scholarly journals New halo- and thermotolerant fermenting bacteria producing surface-active compounds

1995 ◽  
Vol 44 (1-2) ◽  
pp. 161-166 ◽  
Author(s):  
K. Denger ◽  
B. Schink
Keyword(s):  
Active Compounds ◽  
Fermenting Bacteria ◽  
Surface Active ◽  
Surface Active Compounds

The Isolation and Prospect of Biosurfactants

2012 ◽  
Vol 550-553 ◽  
pp. 1124-1127
Author(s):  
Yun Yun Xu ◽  
Tao Zhang ◽  
Xin Nian Li ◽  
Lei Chen ◽  
Hao Wang
Keyword(s):  
Environmental Remediation ◽  
Oil Production ◽  
Active Compounds ◽  
Strong Interest ◽  
Biological Technology ◽  
Natural Surface ◽  
Potential Applications ◽  
Surface Active ◽  
Surface Active Compounds

Biosurfactants are natural surface-active compounds mainly synthesized by microorganisms, which have distinct advantages like no secondly pollution and friendly to environment compared with chemical surfactants. With the development of modern biological technology, biosurfactants have been shown a variety of potential applications, including medicine, agriculture, oil production and environmental remediation, so it has already caused many researchers a strong interest in the production of biosurfactants making use of biological technology. A review is made from the isolation of biosurfactants. In addition, on the foundation of the analysis,several suggestions about the development of biosurfactants are proposed.

scholarly journals Aerosol hygroscopicity at high (99 to 100%) relative humidities

2009 ◽  
Vol 9 (4) ◽  
pp. 15595-15640 ◽  
Author(s):  
C. R. Ruehl ◽  
P. Y. Chuang ◽  
A. Nenes
Keyword(s):  
Surface Tension ◽  
Inorganic Compounds ◽  
Droplet Diameter ◽  
Pure Water ◽  
Sodium Dodecyl ◽  
Bulk Solution ◽  
Active Compounds ◽  
Surface Active ◽  
Surface Active Compounds ◽  
Aerosol Hygroscopicity

Abstract. The hygroscopicity of an aerosol largely determines its influence on climate and, for smaller particles, atmospheric lifetime. While much aerosol hygroscopicity data is available at lower relative humidities (RH) and under cloud formation conditions (RH>100%), relatively little data is available at high RH (99.2 to 99.9%). We measured the size of droplets at high RH that had formed on particles composed of one of seven compounds with dry diameters between 0.1 and 0.5 μm, and calculated the hygroscopicity of these compounds. We use a parameterization of the Kelvin term, in addition to a standard parameterization (κ) of the Raoult term, to express the hygroscopicity of surface-active compounds. For inorganic compounds, hygroscopicity could reliably be predicted using water activity data and assuming a surface tension of pure water. In contrast, most organics exhibited a slight to mild increase in hygroscopicity with droplet diameter. This trend was strongest for sodium dodecyl sulfate (SDS), the most surface-active compound studied. The results suggest that partitioning of surface-active compounds away from the bulk solution, which reduces hygroscopicity, dominates any increases in hygroscopicity due to reduced surface tension. This is opposite to what is typically assumed for soluble surfactants. Furthermore, we saw no evidence that micellization limits SDS activity in micron-sized solution droplets, as observed in macroscopic solutions. These results suggest that while the high-RH hygroscopicity of inorganic compounds can be reliably predicted using readily available data, surface-activity parameters obtained from macroscopic solutions with organic solutes may be inappropriate for calculations of the hygroscopicity of micron-sized droplets.

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