The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Curr Microbiol. 2011 Feb;62(2):427-33. doi: 10.1007/s00284-010-9725-z. Epub 2010 Aug 1.
In this study, the effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on bacterial strains, laboratory strains, and isolates from industrial wastewater was investigated. It was shown that biosurfactant, depending on the concentration, has a neutral or detrimental effect on the growth and protein release of model Gram (+) strain Bacillus subtilis 168. The growth and protein release of model Gram (-) strain Pseudomonas aeruginosa 1390 was not influenced by the presence of biosurfactant in the medium. Rhamnolipid biosurfactant at the used concentrations supported the growth of some slow growing on hexadecane bacterial isolates, members of the microbial community. Changes in cell surface hydrophobicity and permeability of some Gram (+) and Gram (-) isolates in the presence of rhamnolipid biosurfactant were followed in experiments in vitro. It was found that bacterial cells treated with biosurfactant became more or less hydrophobic than untreated cells depending on individual characteristics and abilities of the strains. For all treated strains, an increase in the amount of released protein was observed with increasing the amount of biosurfactant, probably due to increased cell permeability as a result of changes in the organization of cell surface structures. The results obtained could contribute to clarify the relationships between members of the microbial community as well as suggest the efficiency of surface properties of rhamnolipid biosurfactant from Pseudomonas fluorescens making it potentially applicable in bioremediation of hydrocarbon-polluted environments.
在这项研究中，研究了荧光假单胞菌产生的鼠李糖脂生物表面活性剂对细菌菌株、实验室菌株和工业废水中分离株的影响。结果表明，生物表面活性剂根据浓度对模式革兰氏阳性菌株枯草芽孢杆菌 168 的生长和蛋白质释放具有中性或有害影响。模式革兰氏阴性菌株铜绿假单胞菌 1390 的生长和蛋白质释放不受培养基中生物表面活性剂存在的影响。在所用浓度下，鼠李糖脂生物表面活性剂支持一些在十六烷上生长缓慢的细菌分离株的生长，这些分离株是微生物群落的成员。在体外实验中，研究了鼠李糖脂生物表面活性剂存在下某些革兰氏阳性和革兰氏阴性分离株的细胞表面疏水性和通透性的变化。结果发现，根据菌株的个体特征和能力，用生物表面活性剂处理的细菌细胞变得或多或少具有疏水性。对于所有处理的菌株，随着生物表面活性剂用量的增加，释放的蛋白质量增加，这可能是由于细胞表面结构组织变化导致细胞通透性增加所致。所得结果有助于阐明微生物群落成员之间的关系，并表明荧光假单胞菌产生的鼠李糖脂生物表面活性剂的表面性质效率，使其有可能在受碳氢化合物污染的环境的生物修复中得到应用。
