OPTIMIZATION AND CHARACTERIZATION OF RHAMNOLIPID AND SOPHOROLIPID PRODUCED FROM ASPERGILLUS NIGER IN A SOLID STATE FERMENTATION SYSTEM USING POTATO PEELSAS CARBON SOURCE
OPTIMIZATION AND CHARACTERIZATION OF RHAMNOLIPID AND SOPHOROLIPID PRODUCED FROM ASPERGILLUS NIGER IN A SOLID STATE FERMENTATION SYSTEM USING POTATO PEELSAS CARBON SOURCE
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Date
2015-07
Authors
ABBA, DANIEL
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Abstract
This study was aimed at optimizing and characterizing rhamnolipid and sophorolipid produced by Aspergillusniger in a solid state fermentation system using potato peels as carbon source. A two-level Plackett–Burman (PB) design was implemented to screen the medium components that significantly influence the production and response surface methodology was used for the optimization. Following the one factor at a time analysis (OFAT), a central composite design was conducted to optimize the three selected factors for rhamnolipid and sophorolipid productions. Characterization of the biosurfactants involved determination of Emulsification index, surface tension; blood hemolysis and fourier transform infrared analysis. Three vital components influencing rhamnolipid production were identified as magnesium sulphate, sodium chloride and zinc sulphate while the three vital component influencing sophorolipid productions were identified as magnesium sulphate, sodium chloride and potassium dihydrogen phosphate. The validity of the model developed was verified, and the optimum medium containing 0.49% (w/v) magnesium sulphate, 0.2% (w/v) sodium chloride and 0.49% (w/v) zinc sulphate, 0.74%(w/v) magnesium sulphate, 0.1%(w/v) sodium chloride and 0.9%(w/v) of potassium dihydrogen phosphate led to a maximum rhamnolipid and sophorolipid production of 226.60±50.91 mg/gds and 84.41±8.73 mg/gds respectively. The analysis of variance indicated that the established models were significant (P < 0.05). Characterization of rhamnolipid and sophorolipid showed that they were able to form clear zone with a hemolyic activity. The biosurfactants were able to emulsify petrol with an emulsification index of 54.87±1.23 and 54.86±3.64 for rhamnolipid and sophorolipid respectively. The produced rhamnolipid and sophorolipid were able to reduce surface tension of distilled water from 71mN/m to 28.09 and 30.30mN/m respectively. The results of this work reveals that rhamnolipid and sophorolipid can
be produced fromAspergillusniger using potato peels and the production could be optimize using statistical tools.
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES,
AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE AWARD
OF A
MASTER OF SCIENCE IN BIOCHEMISTRY
DEPARTMENT OF BIOCHEMISTRY
FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY,
ZARIA, NIGERIA
Keywords
OPTIMIZATION,, CHARACTERIZATION,, RHAMNOLIPID,, SOPHOROLIPID PRODUCED,, ASPERGILLUS NIGER,, SOLID STATE FERMENTATION SYSTEM,, POTATO PEELSAS,, CARBON SOURCE,