Temperature and pH conditions for mycelial growth of Agaricus brasiliensis on axenic cultivation Condições de temperatura e pH para o crescimento micelial de Agaricus brasiliensis em cultivo axênico

Few studies have been done to determine Agaricus brasiliensis Wasser et al. (A. blazei; A. subrufescens) basic mycelial growth characteristics on axenic cultivation. This study aimed to determine the optimal temperature and initial pH for mycelial growth of A. brasiliensis on malt extract agar medium to develop axenic cultivation techniques. Studied initial pH values for mycelial growth were adjusted to 3.0, 4.0, 5.0, 5.5, with HCl, 6.0, 7.0, 8.0, with NaOH, and again 7.0 and 8.0, with CaCO 3 . Studied temperatures for mycelial growth were 22 oC, 25 oC, 28 oC, 31 oC and 34 oC. It was concluded that A. brasiliensis can grow in axenic cultivation at temperature range from 22 o C to 34 oC, with optimal temperature range from 28 o C to 31 oC and optimal temperature value of 30.5 oC ± 0.3 oC. It also grows in initial pH range from 4.0 to 7.0, adjusted with HCl or NaOH but not CaCO 3 , with optimal initial pH range from 5.5 to 6.0 and optimal initial pH value of 5.56 ± 0.05. Mycelial growth is inhibited with pH of 3.0 or lower, 8.0 or higher, or when CaCO 3 is used to adjust pH in the substratum to 7.0 or higher.