Biodegradation of erythromycin by Delftia lacustris RJJ‐61 and characterization of its erythromycin esterase

Abstract

The residual erythromycin in fermentation waste can pollute the environment and threaten human health. However, there are no effective approaches to remedy this issue. In this study, an erythromycin‐degrading bacterium named RJJ‐61 was isolated and identified as a strain of Delftia lacustris based on morphological and phylogenetic analyses. The degradation ability of this strain was also evaluated; it could degrade 45.18% of erythromycin at 35°C in 120 h. Furthermore, the key degradation gene ereA was cloned from strain RJJ‐61 and expressed in Escherichia coli BL21; the molecular weight of the expressed protein was ~45 kDa. The enzyme activity of EreA was 108.0 mU ml−1 at 35°C and pH 7.0. Finally, the EreA protein was used to degrade erythromycin from mycelial dregs and 50% diluted solution, and the removal rates in them were 41.42% and 69.78%, respectively. In summary, D. lacustris RJJ‐61 is a novel erythromycin‐degrading strain that has great potential to remove erythromycin pollutants from the environment.

Immobilization of EreB on Acid-Modified Palygorskite for Highly Efficient Degradation of Erythromycin

“…The erythromycin could eventually be degraded to a concentration of about 20 mg·L −1 , regardless of the initial substrate concentration; the half-life of erythromycin was about 100 min. Such degradability is better than that reported for other erythromycin treatment methods [ 9 , 11 , 31 , 33 ]. Therefore, the enhanced tolerance and reusability increased the potential for utilizing the enzyme in harsh conditions.…”

“…During the past few decades, studies of natural treatment processes have focused on the screening and isolation of erythromycin-degrading bacteria. For example, degradation rates of Delftia lacustris and Penicillium oxalicum of 45.18% [ 11 ] and 84.88%, respectively, were reported. However, the direct use of microorganisms might lead to the enrichment of resistance genes [ 12 ].…”

Promising approaches and kinetic prospects of the microbial degradation of pharmaceutical contaminants

“…At a bacterial load of 2%, a maximum of 60-65% degradation efficiency was achieved. 98 The nature and characteristics of medicinal compounds play an additional role in biodegradation. The more stable and complex pharmacological substances are more difficult to breakdown.…”

“…93 Different microbial remediation studies on the removal efficiency of pharmaceutical pollutants are listed in Table 3. 95–119…”