Bioprocess conditions for treating mineral transformer oils contaminated with polychlorinated biphenyls (PCBs)

SADAÑOSKI, MARCELA ALEJANDRA; BENITEZ, SILVANA FLORENCIA; VELÁZQUEZ, JUAN ERNESTO; FONSECA, MARÍA ISABEL; ZAPATA, PEDRO DARÍO; LEVIN, LAURA NOEMÍ; VILLALBA, LAURA LIDIA

Journal of Environmental Chemical Engineering

Elsevier BV

Año: 2020 vol. 8

2213-3437

This work was aimed at developing a bioprocess for the mycoremediation of polychlorinated biphenyls (PCBs)and generating a matching early stage mass and energy balance approach to be applied in a large-scale process.Irpex lacteus BAFC 1171 and Trametes sanguinea LBM 023 capacity for PCBs biodegradation was tested under twodifferent nutritional conditions, with 217 mg L−1 of a technical mixture of Aroclor 1242, 1254 and 1260 in oiltransformer. Mass and energy balances were calculated based on a generic model developed for early stages ofmicrobial bioprocesses estimation, employing a low-cost culture medium. Both strains not only demonstratedability to growth, but also degraded about 68% of the PCBs mixture in an N-limited liquid medium after 35 daysof incubation at 29 ± 1 °C under static conditions. PCBs addition at 217 mg L-1 modified fungal morphology,biomass, glucose consumption, proteins and laccase secretion. A 3-fold increase in protein content was observedin complex medium in PCBs presence, whereas PCBs supplementation enhanced laccase production by T. sanguinea, 5- and 40-fold in both culture media. Both strains produced approx. 34% of bioemulsifiers in absence ofPCBs after 21 days of treatment, but only I. lacteus secreted them in pollutants presence (20% after 28 days). Thisapproach provides an insight into a mycoremediation process applied to treat PCBs mineral oil