Showing papers on "Trichoderma longibrachiatum published in 1993"

Efficient production of antibody fragments by the filamentous fungus Trichoderma reesei

Abstract: We have engineered the filamentous fungus Trichoderma reesei to assemble and secrete immunologically authentic engineered Fab antibody fragments into the culture medium. A major improvement in yield was achieved by fusing the heavy Fd chain to the T. reesei cellulase, CBHI. The yields of secreted, immunologically active Fab and CBHI-Fab fusion were 1 mg/1 and 150 mg/1, respectively. The Fab fragment can be released from the fusion protein CBHI-Fab by an extracellular T. reesei protease. There was no detectable difference in affinity for the antigen between the engineered Fab and the idiotypic antibody.

DNA sequence encoding endoglucanase III cellulase

Abstract: The present invention is directed to purified EG III cellulase enzyme isolated from Trichoderma longibrachiatum and the amino acid sequence of the secreted (mature) and non-secreted (preprotein) forms. The present invention is further directed to the DNA fragment and sequence that encodes the EG III cellulase enzyme. Also disclosed are methods for isolating either purified or highly enriched EG III cellulase obtained from Trichoderma spp. or genetically modified strains of Trichoderma spp.

Efficacy of Gliocladium virens and Trichoderma longibrachiatum as biological control agents of groundnut root and stem rot diseases

Abstract: The biocontrol potential of Gliocladium virens (G1 and G2) and Trichodenma longibrachiatum (T1 and T2) against groundnut root and stem rot diseases, their survival patterns and effects on the pathogen survivability have been investigated. Isolates G1 and T1, delivered as a wheat bran‐sawdust (WBSD) preparation gave significant protection (65–74%) against root rot incited by Rhizoctonia solani. A linear correlation was obtained between the dosage (g/kg soil) of antagonists and their disease control efficacy. Seed coating with spore suspension (1 × 109spores/ml) also considerably reduced the root rot incidence but to a lesser degree than the WBSD preparation. On the other hand, only moderate protection (21–36%) against stem rot caused by Sclerotium rolfsii was recorded with either of the antagonists. The antagonists applied to soil, despite a sharp decrease by the 7th day, gradually increased in their population density over a period of time. G1 exerted a 65% reduction in R. solani viability follow...

Improved technique on reversion of mycelial protoplast of Trichoderma reesei into mycelia

Abstract: Important parameters in the regeneration of protoplasts are viability, the capacity to synthesize cell walls and the retention of properties of the parent cell. Mycelial protoplasts of Trichoderma longibrachiatum (Trichoderma reesei) have been regenerated. Factors influencing the regeneration of protoplasts of T. longibrachiatum QM 9414 were found to be, the nature of osmotic stabilizer, the concentration of osmotic stabilizer, pH, temperature, and the composition of regeneration medium. With glucose-mineral regeneration medium, the optimum conditions for protoplasts regeneration were 0.5 M KCl, pH 6.0 and temperature 30°C. With Czapek-Dox medium, the optimum conditions were 0.7 M mannitol, pH 6.0 and temperature 30°C. Maximum regeneration frequency of T. longibrachiatum protoplasts were obtained using glucose-mineral medium.

Nucleotide sequence of a Trichoderma longibrachiatum DNA fragment encoding the 5.8S rRNA gene

Abstract: Trichoderma longibrachiatum IMI061758 possesses a powerful cellulose enzyme complex composed by different cellobiohydrolase, endoglucanase and /3-glucosidase activities. Recently we have cloned the T. longibrachiatum egll gene encoding a /S-{l,4)-endoglucanase activity (1). From an industrial point of view, we are interested in the design of strains which have an increased egll gene dosage. To construct these strains, we have developed an integrative transformation system for T. longibrachiatum (2), but the transformants are mitotically unstable. To solve this problem, one of the strategies could be the development of new vectors in which a repetitive sequence of the fungal genome has been included which favours the stability of the transformants. In this report we present the cloning and sequencing of a T. longibrachiatum DNA fragment encoding part of the ribosomal repeat unit. Due to the taxonomical difficulties related to the Trichoderma group (3), this sequence could be also of interest for the classification of this fungal species. Amplification of the 5.8S rRNA gene and the noncoding adjacent regions was accomplished by PCR using the ITS1 and ITS4 primers described in (4). The amplicon was cloned in both orientations into the pCRTM1000 vector (Invitrogen, San Diego CA), and the resulting plasmids were used to construct a restriction map of the insert. Series of nested deletions were obtained by the exonuclease HI-SI nuclease digestion method, and selected deletion mutants or directed subcloned fragments were used as templates for sequencing. The nucleotide sequence (Figure 1) was determined in both strands using the dideoxynucleotide chain termination method. All the restriction sites used for subcloning were sequenced through. The 5.8S rRNA encoding gene (nt 234 to 379) was located by its highly similarity with other filamentous fungal 5.8S rRNA genes. It shows minor changes with respect to the Acremonium chrysogenum, Fusarium sambucinum or Neurospora crassa genes (8, 4 and 5 nt changes respectively). With respect to the noncoding regions, only minor stretches of identity could be detected, particularly in the case of the F.sambucinum sequences. ACKNOWLEDGEMENTS