scholarly journals Effects of Nitrogen and Carbon Sources on Biosurfactant Production by Hydrocarbon-utilizing Stenotrophomonas sp.

Author(s):  
Victor Ezebuiro ◽  
Ipeghan Jonathan Otaraku ◽  
Boma Oruwari ◽  
Gideon Chijioke Okpokwasili

Aim: This study investigated effects of nitrogen and carbon sources on the production of biosurfactant by a hydrocarbon-utilizing bacterium, Stenotrophomonas sp. Methodology: The hydrocarbon-utilizing bacterium was isolated with Bushnell Haas (BH) broth using enrichment method. Biosurfactant production was screened by evaluating the following characteristics: Emulsification index (E-24), oil spreading (displacement), tilted glass slide, haemolysis on blood agar, and lipase production. Effects of combination of nitrogen sources (yeast extract and NH4NO3, yeast extract and urea, yeast extract and asparagine, yeast extract and peptone, NaNO3 and peptone, NaNO3 and asparagine, and yeast extract and NaNO3) and carbon sources (glucose, fructose, galactose, cassava peel, soya bran, olive oil, sucrose, crude oil, diesel and glycerol) on biosurfactant production were determined with emulsion stability and surface tension as responses. The bacterium was identified based on phenotypic, microscopic, and biochemical characteristics. Results: The isolate produced colonies on BH agar containing either naphthalene or hexadecane as sole source of carbon after 48-h incubation. Screening characteristics for the production of biosurfactant by the isolate were as follows: 46% emulsification index, 3.1 cm2 oil displacement, 1.8 cm zone of clearance on tributyrin agar, γ-haemolysis, and positive tilted glass slide. The best carbon source with the highest emulsion stability (51.6%) was fructose whereas the best surface tension reduction (30.85 mN/m) was observed with olive oil as carbon sources after 7 days of incubation. For nitrogen, the combination of yeast extract and NH4NO3 gave the highest emulsion stability (60.7%) and the best surface tension reduction (39.58 mN/m). The data obtained were significant at P<0.05 and the bacterial isolate identified as Stenotrophomonas sp. Conclusion: This study has demonstrated the ability of the hydrocarbon-utilizing bacterium, Stenotrophomonas sp. to produce biosurfactant, indicated by reduction of surface tension and formation of stable emulsion. This method of biosurfactant production can be further scaled up for industrial purpose. 

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Gizele Cardoso Fontes ◽  
Priscilla Filomena Fonseca Amaral ◽  
Marcio Nele ◽  
Maria Alice Zarur Coelho

In order to improve biosurfactant production byYarrowia lipolyticaIMUFRJ 50682, a factorial design was carried out. A24full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (ΔST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mNm−1ofΔST) were obtained in a medium composed of 10 g 1−1of ammonium sulfate and 0.5 g 1−1of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and aΔST of 19.5 mN m−1. The experimental design optimization enhancedΔEI by 110.7% andΔST by 108.1% in relation to the standard process.


2017 ◽  
Vol 76 (7) ◽  
pp. 1706-1714 ◽  
Author(s):  
Parvin Hasanizadeh ◽  
Hamid Moghimi ◽  
Javad Hamedi

Biosurfactants are biocompatible surface active agents which many microorganisms produce. This study investigated the production of biosurfactants by Mucor circinelloides. The effects of different factors on biosurfactant production, including carbon sources and concentrations, nitrogen sources, and iron (II) concentration, were studied and the optimum condition determined. Finally, the strain's ability to remove the crude oil and its relationship with biosurfactant production was evaluated. The results showed that M. circinelloides could reduce the surface tension of the culture medium to 26.6 mN/m and create a clear zone of 12.9 cm diameter in an oil-spreading test. The maximum surface tension reduction was recorded 3 days after incubation. The optimum condition for biosurfactant production was achieved in the presence of 8% waste frying oil as a carbon source, 2 g/L yeast extract as a nitrogen source, and 0.01 mM FeSO4. M. circinelloides could consume 8% waste frying oil in 5 days of incubation, and 87.6% crude oil in 12 days of incubation. A direct correlation was observed between oil degradation and surface tension reduction in the first 3 days of fungal growth. The results showed that the waste frying oil could be recommended as an inexpensive oily waste substance for biosurfactant production, and M. circinelloides could have the potential to treat waste frying oil. According to the results, the produced crude biosurfactant or fungal strain could be directly used for the mycoremediation of crude oil contamination in oil fields.


