COMPARATIVE ANALYSIS OF BIOSURFACTANT PRODUCTION FROM BREWERY EFFLUENT USING PSEUDOMONAS SPECIES (PSEUDOMONAS AERUGINOSA AND PSEUDOMONAS FLUORESCENS)
COMPARATIVE ANALYSIS OF BIOSURFACTANT PRODUCTION FROM BREWERY EFFLUENT USING PSEUDOMONAS SPECIES (PSEUDOMONAS AERUGINOSA AND PSEUDOMONAS FLUORESCENS)
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Date
2015-05
Authors
KOLAWOLE, OLADIMEJI TAYO
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Abstract
The increasing demand for surfactant calls for an alternative to the chemically synthesized
surfactant, which poses a lot of threat to the environment due to bio-accumulation of its undegradable
toxic component. Accumulation of industrial and domestic waste also threatens the
environment by contributing unfriendly gases and toxic compounds, therefore due to tighten
environmental regulations and increasing need to protect the ecosystem, alternatives to
chemically synthesized surfactant, which is biosurfactant, is a necessity. Biosurfactants are
biodegradable and stable at extreme temperatures and pH. Brewery effluent is an excellent
substrate for the production of biosurfactant. Pseudomonas aeruginosa and Pseudomonas
fluorescens isolated from soil produced glycolipid biosurfactant from brewery effluent. The
brewery effluent used as substrate had chemical oxygen demand of 15,000mg/l, dissolved
oxygen of 2.9mg/l and biological oxygen demand of 1.8mg/l. Screening both isolates for their
ability to produce biosurfactant, both were positive for drop collapse assay and hemolytic test.
For the oil displacement assay 28mm and 23mm were observed for Pseudomonas aeruginosa
and Pseudomonas fluorescens respectively. Fermentation process was observed for 168hrs and
readings of surface tension and optical density was taken every 24hrs. Three factors were
evaluated in the fermentation of the effluent which include; incubation period, pH and
temperature. For the incubation period 31.30mN/m and 33.76mN/m was observed for
Pseudomonas aeruginosa and Pseudomonas fluorescens respectively. For ionic concentration
ranging from pH 4.0 to 10.0, pH 7.0 had the least surface tension reading with 31.87mN/m and
33.04mN/m for Pseudomonas aeruginosa and Pseudomonas fluorescens respectively. Among
the pH considered, difference in surface tension was insignificant, indicating a stable
biosurfactant. For the temperature ranging from 25oC to 80oC, temperatures 30oC and 35oC had
the least surface tension reading though with minimal difference across the temperatures range.
The growth of the cells used in fermentation was monitored using the colorimeter at 600nm. The
peak growth was generally recorded at 72hrs and peak growth highest at 1.07 for he growth of the cells used in fermentation was monitored using the colorimeter at 600nm. The
peak growth was generally recorded at 72hrs and peak growth highest at 1.07 for incubation
factor. The best growth for pH factor was observed at pH 5.0 and 7.0. The control set-up for
fermentation had the least surface tension reading as compared to all other factors with
30.87mN/m and 32.87mN/m for Pseudomonas aeruginosa and Pseudomonas fluorescens
respectively. The application of the biosurfactant produced was tested by checking it ability to
emulsify hydrocarbons (diesel, premium motor spirit, kerosene and olive oil). Also applying the
various factors (incubation period, pH and temperature), they all showed stable emulsion in
24hrs excluding pH4 with poor or no emulsion formation. Ionic concentration 10.0 had the
highest emulsion formation within 24hrs with 87% to 80%. Biosurfactant extracted from
Pseudomonas aeruginosa induced fermentation was 3.6g/l and 2.8g/l from Pseudomonas
fluorescens. The spectra analysis (FT-IR) of the extract revealed the probable presence of
glycolipid biosurfactant as the surface active compound produced by both isolate. From
statistical evaluation of data collected, neither of the isolates performed better than the other but
shows that there is a significant association between growth rate and surface tension reduction
(biosurfactant production)in both isolates at P=0.005
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES,
AHMADU BELLO UNIVERSITY, ZARIA
IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE AWARD
OF A
MASTER DEGREE IN MICROBIOLOGY
DEPARTMENT OF MICROBIOLOGY
FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY, ZARIA
NIGERIA.
Keywords
COMPARATIVE ANALYSIS,, BIOSURFACTANT PRODUCTION,, BREWERY EFFLUENT,, PSEUDOMONAS SPECIES,, (PSEUDOMONAS AERUGINOSA,, PSEUDOMONAS FLUORESCENS),