Simultaneous copper, cobalt and phenol removal from aqueous solutions by alternating biosorption and biodegradation

Detoxification and simultaneous removal of phenolic xenobiotics and heavy metals with endocrine-disrupting activity by the non-ligninolytic fungus Umbelopsis isabellina

Organic and inorganic pollutants well known to interfere with the major functions of the endocrine system co-occur widely in contaminated ecosystems. The aim of the study was to evaluate the ability of Umbelopsis isabellina fungus to simultaneously remove and detoxify multiple environmentally significant endocrine disruptors: the heavy metals Cd(II), Zn(II), Mn(II), Pb(II) and Ni(II) and the phenolic xenobiotics nonylphenol (t-NP), 4-cumylphenol (CP) and 4-tert-octylphenol (4-t-OP). The effects of the metals on fungal growth and efficiency of single-metal uptake were also investigated. U. isabellina exhibited considerable tolerance to Zn(II), Mn(II), Pb(II) and Ni(II), with IC50/24 values ranging from 5.08 for Ni(II) to 13.1 mM for Zn(II). In the presence of CP, the maximum efficiency of Pb(II) removal increased 25% relative to that of the control. Supplementation with Mn(II) or Zn(II) enhanced the 4-t-OP degradation by 18 or 9%, respectively, after 6 h of cultivation. Ecotoxicological assays monitoring bioindicators from different aquatic ecosystems revealed detoxification coinciding with the removal of metals and organic xenobiotics from binary mixtures. This work indicates the potential of a single microorganism, U. isabellina, to remove both heavy metals and organic xenobiotics from co-contaminated sites, making it a suitable candidate for the development of bioremediation strategies.

Influence of phenolic substrates utilised by yeast Trichosporon cutaneum on the degradation kinetics

The degradation kinetics of different phenolic substrates utilised by Trichosporon cutaneum R57 was studied. The following compounds were used as substrates: phenol, resorcinol, hydroquinone, 3-nitrophenol, 2,6-dinitrophenol, 3-chloro phenol and p-cresol. The specific degradation rates (Q_s) were described by a Haldane kinetic model. The unknown model parameters were estimated using the mathematical optimisation procedure for direct search. The results obtained demonstrated that Q_s varied greatly in the experiments carried out. The level of biodegradability depended on the different structure and toxicity of compounds used as carbon substrates. The highest Q_s values were observed for less toxic hydroxylated phenols (0.77–0.85 h⁻¹), while the most toxic chlorinated phenols were characterised with the lowest Q_s values (0.224 h⁻¹). The results obtained with different concentrations of resorcinol (from 0.2 to 0.8 g L⁻¹) and 2,6-dinitrophenol (from 0.2 to 0.7 g L⁻¹) demonstrated a growing inhibitory effect directly correlating with the extended time necessary for complete degradation of both compounds.