Influence of cadmium and mercury on activities of ligninolytic enzymes anddegradation of polycyclic aromatic hydrocarbons by Pleurotus ostreatus in soil
P. Baldrian et al., Influence of cadmium and mercury on activities of ligninolytic enzymes anddegradation of polycyclic aromatic hydrocarbons by Pleurotus ostreatus in soil, APPL ENVIR, 66(6), 2000, pp. 2471-2478
The white-rot fungus Pleurotus ostreatus was able to degrade the polycyclic
aromatic hydrocarbons (PAHs) benzo[a]anthracene, chrysene, benzo [k] fluor
anthene, benzo [k] fluoranthene, benzo [a] pyrene, dibenzo [a,h] anthracene
, and benzo[ghi]perylene in nonsterile soil both in the presence and in the
absence of cadmium and mercury. During 15 weeks of incubation, recovery of
individual compounds was 16 to 69% in soil without additional metal. While
soil microflora contributed mostly to degradation of pyrene (82%) and benz
o[a]anthracene (41%), the fungus enhanced the disappearance of less-soluble
polycyclic aromatic compounds containing five or six aromatic rings. Altho
ugh the heavy metals in the soil affected the activity of ligninolytic enzy
mes produced by the fungus (laccase and Mn-dependent peroxidase), no decrea
se in PAH degradation was found in soil containing Cd or Hg at 10 to 100 pp
m. In the presence of cadmium at 500 ppm in soil, degradation of PAHs by so
il microflora was not affected whereas the contribution of fungus was negli
gible, probably due to the absence of Mn-dependent peroxidase activity. In
the presence of Hg at 50 to 100 ppm or Cd at 100 to 500 ppm, the extent of
soil colonization by the fungus was limited.