Biosurfactant production and diauxic growth of Rhodococcus aurantiacus when using n-alkanes as the carbon source

1988 ◽  
Vol 34 (11) ◽  
pp. 1209-1212 ◽  
Author(s):  
B. Ramsay ◽  
J. McCarthy ◽  
L. Guerra-Santos ◽  
O. Kappeli ◽  
A. Fiechter ◽  
...  
Keyword(s):  
Surface Tension ◽  
Carbon Source ◽  
Cell Surface ◽  
Nitrogen Source ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Deionized Water ◽  
Diauxic Growth ◽  
Growth Data ◽  
Hydrocarbon Transport

When grown on hydrocarbons, Rhodococcus aurantiacus produced four glycolipid biosurfactants which could lower the surface tension of distilled, deionized water to between 26 and 30 nM∙m−1. The biosurfactants were found both extracellularly and associated with the cells. They could be extracted with solvents such as chloroform and pentane. Greater quantities of biosurfactant were produced when NaNO3 was used in place of (NH4)2SO4 as the nitrogen source. When grown on n-alkanes using (NH4)2SO4 as the nitrogen source, R. aurantiacus exhibited an unusual form of diauxic growth. Data suggested that the mechanism of diauxy involved changes in the degree of cell-surface hydrophobicity which resulted in hydrocarbon-transport limitation.

scholarly journals Biodegradation of Petroleum Hydrocarbons by Bacillus subtilis BL-27, a Strain with Weak Hydrophobicity

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3021 ◽  
Author(s):  
Dan Wang ◽  
Jiahui Lin ◽  
Junzhang Lin ◽  
Weidong Wang ◽  
Shuang Li
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Cell Surface ◽  
Petroleum Hydrocarbons ◽  
Cell Surface Hydrophobicity ◽  
Tween 80 ◽  
Surface Hydrophobicity ◽  
Adherence Rate ◽  
Degrading Bacterium ◽  
Rpod Gene

The biodegradation of petroleum hydrocarbons has many potential applications and has attracted much attention recently. The hydrocarbon-degrading bacterium BL-27 was isolated from petroleum-polluted soil and was compounded with surfactants to improve biodegradation. Its 16S rDNA and rpoD gene sequences indicated that it was a strain of Bacillus subtilis. Strain BL-27 had extensive adaptability and degradability within a broad range of temperatures (25–50 °C), pH (4.0–10.0) and salinity (0–50 g/L NaCl). Under optimal conditions (45 °C, pH 7.0, 1% NaCl), the strain was able to degrade 65% of crude oil (0.3%, w/v) within 5 days using GC-MS analysis. Notably, strain BL-27 had weak cell surface hydrophobicity. The adherence rate of BL-27 to n-hexadecane was 29.6% with sucrose as carbon source and slightly increased to 33.5% with diesel oil (0.3%, w/v) as the sole carbon source, indicating that the cell surface of BL-27 is relatively hydrophilic. The strain was tolerant to SDS, Tween 80, surfactin, and rhamnolipids at a concentration of 500 mg/L. The cell surface hydrophobicity reduced more with the addition of surfactants, while the chemical dispersants, SDS (50–100 mg/L) and Tween 80 (200–500 mg/L), significantly increased the strain’s ability to biodegrade, reaching 75–80%. These results indicated that BL-27 has the potential to be used for the bioremediation of hydrocarbon pollutants and could have promising applications in the petrochemical industry.

Autecology of scum producing bacteria

1998 ◽  
Vol 37 (4-5) ◽  
pp. 527-530 ◽  
Author(s):  
Hilde Lemmer ◽  
George Lind ◽  
Margit Schade ◽  
Birgit Ziegelmayer
Keyword(s):  
Wastewater Treatment ◽  
Cell Surface ◽  
Wastewater Treatment Plants ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Residence Times ◽  
Loading Conditions ◽  
Emulsifying Activity ◽  
Substrate Preferences

Non-filamentous hydrophobic scum bacteria were isolated from scumming wastewater treatment plants (WWTP) by means of adhesion to hydrocarbons. They were characterized with respect to taxonomy, substrate preferences, cell surface hydrophobicity, and emulsification capability. Their role during flotation events is discussed. Rhodococci are selected by hydrolysable substrates and contribute to flotation both by cell surface hydrophobicity and emulsifying activity at long mean cell residence times (MCRT). Saprophytic Acinetobacter strains are able to promote flotation by hydrophobicity and producing emulsifying agents under conditions when hydrophobic substrates are predominant. Hydrogenophaga and Acidovorax species as well as members of the Cytophaga/Flavobacterium group are prone to proliferate under low loading conditions and contribute to flotation mainly by emulsification.

Phenol and n-alkanes (C12 and C16) utilization: influence on yeast cell surface hydrophobicity

2008 ◽  
Vol 24 (9) ◽  
pp. 1943-1949 ◽  
Author(s):  
Łukasz Chrzanowski ◽  
Katarzyna Bielicka-Daszkiewicz ◽  
Mikołaj Owsianiak ◽  
Andreas Aurich ◽  
Ewa Kaczorek ◽  
...  
Keyword(s):  
Cell Surface ◽  
Yeast Cell ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Yeast Cell Surface
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