Effects of jasmonic acid and hydrogen peroxide on production of phenolic compounds in a melanin-deficient mutant of Phaeoporus obliquus
茉莉酸和双氧水对斜生褐孔菌一株黑色素缺失突变体产生酚类化合物的影响

Melanogenesis is a key secondary metabolic process in the fungus Phaeoporus obliquus grown in natural habitats and laboratory conditions, and an overproduction of melanins reduces accumulation of other phenolic compounds. In this study, a melanin-deficient mutant of P. obliquus grown in submerged cultures was investigated for the production phenolic compounds in the presence of jasmonic acid (JA) and H2O2. The maximum level of total phenolics (MTP) produced reached 317.45mg/L. These consisted of benzoate derivatives (BD) (45.3mg/L), flavonoid aglycones (FAG) (74.4mg/L), glycosylated flavonoids (GF) (160mg/L) and hispidin analogs (HA) (18.5mg/L). With JA addition, MTP production increased to 620.45mg/L, with this increase mainly due to higher production of BD and FAG which reached 230.26mg/L and 166.86mg/L respectively. On the other hand GF and HA production fell to 98.5mg/L and 7.1mg/L, respectively. Exposure of mycelium to H2O2 reduced MTP levels to 315.69mg/L. Thus, compared to those in the wild-type, the accumulation of phenolic compounds increased after melanogenesis deletion, and was enhanced further by JA addition. Though H2O2 enhanced phenylalanine lyase (PAL) activity, MTP levels fell probably from their consumption for H2O2 detoxification.