Pleurotus ostreatus based bioremediation of polycyclic aromatic hydrocarbon (PAH) anthracene / Adibah Nur Zainol Abidin

Bioremediation technique has been an active field of research for the past three decades.However, the rise of PAH contamination level in the environment demands for new andmore efficient bioremediation technique The study aims to explore biostimulationefforts on bioremediation of anthracene by fungi. The objective of this study are toscreen potential fungus for bioremediation of anthracene, to determine bioremediationparamaters for fungal bioremediation including addition of biodegradable adsorbentagar and addition of surfactant Tween 80, as well as to elucidate bioremediationpathway prediction through anthracene degrading enzymes of manganese peroxidaseand laccase in selected fungus. Methodologies included the screening of fungi towardsanthracene, optimization bioremediation parameters based on anthracene concentrationand initial pH of medium and optimization of biostimulation study by addition ofbiodegradable adsorbent agar as well as addition of surfactant Tween 80 for anthracenebioremediation. At the same time, growth of fungus and enzyme assays of manganeseperoxidase (MnP) and laccase were monitored in all conditions. The resultdemonstrated that Pleurotus ostreatus was selected due to non-pathogenic character andgrowth performance that indicated potential in using anthracene as a carbon source. Theconcentration of 1 mgL-1 of anthracene in pH 7 condition was selected to proceed withbiostimulation studies. Biostimulation with addition of two biodegradable adsorbentagar delayed bioremediation but enhanced final bioremediation performance, improvedgrowth and increased MnP and laccase enzyme activity. In addition, biostimulation by0.1% surfactant Tween 80 yielded similar outcome but boosted growth and enzymeactivities the most. Overall, the results also revealed the sequence of activities preferredby fungus in a general bioremediation situation and in biostimulated conditions. Thepresence of enzymes laccase and MnP elucidated the degradation mechanisms andpathway prediction of anthracene. 9,10-anthraquinone was a major metabolite producedupon oxidative action by laccase and MnP. Subsequent and continuous fungalmetabolisms provided insights on the involvement of MnP and laccase in anthracenebioremediation and the transformation of anthracene to carbon dioxide. Ultimately, thissustainable bioremediation technology adopted green chemistry where generation ofhazardous substances are eliminated.