Project description:This genome report describes the draft genome and physiological characteristics of Bosea sp. WAO (=DSM 102914), a novel strain of the genus Bosea in the family Bradyrhizobiaceae. Bosea sp. WAO was isolated from pulverized pyritic shale containing elevated levels of arsenic. This aerobic, gram negative microorganism is capable of facultative chemolithoautotrophic growth under aerobic conditions by oxidizing the electron donors arsenite, elemental sulfur, thiosulfate, polysulfide, and amorphous sulfur. The draft genome is of a single circular chromosome 6,125,776 bp long consisting of 21 scaffolds with a G?+?C content of 66.84%. A total 5727 genes were predicted of which 5665 or 98.92% are protein-coding genes and 62 RNA genes. We identified the genes aioA and aioB, which encode the large and small subunits of the arsenic oxidase respectively. We also identified the genes for the complete sulfur oxidation pathway sox which is used to oxidize thiosulfate to sulfate.
Project description:Many Gram-negative bacteria employ N-acylhomoserine lactones (AHLs) as quorum-sensing (QS) signal molecules to regulate virulence expression in a density-dependent manner. Quorum quenching (QQ) via enzymatic inactivation of AHLs is a promising strategy to reduce bacterial infections and drug resistance. Herein, a thermostable AHL lactonase (AidB), which could degrade different AHLs, with or without a substitution of carbonyl or hydroxyl at the C-3 position, was identified from the soil bacterium Bosea sp. strain F3-2. Ultrahigh-performance liquid chromatography analysis demonstrated that AidB is an AHL lactonase that hydrolyzes the ester bond of the homoserine lactone (HSL) ring. AidB was thermostable in the range 30 to 80°C and showed maximum activity after preincubation at 60°C for 30?min. The optimum temperature of AidB was 60°C, and the enzyme could be stably stored in double-distilled water (ddH2O) at 4°C or room temperature. AidB homologs were found only in Rhizobiales and Rhodospirillales of the Alphaproteobacteria AidB from Agrobacterium tumefaciens and AidB from Rhizobium multihospitium (with amino acid identities of 50.6% and 52.8% to AidB, respectively) also showed thermostable AHL degradation activity. When introduced into bacteria, plasmid-expressed AidB attenuated pyocyanin production by Pseudomonas aeruginosa PAO1 and the pathogenicity of Pectobacterium carotovorum subsp. carotovorum Z3-3, suggesting that AidB is a potential therapeutic agent by degrading AHLs.IMPORTANCE A quorum-sensing system using AHLs as the signal in many bacterial pathogens is a critical virulence regulator and an attractive target for anti-infective drugs. In this work, we identified a novel AHL lactonase, AidB, from a soil bacterial strain, Bosea sp. F3-2. The expression of aidB reduced the production of AHL signals and QS-dependent virulence factors in Pseudomonas aeruginosa and Pectobacterium carotovorum The homologs of AidB with AHL-degrading activities were found only in several genera belonging to the Alphaproteobacteria Remarkably, AidB is a thermostable enzyme that retained its catalytic activity after treatment at 80°C for 30?min and exhibits reliable storage stability at both 4°C and room temperature. These properties might make it more suitable for practical application.