Showing papers on "Trichoderma longibrachiatum published in 1992"
TL;DR: As a first step to exploit the potential of Trichoderma reesei to produce hemicellulases, two endo-β-1,4-xylanases are purified and cloned and the enzyme encoded by xyn2 appears to more closely resemble several other bacterial and fungal xylanases than does that of xyn1.
Abstract: As a first step to exploit the potential of Trichoderma reesei to produce hemicellulases, we have purified two endo-β-1,4-xylanases (1,4-β-D-xylan xylanohydrolase, EC 3.2.1.8) and cloned their genes. The enzymes were isolated from culture filtrates of T. reesei C 30 grown on xylan as a carbon source, using two steps of cation exchange chromatography. They exhibited molecular weights of 19 (XYN I) and 21 (XYN II) kD, and isoelectric points of 5.2 and 9.0, respectively. These enzymes differed in their pH optimum for activity and affinity for xylan, and accounted for more than 90% of the total xylanolytic activity of the fungus. The purified enzymes were subjected to N-terminal sequence analysis, and after cleavage with trypsin and endoproteinase Glu-C the resulting peptides were sequenced. Oligonucleotides based on these sequences were used to clone gene fragments via PCR, and these were used as probes to isolate full-length copies of xyn1 and xyn2 from a lambda gene bank of T. reesei. The products of xyn1 and xyn2 share considerable homology, but the enzyme encoded by xyn2 appears to more closely resemble several other bacterial and fungal xylanases than does that of xyn1.
222 citations
TL;DR: Trichogin A IV (GA IV) is the main component of the natural trichog in mixture, a new peptide group extracted from in vitro cultures of the fungus Trichoderma longibrachiatum, and its amino acid sequence was elucidated by FAB mass spectrometry and high-field NMR.
Abstract: Trichogin A IV (GA IV) is the main component of the natural trichogin mixture, a new peptide group extracted from in vitro cultures of the fungus Trichoderma longibrachiatum. GA IV was isolated by reversed-phase HPLC, and its amino acid sequence was elucidated by FAB mass spectrometry and high-field NMR. Complete 1 H and 13 C resonance assignments were carried out using HOHAHA, ROESY, 1 H- 13 C COSY, and COLOC two-dimensional spectroscopies
176 citations
TL;DR: It is suggested that the growth inhibition of Trichoderma by hydrolytic enzymes is the consequence of a thinning of the cell wall in the hyphal apex, leading to an imbalance of turgor pressure and wall tension which causes the tip to swell and to burst.
Abstract: Plant chitinases and β-1,3-glucanases have been demonstrated to inhibit fungal growth in model experiments, both on agar plates or in liquid media. Here,Trichoderma longibrachiatum was taken as a model to study the morphological changes caused by chitinase and glucanase treatments, using cytochemical techniques in combination with fluorescence and electron microscopy. Chitinase, alone or in the presence of glucanase, arrested growth of the hypha: it affected the extreme tip of the fungus producing a thinning of the wall, a balloon-like swelling and a rupture of the plasma membrane. Chitin and glucans were present in the wall, as shown by lectinand enzyme-binding experiments, but they had a different susceptibility to chitinase and β-1,3-glucanase. Chitin was present at the apex and in the inner parts of the lateral walls; it was more susceptible to chitinase at the tip than in the subapical part. Glucans mostly occurred on the outer layer where they were degraded by glucanase. The latter did not affect the inner hyphal skeleton. It is suggested that the growth inhibition ofTrichoderma by hydrolytic enzymes is the consequence of a thinning of the cell wall in the hyphal apex, leading to an imbalance of turgor pressure and wall tension which causes the tip to swell and to burst.
109 citations
TL;DR: An electrophoretic karyotype of Trichoderma longibrachiatum (reesei) was obtained using contourclamped homogeneous electric field (CHEF) gel electrophoresis and three hyper-cellulolytic mutant strains, which showed striking differences in their karyotypes compared to the initial parent.
Abstract: An electrophoretic karyotype of Trichoderma longibrachiatum (reesei) was obtained using contourclamped homogeneous electric field (CHEF) gel electrophoresis. Seven chromosomal DNA bands were separated in the wild-type T. longibrachiatum strain QM6a. The sizes of the chromosomal DNA bands ranged from 2.8 to 6.9 Mb, giving an estimated total genome size of about 33 Mb. The electrophoretic karyotype of the strain QM6a was compared to three hyper-cellulolytic mutant strains, QM9414, RutC30 and VTT-D-79125. The chromosome pattern of the mutant QM9414 was quite similar to that of the wild-type QM6a except that the smallest chromosome differed somewhat in size. The VTT-D-79125 and RutC30 strains, which have undergone several mutagenesis steps, showed striking differences in their karyotype compared to the initial parent. The chromosomal DNA bands were identified using the previously characterized T. longibrachiatum genes (egl1, egl2, cbh1, cbh2, pgk1, rDNA) and random clones isolated from a genomic library. In all strains the cellulase genes cbh1, cbh2 and egl2 were located in the same linkage group (chromosome II in the wild-type), while the main endoglucanase, egl1, hybridized to another chromosomal DNA band (chromosome VI in the wild-type).
