Showing papers on "Trichoderma longibrachiatum published in 1999"

Molecular reidentification of human pathogenic Trichoderma isolates as Trichoderma longibrachiatum and Trichoderma citrinoviride

Abstract: Several species of the well-known saprophytic genus Trichoderma have been identified as the cause of infections in immunosuppressed humans. Because the differentiation and identification of Trichoderma species based on morphological characters only, is very difficult, two molecular approaches were applied for species identification. Six human pathogenic Trichoderma isolates were investigated by PCR-fingerprinting and analysis of ribosomal DNA internal transcribed spacer (ITS) sequences and compared with the corresponding data sets established for described species of the genus. Five of these strains were identified as T. longibrachiatum, whereas one single strain turned out to be T. citrinoviride. Both species are very closely related and belong to Trichoderma section Longibrachiatum. These data indicate that the occurrence of pathogenic Trichoderma strains may be restricted to species of section Longibrachiatum.

Fatal disseminated Trichoderma longibrachiatum infection in an adult bone marrow transplant patient: species identification and review of the literature.

Abstract: Trichoderma longibrachiatum was recovered from stool surveillance cultures and a perirectal ulcer biopsy specimen from a 29-year-old male who had received an allogeneic bone marrow transplant for acute lymphoblastic leukemia The amphotericin B (20 μg/ml) and itraconazole (10 μg/ml) MICs for the organism were elevated Therapy with these agents was unsuccessful, and the patient died on day 58 posttransplantation At autopsy, histologic sections from the lungs, liver, brain, and intestinal wall showed infiltration by branching septate hyphae Cultures were positive for Trichoderma longibrachiatum While Trichoderma species have been recognized to be pathogenic in profoundly immunosuppressed hosts with increasing frequency, this is the first report of probable acquisition through the gastrointestinal tract Salient features regarding the identification of molds in the Trichoderma longibrachiatum species aggregate are presented

Mycoparasitic action of some fungi on spot blotch pathogen (Drechslera sorokiniana) of wheat

Abstract: Inhibitory effect of Trichoderma reesei [Trichoderma longibrachiatum], T. pseudokoningii, T. hamatum, Talaromyces flavus, Chaetomium globosum and Trichothecium roseum on mycelial growth of Drechslera sorokiniana [Cochliobolus sativus] was observed.Culture filtrates of these fungi inhibited conidial germination up to 92%. Soil application of antagonists enhanced the germination of Cochliobolus sativus inoculated wheat seeds and reduced browning on collar region of the seedlings caused by the pathogen. Foliar application of the culture filtrate of the antagonists reduced number of spot blotch lesions and protected green leaf area from drying due to infection. The antagonists mixed in soil showed beneficial effects on plant growth with enhanced rootand shoot weight over infected check. SEM micrographs showed lysis of host mycelium due to overgrowth and penetration through hyphal pegs and tight coiling produced by the antagonists.

Optimization of Solid-State Fermentation Parameters for the Production of Xylanase by Trichoderma longibrachiatum on Wheat Bran in a Forced Aeration System

Abstract: The effect of aeration on the production of xylanase by Trichoderma longibrachiatum on wheat bran in a solid-state fermentation (SSF) system has not been investigated. This study was conducted to investigate the interactive effects of aeration, initial moisture content of the substrate, and depth of the substrate on xylanase activity produced in a tray fermenter. The experiment was conducted as a split plot experiment with factorial treatments and three replications of each treatment combination. The whole plot treatment was aeration rate (0, 2.9, 5.7 L/min/kg bran). Initial moisture content (45, 55, 65% w.b.) and depth of substrate (1.0 and 2.5 cm) were investigated factorially. Trays of wheat bran were assayed after fermentation by Trichoderma longibrachiatum to determine the production of xylanase activity. Aeration rate had a significant nonlinear effect on enzyme activity with highest yields obtained at an aeration rate of 2.9 L/min/kg bran (738 U/g, averaged over all initial moisture contents and depth of substrates). Initial moisture content of the substrate also had a significant nonlinear effect on enzyme activity with the highest yields at 55% (556 U/g, averaged over all airflow rates and depths of substrate). Depth of substrate had no significant statistical effect on enzyme activity. The treatment combination of 2.9 L/min/kg airflow rate and 55% moisture content resulted in the highest yields (948 U/g, averaged over depth of substrate).