Analysis of Effect on Harmful Microorganism Death Rate According to Ultraviolet Irradiation and Sterilization Condition of Substrate for Cultivation of Oyster Mushroom

Mycelial growth of oyster mushroom is very important. Careless management of mycelial growth can cause contamination and low yield of the mushroom. To reduce contamination, it is necessary to maintain clean cooling rooms, inoculation rooms, and cultivation rooms. We first investigate the death rate of microorganisms from ultraviolet (UV) irradiation in the cooling and inoculation rooms and the contamination rate according to the sterilization condition of substrate. Though contamination rates based on sterilization conditions did not show large differences, the amount of electricity used was the lowest at 121°C for 90 min. As a result, UV irradiation time killed the microorganisms and bacteria was not detected after UV irradiation for 6 hours using 40-W UV lamps in a 56-m³ room. The death rate of fungi is not substantial in the same UV irradiation conditions.