Project description:<p>Background: The use of sulfonamides (SAs) caused residual pollution in the environment. Bacteria play an important role in the degradation of sulfonamide antibiotics, and microbial consortium offers advantages over single bacterium. However, the complex degradation process and interaction mechanisms within such consortiums still poorly understood. </p><p>Results: Here, a consortium named ACJ, consisting of Leucobacter sp. HA-1, Bacillus sp. HC-1 and Gordonia sp. HAEJ-1, obtained from activated sludge of pharmaceutical plants, was identified as capable of degrading various SAs. Several papers failed to get the pure culture of Leucobacter sp. in the degradation of SAs, here we successfully obtained the Leucobacter sp. HA-1 pure culture involved in the degradation of SAs with the growth factors provided by strain HC-1 or HAEJ-1. Strain HA-1 was responsible for the initial attack of sulfonamide molecules resulting in the release of 2-aminoquinoxaline (2-AQ) and trihydroxybenzene (HHQ), which were further degraded and used for growth by strain HAEJ-1. Genomic, metabolomic and transcriptomic analyses revealed genes associated with nucleotide repair, ABC transporters, quorum sensing, TCA cycle and cell cycle in strain HA-1 were up-regulated during co-culture compared without the other two strains, which indicated that HA-1 utilized certain factors from strain HC-1 or HAEJ-1 for growth. </p><p>Conclusion: These results revealed that there was a bidirectional ecological relationship of cross-feeding and co-degradation among consortium ACJ. In summary, this study provides new insights into the mechanisms of microbial consortium interaction and co-degradation in antibiotic-contaminated environments.</p>
