Effects of temperature on growth, proteins, peroxidases, protease, RNA, RNase, and HCN production of ageing cultures of a low-temperature basidiomycete

Growth studies of a low-temperature hydrogen cyanide producing basidiomycete were carried out using a synthetic medium in solid, liquid static, and liquid shake cultures at various temperatures. At 1 °C growth was slower but more mycelium was produced in liquid static and liquid shake cultures than at 15 °C. Analyses of cell-free extracts by disc gel electrophoresis indicated that the patterns of protein and peroxidase isozyme bands varied markedly with age of culture and incubation temperature. The number of electrophoretic protein bands representing mycelium incubated at 1 °C was greater than that for mycelium incubated at higher temperatures. The number of protein bands decreased with increasing age of cultures but the decrease was less for cultures incubated at 1 °C than at higher temperatures. Protease activity of cell-free extracts was higher at 1° than at 15 °C. A higher level of ribonucleic acid (RNA) was observed for mycelium incubated at 1° than at 15 °C. Relative to RNA, RNase activity did not follow the same pattern at 15° as at 1 °C. At 15 °C, in younger cultures, RNase activity increased with decreasing amounts of RNA, but at 1 °C, increase in RNase paralleled increases in RNA. HCN was released earlier in cultures incubated at 15° than at 1 °C but higher levels were maintained longer at 1 °C.