Effect of Benomyl on Chitinase and β-1,3-Glucanase Production by Free and Alginate Encapsulated Trichoderma harzianum

On PDA-benomyl plates growth of Trichoderma harzianum was inhibited by 20 and 30 % at benomyl 1 and 2 μg/mL, respectively, and was completely inhibited at 5 μg/mL. In minimal synthetic medium (MSM) amended with different concentrations of benomyl (1.0, 3.0, 5.0, 7.0 and 10.0 μg/mL), fungal immobilisation improved chitinase and β-1,3-glucanase production at low benomyl concentrations (1, 3 and 5 μg/mL). Further increase in the production of both enzymes was obtained by immobilisation at higher benomyl concentrations (7 and 10 μg/mL). Fungal immobilisation increased bound chitinase by 15- to 30-fold at 3 and 5 μg/mL benomyl concentration, respectively. However, no effect was obtained on the bound β-1,3-glucanase. Different benomyl concentrations (0.3 to 1500 μg/mL) had no significant inhibitory effect on the activities of free or immobilised chitinase and β-1,3-glucanase. It could be suggested that either immobilised Trichoderma or immobilised chitinase and β-1,3-glucanase could be used in combination with benomyl to control plant pathogens

Improvement of Cell Wall Degrading Enzymes Production by Alginate Encapsulated Trichoderma spp.

Conidia of three Trichoderma isolates were formulated to make alginate pellets with or without 0.5 % chitin or dried fungal mycelium of Fusarium oxysporum as carbon source. The formulations were compared for their ability of in vitro chitinase and β-1,3-glucanase production with free fungal spore suspensions. Conidia entrapped in alginate with or without adjuvant showed high production of enzymes (especially for chitinase) even when repeated 4 times. The addition of chitin or dried fungal mycelium as adjuvant enhanced the enzyme production up to 5 and 2-fold for chitinase and β-1,3-glucanase, respectively. Alginate concentration and surface area of the beads affected the enzyme production. The optimum initial pH, incubation time and temperature were pH=6, 12 days and 40 °C for chitinase, and pH=7, 10 days and 35 °C for β-1,3-glucanase production. The improvement of cell wall degrading enzyme production by alginate encapsulated Trichoderma could explain the in vivo inhibitory effect of such formulations on the target phytopathogenic fungi

Evaluation of indigenous Trichoderma isolates from Manipur as biocontrol agent against Pythium aphanidermatum on common beans

Pythium aphanidermatum is one of the common causal pathogen of damping-off disease of beans (Phaseolus vulgaris L.) grown in Manipur. A total of 110 indigenous Trichoderma isolates obtained from North east India were screened for their biocontrol activity which can inhibit the mycelial growth of P. aphanidermatum, the causal organism of damping-off in beans. Out of the total isolates, 32% of them showed strong antagonistic activity against P. aphanidermatum under in vitro condition and subsequently 20 best isolates were selected based on their mycelial inhibition capacity against P. aphanidermatum for further analysis. Different biocontrol mechanisms such as protease, chitinase, β-1,3-glucanase activity, cellulase and production of volatile and non-volatile compounds were also assayed. Based on their relative biocontrol potency, only three indigenous Trichoderma isolates (T73, T80 and T105) were selected for pot culture experiment against damping-off diseases in common beans. In greenhouse experiment, Trichoderma isolates T-105 significantly reduced the pre- and post-emergence damping-off disease incidence under artificial infection with P. aphanidermatum and showed highest disease control percentage

Sludy of the Dermatophytes in the Students Houses of Minia University, Egypt

A survey of dermatophytes and other fungi was carried out in 100 air - dust samples from bedrooms and dinning halls of male and female student resident houses. By hair baiting technique the common dermatophytes were obtained namely Microsporum canis, M. gypseum and Trichophyton mtntagrophytes. Also five species of Chrysasporium were isolated in the following order of dominance C. tropicum, C. keratinophilum, C. indicum, C. pannicola and C. quecnslandicum. By dilution plate method, 37 species representing 20 genera of which Aspergilus niger, A. flavus, Rhizopus nigricans, Penicillium chrysogenum and Cladosporium cladosporioides were most frequently isolated

The anti-infective potential of the endophytic fungi associated with Allium cepa supported by metabolomics analysis and docking studies

Endophytic fungi are known to be a rich source of anti-infective drugs. In our study, Allium cepa was investigated for fungal diversity using different media to give 11 isolates which were identified morphologically. Out of the isolated fungal strains, Penicillium sp. (LCEF10) revealed potential anti-infective activity against the tested microbes (Fusarium solaniATTC 25922, Pseudomonas aeruginosa(ATTC 29231), Staphylococcus aureusATTC 27853, Candida albicansATTC 10231), besides, their MICs were measured by well diffusion method, therefore, it was subjected to molecular identification in addition to phylogenetic analysis. Moreover, the ITS sequence of strain LCEF10 showed a consistent assignment with the highest sequence similarity (99.81%) to Penicillium oxalicum NRRL 787. The crude ethyl acetate extract of Penicillium sp. LCEF10 was investigated for metabolomic analysis using LC-HR-ESI-MS. The metabolic profiling revealed the presence of polyketides, macrolides, phenolics and terpenoids. Furthermore, in silico molecular docking study was carried out to predict which compounds most likely responsible for the anti-infective activity