Effects of cultural conditions on high temperature tolerance of Lentinula edodes mycelia.

The effects of several cultural conditions on high temperature tolerance of vegetative mycelia of five Lentinula edodes strains were investigated. Mycelium of longer culture age (70 days) was significantly shown high temperature tolerance compared to mycelium of shorter culture ages (14 and 30 days) for four strains, whereas SA142 that showed reverse. When the culture plates were pretreated at 30 and 33 degrees C for 48 h incubation before heat treatment (40 degrees C, 8 h), mycelia of L. edodes strains were shown high temperature tolerance. Effects of nutritional factors in BM (basic medium) for the high temperature tolerance of L. edodes strains were also investigated. While yeast extract (as nitrogen source) and starch (as carbon source) were added to BM media, as a result cultured vegetative mycelia of L. edodes strains were significantly shown high temperature tolerance against heat treatment (40 degrees C, 6 and 8 h). Further more, addition of bases (adenine + cytosine), vitamin (biotin) and organic acid (tartaric acid) to BM media, consequently vegetative mycelia of some L. edodes strains were also effective to increase high temperature tolerance.