Influence of PAHs on ligninolytic enzymes of the fungus Pleurotus ostreatus D1

2010 ◽  
Vol 5 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Natalia Pozdnyakova ◽  
Svetlana Nikiforova ◽  
Olga Turkovskaya

AbstractPolycyclic aromatic hydrocarbons (PAHs), their derivatives, and their degradation products were assayed for the ability to enhance activities of ligninolytic enzymes (laccase and versatile peroxidase) of the fungus Pleurotus ostreatus D1. The activities of both laccase and versatile peroxidase were induced by the PAHs, their derivatives, and their degradation products. Laccase was produced mostly in the first 7–10 days, whereas the production of versatile peroxidase began after 5–7 days of cultivation. Non-denaturing PAGE showed the presence of additional forms of laccase and versatile peroxidase in the presence of the xenobiotics in the cultivation medium. The difference in the production time for these enzymes may reflect that laccases are involved in the first stages of PAHs degradation and that versatile peroxidase can be necessary for oxidation of some degradation products. This is the first report on versatile peroxidase induction by PAHs and their derivatives.

2000 ◽  
Vol 66 (6) ◽  
pp. 2471-2478 ◽  
Author(s):  
Petr Baldrian ◽  
Carsten in der Wiesche ◽  
Jiří Gabriel ◽  
František Nerud ◽  
František Zadražil

ABSTRACT The white-rot fungus Pleurotus ostreatus was able to degrade the polycyclic aromatic hydrocarbons (PAHs) benzo[a]anthracene, chrysene, benzo[b]fluoranthene, 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 benzo[a]anthracene (41%), the fungus enhanced the disappearance of less-soluble polycyclic aromatic compounds containing five or six aromatic rings. Although the heavy metals in the soil affected the activity of ligninolytic enzymes produced by the fungus (laccase and Mn-dependent peroxidase), no decrease in PAH degradation was found in soil containing Cd or Hg at 10 to 100 ppm. In the presence of cadmium at 500 ppm in soil, degradation of PAHs by soil microflora was not affected whereas the contribution of fungus was negligible, 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.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1040 ◽  
Author(s):  
Edina Reizer ◽  
Imre Csizmadia ◽  
Árpád Palotás ◽  
Béla Viskolcz ◽  
Béla Fiser

The formation of polycyclic aromatic hydrocarbons (PAHs) is a strong global concern due to their harmful effects. To help the reduction of their emissions, a crucial understanding of their formation and a deep exploration of their growth mechanism is required. In the present work, the formation of benzo(a)pyrene was investigated computationally employing chrysene and benz(a)anthracene as starting materials. It was assumed a type of methyl addition/cyclization (MAC) was the valid growth mechanism in this case. Consequently, the reactions implied addition reactions, ring closures, hydrogen abstractions and intramolecular hydrogen shifts. These steps of the mechanism were computed to explore benzo(a)pyene formation. The corresponding energies of the chemical species were determined via hybrid density funcional theory (DFT), B3LYP/6-31+G(d,p) and M06-2X/6-311++G(d,p). Results showed that the two reaction routes had very similar trends energetically, the difference between the energy levels of the corresponding molecules was just 6.13 kJ/mol on average. The most stable structure was obtained in the benzo(a)anthracene pathway.


2018 ◽  
Vol 122 (5) ◽  
pp. 363-372 ◽  
Author(s):  
Natalia Pozdnyakova ◽  
Ekaterina Dubrovskaya ◽  
Marina Chernyshova ◽  
Oleg Makarov ◽  
Sergey Golubev ◽  
...  

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