73 citations
TL;DR: In this article, a low molecular weight fraction of lignin was recovered by adsorption on poly(vinylpyrrolidone, and the C=O signals of this fraction were strongly increased by the ligninolytic species, whereas the accumulation of aromatic compounds was observed after straw degradation by P. chrysosporium.
Abstract: After solid-state fermentation of wheat straw with five lignocellulose-degrading fungi, lignin was extracted and studied by CPMAS 13C NMR. The increase in the intensity of the signals in the 200-164 ppm range is evidence for the oxidative alteration of lignin. The lignins degraded by the white-rot fungi Ganoderma australe and Phanerochaete chrysosporium showed a decrease in the amounts of aryl carbons, whereas the intensity of the 33 ppm signal from saturated alkyl structures was strongly increased by the latter fungus. The cellulolytic Chaetomium virescens and Trichoderma longibrachiatum and the ligninolytic Fomes fomentarius caused the selective decrease of some signals assigned to lignin-carbohydrate complexes. A low molecular weight fraction was recovered by adsorption on poly(vinylpyrrolidone). The C=O signals of this fraction were strongly increased by the ligninolytic species, whereas the accumulation of aromatic compounds was observed after straw degradation by P. chrysosporium.
54 citations
TL;DR: The most suitable conditions for protoplasting were as follows: age of the organism in slant, 3 days; mycelium age, 20 h; volume of lytic enzymes, 190 ml;Mycelial weight (dry equivalent), 1.66 g; time of contact with lytic enzyme, 2 h; temperature of protoplasts, 30°C; phosphate buffer, 25 m m , pH 6.5; KCl as osmotic stabilizer, 0.7 m
43 citations
TL;DR: A cDNA fragment obtained by the rapid amplification of cDNA ends method, which takes advantage of the polymerase chain reaction, has been expressed in yeast under control of the cyc-gal inducible promoter and yeast clones able to secrete active enzyme have been obtained.
Abstract: A gene (egl1) encoding an endoglucanase (EGL1) from Trichoderma longibrachiatum has been cloned and sequenced. This gene, homologous to the T. reesei egl1 gene, differs from it in the length of the introns (particularly the first one) and encoded protein. A cDNA fragment obtained by the rapid amplification of cDNA ends method, which takes advantage of the polymerase chain reaction, has been expressed in yeast under control of the cyc-gal inducible promoter and yeast clones able to secrete active enzyme have been obtained.
39 citations
TL;DR: In this article, the trichogin A IV (GA IV) peptide group extracted from in vitro cultures of the fungus Trichoderma longibrachiatum was isolated by reversed-phase HPLC and its amino acid sequence was elucidated by FAB mass spectrometry and high-field NMR.
Abstract: Trichogin A IV (GA IV) is the main component of the natural trichogin mixture, a new peptide group extracted from in vitro cultures of the fungus Trichoderma longibrachiatum. GA IV was isolated by reversed-phase HPLC, and its amino acid sequence was elucidated by FAB mass spectrometry and high-field NMR. Complete 1 H and 13 C resonance assignments were carried out using HOHAHA, ROESY, 1 H- 13 C COSY, and COLOC two-dimensional spectroscopies
26 citations
TL;DR: Six organic amendments and one soil sterilant were screened at different rates to a given amount of soil, for their efficiency to enhance the population of Trichoderma spp.
Abstract: Six organic amendments and one soil sterilant (Basamid) were screened at different rates to a given amount of soil, for their efficiency to enhance the population of Trichoderma spp. Coffee pulp significantly (P = 0.01) enhanced the population of Trichoderma spp. in the soil compared to other amendments. The enhancement was rate‐dependent with 16 and 22 g carbon giving the optimum population. The Trichoderma species enhanced included T. koningii, T. harzianum and T. longibrachiatum. The implications of these results in relation to biological control of soil‐borne plant pathogens are discussed.
11 citations
TL;DR: Purified xylanase A of Trichoderma longibrachiatum was active on one of two carboxymethyl cellulose (CMC) preparations used as cellulase assay substrates, suggesting that the enzyme had acted on xylan present in the CMC.
Abstract: Purified xylanase A ofTrichoderma longibrachiatum was active on one of two carboxymethyl cellulose (CMC) preparations used as cellulase assay substrates. The pattern of enzyme activity, and analysis of the substrate by acid hydrolysis and thin-layer chromatography (TLC) suggested that the enzyme had acted on xylan present in the CMC.
8 citations