In this study, the effects of siderophores produced by six bacteria on mycelium growth, Cd and Pb accumulation, lipid peroxidation, protein content and antioxidant enzyme in Oudemansiella radicata were investigated in Cd and Pb-containing liquid medium. The results showed that inoculation with siderophore-containing filtrates (SCF) partly enhanced the growth of O. radicata after 15 days, with 0.8-32.4% biomass increase for Cd and 0.7-20.8% for Pb compared to control(s), which lacked siderophore. The maximum enhancement for accumulation were found to be confined to Bacillus sp. FFQ2(s) (26.5%) for Cd and Pseudomonas sp. CY63(s) (158.9%) for Pb. A significant decrease in MDA content indicated that lipid peroxidation in O. radicata was alleviated by siderophores. Besides, antioxidant enzyme SOD and POD activities also displayed obviously decrease in SCF-treated mycelium compared to control(s) treatment, while CAT activity did not present significant change. Protein level in O. radicata treated by SCF increased from 0.3 to 138.0% for Cd and from 10.9 to 107.1% for Pb compared to control(s). Therefore, the present work suggests that microbial siderophores can reduce the toxicity of metals to mycelium and then alleviate heavy metals-inducing oxidative stress in O. radicata.

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1To enhance metal biosorption capacity, magnesium chloride modified Lentinula edodes (MMLE) 2 were prepared by treating Lentinula edodes with the mixture of NaOH, ethanol and MgCl 2. In this 3 study, MMLE was successfully applied for removing Cd(II) and Cu(II) from aqueous solution 4 with a high biosorption capacity of 51.64 ± 0.65 and 59.03 ± 0.64 mg g -1 , respectively, which 5 were higher than many other biosorbents. After pretreatment, the surface of spent Lentinula 6 edodes changed significantly and exposed more metal binding sites. When the initial 7 concentration of heavy metal was 50 mg L -1 and the biosorbent dosage was 5 g L -1 , the maximum 8 uptake of Cu(II) and Cd(II) by MMLE at pH 5.0 and 25 °C was more than one order of magnitude 9 higher than the raw biomass.. The equilibrium biosorption data of Cd(II) and Cu(II) could be well 10 described by Langmuir isotherm model. The experimental data obtained from the biosorption 11 process was successfully correlated with pseudo-second-order kinetics model. The determined 12 thermodynamic parameters indicated that the biosorption process was endothermic and 13 spontaneous. Both physisorption and chemisorption were involved in the biosorption of Cd(II) and 14 Cu(II) onto the surface of MMLE through electrostatic interaction, ion exchange and complex 15 formation. After three biosorption-desorption cycles, the biosorption and recovery efficiency of 16 heavy metals from real industrial wastewater could reached about 90% and 80%, respectively. The 17 results show that MMLE could be an effective and alternative biosorbent for the removal of heavy 18 metals from the real industrial wastewater. 19

Correction for 'Efficient removal of Cd(II) and Cu(II) from aqueous solution by magnesium chloride-modified Lentinula edodes' by Han Xie et al., RSC Adv., 2015, 5, 33478-33488.