type of cereal used in the diets, no ...

Study on the Antaganistic Mechanism of Trichoderma sp.for Phytophthora Nicotianae and it's Biocontrol Effection

Abstract: One isolate of Trichoderma sp was obtained by the method of baiting The antagonistic test of the isolate to strains of Phtophthora nicotiana (pathogen of tobacco black shank) from diseased tobacco stems from different area of Yunnan were carried out by pairing culture on PDA The results showed that this isolate was strong antagonistic to black shank fungus The antagonistic mechanism appeared to be competitive growth and antibiosis The control effect of this isolate applied for tobacco black shank in greenhouse was as high as 976% (10~(6) cfu/mL) When applied in field soil around the tobacco root at 4 g every root, the control effect could arrive at 67%