Characterization of Extracellular Biosurfactants Expressed by a Pseudomonas putida Strain Isolated from the Interior of Healthy Roots from Sida hermaphrodita Grown in a Heavy Metal Contaminated Soil
Characterization of Extracellular Biosurfactants Expressed by a Pseudomonas putida Strain Isolated from the Interior of Healthy Roots from Sida hermaphrodita Grown in a Heavy Metal Contaminated Soil
复制标题
DOI：
10.1007/s00284-019-01757-x
复制
发表时间：
2019-11-01
影响因子：
2.6
通讯作者：
Plaza, Grazyna
中科院分区：
文献类型：
--
作者：
Bernat, Przemyslaw;Nesme, Joseph;Plaza, Grazyna
从重金属污染土壤中分离到的恶臭假单胞菌E41具有较高的表面活性。在本文中，我们描述了来自质谱学和基因组分析的数据，以提高我们对该菌株表型特性的理解。恶臭假单胞菌E41液体培养上清液的表面张力显著降低，同时具有稳定乳状液的能力。我们鉴定了细胞外脂多肽、腐解素I和II的表达，但没有检测到鼠李糖脂。用基质辅助激光解吸电离(MALDI)TOF/TOF技术证实了它们的存在。此外，还检测到囊泡排泄的10种磷脂(主要是磷脂酰乙醇胺PE33：1和PE32：1)。相比之下，细菌细胞颗粒以磷脂酰甘油(PGs)为主，上清液中几乎不存在磷脂酰甘油。似乎这种菌株的胞外(分泌到环境中)和细胞脂的成分不同。长时间的测序和完整的基因组重建使我们能够鉴定出完整的腐殖素生物合成途径。在恶臭假单胞菌E41的基因组中也发现了与甘油磷脂生物合成有关的所有基因，它们可能与检测到的磷脂的产生有关。总的来说，这是首次报道恶臭假单胞菌表达胞外脂肽(经鉴定为腐解素)和磷脂，这可能是由于需要适应高度污染的环境所致。
Pseudomonas putida E41 isolated from root interior of Sida hermaphrodita (grown on a field contaminated with heavy metals) showed high biosurfactant activity. In this paper, we describe data from mass spectrometry and genome analysis, to improve our understanding on the phenotypic properties of the strain. Supernatant derived from P. putida E41 liquid culture exhibited a strong decrease in the surface tension accompanied by the ability for emulsion stabilization. We identified extracellular lipopeptides, putisolvin I and II expression but did not detect rhamnolipids. Their presence was confirmed by matrix-assisted laser desorption and ionization (MALDI) TOF/TOF technique. Moreover, ten phospholipids (mainly phosphatidylethanolamines PE 33:1 and PE 32:1) which were excreted by vesicles were also detected. In contrast the bacterial cell pellet was dominated by phosphatidylglycerols (PGs), which were almost absent in the supernatant. It seems that the composition of extracellular (secreted to the environment) and cellular lipids in this strain differs. Long-read sequencing and complete genome reconstruction allowed the identification of a complete putisolvin biosynthesis pathway. In the genome of P. putida E41 were also found all genes involved in glycerophospholipid biosynthesis, and they are likely responsible for the production of detected phospholipids. Overall this is the first report describing the expression of extracellular lipopeptides (identified as putisolvins) and phospholipids by a P. putida strain, which might be explained by the need to adapt to the highly contaminated environment.