Mycoremediation of Benzo[a]pyrene by Pleurotus ostreatus in the presence of heavy metals and mediators

Abstract

Benzo[a]pyrene is considered as a priority pollutant because of its carcinogenic, teratogenic and mutagenic effects. The highly recalcitrant nature of Benzo[a]pyrene poses a major problem for its degradation. White-rot fungi such as Pleurotus ostreatus can degrade Benzo[a]pyrene by enzymes like laccase and manganese peroxidase. The present investigation was carried out to determine the extent of Benzo[a]pyrene degradation by the PO-3, a native isolate of P. ostreatus, in the presence of heavy metals and ligninolytic enzyme mediators. Modified mineral salt medium was supplemented with 5 mM concentration of different heavy metal salts and ethylenediaminetetraacetic acid. Vanillin and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (1 and 5 mM) were used to study the effect of mediators. Results indicated that P. ostreatus PO-3 degraded 71.2 % of Benzo[a]pyrene in the presence of copper ions. Moderate degradation was observed in the presence of zinc and manganese. Both biomass formation and degradation were severely affected in the presence of all other heavy metal salts used in the study. Copper at 15 mM concentration supported the best degradation (74.2 %), beyond which the degradation progressively reduced. Among the mediators, 1 mM 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) supported 78.7 % degradation and 83.6 % degradation was observed under the influence of 5 mM vanillin. Thus, metal ion like copper is essential for better biodegradation of Benzo[a]pyrene. Compared to synthetic laccase mediator like 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate), natural mediator such as vanillin may play a significant role in the degradation of aromatic compounds by white-rot fungi.

Combined remediation of Cd–phenanthrene co-contaminated soil by Pleurotus cornucopiae and Bacillus thuringiensis FQ1 and the antioxidant responses in Pleurotus cornucopiae

“…Besides, mushrooms are also found to have the ability to biodegrade PAHs both in the absence (Lau et al, 2003;Lettera et al, 2010;Li et al, 2010) and in the presence of heavy metals (Atagana, 2009;Baldrian et al, 2000;Bhattacharya et al, 2013), as mushrooms could secrete extracellular enzymes, such as laccase, lignin peroxidase and manganese dependent peroxidase, a series of enzymes with the capacity to degrade and transform PAHs (Burns et al, 2013;Rao et al, 2014). That is to say, mushrooms might have a great potential to remediate the HM-PAHs co-contaminated soils.…”

Mushrooms in the Bio-Remediation of Wastes from Soil

“…Pleurotus ostreatus is able to degraded Benzo[a]pyrene but the presence of heavy metal cations and mediators such as vanillin and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) highly influence the degradation process. Bhattacharya et al, (2014), reported that 15 mM concentration of copper was found to best enhance the degradation (74.2%), progressively worsened as the Cu concentration increased. At the same time the extent of degradation was increased to 83.6 % when 5 mM of vanillin was included in the medium.…”

Enhanced Culture in Static Batch Systems for Benzo[a]pyrene Degradation by Bjerkandera Adusta SM46 under Acidic and Saline Conditions

“…Production enhancement of MnP by some white rot fungus with MnSO4 has also been reported in some studies. However, each reported WRF has a different concentration tolerance in the presence of mineral inducer [7][16]. The second method is by increasing the solubility of BaP in the water based-liquid medium.…”