A New Perspective on Sustainable Soil Remediation—Case Study Suggests Novel Fungal Genera Could Facilitate in situ Biodegradation of Hazardous Contaminants

Abstract

Deciding upon a cost effective and sustainable method to address soil pollution is a challenge for many remedial project managers. High pressure to quickly achieve cleanup goals pushes for energy-intensive remedies that rapidly address the contaminants of concern with established technologies, often leaving little room for research and development especially for slower treatment technologies, such as bioremediation, for the more heavily polluted sites. In the present case study, new genomic approaches have been leveraged to assess fungal biostimulation potential in soils polluted with particularly persistent hydrophobic contaminants. This new approach provides insights into the genetic functions available at a given site in a way never before possible. In particular, this article presents a case study where next generation sequencing (NGS) has been used to categorize fungi in soils from the Atlantic Wood Industries Superfund site in Portsmouth, Virginia. Data suggest that original attempts to harness fungi for bioremediation may have focused on fungal genera poorly suited to survive under heavily polluted site conditions, and that more targeted approaches relying on native indigenous fungi which are better equipped to survive under site specific conditions may be more appropriate.

Evaluating the mycostimulation potential of select carbon amendments for the degradation of a model PAH by an ascomycete strain enriched from a superfund site

“…The wood treatments did not stimulate anthracene removal significantly over the control (p>0.05). This result is consistent with the limitations observed in previous wood-based mycostimulation tests in polluted soils [50] and also explains the persistence of woodchips in contaminated media also piled on the site where samples were collected [19]. …”

“…Reactors were set up to test the influence of three amendments (cellulose, chitin, and wood substrates) supplied at two different concentrations (0.1% and 1% w/v) on the degradation of anthracene introduced at three concentrations (0.4 mg/L, 4mg/L, and 40 mg/L). Anthracene was selected as the model PAH as it tends to be ubiquitous at PAH contaminated sites and has been well studied previously [19, 24, 25]. Carbon amendments were selected to mimic the substrates used by fungi in natural ecosystems.…”

“…In previous work, we found that fungi belonging to the phylum Ascomycota were especially numerous at a heavily contaminated PAH Superfund site [19]. Thus, herein, we sought to identify an ascomycete resistant to high PAH concentrations and test various lineage-targeted mycostimulation treatment approaches.…”

Roles of saprotrophic fungi in biodegradation or transformation of organic and inorganic pollutants in co-contaminated sites

“…Isolation of indigenous fungi could provide the best candidate organisms for bioremediation of polluted soil since they already belong to an established soil microbial community and may be adapted to the site conditions (Czaplicki et al 2016). For example, Srivastava and Thakur (2006) Coprinus comatus on a soil affected by cadmium and an organic pollutant (endosulfan).…”

Metabolic synergies in the biotransformation of organic and metallic toxic compounds by a saprotrophic soil fungus

“…The potential of fungi to tolerate and transform both organic and inorganic pollutants has been highlighted in many studies which have also reported some unusual abilities shown by fungi isolated from contaminated soil (;Tigini et al 2009;Ma et al 2014;Mishra and Malik 2014). In fact, isolation of indigenous fungi could provide the best candidate organisms for bioremediation of polluted soil since they 3 already belong to an established soil microbial community, and are best adapted to the site conditions (Czaplicki et al 2016).…”