The MIC test was conducted in a sterile 96-well plate, with each well containing 100 μl of potato dextrose broth (PDB) (HIMEDIA-India). Every four wells made one replication, nine different concentrations of the crude extracts were tested (1:1 dilutions) ranging from 42 to 0.16 g L−1. Wells were then inoculated with one of the two tested microorganisms’ spore suspensions (A. alternata and C. gloeosporioides). The last three rows are control rows: no spores and no extract control wells, negative control with spores but no extract wells, and positive control with spores and 10 µl of the fungicidal Clatrimazole (1%) wells.
Fungal spore suspensions were adjusted to the range of 104 spores L−1 using a 10 day old fungal plate and sterile distilled water, the spore concentration was calculated using a heamatocytometer.
Fungal growth in each well was monitored using Resazurin (HIMEDIA-India) dye. Upon cells division, Resazurin changes its color from blue to pink and fluorescent27 (link). Results were taken within 48 h of incubation at 25 °C. MIC was recorded as the last extract concentration that shows no change in the color of Resazurin within the incubation period.
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