کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8853049 | 1618900 | 2018 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
High phenol degradation capacity of a newly characterized Acinetobacter sp. SA01: Bacterial cell viability and membrane impairment in respect to the phenol toxicity
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم محیط زیست
شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: High phenol degradation capacity of a newly characterized Acinetobacter sp. SA01: Bacterial cell viability and membrane impairment in respect to the phenol toxicity High phenol degradation capacity of a newly characterized Acinetobacter sp. SA01: Bacterial cell viability and membrane impairment in respect to the phenol toxicity](/preview/png/8853049.png)
چکیده انگلیسی
An efficient phenol-degrading bacterial strain, belonging to Acinetobacter genus, was isolated and selected to study the impact of different environmentally relevant phenol concentrations on the degradation process. The bacterial isolate, labeled as Acinetobacter sp. SA01 was able to degrade the maximum phenol concentration of 1â¯g/l during 60â¯h at optimum condition of pH 7, 30â¯Â°C and 180â¯rpm. Aeration and initial cell density, the two important factors, were carefully examined in the optimal growth conditions. The results showed that these two variables related proportionally with phenol degradation rate. Further investigations showed no effect of inoculum size on the enhancement of degradation of phenol at over 1â¯g/l. Flow cytometry (FCM) study was performed to find out the relationship between phenol-induced damages and phenol degradation process. Single staining using propidium iodide (PI) showed increased cell membrane permeability with an increase of phenol concentration, while single staining with carboxyfluorescein diacetate (cFDA) demonstrated a considerable reduction in esterase activity of the cells treated with phenol at more than 1â¯g/l. A detailed investigation of cellular viability using concurrent double staining of cFDA/PI revealed that the cell death increases in cells exposed to phenol at more than 1â¯g/l. The rate of cell death was low but noticeable in the presence of phenol concentration of 2â¯g/l, over time. Phenol at concentrations of 3 and 4â¯g/l caused strong toxicity in living cells of Acinetobacter sp. SA01. The plate count method and microscopy analysis of the cells treated with phenol at 1.5 and 2â¯g/l confirmed an apparent reduction in cell number over time. It was assumed that the phenol concentrations higher than 1â¯g/l have destructive effects on membrane integrity of Acinetobacter sp. SA01. Our results also revealed that the toxicity did not reduce by increasing initial cell density. Scanning electron microscopy (SEM) examination of bacterial cells revealed the surface morphological changes following exposure to phenol. The bacterial cells, with wizened appearance and wrinkled surface, were observed by exposing to phenol (1â¯g/l) at lag phase. A morphological change occurred in the mid-logarithmic phase as the bacterial cells demonstrated coccobacilli form as well as elongated filamentous shape. The wrinkled cell surface were totally disappeared in mid-stationary phase, suggesting that the complete degradation of phenol relieve the stress and direct bacterial cells toward possessing smoother cell membrane.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ecotoxicology and Environmental Safety - Volume 164, 30 November 2018, Pages 455-466
Journal: Ecotoxicology and Environmental Safety - Volume 164, 30 November 2018, Pages 455-466
نویسندگان
Shahab Shahryari, Hossein Shahbani Zahiri, Kamahldin Haghbeen, Lorenz Adrian, Kambiz Akbari Noghabi,