1994 ◽  
Vol 344 ◽  
Author(s):  
C. Vipulanandan ◽  
G. L. Ghurye ◽  
R. C. Willson

AbstractSurfactants increase the accessibility of adsorbed hydrocarbons and mobilize immiscible petroleum hydrocarbons for treatment. Biosurfactants have the advantage of biodegradability and non-toxicity over their synthetic counterparts, and can be produced from renewable sources. In this study the production of biosurfactant from molasses was investigated in continuously stirred batch reactors. The effects of substrate concentration, yeast extract and peptone on biomass accumulation and biosurfactant production were investigated. Biosurfactant production was quantified by surface tension reduction and critical micelle dilution (CMD). Biosurfactant production was directly correlated with biomass production, and was improved with the addition of yeast extract. Centrifugation of the whole broth reduced surface tension. The performance of the biosurfactant produced from molasses under non-aseptic condition is comparable to other published results.


2007 ◽  
Vol 12 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Fatimah Fatimah

Biosurfactant, microbial metabolite whose properties like surfactant, was suggested to replace chemically synthesized surfactant for take in hand environtmental pollution by petroleum hydrocarbon. This work was done to examine potency of Pseudomonas sp. isolated from Tanjung Perak Harbor to produce biosurfactant. Also, to know the effect of different substrates (glucose plus yeast extract, lubricating oil and hexadecane) toward biosurfactant production. Pseudomonas sp. grown in mineral synthetic water and biosurfactant production was measured on stationary phase. Biosurfactant production based on emulsification activity and surface tension reduction of supernatant (using Du Nouy tensiometer). Solar, lubricating oil, and hexadecane were used to examine emulsification activity. Results indicated that Pseudomonas sp. have a potency to produce biosurfactant. Surface tension of supernatant decreased up to 20 dyne/cm, when grown on hexadecane substrate. Hexadecane is the best growing substrate for biosurfactant production than others.


2018 ◽  
Author(s):  
Nonne L. Prisle ◽  
Bjarke Molgaard

Abstract. Cloud condensation nuclei (CCN) activity of aerosol particles comprising surface active Nordic Aquatic Fulvic Acid (NAFA) and NaCl was modeled with four different approaches to account for NAFA bulk-to-surface partitioning and the combined influence of NAFA and NaCl on surface tension and water activity of activating droplets. Calculations were made for particles with dry diameters of 30–230 nm and compositions covering the full range of relative NAFA and NaCl mixing ratios. Continuous ternary parametrizations of aqueous surface tension and water activity with respect to independently varying NAFA and NaCl mass concentrations were developed from previous measurements on macroscopic bulk solutions and implemented to a Köhler model framework. This enabled comprehensive thermodynamic predictions of cloud droplet activation, including equilibrium surface partitioning, for particles comprising chemically unresolved organic NAFA mixtures. NAFA here serves as a model for surface active atmospheric humic-like substances (HULIS) and for chemically complex organic aerosol in general. Surfactant effects are gauged via predictions of a suite of properties for activating droplets, including critical supersaturation and droplet size, bulk phase composition, surface tension, Kelvin effect, and water activity. Assuming macroscopic solution properties for activating droplets leads to gross overestimations of reported experimental CCN activation, mainly by overestimating surface tension reduction from NAFA solute in droplets. Failing to account for bulk-to-surface partitioning of NAFA introduces severe biases in evaluated droplet bulk and surface composition and critical size, which here specifically affect cloud activation thermodynamics, but more generally could also impact heterogeneous chemistry on droplet surfaces. Model frameworks based on either including surface partitioning and/or neglecting surface tension reduction give similar results for both critical supersaturation and droplet properties and reproduce reported experimental CCN activity well. These perhaps counterintuitive results reflect how the bulk phase is nearly depleted in surface active organic from surface partitioning in submicron droplets with large surface area for a given bulk volume. As a result, NAFA has very little impact on surface tension and water activity at the point of droplet activation. In other words, the predicted surfactant strength of NAFA is significantly lower in sub-micron activating droplets than in macroscopic aqueous solutions of the same overall composition. These results show similar effects of chemically complex surfactants as have previously been seen only for simple surfactants with well-defined molecular properties and add to the growing appreciation of the complex role of surface activity in cloud droplet activation.


MRS Bulletin ◽  
2007 ◽  
Vol 32 (10) ◽  
pp. 801-806 ◽  
Author(s):  
Anthony J. O'Lenick ◽  
Kevin A. O'Lenick

AbstractSilicone polymers have become increasingly important as ingredients in skin care products, and the trend has accelerated over the last decade. While silicone compounds have existed since the 1860s, their increasing popularity in recent years is due in large part to a better understanding of their unique functions. This increased understanding of the properties of silicone, coupled with an increased ability of the silicone chemist to modify compounds, has resulted in more effective utilization of these materials in skin care formulations. Silicone polymers bring to formulations a phase that is soluble neither in oil nor in water. They are third-phase ingredients that when properly chosen can provide to formulations properties including surface-tension reduction, wetting, and emulsification.


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