Metabolic engineering of Oryza sativa for complete biodegradation of thiocyanate

• Published in: The Science of the total environment Vol. 820; p. 153283
• Main Authors: Gao, Jian-Jie, Wang, Bo, Li, Zhen-Jun, Xu, Jing, Fu, Xiao-Yan, Han, Hong-Juan, Wang, Li-Juan, Zhang, Wen-Hui, Deng, Yong-Dong, Wang, Yu, Gong, Ze-Hao, Tian, Yong-Sheng, Peng, Ri-He, Yao, Quan-Hong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.05.2022
• Subjects: Biodegradation, Environmental; Metabolic Engineering; Oryza - metabolism; Phytoremediation; Seedlings - metabolism; Thiocyanate; Thiocyanate hydrolase module; Thiocyanates; Metabolic engineering; Thiocyanate hydrolase module; Thiocyanate; Phytoremediation
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.153283

Industrial thiocyanate (SCN−) waste streams from gold mining and coal coking have caused serious environmental pollution worldwide. Phytoremediation is an efficient technology in treating hazardous wastes from the environment. However, the phytoremediation efficiency of thiocyanate is very low due to the fact that plants lack thiocyanate degradation enzymes. In this study, the thiocyanate hydrolase module was assembled correctly in rice seedlings and showed thiocyanate hydrolase activity. Rice seedlings engineered to express thiocyanate degrading activity were able to completely remove thiocyanate from coking wastewater. Our findings suggest that transforming the thiocyanate hydrolase module into plants is an efficient strategy for rapid phytoremediation of thiocyanate in the environment. Moreover, the rice seedlings expressing apoplastic or cytoplasmic targeted thiocyanate hydrolase module were constructed to compare the phytoremediation efficiency of secretory/intracellular recombinant thiocyanate hydrolase. The most obvious finding from this study is that the apoplastic expression system is more efficient than the cytoplasm expression system in the phytoremediation of thiocyanate. At last, this research also shows that the secreted thiocyanate hydrolase from engineered rice plants does not influence rhizosphere bacterial community composition. [Display omitted] •Two thiocyanate hydrolase modules are constructed and expressed in plants.•The thiocyanate hydrolase modules were assembled correctly in the rice plant and showed SCNase activity.•The plants expressing the thiocyanate hydrolase module can degrade thiocyanate completely.•The plants expressing thiocyanate hydrolase module enhances phytoremediation of thiocyanate.•Apoplast-targeted expressing plants showed high-level phytoremediation than the cytoplasm expressing plants