Bioremediation of complex organic pollutants by engineered Vibrio natriegens

Abstract

Industrial wastewater, petroleum pollution and plastic contamination are significant threats to global marine biosecurity because of their toxic, mutagenic and persistent nature¹. The use of microorganisms in bioremediation has been constrained by the complexity of organic pollutants and limited tolerance to saline stress². In this study, we used synthetic biology to engineer Vibrio natriegens into a strain capable of bioremediating complex organic pollutants in saline wastewater and soils. The competence master regulator gene tfoX was inserted into chromosome 1 of the V. natriegens strain Vmax and overexpressed to enhance DNA uptake and integration. Degradation gene clusters were chemically synthesized and assembled in yeast. We developed a genome engineering method (iterative natural transformation based on Vmax with amplified tfoX effect) to transfer five gene clusters (43 kb total) into Vmax. The engineered strain has the ability to bioremediate five organic pollutants (biphenyl, phenol, naphthalene, dibenzofuran and toluene) covering a broad substrate range, from monocyclic to multicyclic compounds, in industrial wastewater samples from a chlor-alkali plant and a petroleum refinery.