TECHNOLOGY FOCUS - BIOLOGY - Preferred Method: The step (a) involves (i) inoculating T.reesei, T.viride and Aspergillus fumigatus in separate flasks containing inorganic culture medium containing 1% ethanol extract of turmeric, culturing at 30 degrees C for 7 days and shaking continuously, (ii) repeating culturing step for 3 times, selecting the culture flask having highest content of diosgenin, separating mold spores from selected flasks, and (iii) culturing separated spores in medium containing 10-15% ethanol extracts of turmeric and finally storing in 50% ethanol extract of turmeric. The method involves sterilizing solid state fermentation device by passing sterile air into each tray through the perforations, where the sterile air is obtained by filtering outdoor air using 4 layers of 0.45 mu m membrane filter. The step (d) involves inoculating 106-107 spores/g T.reesei strain, fermenting at 30-35 degrees C for 1 day, inoculating 107-108 spores/g T.viride, fermenting at 30-35 degrees C for 1 day, then inoculating 107-108 spores/g A.fumigatus and fermenting at 30-35 degrees C for 5 days, where the fermentation is performed by maintaining 80-90% relative humidity and aerating 1-1.5 vvm sterile wind. Preferred Components: The inorganic culture medium (pH 6.6) comprises 0.3% sodium nitrate, 0.1% dipotassium phosphate, 0.001% ferrous sulfate, 0.05% potassium chloride, and 0.05% magnesium sulfate heptahydrate. The preservation medium (pH 6.6) comprises 50% ethanol extract of turmeric and components of above-mentioned inorganic culture medium. The activation medium (pH 6.6) comprises 5% ethanol extract of turmeric and components of above-mentioned inorganic culture medium. The fermentation medium (pH 5.5-6) is prepared by mixing 25-30% turmeric residue, 1-1.2% Tween 80 (RTM: Polysorbate 80), 2.5-3% peptone and 0.2-0.3% dipotassium phosphate, placing mixture in ultrasonic generator producing 25-50 kHz ultrasonic waves for 15 minutes, and sterilizing at 121 degrees C for 30 minutes.