Burkholderia thailandensis harbors two identical rhl gene clusters responsible for the biosynthesis of rhamnolipids.
Burkholderia thailandensis harbors two identical rhl gene clusters responsible for the biosynthesis of rhamnolipids.
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DOI：
10.1186/1471-2180-9-263
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发表时间：
2009-12-17
期刊：
影响因子：
4.2
通讯作者：
Lépine F
中科院分区：
文献类型：
--
作者：
Dubeau D;Déziel E;Woods DE;Lépine F
鼠李糖脂是由鼠李糖和β-羟基癸酸组成的表面活性分子。这些生物表面活性剂主要由铜绿假单胞菌产生，并且自其早期发现以来已被彻底研究。最近，由于它们参与了各种多细胞行为，引起了人们的新的关注。尽管如此高的兴趣，只有很少的研究集中在生产的鼠李糖脂伯克霍尔德氏菌属物种。在非感染性的Burkholderia thailandensis中以及在遗传上相似的重要病原体B中发现了负责铜绿假单胞菌中鼠李糖脂生物合成的rhlA、rhlB和rhlC的直系同源物。假鼻疽与铜绿假单胞菌相反，两种伯克霍尔德氏菌在单个基因簇内含有这三种产生鼠李糖脂所必需的基因。此外，在这些细菌的第二条染色体上发现了该基因簇的两个相同的旁系同源拷贝。伯克霍尔德氏菌属（Burkholderia spp.）产生含有3-羟基脂肪酸部分的鼠李糖脂，其侧链比铜绿假单胞菌所述的那些更长。此外，B.与铜绿假单胞菌相比，泰国假单胞菌含有更大比例的二鼠李糖脂。由B产生的鼠李糖脂。thailandensis使水的表面张力降低到42 mN/m，同时显示出225 mg/L的临界胶束浓度值。两个rhlA等位基因中的单独突变，其负责合成鼠李糖脂前体3-（3-羟基烷酰氧基）链烷酸，证明rhl基因簇的两个拷贝都是功能性的，但一个对总产量的贡献大于另一个。最后，完全缺乏鼠李糖脂产生的双ΔrhlA突变体不能群集运动，表明两个基因簇都有助于这种表型。总的来说，这些结果通过两个相同的功能基因簇将另一个伯克霍尔德菌物种添加到能够产生鼠李糖脂的细菌列表中。我们的结果还表明，与来自铜绿假单胞菌的经过充分研究的短链鼠李糖脂相比，这些长链鼠李糖脂具有非常令人印象深刻的张力活性特性。
Rhamnolipids are surface active molecules composed of rhamnose and β-hydroxydecanoic acid. These biosurfactants are produced mainly by Pseudomonas aeruginosa and have been thoroughly investigated since their early discovery. Recently, they have attracted renewed attention because of their involvement in various multicellular behaviors. Despite this high interest, only very few studies have focused on the production of rhamnolipids by Burkholderia species. Orthologs of rhlA, rhlB and rhlC, which are responsible for the biosynthesis of rhamnolipids in P. aeruginosa, have been found in the non-infectious Burkholderia thailandensis, as well as in the genetically similar important pathogen B. pseudomallei. In contrast to P. aeruginosa, both Burkholderia species contain these three genes necessary for rhamnolipid production within a single gene cluster. Furthermore, two identical, paralogous copies of this gene cluster are found on the second chromosome of these bacteria. Both Burkholderia spp. produce rhamnolipids containing 3-hydroxy fatty acid moieties with longer side chains than those described for P. aeruginosa. Additionally, the rhamnolipids produced by B. thailandensis contain a much larger proportion of dirhamnolipids versus monorhamnolipids when compared to P. aeruginosa. The rhamnolipids produced by B. thailandensis reduce the surface tension of water to 42 mN/m while displaying a critical micelle concentration value of 225 mg/L. Separate mutations in both rhlA alleles, which are responsible for the synthesis of the rhamnolipid precursor 3-(3-hydroxyalkanoyloxy)alkanoic acid, prove that both copies of the rhl gene cluster are functional, but one contributes more to the total production than the other. Finally, a double ΔrhlA mutant that is completely devoid of rhamnolipid production is incapable of swarming motility, showing that both gene clusters contribute to this phenotype. Collectively, these results add another Burkholderia species to the list of bacteria able to produce rhamnolipids and this, by the means of two identical functional gene clusters. Our results also demonstrate the very impressive tensio-active properties these long-chain rhamnolipids possess in comparison to the well-studied short-chain ones from P. aeruginosa.
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影响因子：
3.2
作者：
DeShazer, D;Brett, PJ;Woods, DE
通讯作者：
Woods, DE
DOI：
10.1099/00207713-48-1-317
发表时间：
1998-01-01
期刊：
INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY
影响因子：
--
作者：
Brett, PJ;DeShazer, D;Woods, DE
通讯作者：
Woods, DE
影响因子：
48
作者：
Choi, KH;Gaynor, JB;Schweizer, HP
通讯作者：
Schweizer, HP
影响因子：
5.1
作者：
Lai, Sandra;Tremblay, Julien;Deziel, Eric
通讯作者：
Deziel, Eric
DOI：
10.1016/s1388-1981(99)00129-8
发表时间：
1999-09-22
影响因子：
4.8
作者：
Déziel, E;Lépine, F;Villemur, R
通讯作者：
Villemur, R