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.

Antibiofilm Activity of Crude Cell Free Extract from Bacillus subtilis S01 against E. coli

2018 ◽  
Vol 10 (2) ◽  
pp. 211-221 ◽  
Author(s):  
S. M. A. Sayem ◽  
A. J. M. T. Chowdhury ◽  
M. Z. Alam ◽  
P. K. Sarker
Keyword(s):  
Bacillus Subtilis ◽  
Cell Surface ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Microtiter Plate ◽  
Antibiofilm Activity ◽  
Potential Candidate ◽  
Growth Curve Analysis ◽  
E Coli ◽  
Crude Extracts

Antibiofilm phenomenon has become a novel area of research for removing deleterious biofilm. In the present study, strains from different environmental sources were tested for screening antibiofilm compounds. Crude extracts from various microorganisms were evaluated for antibiofilm phenomenon through crystal violet assay and growth curve analysis. Characterization of antibiofilm compound was performed by pre-coating microtiter plate and Cell Surface Hydrophobicity experiment. Among the organisms, cell free extracts (5% v/v) from Bacillus subtilis S01 inhibited the development of E. coli PHL628 biofilm by 63%. The cell free extracts possessed no amylase activity and had no effect on the planktonic growth of biofilm forming bacteria. Moreover, no competition with quorum sensing analogues was found with the extract. Biofilm formation was more inhibited (76%) in the B. subtilis S01 extract pre-coated wells than uncoated wells (62%). However, no effect on preformed biofilm was observed with the extracts of B. subtilis S01. The extract also reduced the cell surface hydrophobicity (69%) of the biofilm forming bacteria. The present study indicated that the crude extracts of B. subtilis S01 from soil origin has anti-adherence properties towards biotic and abiotic surfaces and thus can be a potential candidate in preventing the development of biofilm.

Influence of growth and environmental conditions on cell surface hydrophobicity ofPseudomonas fluorescensin non-specific adhesion

1999 ◽  
Vol 46 (1) ◽  
pp. 28-37 ◽  
Author(s):  
T K Jana ◽  
A K Srivastava ◽  
K Csery ◽  
D K Arora
Keyword(s):  
Cell Surface ◽  
Pseudomonas Fluorescens ◽  
Environmental Conditions ◽  
Prolonged Exposure ◽  
Cell Surface Hydrophobicity ◽  
Tween 80 ◽  
Macrophomina Phaseolina ◽  
Surface Hydrophobicity ◽  
Proteinase K ◽  
Outer Cell

The relative cell surface hydrophobicity (CSH) of 18 soil isolates of Pseudomonas fluorescens, determined by phase exclusion, hydrophobic interaction chromatography (HIC), electrostatic interaction chromatography (ESIC), and contact angle, revealed large degrees of variability. Variation in the adhesion efficiency to Macrophomina phaseolina of the hyphae/sclerotia of these isolates was also examined. Two such isolates with maximum (32.8%; isolate 12-94) and minimum (12%; isolate 30-94) CSH were selected for further study. Early- to mid-log exponential cells of these isolates were more hydrophobic than those in stationary phase, and the CSH of these isolates was also influenced by fluctuations in temperatures and pH. Isolate 12-94 exhibited high CSH (32.3%) at 30°C, compared to lower values (28-24%) in the higher temperature range (35-40°C). Increasing concentrations of either Zn2+, Fe3+, K+, and Mg2+in the growth medium were associated with the increased CSH. Trypsin, pepsin, and proteinase K (75 to 150 μg·mL-1) reduced the CSH of isolate 12-94 cells. CSH was reduced, following exposure to DTT, SDS, Triton X-100, or Tween 80. Prolonged exposure of cells to starvation (60 days) also caused a significant decline in CSH. Several protein bands (18, 21, 23, 26 kDa) of the outer cell membrane were absent in 60-day starved cells compared to unstarved cells. In conclusion, our findings demonstrate that CSH of P. fluorescens isolates may contribute to non-specific attachment/adhesion onto M. phaseolina hyphae/sclerotia, and the efficiency of adhesion is regulated by growth and other environmental conditions. Key words: adhesion, hydrophobicity, Pseudomonas fluorescens, Macrophomina phaseolina

