Bioemulsifier production by Aspergillus niger MYA 135: presumptive role of iron and phosphate on emulsifying ability

Microbial emulsifiers are compounds employed in primary mechanisms for bioremediation of petroleum and other hydrocarbon pollutants from the environment. Although emulsifiers of biological origin are produced by microorganisms generally in response to growth on hydrocarbons, Aspergillus niger MYA 13...

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Bibliographic Details
Authors: Colin, Veronica Leticia, Baigori, Mario Domingo, Pera, Licia Maria
Format: article
Status:Published version
Publication Date:2010
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/76698
Online Access:http://hdl.handle.net/11336/76698
Access Level:Open access
Keyword:Aspergillus Niger
Bioemulsifier
Emulsification Index
Factorial Design
https://purl.org/becyt/ford/2.9
https://purl.org/becyt/ford/2
Description
Summary:Microbial emulsifiers are compounds employed in primary mechanisms for bioremediation of petroleum and other hydrocarbon pollutants from the environment. Although emulsifiers of biological origin are produced by microorganisms generally in response to growth on hydrocarbons, Aspergillus niger MYA 135 produced a bioemulsifier during fermentation in a sucrose-based culture medium at an initial pH of 5.0 and at 30 °C. The production of bioemulsifiers can be strongly influenced by environmental factors. In this connection, a study of the effect of initial pH, the incubation temperature and presence of CaCl2 or FeCl3 in the culture medium was conducted. Emulsification index was increased by 112 and 206% at an initial pH 2.0 or in medium supplemented with FeCl3, respectively. On the other hand, emulsifying ability of Aspergillus niger supernatants was detected during the exponential phase, suggesting that bioemulsifiers accumulation and microbial growth would be related. Interestingly, this study suggests that iron and/or phosphate ions would play a key role in maintaining the emulsifying ability. Finally, factorial design was also employed to study the effects of the initial pH, the presence of FeCl3 and the concentration of KH2PO4 on the emulsification index.