Trichoderma harzianum

About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.

Purification and characterization of a beta-Glucanase produced by Trichoderma harzianum showing biocontrol potential

Abstract: A b-1,3-glucanase was produced by Trichoderma harzianum in cultures containing chitin as the sole substrate. Two proteins showing b-1,3-glucanase activity were purified to apparent homogeneity by hydrophobic chromatography. The molecular masses of these proteins were 29 and 36 kDa. The 36 kDa protein was further characterized. It was active on a broad pH range, and maximal activity was detected at pH 5.0. The optimum temperature of the 36 kDa b-1,3-glucanase was 50oC, but the purified enzyme was very sensitive to temperature. It lost about 60% or more of the activity after incubation for 30 min at 45, 50 and 60oC. The apparent KM and Vmax for hydrolysis of laminarin at pH 5.0 and 37oC, were 0.099 mg of reducing sugar/mL and 0.3 mg of reducing sugar/min.mL, respectively. The enzyme was insensitive to organic compound and metal ions, except for the ferric ion which inhibited about 100% of the original activity at the concentration of 1 mM. In contrast to other hydrolytic enzymes (a chitinase and a protease) produced by the same T. harzianum isolate (1051), the b-1,3-glucanase showed no effect on the cell wall of the phytopathogenic fungus Crinipellis perniciosa.

Evaluation of Trichoderma isolates as potential biological control agent against soybean charcoal rot disease caused by Macrophomina phaseolina

Abstract: Macrophomina phaseolina (Tassi) Goid remains the prevailing causal agent of charcoal rot disease that significantly suppresses the yield of a variety of oilseed crops. Its wide host range and ability to survive under arid conditions, coupled with the ineffective use of fungicides against it, have spurred scientific endeavours for alternative avenues to control this phytopathogen. Hence, the present study aimed to provide empirical evidence of the efficacy of three fungal isolates (T2, T10 and T12) of Trichoderma harzianum as biological control agents against charcoal rot in soybean (Glycine max L.). The results of the in vitro studies revealed that all three fungal isolates significantly inhibited the growth of M. phaseolina phytopathogen, with T12 showing considerably higher inhibition effect than T2 and T10 isolates. T12 inhibited the growth of M. phaseolina in the dual culture (72.31%) and volatile production (63.36%) assays, and the hyperparasitism test indicated cell lysis following the inter...

Complexity of Trichoderma-Fusarium interaction and manifestation of biological control

Abstract: Several Trichoderma isolates were screened for their biocontrol activity against Fusarium oxysporum f.sp. pisi. Eighteen of these isolates (T1 to T18) showed considerable biocontrol potential and were taken further in the study. Initial counter inhibition was observed in all the eighteen dual culture sets where Trichoderma and Fusarium both posed varying degree of inhibition on each other. In three of the sets, Fusarium was found extending narrow outgrowths towards Trichoderma. Trichoderma was later found extending its mycelia along these narrow outgrowths of Fusarium representing a chemo-attractive mechanism of interaction. Finally, parasitic interaction was noticed in all the sets except two. In these two sets, Trichoderma was unable to overcome inhibition posed by Fusarium and, therefore, could not parasitize Fusarium. In the interaction between Trichoderma and Fusarium, the sequence of events noticed was categorized as pre-contact antagonistic interaction, chemo-attractive intermediate phase and, finally, parasitic interaction. Most of the Trichoderma isolates showed considerably good antibiosis and parasitism. Therefore, the primary criterion for selection of the best potential biocontrol agent was poised on the time taken by Trichoderma to complete the sequence of events until parasitism of target pathogen. Among the eighteen isolates of Trichoderma, T. atroviride (Isolate T1) was found to show best activity followed by two isolates of Trichoderma harzianum (Isolate T8 and T11) in terms of time taken to parasitize Fusarium. The present study stresses on quick control on plant disease as a desired quality for popularization of biocontrol agents.