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 Monolayer Adsorption of a “Bald” Mutant of the Highly Adhesive and Hydrophobic Bacterium Acinetobacter sp. Strain Tol 5 to a Hydrocarbon Surface

2008 ◽  
Vol 74 (8) ◽  
pp. 2511-2517 ◽  
Author(s):  
Katsutoshi Hori ◽  
Hisami Watanabe ◽  
Shun'ichi Ishii ◽  
Yasunori Tanji ◽  
Hajime Unno
Keyword(s):  
Cell Surface ◽  
Pure Water ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Green Technologies ◽  
Phase Partitioning ◽  
Degrading Bacterium ◽  
Monolayer Adsorption ◽  
Bacterium Strain ◽  
Math Test

ABSTRACT The affinity of microbial cells for hydrophobic interfaces is important because it directly affects the efficiency of various bioprocesses, including green biotechnologies. The toluene-degrading bacterium Acinetobacter sp. strain Tol 5 has filamentous appendages and a hydrophobic cell surface, shows high adhesiveness to solid surfaces, and self-agglutinates. A “bald” mutant of this bacterium, strain T1, lacks the filamentous appendages and has decreased adhesiveness but retains a hydrophobic cell surface. We investigated the interaction between T1 cells and an organic solvent dispersed in an aqueous matrix. During a microbial-adhesion-to-hydrocarbon (MATH) test, which is frequently used to measure cell surface hydrophobicity, T1 cells adhered to hexadecane droplet surfaces in a monolayer, whereas wild-type cells aggregated on the droplet surfaces. The adsorbed T1 cells on the hexadecane surfaces hindered the coalescence of the droplets formed by vortexing, stabilizing the emulsion phase. Following the replacement of the aqueous phase with fresh pure water after the MATH test, a proportion of the T1 cells that had adsorbed to the hydrocarbon surface detached during further vortexing, suggesting a reversible adsorption of T1 cells. The final ratio of the adhering cells to the total cells in the detachment test coincided with that in the MATH test. The adhesion of T1 cells to the hydrocarbon surface conformed to the Langmuir adsorption isotherm, which describes reversible monolayer adsorption. Reversible monolayer adsorption should be useful for green technologies employing two-liquid-phase partitioning systems and for bioremediation because it allows effective reaction and transport of hydrophobic substrates at oil-water interfaces.

scholarly journals Starvation Improves Survival of Bacteria Introduced into Activated Sludge

2000 ◽  
Vol 66 (9) ◽  
pp. 3905-3910 ◽  
Author(s):  
Kazuya Watanabe ◽  
Mariko Miyashita ◽  
Shigeaki Harayama
Keyword(s):  
Population Density ◽  
Cell Surface ◽  
Activated Sludge ◽  
Ralstonia Eutropha ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Luria Bertani ◽  
Exponential Growth Phase ◽  
Degrading Bacterium ◽  
Metabolic Activities

ABSTRACT A phenol-degrading bacterium, Ralstonia eutropha E2, was grown in Luria-Bertani (LB) medium or in an inorganic medium (called MP) supplemented with phenol and harvested at the late-exponential-growth phase. Phenol-acclimated activated sludge was inoculated with the E2 cells immediately after harvest or after starvation in MP for 2 or 7 days. The densities of the E2 populations in the activated sludge were then monitored by quantitative PCR. The E2 cells grown on phenol and starved for 2 days (P-2 cells) survived in the activated sludge better than those treated differently: the population density of the P-2 cells 7 days after their inoculation was 50 to 100 times higher than the population density of E2 cells without starvation or that with 7-day starvation. LB medium-grown cells either starved or nonstarved were rapidly eliminated from the sludge. The P-2 cells showed a high cell surface hydrophobicity and retained metabolic activities. Cells otherwise prepared did not have one of these two features. From these observations, it is assumed that hydrophobic cell surface and metabolic activities higher than certain levels were required for the inoculated bacteria to survive in the activated sludge. Reverse transcriptase PCR analyses showed that the P-2 cells initiated the expression of phenol hydroxylase within 1 day of their inoculation into the sludge. These results suggest the utility of a short starvation treatment for improving the efficacy of bioaugumentation.

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.

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