Biotransformation of minocycline by a novel strain Kluyvera sp. DM13 isolated from municipal sludge: Performances, removal pathways, and toxicity.

Minocycline has been widely used in clinical treatment and its residues were considered to have environmental safety risks due to complex chemical structure. Therefore, it is necessary to find an efficient and environmentally friendly method to remove minocycline from the environment. This study screened and isolated a minocycline degrading strain DM13 from the activated sludge for municipal sewage pipeline, and optimized the biodegradation of minocycline by DM13 under various environmental conditions.

Simultaneous degradation of roxithromycin and nitrogen removal by Acinetobacter pittii TR1: Performances, pathways, and mechanisms.

Pharmaceutical and aquaculture wastewater contains not only antibiotics but also high concentrations of nitrogen, but few studies have been conducted on bacteria that target this complex pollution for degradation. A novel heterotrophic nitrifying aerobic denitrifying (HN-AD) strain Acinetobacter pittii TR1 isolated from soil. When the C/N ratio was 20, the strain could degrade 50 mg/L roxithromycin (ROX) and the nitrogen removal rate was 96.

Formation characteristics of algal-bacteria granular sludge under low-light environment: From sludge characteristics, extracellular polymeric substances to microbial community.

In this study, the formation characteristics of algal-bacteria granular sludge (ABGS) under low-light environment (80, 110, and 140 μmol/m/s) were investigated. The findings revealed that the stronger light intensity favored the improvement of sludge characteristics, nutrient removal performances, and extracellular polymeric substance (EPS) secretion at the growing stage, which were more preferential to facilitate the formation of ABGS. However, after the mature stage, the weaker light intensity ensured more stable operation of the system, as shown by contributing to sludge settlement performance, denitrification, and EPS secretion.

Trace antibiotics increase the risk of antibiotic resistance genes transmission by regulating the biofilm extracellular polymeric substances and microbial community in the sewer.

Sewer is considered a potential hotspot for antibiotic resistance, but the occurrence and proliferation of antibiotic resistance genes (ARGs) under trace antibiotics exposure have received little attention. This work evaluated the effects of tetracycline (TC) and sulfamethoxazole (SMX) individually and in combination in the sewer system and revealed the related mechanisms of ARG proliferation. The relative abundance of tetA and sul1 increased the most under TC and SMX stress, respectively, whereas sul1 increased the most under combined stress.

Effect of minocycline on the changes in the sewage chemical index and microbial communities in sewage pipes.

With the increasing use of drugs in cities, the sewer is becoming the most suitable place for antibiotic accumulation and transfer. In order to reveal the occurrence and fate of antibiotic sewage during pipeline migration, we used an anaerobic reactor device to simulate the concentration change of minocycline in the sewer and its impact on the sewage quality. The results showed that 90.

Biodegradation of N,N-dimethylacetamide by Rhodococcus sp. strain B83 isolated from the rhizosphere of pagoda tree.

The biodegradation characteristic and potential metabolic pathway for removal of environmental N,N-dimethylacetamide (DMAC) by Rhodococcus sp. strain B83 was studied. Rhodococcus sp.

[Isolation and identification of hydrogen-oxidizing bacteria producing 1-aminocyclopropane-1-carboxylate deaminase and the determination of enzymatic activity].

Objective: We used Medicago sativa rhizosphere in Shaanxi province of China to isolate and identify hydrogen-oxidizing bacteria that produced ACC (1-aminocyclopropane-1-carboxylate) deaminase, and then studied the mechanism why they can promote the growth of plants.

Methods: Hydrogen-oxidizing bacteria were isolated by gas-cycle incubation system. We studied the morphological character, physiological characteristics, 16S rDNA sequence analysis and built the phylogenic tree.