Enhancement of soil high-molecular-weight polycyclic aromatic hydrocarbon degradation by Fusarium sp. ZH-H2 using different carbon sources

• Published in: Ecotoxicology and environmental safety 2023-01, Vol.249, p.114379, Article 114379
• Main Authors: Zhang, Xiaoxue, Zhang, Yukun, Wang, Xiaomin, Zhang, Lixiu, Ning, Guohui, Feng, Shengdong, Zhang, Aijun, Yang, Zhixin
• Format: Article
• Language: English
• Subjects: C:N:P ratios; Fusarium sp. ZH-H2; HMW-PAHs; Humic acid; Starch
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.114379

High-molecular-weight PAHs (HMW-PAHs) in soil cannot be easily degraded. However, nutrient supplementation could stimulate the growth of exogenously added strains to enhance the degradation of HMW-PAHs in polluted soil. This study evaluated the applicability of Fusarium sp. ZH-H2, a polycyclic aromatic hydrocarbon (PAH)-degrading strain isolated by our research group, for the bioremediation of contaminated soil from the Hebei coal mining area in China. A soil incubation experiment was conducted to investigate the effect of two carbon sources and different carbon, nitrogen, and phosphorus (C:N:P) ratios on the remediation of high-molecular-weight PAHs (HMW-PAHs) in soil by Fusarium sp. ZH-H2, as well as the induction of lignin peroxidase activity. Our findings indicated that the HDF2 treatment (equal parts of humic acid and starch as carbon sources at a 50:1:0.5 C:N:P ratio) enhanced the removal rate of total HMW-PAHs from soil, reaching a maximum removal rate of 37.15 %. The removal rates of Pyr (a 4-ring PAH), BaP (a 5-ring PAH), and BghiP (a 6-ring PAH) were the highest in HDF2 treatment, and the removal rates were 39.51 %, 54.63 %, and 38.60 %, respectively. Compared with the ZH-H2 treatment, different carbon sources and C:N:P ratios significantly induced soil lignin peroxidase activity and the HDF2 treatment also resulted in the highest enzyme activity (up to 34.68 U/L). Furthermore, there was a significant or highly significant linear positive correlation between the removal rate of HMW-PAHs and enzyme activity in all cases. Our findings suggest that the optimal HMW-PAH degradation performance and enhancement of lignin peroxidase activity by ZH-H2 were achieved when both starch and humic acid were used as carbon sources at a C:N:P ratio of 50:1:0.5. •The study elucidated the effect of two carbon sources on the removal of HMW-PAHs in aging polluted soil by Fusarium sp. ZH-H2.•The optimal HMW-PAH degradation performance were achieved at a C:N:P ratio of 50:1:0.5 with carbon mixtures.•Both starch and humic acid as carbon sources at a 50:1:0.5 C:N:P ratio maximized soil lignin peroxidase activity.