Wheat straw amendment to an oily sludge pretreated with ammonium persulfate and its impact on the indigenous mycobiota

Abstract

Numerous studies have addressed the dynamics of bacterial communities in responseto remediation strategies, while fungal communities, despite their potential as bioremediationagents, remain comparatively understudied. The aim of this work was to evaluate the impactof wheat straw amendment (WSA) on an oily sludge untreated and treated with ammoniumpersulfate on indigenous mycobiota after 60 days. Culture-independent 18S rRNA ampliconsequencing, microbial enzymatic activity and chemical parameters were analyzed. WSA on apreoxidized oily sludge promoted high total petroleum hydrocarbon (TPH) removal after 60days, exhibiting the highest laccase activity. Fungal diversity and equitability were also recovereduntil reaching similar index values to those of the untreated microcosms. However, changesin fungal taxonomical groups were detected, with Eurotiales (93.4%) being replaced by Microascales(57.9%) and Sordariales (32.8%) at the end of the treatment. Our results suggest that inputsof easily assimilable organic matter in oily sludge might accelerate changes and replacement offungal taxa, also affecting microbial colonization and, consequently, pollutant removal. Thesefindings highlight the relevance of incorporating fungal dynamics into bioremediation strategiesas a complementary approach to oily sludge treatment.