The effects of improved aeration in saw dust bag cultivation on the Lentinula edodes hyphal growth were measured by CO2 concentration within the bags, the hyphal growth and bag weight loss. The aeration of the bags was controlled with 10 kinds of pore sizes of the lid and with pores on one side only or both side on the lid. In the conventional bags with a cotton plug CO2 concentration was 3.83%, the hyphal growth 2.25 ㎜/day and bag weight loss 0.84g, while in the bags with a lid 20.4㎜ diameter pore the CO2 concentration was 4.00%, the hyphal growth 2.68㎜/day and bag weight loss 1.3g. The bag with a lid pored on both top and bottom side was lower in CO2 concentration by 0.50%, higher hyphal growth rate by 0.04 ㎜/day and lower weight loss by 0.26g than the bag with a lid pored bottom side only. We concluded that the most effective lid for bag cultivation of L. edodes was the one with 20.4㎜ pores on both side of the lid.
The effect of sterilization and incubation temperatures of fermented oak sawdust on Lentinula edodes hyphal growth was investigated. The pile of 33 tonnes of oak sawdust fermented in a plastic shed for 24 days. During the fermentation the acidity of the sawdust within the pile was lowered to pH 4.2 and temperatures increased to 58℃ in over 20cm depth. The sawdust samples collected at 20, 60, 80 and 100㎝ depth each and moistened to 65% water content were sterilized at 65, 100 and 121℃ each for an hour. The sterilized sawdust contained in 50㎖ test tubes was inoculated with L. edodes hyphae cultured on potato dextrose agar medium and then was incubated at 15, 20, 25℃ for four weeks. L. edodes hyphae grew faster, 94.6mm, on the sawdust collected from 60cm depth than other depths, and did at 25 incubation temperature after sterilization at 121℃. The hypahe grew only 9.9cm on the sawdust from 100cm depth. When the sawdust from 60cm depth was sterilized at 100℃, the hyphae grew best by 22.1cm at 15℃. However, on the sawdust sterilized at 65℃ the hyphae did not grow at all. Thus, we conclude that sawdust fermentation under 60㎝ depth and autoclaving it can improve L. edodes hyphal growth, but the sterilization of sawdust at 65℃ is not sufficient for the hyphal growth.