Phylogenetic Analysis Of Fusarium Species From Vegetable Fruits
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Date
2014-07
Authors
Zambry, Nor Syafirah
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
The present study focused on screening and evaluating extracellular
biosurfactant production from 33 actinomycete isolates. Out of 33 isolates, isolate
R1, characterized as the genus Streptomyces based on phenotypic and genotypic
analyses, was selected as a model filamentous organism in an aerobic fermentation
for biosurfactant production. The production of biosurfactant was investigated in
batch mode using shake flasks and 3 L stirred tank bioreactor. The maximum
biosurfactant production in shake flasks with reduction in surface tension of water
(39.37±1.73%) and emulsification activity (20.69±4.88%) was obtained at 144 hours
in a medium containing 6% (v/v) palm oil, 0.6% (w/v) yeast extract, 2% (v/v) Tween
80, 0.7% (w/v) NaCl and initial pH 6 with 4% (v/v) inoculum concentration. Further
improvement in the biosurfactant production was achieved using a well-controlled
stirred tank reactor. An increase of 3-fold of emulsification activity and lowest
surface tension measurement (40.5±0.05 dynes/cm) was attained when the culture
was agitated at 600 rpm. In batch cultures, the production of biosurfactant was not
dependent on biomass but was influenced by culture morphology. Solvent extraction
method using methanol, chloroform and 1-butanol (1:1:1) gave the highest
concentration (58.04 g/L) of crude biosurfactant extract that was characterized as
glycolipid biosurfactant. The glycolipid biosurfactant produced by Streptomyces sp.
R1 is able to reduce the surface tension of water from 74±0.58 to 38 dynes/cm with a
critical micelle concentration (CMC) of 10% (v/v) biosurfactant spent broth. It was
found stable over a wide range of temperature, pH and salinity.
Description
Keywords
Phylogenetic analysis of , Fusarium species