Project description:We isolated an efficient tetracycline degrading strain Sphingobacterium sp. WM1. To investigate gene expression patterns during tetracycline degradation by strain WM1, we conducted a comparative transcriptomic analysis using cultures of strain WM1 with and without tetracycline addition. The RNA-Seq data revealed that 90.44-96.56% of the reads mapped to the genome of Sphingobacterium sp. WM1 across all samples. Differentially expressed genes (DEGs) analysis (|log2FC| >2; p < 0.01) showed that 693 genes were significantly up-regulated and 592 genes were significantly down-regulated.
Project description:Sulfamethoxazole (SMX) is the most commonly used antibiotic in worldwide for inhibiting aquatic animal diseases. However, the residues of SMX are difficult to eliminate and may enter the food chain, leading to considerable threats on human health. The bacterial strain Sphingobacterium mizutaii LLE5 was isolated from activated sludge. This strain could utilize SMX as its sole carbon source and degrade it efficiently. Under optimal degradation conditions (30.8 °C, pH 7.2, and inoculum amount of 3.5 × 107 cfu/mL), S. mizutaii LLE5 could degrade 93.87% of 50 mg/L SMX within 7 days. Four intermediate products from the degradation of SMX were identified and a possible degradation pathway based on these findings was proposed. Furthermore, S. mizutaii LLE5 could also degrade other sulfonamides. This study is the first report on (1) degradation of SMX and other sulfonamides by S. mizutaii, (2) optimization of biodegradation conditions via response surface methodology, and (3) identification of sulfanilamide, 4-aminothiophenol, 5-amino-3-methylisoxazole, and aniline as metabolites in the degradation pathway of SMX in a microorganism. This strain might be useful for the bioremediation of SMX-contaminated environment.
Project description:Investigation of whole genome gene expression level changes in a Gluconacetobacter xylinus NBRC 3288 delta-fnrG mutant, compared to the wild-type strain.
