Isolation and working mechanism characterization of a lincomycin-degrading bacterial strain

Abstract:

[Background] Antibiotic pollution has aroused increasing concern. Degradation of environmental antibiotics by biological methods is considered to be an environmentally friendly approach to deal with antibiotic contamination. [Objective] To screen out a bacterial strain with efficient lincomycin degradation and study its degradation mechanism. [Methods] The strain was identified based on physiological and biochemical characteristics and 16S rDNA sequence. The antibiotic resistance genes were identified by PCR and the degradation products of lincomycin by mass spectrometry. [Results] An efficient lincomycin-degrading strain Pseudomonas RST-1 was isolated from a lincomycin mycelia dreg composting sample. After incubation in the beef extract peptone medium with 3.0 g/L lincomycin for 40 h, Pseudomonas RST-1 degraded up to 57.3% of lincomycin. The strain carried antibiotic resistance genes such as intI1, sul1, and sul2. The results of mass spectrometry revealed that lincomycin was degraded into demethyllincomycin and 2-propyl-N-methylproline. [Conclusion] The strain RST-1 has the ability to degrade lincomycin efficiently, which may be achieved through demethylation and amide bond hydrolysis. These results laid a foundation for the construction of lincomycin-degrading strains and development of efficient degradation microbial agents.

Key words:antibiotic;lincomycin;Pseudomonas;antibiotic resistance genes;degradation products