Author(s): Lean Zhou
Email (s): leanzhou@csust.edu.cn
Institution or organization of origin: Changsha University of Science and Technology
Country: China
Abstract
Tetracycline (TC) is widely used pharmaceutical and personal care products (PPCPs) and considering its biotoxicity in aquatic system, the metabolites and regulation of TC in wastewater treatment process are still deserving concerns. This study reveals the stimulation of acetate on the TC biodegradation in bioelectrochemical systems (BESs). Attributing to the abundance of exoelectrogens Geobacter (mainly G. sulfurreducens) and putative TC-degraded bacteria (PTDB) in the electroactive biofilm samples, 94% of 100 mg/L TC have been decomposed within 48 hours. Limited acetate (0.1 g/L, AC-0.1) as co-substrate enhanced the removal efficiency of TC by 44% when compared to abundant acetate (1 g/L, AC-1) and controls. That is resulted from the enhancement of PTDB and the stability of Geobacter population under limited acetate stimulation. With the differentiation of microbial community, ubiquinone and other terpenoid-quinone biosynthesis and histidine metabolism are significantly up-regulated in AC-0.1 but reversely down-regulated in AC-1 is another factor that enhanced the removal efficiency of TCs. Here we concluded that limited acetate could partially relieve the selective pressure of TC and improve the biodegradation of TC, and the catabolism pathways as well as the main metabolites were stimulated by acetate and its concentration.