Gong Yuan, Ding Peng, Xu Ming-Jie, Zhang Chun-Mei, Xing Ke, Qin Sheng
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, 221116, PR China.
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, 221116, PR China.
J Environ Manage. 2021 Jul 1;289:112525. doi: 10.1016/j.jenvman.2021.112525. Epub 2021 Apr 6.
In this study, a novel halotolerant phenol-degrading yeast strain, SDP-1, was isolated from a coastal soil in Jiangsu, China, and identified as Candida tropicalis by morphology and rRNA internal transcribed space region sequence analysis. Strain SDP-1 can efficiently remove phenol at wide ranges of pH (3.0-9.0), temperature (20-40 °C), and NaCl (0-5%, w/v), as well as the tolerance of Mn, Zn and Cr in aquatic phase. It also utilized multiple phenol derivatives and aromatic hydrocarbons as sole carbon source and energy for growth. Free cells of SDP-1 were able to degrade the maximum phenol concentration of 1800 mg/L within 56 h under the optimum culture conditions of 10% inoculum volume, pH 8.0, 35 °C and 200 rpm agitation speed. Meanwhile, SDP-1 was immobilized on sodium alginate, and the capability of efficiently phenol degradation of free cells and immobilized SDP-1 were evaluated. Shortened degradation time and long-term utilization and recycling for immobilized SDP-1 was achieved compared to free cells. The 1200 mg/L of phenol under 5% NaCl stress could be completely degraded within 40 h by immobilized cells. In actual industrial coking wastewater, immobilized cells were able to completely remove 383 mg/L phenol within 20 h, and the corresponding chemical oxygen demand (COD) value was decreased by 50.38%. Besides, in phenol-contained salinity soil (3% NaCl), 100% of phenol (500 and 1000 mg/kg) removal efficiency was achieved by immobilized SDP-1 within 12 and 26 days, respectively. Our study suggested that versatile yeast Candida tropicalis SDP-1 could be potentially used for enhanced treatment of phenol-contaminated wastewater and soil under hypersaline or no-salt environmental conditions.
在本研究中，从中国江苏的沿海土壤中分离出一株新型耐盐苯酚降解酵母菌株SDP-1，并通过形态学和rRNA内部转录间隔区序列分析鉴定为热带假丝酵母。菌株SDP-1能够在较宽的pH范围（3.0 - 9.0）、温度范围（20 - 40°C）和NaCl浓度范围（0 - 5%，w/v）下高效去除苯酚，同时对水相中Mn、Zn和Cr也具有耐受性。它还能利用多种苯酚衍生物和芳烃作为唯一碳源和生长能量。在接种量10%、pH 8.0、35°C和搅拌速度200 rpm的最佳培养条件下，SDP-1的游离细胞能够在56小时内降解高达1800 mg/L的苯酚。同时，将SDP-1固定在海藻酸钠上，并评估了游离细胞和固定化SDP-1高效降解苯酚的能力。与游离细胞相比，固定化SDP-1实现了降解时间缩短以及长期利用和循环。在5% NaCl胁迫下，固定化细胞能够在40小时内将1200 mg/L的苯酚完全降解。在实际工业焦化废水中，固定化细胞能够在20小时内完全去除383 mg/L的苯酚，相应的化学需氧量（COD）值降低了50.38%。此外，在含苯酚的盐渍土壤（3% NaCl）中，固定化SDP-1分别在12天和26天内实现了对500和1000 mg/kg苯酚100%的去除效率。我们的研究表明，多功能酵母热带假丝酵母SDP-1在高盐或无盐环境条件下可潜在用于强化处理苯酚污染的废水和土壤。
