title: Efficient dibutyltin (DBT) elimination by the microscopic fungus Metarhizium robertsii under conditions of intensive aeration and ascorbic acid supplementation.
abstract: Dibutyltin (DBT) is an environmental pollutant characterized by immunotoxic, neurotoxic, and pro-oxidant properties. In this study, an attempt was made to enhance DBT elimination by the Metarhizium robertsii strain. We observed enhanced fungal growth in the bioreactor (pO2≥ 20%) compared to flask cultures (μmaxincreased from 0.061 to 0.086 h-1). Moreover, under aerated conditions, M. robertsii mycelium with "hairy" morphology biodegraded DBT (20 mg l-1) 10-fold faster in the bioreactor than in the flask cultures. Monobutyltin (MBT) and a hydroxylated derivative of MBT (OHBuSnH2) were detected as by-products of dibutyltin debutylation. Simultaneous usage of glucose and butyltins indicates the comatabolic nature of monobutyltin and dibutyltin removal. In order to protect fungal cells from oxidative stress caused by DBT presence, vitamin C (20 mg l-1) was applied. Supplementation with ascorbic acid (AA) resulted in a 3-fold acceleration of MBT removal during the first 7 h of incubation. Using the HPLC-MS/MS technique, a quantitative analysis of malondialdehyde (MDA), a marker of oxidative stress, was performed. In the AA presence, a decrease in the MDA amount (about 45%) was observed compared to the case with fungal cells exposed to DBT alone.
authors.affiliation: Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland.
authors.forename: Paulina
authors.initials: P
authors.lastname: Siewiera
authors.affiliation: Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Różalska
authors.affiliation: Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland. pbernat@biol.uni.lodz.pl.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Bernat
mesh_terms: D001205:Ascorbic Acid; D052981:Metarhizium; D009947:Organotin Compounds / Q000302:isolation & purification*; D053719:Tandem Mass Spectrometry
chemical_list: D009947:Organotin Compounds; C516409:mono-n-butyltin; C056189:di-n-butyltin; D001205:Ascorbic Acid
keywords: Antioxidants; Dibutyltin utilization; Hyphae morphology; Intense aeration; Liquid chromatography; Malondialdehyde; Metarhizium robertsii; Oxidative stress alleviation