铅胁迫对姬松茸菌丝生长和抗氧化系统的影响OA

The effects of lead stress to mycelia growth and antioxidant system of Agaricus blazei were studied by adding lead nitrate into the culture medium to Pb2+concentrations of 5,10,20,50,and 100 mg·L-1,respectively.Different Pb2+groups were determined for mycelial growth,lead content in mycelia and mycelial fermentation broth,contents of hydrogen peroxide(H2O2),malondialdehyde(MDA),ascorbic acid(ASA),reduced glutathione(GSH),and oxidized glutathione(GSSG)in mycelia,and activities of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),glutathione reductase(GR),glutathione peroxidase(GPX),and ascorbate peroxidase(APX)in mycelia.The results showed that lead stress inhibited mycelial growth.Both Pb2+content in mycelia and Pb2+concentration in the fermentation broth increased as the Pb2+concentration increased,peaking at(16.05±1.61)mg·kg-1 and(42.77±6.83)mg·L-1 under 100 mg·L-1 Pb2+,respectively.The contents of H2O2,MDA,and GSH,as well as the activities of SOD,CAT,POD,GR,and GPX in mycelia initially increased and then decreased.At 50 mg·L-1 Pb2+,the contents of H2O2 and MDA were relatively high,reaching(5.01±0.53)μmol·g-1 and(8.98±0.53)nmol·g-1,respectively.The GSH content and SOD activity under 50 mg·L-1 Pb2+reached the peak of(1 052.57±71.62)nmol·g-1 and(220.56±21.23)U·g-1,respectively.As the Pb2+concentration increased,both ASA content and APX activity continuously increased,reaching their highest levels at(4.70±0.08)μg·g-1 and(305.05±13.45)U·mg-1·min-1,respectively,when the Pb2+concentration was 100 mg·L-1.As the Pb2+concentration increased,mycelial GSSG content initially increased,followed with a decrease,and then increased again.It remained significantly higher than that of the control group,peaking at(104.19±8.02)nmol·g-1 under 20 mg·L-1 Pb2+.These results provided a reference for addressing Pb2+contamination in A.blazei cultivation.