Department of Bioengineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Interdisciplinary Research Center for Membranes and Water Security, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Int J Environ Res Public Health. 2023 Jan 19;20(3):1855. doi: 10.3390/ijerph20031855.
To date, only a handful of bacterial strains that can independently degrade and utilize benzo[a]pyrene (BaP) as the sole carbon source has been isolated and characterized. Here, three new bacterial strains-JBZ1A, JBZ2B, and JBZ5E-were isolated from contaminated soil and, using 16S rRNA sequencing, were identified as , , and , respectively. The growth ability of each individual strain and a consortium of all strains in the presence of BaP (4-400 µmol·L, pH 7, 37 °C) was identified by the doubling time (dt). The results illustrate that dt decreased with increasing BaP concentrations for individual strains and the consortium. The optimum growth conditions of the consortium were 37 °C, 0.5% NaCl (/), and pH 7. Under these conditions, the degradation rate was 1.06 µmol·L·day, whereas that of individual strains ranged from 0.9 to 0.38 µmol·L·day. had the strongest contribution to the consortium's activity, with a degradation rate of 0.9 µmol·L·day. The consortium could also remove BaP spiked with soil but at a lower rate (0.01 µmol L.day). High-performance liquid chromatography-high-resolution tandem mass spectrometry permitted the detection of the metabolites of these strains, and a biodegradation pathway is proposed.
迄今为止，仅分离和鉴定了少数几种能够独立降解和利用苯并[a]芘（BaP）作为唯一碳源的细菌菌株。在这里，从污染土壤中分离出了三株新的细菌菌株-JBZ1A、JBZ2B 和 JBZ5E，并通过 16S rRNA 测序分别鉴定为 、 和 。通过倍增时间（dt）确定了每种菌株和所有菌株的混合物在 BaP（4-400µmol·L，pH7，37°C）存在下的生长能力。结果表明，dt 随着个体菌株和混合物中 BaP 浓度的增加而降低。混合物的最佳生长条件为 37°C、0.5%NaCl（/）和 pH7。在这些条件下，降解率为 1.06µmol·L·day，而个体菌株的降解率范围为 0.9 至 0.38µmol·L·day。对混合物活性的贡献最大，降解率为 0.9µmol·L·day。该混合物还可以去除添加到土壤中的 BaP，但降解率较低（0.01µmol·L·day）。高效液相色谱-高分辨率串联质谱允许检测这些菌株的代谢物，并提出了一种生物降解途径。
