Role of different microorganisms in remediating PAH-contaminated soils treated with compost or fungi. (15th December 2019)

• Record Type: Journal Article
• Authors: Bellino, Alessandro; Baldantoni, Daniela; Picariello, Enrica; Morelli, Raffaella; Alfani, Anna; De Nicola, Flavia
• Is Part Of: Journal of environmental management. Volume 252(2019)
• Publication Date: 2019-12-15
• Subjects: Anthracene -- benzo[a]pyrene -- PLFA -- Biowaste compost -- Fungal consortium -- Random forest; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2019.109675
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Microbial degradation is the main responsible for polycyclic aromatic hydrocarbons (PAHs) removal from contaminated soils, and the understanding of this process is pivotal to define effective bioremediation approaches. To evaluate the contribution of several microbial groups in soil anthracene and benzo[a]pyrene degradation, the analysis of phospholipid fatty acid (PLFA) profiles and machine learning techniques were employed. To this end, PLFAs and PAH concentrations were analysed, along 274 days of incubation in mesocosms, in soils artificially contaminated with anthracene and benzo[a]pyrene, subjected to different treatments: untreated soil and soils treated with biowaste compost or fungal consortium. Random forest models, figuring anthracene or benzo[a]pyrene concentrations as dependent variables and PLFAs as predictors, were then built to evaluate the contribution of each variable in PAH degradation. PLFA profiles varied substantially among soil treatments and along time, with the increase of Actinomycetes in soils added with fungi and other Gram+ bacteria in compost amended soils. The former, together with fungi, are primarily responsible for anthracene and benzo[a]pyrene degradation in both treated soils, a process in which also metanotrophs and other Gram+ and Gram- bacteria participate. In untreated soil, the cooperation of a multitude of different microorganisms was, instead, responsible for PAH removal, a process with lower efficiency in respect to treated soils. Highlights: The role of PLFA-identified microbial groups in PAH degradation was clarified. Random forests accurately modeled the PAH-PLFA relationships. The same microbial groups degrade PAHs in soils added with fungi or biowaste compost. Fungi and Actinomycetes mainly degrade PAHs in soils added with fungi or compost. Several microbial groups, each with limited role, degrade PAHs in untreated soil.