求一篇外文期刊大概七八页,带中文翻译的 834027320@qq.com
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发布时间：2022-04-25 15:43
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时间：2023-10-14 01:04
作者：luyunqiang
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Quorum sensing relies upon the interaction of a diffusible signal molecule with a transcriptional activator protein to couple gene expression with cell population density. In Gram-negative bacteria, such signal molecules are usually N-acylhomoserine lactones (AHLs) which differ in the structure of their N-acyl side chains. Chromobacterium violaceum, a Gram-negative bacterium commonly found in soil and water, proces the characteristic purple pigment violacein. Previously the authors described a violacein-negative, mini-Tn5 mutant of C. violaceum (CV026) in which pigment proction can be restored by incubation with supernatants from the wild-type strain. To develop this mutant as a general biosensor for AHLs, the natural C. violaceum AHL molecule was first chemically characterized. By using solvent extraction, HPLC and mass spectrometry, a single AHL, N-hexanoyl-L-homoserine lactone (HHL), was identified in wild-type C. violaceum culture supernatants which was absent from CV026. Since the proction of violacein constitutes a simple assay for the detection of AHLs, we explored the ability of CV026 to respond to a series of synthetic AHL and N-acylhomocysteine thiolactone (AHT) analogues. In CV026, violacein is incible by all the AHL and AHT compounds evaluated with N-acyl side chains from C4 to C8 in length, with varying degrees of sensitivity. Although AHL compounds with N-acyl side chains from C10 to C14 are unable to ince violacein proction, if an activating AHL (e.g. HHL) is incorporated into the agar, these long-chain AHLs can be detected by their ability to inhibit violacein proction. The versatility of CV026 in facilitating detection of AHL mixtures extracted from culture supernatants and separated by thin-layer chromatography is also demonstrated. These simple bioassays employing CV026 thus greatly extend the ability to detect a wide spectrum of AHL signal molecules.追问太少了，不能用啊
