Inoculum Disc

A seven day old culture of the test fungus is used for the preparation of a 6 mm diameter inoculum disc. 

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Fig. 7.4. Differential effect of nutrient supply on biomass and cord development in Serpula lacrymans. The fungus was inoculated centrally on uniform defined agar media in a factorial experiment with 5,10, 20, 40 and 80g/l sucrose and 1.5, 3, 6 and 12.5 g/1 sodium aspartate. Biomass was measured as oven dry weight at 8 weeks, cords were counted crossing a circular transect 3 cm from the inoculum disc. Left to right C/N ratio of each of the twenty combinations of carbon and nitrogen concentration biomass cord development. (Adapted from Watkinson, 1975).

The antibacterial activity of the compounds is determined by the disc diffusion method [42]. The bacteria are cultured in nutrient agar medium and used as inoculum for the study. Bacterial cells are swabbed onto nutrient agar medium (prepared from NaCl (5.0 g), peptone (5g), beef extract powder (3g), yeast extract powder (3g), and agar (20 g) in 1000 ml distilled H2O) pH 7.5 0.2 in Petri dishes. The test solutions are prepared in distilled water to a final concentration of 1 %, 2%, and 4% and then appHed to filter paper discs (Whatman No. 4, 5 mm diameter). These discs are placed on the already seeded plates and incubated at 35 2 °C for 24 h. The zones of inhibition around the discs are measured after 24 h. Co-trimoxazole is used as a standard positive control (Table 6.9). 

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