Isolation and characterization of phenol degrading bacterium strain Bacillus thuringiensis J20 from olive waste in Palestine
Isolation and characterization of phenol degrading bacterium strain Bacillus thuringiensis J20 from olive waste in Palestine
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DOI：
10.1080/10934529.2017.1368300
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发表时间：
2018-01-01
影响因子：
2.1
通讯作者：
Abdeen, Ziad A.
中科院分区：
文献类型：
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作者：
Ereqat, Suheir I.;Abdelkader, Ahmad A.;Abdeen, Ziad A.
这项研究旨在从巴勒斯坦橄榄厂废物中分离苯酚降解细菌。研究了苯酚的去除效率和影响苯酚降解的因素。从固体橄榄厂废物中分离出菌株 (J20)，根据标准形态、生化特征和 16SrRNA 序列分析，将其鉴定为苏云金芽孢杆菌。该菌株能够在浓度为 700 mg/L 的苯酚作为唯一碳源和能源的情况下生长。培养条件对这些细胞去除苯酚的能力有显着影响。该菌株在pH 6.57、30℃下表现出最佳的苯酚降解性能。在优化条件下，当初始细胞密度为OD600 0.2时，该菌株在96 h内可降解88.6%的苯酚（700 mg/L）。然而，通过增加细胞密度，降解效率可以从约 88% 提高到近 99%。使用4％海藻酸钠进行J20的固定化。 J20固定化细胞的苯酚降解效率高于游离细胞，120小时内苯酚降解效率为100%，而700 mg/L苯酚120 h的苯酚降解效率为88.6%，表明固定化细胞对苯酚毒性的耐受性有所提高。使用J20对粗OMWW进行解毒，处理五天后，与未处理的OMWW相比，酚类化合物含量降低了61%。因此，苏云金芽孢杆菌-J20可以有效地用于巴勒斯坦苯酚污染场地的生物修复。这些发现可能会带来与橄榄油生产相关的苯酚降解的新生物技术应用。
This study aimed at isolation of phenol degrading bacteria from olive mill wastes in Palestine. The efficiency of phenol removal and factors affecting phenol degradation were investigated. A bacterial strain (J20) was isolated from solid olive mill waste and identified as Bacillus thuringiensis based on standard morphological, biochemical characteristics and 16SrRNA sequence analysis. The strain was able to grow in a phenol concentration of 700 mg/L as the sole carbon and energy source. The culture conditions showed a significant impact on the ability of these cells to remove phenol. This strain exhibited optimum phenol degradation performance at pH 6.57 and 30 degrees C. Under the optimized conditions, this strain could degrade 88.6% of phenol (700 mg/L) within 96 h when the initial cell density was OD600 0.2. However, the degradation efficiency could be improved from about 88% to nearly 99% by increasing the cell density. Immobilization of J20 was carried out using 4% sodium alginate. Phenol degradation efficiency of the immobilized cells of J20 was higher than that of the free cells, 100% versus 88.6% of 700 mg/L of phenol in 120 h, indicating the improved tolerance of the immobilized cells toward phenol toxicity. The J20 was used in detoxifying crude OMWW, phenolic compounds levels were reduced by 61% compared to untreated OMWW after five days of treatment. Hence, B. thuringiensis-J20 can be effectively used for bioremediation of phenol-contaminated sites in Palestine. These findings may lead to new biotechnological applications for the degradation of phenol, related to olive oil production.