Impact of uranium exposure on marine yeast, Yarrowia lipolytica: Insights into the yeast strategies to withstand uranium stress

JOURNAL OF HAZARDOUS MATERIALS

卷:381

Article

Kolhe, Nilesh^1,2  Zinjarde, Smita^1,3  Acharya, Celin^2,4 

[1] Savitribai Phule Pune Univ, Inst Bioinformat & Biotechnol, Pune 411007, Maharashtra, India

[2] Bhabha Atom Res Ctr, Div Mol Biol, Mumbai 400085, Maharashtra, India

[3] Savitribai Phule Pune Univ, Dept Microbiol, Pune 411007, Maharashtra, India

[4] Homi Bhabha Natl Inst, Mumbai 400094, Maharashtra, India

关键词: Yarrowia lipolytica;    Uranium;    Biosorption;    Reactive oxygen species;    Biomineralization;   

DOI  :  10.1016/j.jhazmat.2019.121226

来源: Elsevier

【 摘 要 】

A marine yeast, Yarrowia lipolytica, was evaluated for morphological, physiological and biochemical responses towards uranium (U) exposure at pH 7.5. The yeast revealed biphasic U binding - a rapid biosorption resulting in similar to 35% U binding within 15-30 min followed by a slow biomineralization process, binding up to similar to 45.5% U by 24 h on exposure to 50 mu M of uranyl carbonate. Scanning electron microscopy coupled with Energy Dispersive X-ray spectroscopy analysis of 24 h U challenged cells revealed the deposition of uranyl precipitates due to biomineralization. The loss of intracellular structures together with surface and subcellular localization of uranyl precipitates in 24 h U exposed cells were visualized by transmission electron microscopy. Cells treated with 50 mu M U exhibited membrane permeabilization which was higher at 200 mu M U. Enhanced reactive oxygen species (ROS) accumulation and lipid peroxidation, transient RNA degradation and protein oxidation were observed in U exposed cells. High superoxide dismutase levels coupled with uranium binding and bioprecipitation possibly helped in counteracting U stress in 50 mu M U treated cells. Resistance to U toxicity apparently developed under prolonged uranyl (50 mu M) incubations. However, cells could not cope up with toxicity at 200 mu M U due to impairment of resistance mechanisms.

【 授权许可】

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