Production and stability studies of the bioemulsifier obtained from a new strain of Candida glabrata UCP 1002

Abstract

Evaluation of both tenso-active and emulsifying activities indicated that a biosurfactant was produced by the newly isolated and promising strain Candida glabrata isolated from mangrove sediments. The extracellular water-soluble emulsifying agent was isolated and identified as a heteropolymer. The maximum of bioemulsifier production was observed when the strain was grown on soluble and insoluble substrates cotton seed oil plus glucose, reaching values *Corresponding author of 10.0 g/l after 144 hrs at 200 rpm. The cell-free culture broth containing the examined agent lowered the surface tension of the medium to 31 mN/m. Stable and compact emulsions with emulsifying activity of 75% of cotton seed oil were detected. The emulsification capacity remained practically unaltered within a wide pH (2-12), temperature (4-80ºC) ranges and under NaCl concentrations up to 10%.

Isolation and characterization of hydrocarbon-degrading and biosurfactant-producing yeast strains obtained from a polluted lagoon water

“…Biosurfactant production by Candida species has been reported previously (Shepherd et al 1995;Garcia-Ochoa and Casas 1999;Paraszkiewicz et al 2002;Sarubbo et al 2006). Sarubbo et al (2006) demonstrated that the biosurfactant produced by Candida glabrata when cultured in an n-hexadecane was not recovered from the culture fluid until after the organism entered the stationary growth phase, indicating the molecule was a growth dissociated product. The exact reasons why some microorganisms produce biosurfactants is still not clear.…”

“…They have several advantages over their synthetic counterparts, such as lower toxicity, higher biodegradability (Zajic et al 1977), better environmental compatibility (Georgiou et al 1992), higher foaming (Razafindralambo et al 1996), high selectivity and specific activity at extreme temperature, pH and salinity (Velikong and Kosaric 1993;Ilori and Amund 2001;Ilori et al 2005;Sarubbo et al 2006), and the ability to be synthesized from renewable feedstock (Desai and Banat 1997). These unique properties allow the use of biosurfactants and possible replacement of chemically-synthesized surfactants in a great number of industrial applications.…”

“…MTN11 which was found to enhance hexadecane mineralization by 100-fold. Among yeasts, Candida species have been widely employed for insoluble substrates fermentation and have been reported to produce surface-active agents (Cameron et al 1988;Kosaric 1992;Sarubbo et al 2006). These authors demonstrated biosurfactant production by C. glabrata and were able to show that the emulsification capacity remained practically unaltered with a wide pH (2-12), temperature (4-80°C) ranges and under NaCl concentrations up to 10%.…”

Response Surface Methodology for Optimizing the Production of Biosurfactant by Candida tropicalis on Industrial Waste Substrates

“…High yields in biosurfactants have been reached through the combination between a vegetable oil and carbohydrate as substrate (Santos et al, 2016). Regarding the use of waste frying vegetal oils, isolated or combined with a soluble substrate, promising results have been obtained in the last decades for Candida species in our laboratories (Sarubbo et al, 1999, 2001, 2006, 2007; Coimbra et al, 2009; Campos et al, 2014). Thus, waste frying oil and molasses were used as the insoluble and soluble carbon sources, respectively, while corn steep liquor was used as the nitrogen source.…”

Isolation of Biosurfactant Producing Bacteria From Poultry Breast Skin

“…The E24 (and E72) index is given as percentage of the height of emulsified layer divided by the total height of the liquid column (cm). The percentage of emulsification index calculated by using the following equation (12), E24 = Height of emulsion formed x 100/total height of solution. Centrifuged samples of incubated tubes of sterile LB were used as control for each test strain.…”