The survival and removal mechanism of Sphingobacterium changzhouense TC931 under tetracycline stress and its' ecological safety after application. (August 2021) - Tan, Zewen
Graphical abstract: Highlights: A Sphingobacterium changzhouense strain capable of removing and biodegrading TC was isolated. EPS and cellular surface biosorption, biodegradation and antibiotics efflux was the main survival mechanism for S. changzhouense TC931. Eight possible biotransformation products were identified and the potential degradation pathway was proposed. The ecological safety assessment when applied in microbial bioremediation was evaluated through genomic bioinformation analysis. Abstract: Sphingobacterium changzhouense TC931 was isolated as a novel TC (tetracycline) removal bacterium through adsorption on extracellular polymerase substances (EPS) and cellular surface and biodegradation. TC biodegradation efficiency by strain TC931 was affected by solution initial pH and carbon source. Polysaccharides and hydrocarbons in EPS and cellular surface were responsible for TC biosorption. Eight possible biodegradation products were identified and the biodegradation pathway was proposed. Strain TC931 was rich in antibiotic resistance genes, and tetX -TC931 and antibiotics resistance genome island (GI) may be acquired via horizontal gene transfer in early evolutionary history. The GI was incomplete and may stable in strain TC931, but it could develop into an intact and transferability GI with help of other mobile genetic elements. This work offers a theoretical basis for understanding the survival and biodegradation mechanisms of S. changzhouense TC931 under TC stress, and offers an ecological safety assessment for its application in environmental bioremediation.