Effects of carbon source, nitrogen source, and natural algal powder-derived carbon source on biodegradation of tetracycline (TEC).

The present study aimed to investigate Klebsiella sp. SQY5-mediated tetracycline (TEC) degradation, nitrogen (N) conversion, and mechanisms underlying this process as influenced by various carbon and N sources under aerobic conditions. Effects of additional organic carbon sources on TEC degradation and N conversion processes were explored, and we found that 34.71% of TEC was degraded at removal rates of 0.97 mg·L-1·h-1 for NH4+-N and 1.97 mg·L-1·h-1 for NO3--N. A study examining powder natural algal powder in aquaculture wastewater as a carbon source for TEC degradation and denitrification process was also discussed. It suggested that 49.95% of TEC and 60.45% of NO3--N were removed with a reduction and denitrification rate of 0.11 mg·L-1·h-1 and 1.34 mg·L-1·h-1, respectively, within 72-108 h. Mechanisms underlying TEC degradation and N conversion processes were also proposed, and analysis indicated that specific functional genes played an important role in this process.